A Few Masterpieces

“Living by faith includes the call to something greater than cowardly self-preservation.”

J.R.R. Tolkein

In this post your humble servant will present a few modern masterpieces of the blacksmith’s art produced recently by a single craftsman. I hope you are as thrilled as I am to know there is at least one craftsman left in the world that can produce chisels of this quality.

The Blacksmith

The craftsman that made these chisels is very unusual in that, unlike the frantically self-promoting, technically mediocre Hollywood blacksmiths such as Tasai, Funatsu, Kiyohisa, and the modern Chiyozuru gang, he is reclusive and shuns attention. Accordingly, I have been requested to not share any personal details about him, so please don’t ask. The fact is I don’t even know his real name just the brand he uses.

I won’t discuss why he is reclusive, but I will go so far as to say that he is self-employed, and that chisels are not his primary work product. He makes no more than 5 chisels monthly as a sideline.

His business philosophy and blacksmithing techniques are interesting so I will share some details about them. He has four strict requirements that a Customer must satisfy before he will accept an order. The first two are business-related, and the last two are about the Customer.

  1. The Blacksmith sets the delivery schedule. Period.
  2. The Blacksmith sets the price. Period
  3. The Customer must be a professional worker in wood who needs and will use the tools the Blacksmith will forge daily. His track record must be independently verifiable. Amateurs and/or hobbyists, regardless of their skill levels, need not apply. Collectors are specifically unwelcome.
  4. The Customer must have a minimum level of skills, besides the ability to use chisels, including the ability to make chisel handles and cut a high-quality Japanese plane block using only hand tools. Once again, this must be verified before an order will be accepted.

Your humble servant commissioned a few chisels from the Blacksmith many years ago and went through this same qualification process, although I didn’t realize it at the time.

The quality of his forging and heat-treat technique is unsurpassed producing a crystalline structure in hard steel that will take an extremely sharp edge, will hold that edge without easily dulling, chipping or rolling while cutting a lot of wood, and is easily sharpened.

But it is his metal shaping and finishing skills that are so awe-inspiring. Please notice the straightness and cleanness of the lines and planes, as well as the uniform and smooth curvature at the shoulders, and perfect symmetry. If Gentle Reader is unimpressed, I encourage you to make a full-scale model from cold wood before trying it in hot metal. I promise you will be convinced.

The Blacksmith uses only “free-forging” techniques, and does not employ the rough shaping dies other modern blacksmiths rely on to improve production speed. His forging technique is so sublime that the entire chisel is shaped to nearly final dimension by fire and hammer, not grinders and belt sanders.

He finishes his products using only hand-powered scrapers (sen) and files.

The performance of Blacksmith’s products are equal to or better than those of Kiyotada back in the day, and are more precisely shaped and more beautifully finished than those of Ichihiro (the Yamazaki Brothers) at their very best. They are simply the best chisels that have been made in Japan in the last 70 years.

Let’s take a look at four chisels recently completed for a Beloved Customer in the USA.

34 x 485mm Anaya Chisel

The Anaya chisel is an antique style used for cutting deep mortises and making other joints in large timbers. It is no longer commercially available.

Top view of a Anaya 34x485mm Anaya chisel
Ura view of 34x485mm Anaya chisel
Side view of 34x485mm Anaya chisel

57 x 485mm Anaya Chisel

42 x 490mm Bachi Nomi

The Bachi nomi is the equivalent to the fishtail chisel in English-speaking countries. The word bachi comes from the splayed tool used to play the 3-string Japanese shamisen, a banjo-type musical instrument. Here is a link to a video of two ladies using shamisen and bachi to perform a famous traditional song in Tokyo.

The Bachi nomi excells at getting into tight places to cut joints with acute internal angles such as the dovetail joints that connect beams to purlins.

There are several ways to resolve the angles at the tool’s face, but in this case the Beloved Customer and Blacksmith agreed on the most difficult, rigid and beautiful solution, the shinogi. This design has the advantage of maintaining a shallower side-bevel angle from cutting edge to neck return providing better clearance in tight dovetail joints.

The handwork performed on this chisel’s face is simply amazing, but the hollow-ground ura is even more spectacular to those who know about this things.

54 x 540mm Sotomaru Incannel Gouge

The Sotomaru or incannel gouge is a strong and convenient chisel used for cutting joints in logs and rounded members on architecture. More information can be found at this link.

This is an especially beautiful example as seen the symmetrical confluence of planes and curves at the shoulders.

Conclusion

I hope Gentle Reader found this post informative. You will never find better examples of the Japanese blacksmith’s art outside of one particular museum. It is exciting to consider that there is still one craftsman alive that can routinely perform this level of work.

While your humble servant has praised these chisels and the blacksmith that made them highly, please do not make the mistake of assuming that I am soliciting orders, or even suggesting that commissioning them is possible, because they are simply not available at any price. Please don’t ask.

YMHOS

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. May my ootsukinomi roll from my workbench and land cutting-edge down on my toes if I lie.

The Japanese Handplane Part 5: The Chipbreaker

A 60mm plane blade with its chipbreaker resting on the ura as when installed into the wooden body. Please note that there are no screws connecting these two parts making it a simple and reliable system.

There are three things extremely hard: steel, a diamond, and to know one’s self.

Benjamin Franklin

In this fifth post in our series about the Japanese handplane, we will discuss a single component of the handplane, the chipbreaker.

Professional woodworkers that use handplanes daily usually have this simple widget thoroughly figured out, but your humble servant has been asked to clarify why the chipbreaker is necessary and how to make it work so many times recently that I can no longer gracefully avoid my duty to share a more complete, BS-free written explanation with Beloved Customers, may the hair on their toes ever grow long.

As always, this post is intended to provide a bit of insight, or at least a different viewpoint, to our Beloved Customers, many of whom are professional woodworkers and Luthiers.

This is a longish article. If your humble servant was a lazy man I would simply state stand-alone conclusions as have so many with half-baked knowledge of handplanes, and leave it up to Beloved Customer to figure out the why of things on your own, but that would be boorish behavior.

Even if you already know everything there is know about the chipbreaker, you may still find a new crunchy tidbit or two if you look.

Factors Critical to Controlling Tearout

The sole purpose of the chipbreaker is to control, and whenever possible, completely prevent the unsightly and wasteful tearout that often appears when using a handplane to surface wood. We will examine the causes of and some solutions to tearout below, but let’s begin this discussion by examining factors critical to controlling/eliminating tearout that actually take precedence over the chipbreaker. Your efforts to control tearout should always begin with these factors. But first allow me to share a story.

Back in the mists of time when dinosaurs roamed the earth and your humble servant was but a slender young man with much more hair on his head and far less dignity under his belt, I liked to think I had a sound understanding of both steel and wooden Western-style planes, but I knew little of Japanese planes. Later I was blessed with the opportunity to learn about the Japanese handplane in Japan from master craftsmen.

As is the case with excellent craftsmen of all ages, these gentlemen talked very little but assigned me what seemed at the time to be daunting work assignments.

While they would allow me to examine their tools and observe their techniques in-person, the only instruction they would provide initially were two or three-word critiques of my frequent mistakes. I understand now that they were kind gentlemen, albeit 40~50 years older than me, but at the time this apprenticeship-style of training was frustrating. Only when I showed progress would their answers stretch to 5 or 6 words because, unlike your humble servant at the time, (here is wisdom) they understood that only experience obtained through many failures and a few successes can produce true learning

The first assignments given me were to sharpen everything in the workshop that would hold still long enough to touch with a stone, from axes and adzes to chisels, handplanes and even saws. This went on for months. They weren’t being mean, just wise, because sharpening is the first and most important woodworking skill. Only when I had mastered all aspects of blade preparation and sharpening did they share further light and knowledge with me.

They then assigned me the task of making an old-fashioned Japanese handplane, one without a chipbreaker, entirely by hand. This was an educational effort, one that I magnificently failed twice before finally getting it right, but which taught me the three most important factors in reducing tearout in handplanes, whether with wooden or steel body, with chipbreaker or without. Those three factors can be summarized as follows:

Factor 1: The blade must be sharp. This factor depends on the quality of the blade and the skill of the person who sharpens it. We have a series of 30 posts about sharpening Japanese woodworking blades Beloved Customers may find beneficial. The series starts with this LINK.

Factor 2: The mouth opening (gap between the sole and the cutting edge) must be as tight as practically possible and still pass shavings. Please make an effort to truly understand what this means, because it is not always easily accomplished. Of course, the mouth opening of a super finishing plane intended to take transparent shavings will of necessity be narrower than that of a plane intended to dimension boards by taking thicker shavings;

Factor 3: The area on the sole directly in front of the mouth opening, a strip across the entire width of the sole of the plane and perhaps 3~6mm wide, must be true and flat and apply even pressure on the board being planed right up to the mouth opening.

Why are these three factors critical? To begin with, a dull blade won’t sever fibers cleanly but will tend to pull contrary fibers up and out of the board’s surface. Can’t have that, ergo, Factor 1.

Since the soles of handplanes wear and consequently mouth openings constantly vary, Factors 2 & 3 are dependent on the the team of craftsmen that originally made the handplane as well as the craftsman/owner that uses and maintains the handplane over its lifetime.

Indeed, Factors 2 & 3 act in unison to control the movement of contrary fibers immediately before and after they contact the blade directing them into the cutting edge where they will be cleanly severed by the sharp blade, while at the same time serving to bend and buckle those fibers that would otherwise tend to develop a lever arm and tear out below the surface of the board. If this doesn’t make sense to you, please give it careful thought because you must figure it out if you intend to become proficient with handplanes.

These three factors are bedrock essential to controlling tearout regardless of the type of handplane in question and whether it has a chipbreaker or not. Beloved Customers are strongly encouraged to understand and gain absolute control of these three factors. It will take more than just reading, so consider it an assignment. Indeed, expect to screw it up royally at first and learn from your mistakes. That’s how we learn.

The Chipbreaker & Historical Lumber Processing Techniques

Two carpenters selecting a curved log to use a roof beam

To better understand the chipbreaker, Beloved Customer may find it useful to understand a few historical factors about the wood they are shaving.

Before the proliferation of the large rip saw, and especially the water-powered sawmill, the only practical method of producing boards and beams from logs was to “rive” (split) them out using wedges and axes.

The thing about logs is that not all of them have grain straight enough to produce useful lumber when riven. Large, straight, old-growth trees are most easily processed. As nearby old-growth primeval forests with tall, large, straight trees were cut down and premium logs became harder to come by, much construction and shipbuilding came to rely on more economical beams and posts sawed from logs with wonky grain.

Riven wood has two convenient advantages. The first one is that, because the grain of the lumber is relatively straight and continuous, runout is reduced, making it somewhat stronger structurally. And second, the occurrence of tearout when surfacing riven lumber is often less than sawn lumber.

Unlike a carpenter team using axes and wedges, large rip saws in the hands of sawyers made practical through the proliferation of inexpensive, reliable steel, and especially the sawmill, could more easily and quickly cut long, straight boards and beams out of most any log regardless of grain direction. Consequently, logs that would have been rejected before the days of the sawmill can now be readily processed reducing the man-hours/cost of producing lumber significantly. On the other hand, the grain direction of lumber produced using large saws and sawmills tends to wander everywhere increasing runout and making the job of cleanly surfacing the boards more difficult for subsequent craftsmen. This is the situation we face now.

We don’t know when or where the chipbreaker was invented, or how the concept spread around the world, but it’s a safe bet to assume its ability to calm the wild grain of sawn lumber during surfacing was the reason for its popularity. At least, that’s how it went in Japan. Wood is wood no matter where you are.

Naturally-shaped logs used as roof beams in the restoration of a historically-significant building in Japan

Why Does Tearout Occur?

Let’s next examine some basic causes of tearout.

Please recall that wood is comprised of various types of cells, each with a job to do, but most of those that eventually become lumber specialize in transporting water up from the ground to the leaves, and nutrients formed in the leaves to the rest of the tree. Transporting literally tons of water from the roots far up into the sky is the job of continuous groups of cells that form what are effectively waterpipes. In a living tree these pipes have semi-flexible cell walls, and while they mostly grow parallel with roots, limbs and trunk, their shape is influenced by wind, rain, snowload, shifting soil, microbes, bugs and ever-changing exposure to the sun over the life of the tree, so they are seldom perfectly straight. Indeed, once dried, it’s the changes in direction of these tubular cells, often called fibers, that gives harvested lumber its beautiful grain patterns and shimmering chatoyance.

When planing with the grain, the blade severs fibers which are oriented either parallel with or sloping up to the board’s surface and angled in the plane’s direction of travel producing pretty shavings comprised of relatively short, flexible segments of fiber. But when planing against the grain, the blade must sever fibers that are diving down into the board. Instead of consenting to being cleanly severed, often these longer, more rigid fibers tend to ride up the face of the blade, avoiding the cutting edge.

When this happens, instead of severing them cleanly, the blade tends to lever these longer fibers up out of the board’s surface until they suddenly break off below the surface of the board leaving a rough uneven surface. This damage is called “tear-out” in English and Sakame sah/kah/meh 逆目 in Japanese, which translates directly to “reverse grain.”

The blade on the left is cutting with the grain and is unlikely to produce tearout, while the blade on right is cutting against the grain and is more likely to produce tearout.

How Does the Chipbreaker Work?

Whether the handplane in question be Western or Japanese in design, the chipbreaker, or Uragane 裏金 (oo/rah/gah/neh) as it is called in Japan, seems at first glance to provide little benefit in exchange for the added weight and complication. Indeed, if all the cuts you make when planing wood are in the direction of the grain (id est fibers either oriented parallel with, or rising up to, the surface of the board and angled away from the direction of the cut), the chipbreaker will be about as useful as a brass brassier on a boar. But wood grain is seldom so cooperative, donchano.

With the addition of the chipbreaker, and in combination with the three factors listed above, those contrary fibers that try to ride up the face of the blade without being severed immediately run smack dab into the abrupt face of the chipbreaker thereby bending, buckling, and preventing them from developing a lever arm and breaking off below the surface of the board.

At the same time the collision with the chipbreaker redirects many of these mischievous fibers into the cutting edge to be severed, thereby preventing, or at least reducing, nasty tearout.

Bless us and splash us, preciousss! What a wonderful counterintuitive thing!

To better understand how the chipbreaker works, I highly recommend Beloved Customers devour, like starving little piggies, the video titled “Influence of the Cap-iron on Hand Plane,” Created by Professor Yasunori Kawai and Honorary Professor Chutaro Kato, Faculty of Education, Art and Science, Yamagata University (with subtitles). Much will come into focus after watching this.

Downsides to the Chipbreaker

While your humble servant has written glowing things about the chipbreaker, it would be less than honest to suggest all is blue bunnies and fairy farts because the chipbreaker has some downsides:

  1. The chipbreaker adds weight, complication and cost;
  2. The impact of wood fibers on the chipbreaker produces friction heat and wastes energy whether cutting with or against the grain. This waste is not insignificant;
  3. When cutting with the grain, the chipbreaker adds little benefit while tending to reduce the luster of the planed surface;
  4. To be effective, the chipbreaker must be setup, tuned, installed and maintained properly, requiring the user to have adequate knowledge and to put forth some effort periodically.

Despite these downsides, your humble servant believes, as millions of craftsmen have, that the chipbreaker is a tool worth mastering.

Alternatives to the Chipbreak

In light of the gains and losses associated with the chipbreaker, it would be short-sighted, indeed amateurish, to assume it is always necessary, and just as short-sighted and amateurish to assume it is never necessary. So let’s examine some alternatives next.

Alternative 1: No Chipbreaker

Assuming performance is more important than convenience, the first alternative to the chipbreaker we must consider is, of course, no chipbreaker. Indeed, if you always plane with the grain of the wood, as mentioned above the chipbreaker adds no value. Indeed it may even reduce the quality of the finished surface’s appearance.

In the case of the Japanese plane, the chipbreaker can be easily and speedily removed. The resulting finish created by the plane may or may not be improved, but the force required to motivate the tool will absolutely decrease. Sadly, such cooperative wood can be elusive.

This is an excellent solution, one I highly recommend to Beloved Customers.

Alternative 2: High Bedding Angle Without a Chipbreaker

Another option with a long history worldwide is to install the cutting blade in the plane’s body at a higher bedding angle, perhaps 50~55˚+. Combined with a sharp blade, tight mouth and solid uniform contact/pressure between the board being planed and the area of the sole directly in front of the mouth opening, the more abrupt change in direction forced on shavings by this high-angle blade will then tend to buckle the long contrary fibers on its own without a chipbreaker. But no guarantees.

While a high bedding angle does indeed tend to reduce tearout, adding a chipbreaker is also a proven way to further reduce tearout in woods with contrary grain even more.

The one constant downside to a high bedding angle is the extra energy one must always expend to motivate the plane.

Alternative 3: Bevel-up Handplanes Without a Chipbreaker

Another alternative is the “bevel-up” planes that have become popular in recent years. This style of plane is not a new solution. I own some and have used them, but other than the block plane versions, I regret falling prey to specious marketing claims.

Amateurs like them because parts are fewer, maintenance is easier, and the necessary skills one must acquire are fewer.

One gentleman boldly informed me that he believes bevel-up planes to be superior to all others because he would rather spend the time it takes to master the chipbreaker into making wooden objects. By this logic, there is no need to attend school or even remove the training wheels from our bicycles. Imagine how much work we could accomplish if we stopped wasting time on stupid stuff like reedin, rightin and ritmatik! When I think of the time and money I’ve wasted on silly edumacation, my mind boggles like a weasel snacking on crystal meth….

Bevel-up planes work in the same way high bedding-angle planes do by presenting a steeper angle for contrary fibers to climb causing them to be severed or to buckle instead of tearing-out. This assumes, of course, that the blade is sharp, the mouth is tight and contact between the board being planed and the area of the sole directly in front of the mouth opening is uniform.

Sadly, the efficacy of this action is no more consistent than the high-angle blade without a chipbreaker.

The downside to the bevel-up plane is that the additional, more-consistent results afforded by a well-tuned chipbreaker are, like Heaven’s pearly gates to a California politician, forever unattainable.

Alternative 4: Back-bevels

Another alternative is the quick and dirty back bevel applied to the ura or face side of the cutting edge, as discussed in a previous post. This works for the same reason the high-angle blade does, but it is not an effective long-term solution, and certainly qualifies as tool abuse in the case of Japanese handplanes IMHO. Consider yourself well and truly warned.

Even if the “3 R’s” may be overrated, I highly recommend Beloved Customers use planes with chipbreakers and learn how to sharpen, properly setup, maintain, and adjust them for maximum results. It’s the way advanced professional woodworkers with real skills get the job done.

Keys to Making Chipbreakers Work Effectively

A naturally curved log shaped as a “Nijibari” rainbow beam at the main entrance to a Buddhist temple.

The following is a condensed list of tasks Beloved Customer needs to accomplish to get consistently good results from their chipbreakers. We will discuss all these items in greater detail in future articles in this series. I strongly encourage you to invest in yourself by developing the requisite skills:

  1. Fit the chipbreaker to the blade as lovey dovey as two newlyweds and so there is no gap between the cutting blade and extreme edge of the chipbreaker. This is not difficult to achieve, but the fit must be nearly perfect to prevent naughty shavings from wiggling between the blade and chipbreaker, because if they do get jammed, back-pressure will increase and the finished surface will look like poached crap on toast. We will discuss this more in the next post in this series;
  2. Fit the chipbreaker to both the plane’s body and retention rod so the chipbreaker will remain in-place;
  3. Grind a 70˚~80˚ striking bevel at the cutting edge of the chipbreaker to effectively buckle shavings. It doesn’t need to be a perfect bevel, and if it is rounded, that’s OK too. Yes, I know this seems ridiculously steep; If you don’t like it by all means experiment until your little pink heart sings, but after you’ve wasted a few months on hit-and-miss research, please remember that YMHOS toldjahso;
  4. Polish the striking bevel to reduce friction and prevent wood sap from building up on it too quickly. Re-polish it as necessary. If you pay attention to the condition of this abrupt bevel you will notice that it may actually become pitted from the heat and friction of the wood shavings, especially when planing wood containing hardish minerals. Total neglect will harm efficiency;
  5. Clean away wood sap from the striking face and oil it occasionally with your oilpot to reduce friction;
  6. If shavings tend to become stuck in the mouth, check to see that the chipbreaker is not so thick as to obstruct their smooth passage. If necessary, grind the chipbreaker thinner near the mouth and polish it to improve the flow of shavings;
  7. When you deem the chipbreaker necessary, install it as close as practical to the cutting edge. The ideal distance will depend on your plane, the wood you are cutting, and the depth of cut, but 0.5~0.8mm is usually a good place to start. I highly recommend you actively experiment to find the best distance. With practice it will become second nature. While it is not applicable to Japanese handplanes, Rhett Fulkerson of Nice Planes in Frankfort, Ky., has an intelligent technique for systematically setting chipbreakers and cap irons I find useful. LAP has an article about it here.

Conclusions

The chip breaker has been around a long time, not because it is easy to use or costs nothing, but only because it consistently works.

In Japan, where the single-blade plane was the standard for hundreds of years, with the shift from riven lumber to more economical sawn lumber, the chipbreaker was added to the handplane because it consistently works.

The chip breaker won’t solve all your tearout problems, but it will definitely help on condition that you set it up and maintain it properly. It isn’t difficult and the results of doing so set the professional apart from the amateur.

In the next post in this swashbuckling tale of bare-chested Scottish warriors riding feather-footed war horses over the highlands rescuing buxom lassies clad in flowing gowns from evil Lords, we will describe in detail how to setup and maintain the awesome chip breaker. Don’t forget your kilt and claymore!

YMHOS

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, thuggish Twitter or a manager of the Democrat Congressional IT team and so won’t sell, share, or profitably “misplace” your information. If I lie, may all my chipbreakers chip and fail.

Other Posts in the Japanese Handplane Series:

The Intelligent Chef: Cutting Boards

Government’s first duty is to protect the people, not run their lives.

President Ronald Reagan

This article is about the cutting board, a tool every household contains, but about which relatively few have given serious thought despite it’s constant role in our lives and the potentially huge negative health impacts it sometimes conceals.

Civilization’s Ultimate Tool: The Knife

Some anthropologists have asserted, and with good reason, that the food-preparation knife is not only the oldest, but the single most important tool ever invented by the human race, increasing populations, improving health and longevity, and saving many hours not only in harvesting food, but in making it edible, nutritional and safe to eat.

We will discuss kitchen knives in a separate post, but because a food-preparation knife without a cutting board is less than 100% effective, I will focus on cutting boards in this article.

Cutting Board Materials – Plastic vs. Wood

Allow your humble servant to begin this article by urging Gentle Readers to please use wooden cutting boards in their kitchens.

But before we dig into to the engineering aspects of cutting boards, I would like to make an observation (maybe even a rant) about modern societal trends that have influenced health and safety laws. I beg your kind indulgence.

As I grow older I am constantly amazed at how many people are blithely immune to facts in both their private lives and public duties, and proud as a peacock of it. They demand that their uninformed opinions and personal biases be given precedence over both actual, verifiable evidence and the scientific method, and call anyone who disagrees with them fascist and/or anti-science. Talk about psychological projection.

A recent example of this tendency in the United States is the strange idea that requiring voters to provide personal ID when voting is both unnecessary and “obviously” voter suppression, implying that minorities are either too lazy or too stupid to obtain and keep track of such ID, an insulting, racist, and demonstrably false supposition. Anyone who made such an assertion 20 years ago would have been universally viewed as either corrupt or mentally deranged. What does it mean that, during the last 4~6 years, top leaders of the US Congress and Senate as well as the top executives of major corporations routinely insist this strange concept should govern elections?

Political gamesmanship aside, some health professionals blame this form of brain damage on social media, but it is an unfortunate tendency that was around even before Twitter and facebook.

What people believe in their private lives is up to them, but to allow such tendencies to rule public policy and determine regulations with possible health and penal consequences is a big step back towards barbarism, IMHO.

Sorry, I almost fell of that damned soapbox and broke my silly neck again! Back to the subject at hand.

I am fully aware that many governmental health agencies in advanced countries around the world require commercial kitchens to use non-porous cutting boards made of plastic, HDPE (high-density polyethelene) or other synthetic materials. Like much of what is claimed to be hard scientific fact nowadays by incompetent, lazy, illiterate, irresponsible, unaccountable bureaucrats who then make regulations with teeth based on their poor understanding of unverified results produced contrary to the scientific method, the ban on wooden cutting boards too is based on nothing more than a casual supposition rather than verifiable facts.

This webpage summarizes this fubar beyond all doubt.

Your humble servant first became aware of this cutting board contradiction when I asked sushi chefs in Tokyo some years ago why they used wooden cutting boards in full view of customers instead of the more sterile-looking white plastic boards seen in the commercial kitchens I had constructed over the years. Their response was eye-opening.

Their first point was that wooden cutting boards are easier on their valuable knives keeping them sharper longer. That makes perfect sense, depending on the wood, of course.

Their second point, that wood is simply more sanitary than plastic, shocked me.

Now I know for a fact that the Japanese health agencies that regulate commercial kitchens are very strict about food safety, and that compliance costs commercial kitchens tons of money for special health & safety related equipment. I also know that most commercial kitchens in Japan do indeed use HDPE cutting boards. So why would sushi restaurants that serve raw fish and shellfish be different?

During subsequent conversations over several years with government health agencies, kitchen designers and subcontractors involved in obtaining kitchen permits and inspections for my construction projects, I asked them this same question. One gentleman responded by showing me the studies that formed the basis for health regulations for cutting boards. I have since done more research.

The essence of the concern about the safety of cutting boards in general is that liquids and particles of food, along with bacteria scrambling around on those foods and floating in the air in even the cleanest kitchen, not only spread over the surface of a cutting board in-use, but soak into the many cuts left by knife blades. In the case of wood, these may soak into the wood fibers too. Yuck, right?

Whether made of plastic or wood, liquids, particles and bugs can and do interact on the board’s surface where bugs make lots of baby bugs. Yes, that’s right: bug orgies on your cutting board! Double yuck!!

If the surface of the board is left wet and dirty for long, bacteria can multiply to dangerous levels to contaminate foods placed on the cutting board and later consumed causing food poisoning. BTW, most cases of food poisoning occur when eating out.

Try as we may, we cannot escape microbes and viruses entirely. They contaminate the surface of cutting boards regardless of both our caution and the cutting board material. The only workable solution to the sometimes lethal danger bacteria pose, short of working under burning UV lights, irradiating all foodstuffs with Gama rays (yes, that’s a real thing) and working in a cleanroom periodically drenched with anti-bacterial chemicals, is to limit their numbers and their growth so we can avoid ingesting more than our immune systems can safely deal with.

The misunderstanding that became the basis for health regulations in some areas outlawing wooden cutting boards in commercial kitchens started honestly enough with the observation that bacteria find their way into cuts below the surface of cutting boards and can potentially increase to dangerous levels. But the undeniable fact is that the researchers tested non-porous materials, not wood. Their reason for objecting to wooden cutting boards was based on an assumption, which they did not bother to check, that because wood is more porous than plastic, the bacterial infestation in wooden cutting boards must of course be much much worse than plastic. Government health agencies responsible for making kitchen regulations took this supposition at face value without bothering to do more thorough research. The earth is flat because, well…, it makes sense.

To make wise decisions about materials, responsible and intelligent people always obtain a sound understanding of the materials in question, something the advocates of plastic cutting boards fail to consider. So let us bravely examine plastic cutting boards and wooden cutting boards from a microbe’s eye view.

The first difference between plastic and wood is nothing less than a miracle of nature. Wood comes from trees which are, functionally, big waterpumps reaching up into the sky. Therefore, unlike plastic, which started life as black goo deep in the earth, living wood spends its entire life both wet and exposed to soil, fungi and bacteria. God designed trees and wood specifically to be resistant to fungi and bacteria, producing chemicals to fight them off. Even many years after a tree has been turned into lumber, these chemicals remain more or less effective at killing and preventing the growth of bacteria that cause food poisoning too. Microbes are offended by trees with such noxious flavors, and rightly so. I like my wood spicy. What about you?

Does plastic contain chemicals unpleasant to microbes? No, not unless someone applies them. Tabasco Sauce is a proven antimicrobial, BTW, although I am not suggesting Gentle Readers douse their plastic cutting boards with it, unless they REALLY like spicy flavors, a sure sign of a warm personality. (ツ)

There are of course antimicrobial chemicals, such as silver colloid compounds, that can be added to plastics to control bacterial growth for a time, but you don’t want them in your food.

The second difference between wood and plastic is found in the very structure of wood, because the cellulose tubes that make up wood are designed specifically for transporting water. Consequently, liquids that enter the wood through knife cuts tend to be wicked away and dry relatively quickly denying bacteria the moisture they need to grow out of control. The result is that bacteria in the knife-cuts in wooden cutting boards do not survive long, much less grow to dangerous levels. This assumes standard cleaning and maintenance, of course.

But wait a minute now. Plastic cutting boards dry out too right? Of course they do, but the sucky reality is that, while the surface of a plastic cutting board may be dry, the liquids, food particles, and bacteria inside the knife cuts, having fewer avenues for evaporation and/or dispersion than wood provides, remain wet for much much longer forming a pleasant environment for bacteria to continue their bug orgies and enjoy water sports. The Salmonella Water Polo Team not only kicks ass but is super horny! Goooo Salmo-!!

To eliminate bacteria inside cuts in plastic cutting boards one must either soak boards in chemicals such as chlorine that will permeate all the way into the cuts to kill bacteria, or subject the board to high temperatures almost hot enough to melt the plastic. While they may make your teeth whiter and your breathe less dragon-like, do you think chlorine or other bactericides will improve the flavor of your favorite sushi or salad? Tabasco Sauce might, but chlorine won’t.

In addition, plastic boards are demonstrably harder on the cutting edges of knives, dulling them much quicker than wood does, an important factor for professionals.

Assuming proper cleanliness procedures are performed regularly, a wooden cutting board is better for your health, better for your knives and better for the flavor of your food.

The Bacteria Water Polo League and Your Cutting Board

Although we don’t like to think about it, the fact remains that the materials we make our meals from contain bacteria, some more than others. This is why God gave humans stomach acid.

Heat kills bacteria too, which is why cooked food is much safer than raw food. Next time you belly-up to a salad bar in Bangkok or Beijing, Gentle Reader, think about the cleanliness of the water and fertilizer farmer Bui used to grow those veggies, and if a little heat might not be a good thing.

Chicken, beef, and pork are good examples of problematic foods because these domestic animals all live in feces-covered environments and have higher tolerances to microbes like Salmonella and E.coli than humans in advanced countries typically do. Chicken products from large industrial poultry farms are especially bad. Unfortunately, too frequently these killer fecal bacteria are transferred to meat and poultry when being processed.

According to WebMD, 83% of the chickens tested in a recent Consumer Reports investigation were contaminated with one or both of the leading bacterial causes of food-borne disease — salmonella and campylobacter. Most of this bacteria was found on the chicken’s skin. As someone who has repeatedly suffered painful and debilitating food poisoning from eating contaminated chicken, believe me, Fuzzy Freddie Nietzsche was absolutely wrong because, while salmonella poisoning may not kill you, it won’t make you stronger but will just make you wish you were dead. Seriously.

The Salmonella Water Polo Team kicking back between matches and bug orgies
The screwy Campylobacter Jejuni bacteria cause most food-poisoning cases.

What does all this have to do with cutting boards? Let’s take a common, real-world example.

Say you cut up a chicken for a barbecue using your favorite knife and cutting board. The heat of the grill will kill salmonella, but the bacteria on the chicken skin will have transferred to and remained on your cutting board sure as eggses is eggses.

Now that the chicken is cut down to size, shall we slice some carrots and celery for a dip, and maybe cut some tomatoes, lettuce, cheese and ham for a salad? Sounds like a yummy plan.

But wait a second, Gentle Reader. Do you think the Salmonella or Campylobacter microbes left behind on the surface of the cutting board by that bird-brain chicken will have all died and gone to bug heaven during the two minutes you were getting the lettuce out of the fridge? Not so much. And will either Water Polo Team call a time-out on the surface of board and refuse to transfer to the veggies you will cut on the same board and eat raw 20 minutes from now? See the problem?

There are three potential solutions to keep horny microbes under control. The first is to clean and sterilize cutting boards used to cut poultry or other meats with boiling water before using them to cut foods you will serve raw. I highly recommend this technique, and have made some proven suggestions below.

The second solution is to have two cutting boards on-hand, one for meat and one for veggies.

The third, more economical and space-saving solution is to have only a single cutting board but to designate one side dedicated for cutting meat and the opposite side for veggies and other foods that will be eaten raw. Not a perfect solution but it will help.

Wood Varieties for Cutting Boards

The Japanese are very particular about the taste of the food they eat. Indeed, they claim, and I wholeheartedly agree, that the steel of the knife used to prepare the food, and the sharpness of its blade, both impact the flavor of the food, especially foods eaten raw. This is something worth investigating for yourself if you hadn’t noticed it already.

It makes sense therefore, that the material the cutting board is made from can impart flavors good or bad to the food we prepare. So what are some good woods from the viewpoint of flavor, and why?

Hinoki Cypress

Many Japanese sushi chefs like cutting boards made of Hinoki wood, a type of cypress.

Hinoki is a beautiful, light-yellow colored wood that planes like no other wood in the world. It has a unique characteristic in that it reaches maximum strength approximately 300 years after being felled, which, when combined with the natural resistance of the wood to fungus and bugs, explains why Japanese temples and shrines last for so long. Amazing stuff.

It also contains essential oils that smell very pleasant, and make time spent in a Hinoki bathtub filled with hot water absolutely heavenly.

These preservative chemicals are effective at killing fungus and bacteria, but they also impart flavor to the food they touch, especially when a knife is making fine cuts releasing fresh volatile oils constantly. These essential oils compliment the flavors of rice and most varieties of fish used in sushi and sashimi. But not all foods.

And while Hinoki has layers of soft summer wood, it also has harder layers of winter wood that, while not as harmful to a knife’s cutting edge as is Douglas Fir, for example, are not ideal. So what are the other options in common professional use in Japan?

Willow

Willow wood is considered by many professional Japanese chefs to be the ideal wood for cutting boards. It is soft, easy on knives, and it has a neutral flavor.

Ginkgo Biloba Wood

A quarter-sawn cutting board of Ginkgo wood

Gingko Biloba, also called the Maidenhair tree because of the spreading shape of its leaves, is another wood popular with professional chefs for cutting boards. It is my favorite.

Called the ”Ginnan” or “Ichou” tree in Japanese and written 銀杏 in Chinese characters, it’s the official symbol of Japan’s capital city of Tokyo and is planted along many city streets in part because it is hardy, beautiful, and quite resistant to urban pollution. It is also the symbol of the Japanese university where I earned my graduate degree, and is included in the logo mark of C&S Tools

Despite being a huge deciduous tree, Ginkgo wood has a uniform grain with little difference between summer and winter wood, a feature that helps keep knives sharper longer. It is also flavor neutral. It’s cells naturally contain flavonoids (polyphenolic secondary metabolites) that are effective at reducing odors, rare in woods, and especially suited to food preparation involving strongly aromatic food ingredients such as garlic.

Ginkgo, Willow and Hinoki are the three woods Japanese professional chefs prefer for their cutting boards. We carry cutting boards made from Ginkgo wood, and highly recommend them based on many years of direct experience.

Cutting Board Maintenance

There are two aspects of maintenance Gentle Readers should consider. The first is keeping the cutting board clean and sanitary, and the second is keeping it relatively flat.

Cleaning and Disinfecting a Cutting Board

Obviously we need to keep our cutting boards clean and free of nasty bugs if we are to avoid tummy aches, diarrhea and expensive visits to hospitals, but there is more to proper maintenance and keeping them free of dangerous microbes than wiping them down after each use.

Unless your wooden cutting board becomes covered with oily, greasy stuff, don’t wash it with detergents or scrub it with cleansers. Detergents remove the natural chemicals in the wood that control bacteria. Cleansers do too, but they are much nastier because the hard particles they contain can become embedded in the wood dulling your precious knives and adding unpleasant chemicals to your food for a long time. This applies to plastic cutting boards too.

The best way to clean a cutting board of any variety is to wash it under running water while scrubbing it with a brush, and then stand it on-edge to air-dry. Running water combined with physical force is very effective. Air circulation is important when drying, as is sunlight.

I also recommend you pour boiling water on the board’s work surfaces after each use to sterilize them. Here is wisdom: While disinfectant chemical products packaged in colorful handy-dandy plastic bottles provide employment for thousands of marketing minions and make tons of cashy money for corporations, nothing you can use in a kitchen is more effective at killing bacteria and violating viruses than boiling water. Nothing.

Just place the board in the sink with one end elevated an inch or so to help it drain, and pour boiling hot water over it from a pot or tea kettle. Turn it over and repeat. Don’t dry it by wiping it with a cloth or paper towel, just let it air dry because any cloth you use will be less sanitary than the board is now. Nothing beats hot water or steam for open-air sterilization purposes.

Some people like to oil their cutting boards. Not a good idea, IMHO, because oil makes airborne dust and bugs stick to the cutting board.

Never use any wood finishes on a cutting board because the chemicals they contain are seldom safe to ingest, which you will.

If you don’t plan to use the board for more than a few days, wrap it in clean, fresh newspaper to keep dust and other contaminants off while allowing the wood to dry.

Flattening a Cutting Board

If you use knives on your cutting board, eventually it will become hollowed-out in the center, much like a sharpening stone. A hollowed-out cutting board makes it harder to cut foodstuffs quickly and cleanly.

Yet another advantage of the wooden cutting board is that you can re-flatten its surface and make it absolutely pristine with just a few passes of a handplane, making it once again a pretty, happy tool. Try that with a slab of plastic.

If you have a few minutes here’s an experiment you will find interesting. Use a hand plane to true the face of one wooden cutting board. Then use a belt sander or other abrasive tool to true the face of another. Then gently place a single drop of water in the center of each board at the same time. You will notice that the water drop stands proud of the surface of the planed board, while it quickly soaks into the surface of the sanded board. Which surface do you think stays cleaner and is less inviting to the Salmonella Water Polo Team?

And which surface has more knife-dulling, tooth-wearing abrasive grit embedded in it?

Cutting board maintenance is a good reason for owning and using handplanes even She Who Must Be Obeyed can appreciate.

Here’s how to efficiently flatten your cutting board. You will need a straightedge at least as long as the board, a handplane, a marking gauge, and a carpenter’s pencil.

You don’t want to unduly reduce the useful life-span of your cutting board, so plan your work to return the board to uniform thickness if you can. Examine the ends and sides of the board. Is it uniform thickness on the edges? Many are not.

Use your straightedge to sight the length, width and diagonals of the board, noting where depressed areas are.

Use your pencil to cross-hatch the surface of the board to help you check your progress. Remember to plane the high spots first and avoid the low spots until they are only a wood shaving’s thickness lower than the higher areas. While planing, periodically check the board using your straightedge and apply more graphite cross-hatching.

Once you have one side flat, use a marking gauge to mark the target thickness of the board on its edges. A guestimate of this thickness is fine, but if you want to get a precise measurement, fit feeler gauges between the straightedge and the lowest depressed area, and mark this thickness on the board’s sides and ends using a marking gauge.

I know it’s tempting to just shave wood as fast as you can, but with a little bit of examination, planning and layout, your cutting board will look and cut better and last a lot longer.

Or, if you have an electric thickness planer, knock yourself out. But carefully.

Conclusion

I will end this article with a question: In the case of cutting boards, which material is healthier, tastes better, is easier on expensive kitchen knives, more biodegradable, requires less energy and releases fewer carbon emissions to produce, and is more sustainable – petroleum products or wood? If the answer isn’t obvious, you may want to check your ID.

YMHOS

PS: We carry a special line of Ginkgo wood cutting boards. These are solid wood, not laminated. Most are quartersawn for stability. They make a great gift. If you would like to give one a try, please let us know in the “Contact Us” form below.

An avenue of Ginkgo trees at night in Tokyo

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may the Salmonella Water Polo Team forever have icky orgies in my cereal bowl.

The Marking Knife

A spearpoint marking knife

“Make sure that you always have the right tools for the job. It’s no use trying to eat a steak with a teaspoon and a straw.” 

Anthony T. Hincks

There are many varieties of marking knives used for woodworking around the world. In this article your humble servant would like to discuss the Japanese version.

We will begin with some definitions, followed by an explanation of the design details and structure of the tool. We will save the best for last by describing two subtle but effective professional modifications to improve the tool’s performance and the results produced.

Definitions

The Japanese marking knife is called a “shiragaki” or sometimes “shirabiki.” The characters used vary, but can mean “white pull” (白引き), which makes some sense, or “white persimmon” (白柿), which makes little sense, so I suppose the persimmon character is used as a phonetic substitute for “kaki” (書き) which means to write. I choose to write the word as 白書 so the Kanji translate directly to “white writing.” That makes more sense to me.

Such confusing substitutions are all too common in the Japanese language in the case of words with purely phonetic origins. The fact is that, much like psychologists, lawyers, and priests, the Japanese people enjoy confusing terminology. It’s an ancient habit that probably won’t change soon. I say this as someone that has been reading, writing and speaking the Japanese language at graduate school level for 45 years, been a resident of, attended school and worked in Japan for 30 years, and been married to a Japanese woman and had Japanese relatives for 43 years. I can get into serious trouble in the Japanese language.

Now that we are done with the Japanese language lesson, I will simply call this tool a “marking knife.”

The marking knife is used to cut thin, precise layout lines in a board’s surface, most often but not always at a 90 ° angle to the direction of the wood grain.

Every woodworking tradition I am aware of includes the marking knife, and regardless of their preferred style, anyone serious about woodworking will own at least one, and know how to use it.

Advantages

The marking knife has some advantages over other methods of marking a line more-or-less perpendicular to the direction of the wood grain. Here are a few:

  1. The line it makes can be as thin as the edge of nothing, achieving precision unapproachable by pencils, pens, scribes, sumisashi, inklines, chalklines, laser-sights, or even wishful thinking for layout in wood in the case of lines at more-or-less 90˚ to the direction of the grain. The line it makes, however, is not as easy to see as an ink or even pencil line, so it is not always useful for rough layout work;
  2. The line cut by a marking knife penetrates the wood’s surface providing a physical place into which the woodworker can index the edge of his chisel, or nicker of his plow plane or rabbet plane, or the teeth of his saw, or points of his divider quickly, precisely and confidently without relying heavily on Mark-1 Eyeball, improving the efficiency and quality of both his layout and fabrication efforts. The resulting time savings, improvement in accuracy, and reduction of eye strain the indexing benefits marking knife lines provide are huge.
  3. When making layout lines on perpendicular faces of a member, such as a table apron, for instance, after making one line on the reference face, the remaining three lines can be indexed and extended from each other with a marking knife, confirming the accuracy of the member’s dimensions and ensuring the tenon shoulders will be sawed accurately creating an excellent tenon, assuming the craftsman knows how to use a saw properly, of course.
  4. The line cut by a marking knife severs the fibers near the board’s surface helping to prevent fibers from being torn out of the wood avoiding a ragged cut with saw, chisel or router.

Are you convinced yet?

Design & Materials

Shirabiki Ura by Konobu

There are many styles of marking knives used around the world, and your humble servant has tried most of them at one time or another, but none that I am aware of are as simple as, or functionally superior to, the Japanese version.

Lacking a pretty, turned handle and looking more like a blackened steel popsicle stick than a finished tool, the Japanese marking knife appears unfinished, even barbaric. But despite its stark appearance, it’s a sophisticated design that employs superior metallurgical and blacksmithing techniques.

Like many Japanese woodworking tools, the professional-grade marking knife is made with a layer of hard high-carbon steel forming the cutting edge, forge-welded to a softer layer of low-carbon steel which forms the body of the tool. They are almost always flat, generally thin, and not especially wide tools. Perhaps 1/2 the length of one side is ground flat and bright and includes a hollow-ground depression called the “ura,” while the other side is plain and includes the cutting edge’s bevel.

Some marking knives, such as the photo at the top of this article, have a spear point or “kensaki” (剣先)meaning “sword point” which is convenient because the same knife can be used either left-handed or right-handed. Some people prefer this style, but in my experience it has limited usefulness. To each his own.

The demands on the marking knife in terms of sharpness, durability, and edge-holding capability are not as high as for chisel and plane blades. The better-quality ones are hand-forged of high-carbon steel and quality jigane, properly shaped and filed, and carefully heat-treated.

Because of their thinness, marking knives tend to warp badly during heat treat, and consequently demand either a blacksmith with good skills or the use of high-alloy steels that warp little. Even experienced blacksmiths end up with a few rejects due to cracking and excess warpage, which perhaps explains the relatively high cost of handmade ones. It has mostly been a tool made by specialist blacksmiths.

For this reason, and because the performance demands on the cutting edge are not severe, Blue Label steel is entirely acceptable IMO.

The Ura

I mentioned the “ura” above, but let’s examine it a bit more. Ura is a Japanese word written using the Chinese character  浦. It means a bay or inlet from a lake or ocean, usually without lots of rocks, and often with a sandy or gravelly shore. You can imagine why this word was employed to describe the hollow-ground depression in many Japanese woodworking blades.

In North America, similar curved surfaces and depressions were once called “swamps” even though they were made in metal. This term is obsolete nowadays.

The ura is what makes the Japanese marking knife superior to its Western counterparts for two reasons. The first reason is that the ura makes it easier to keep the hard layer of steel at the reference side flat. Second, in light of the hardness of the cutting edge layer, the ura makes it easier to sharpen the cutting edge.

Without the ura, the hard steel would be time consuming to sharpen and would tend to become rounded instead of remaining a flat reference face to index against a steel square or straightedge. It’s a subtle and clever design more sophisticated than its simple appearance suggests.

In use, the flat ura side is pressed lightly against the leg of a steel square with the point cutting lightly into the wood and the heel floating above. The blade is then pulled toward the user to cut the straight layout line.

Lubrication

I recommend Beloved Customer use an oilpot to lubricate the marking knife’s blade to reduce friction and wear between the blade and the square, as well as friction between the cutting point and the wood. Not only will  your square last longer, but your layout lines will be more accurate. Don’t believe me? Give it a try.

Recommended Modifications

Marking knives are simple tools for a simple job, but there are a couple of subtle improvements some advanced Japanese craftsmen, especially joiners, make that Beloved Customer may want to consider.

1. Habiki

The first improvement is intended to minimize one downside of the marking knife, namely its habit of shaving metal from the square or straightedge used to guide it. In Japanese this modification is called ” habiki “ 刃引き which translates directly to “ blade pulling, ” as in pulling the blade’s cutting edge over a stone to intentionally dull it. It is a term borrowed from the sword world.

The steps to accomplish this modification are as follows:

  1. First, sharpen the blade;
  2. Then, with the tool’s ura side facing you, stand the blade vertically on its cutting edge on the face of a medium grit waterstone or oilstone with the last 2~3 millimeters of the blade, measured from the tip, hanging off the stone’s side so the tip does not contact the stone;
  3. Finally, drag the blade towards you creating a flat on the cutting edge, while leaving 2~3mm of the blade’s tip sharp. Voila.

The dulled portion of the cutting edge will now be less likely to shave your square or straightedge, while the sharp tip will cut the wood and make a pretty, accurate layout line, assuming you do your job, of course.

I know that the idea of sharpening a good blade and then intentionally dulling part of the cutting edge sounds gaga. In fact, when Honda-san showed it to me, I thought the old guy was pulling my leg. But Honda-san was a master among masters, a man in his 80’s who had been making extremely high-end custom joinery since he was 15 years old, one who took his tools extremely seriously. In addition, he let me try his knife so I was quickly convinced.

Honda-san’s technique works, so gather up your courage and give it a try before allowing your inner-troll to embarrass you. I promise you’ll like the results and your square will thank you.

2. Tip Bevel

The second modification is also one Honda-san taught me. There are several ways of doing it, but the essence is to grind an angled flat 15~18mm long  on the top edge of the blade’s side angled away from the ura, ending at the cutting edge’s point. The goal is to create a very sharp “clipped” point.

This angled flat has three purposes: First, it removes metal that would otherwise get in the way of your clearly seeing the knife’s cutting tip. This is important because often a knife must be indexed off a tiny divider point’s mark or a previous layout line, for instance when marking the shoulders of a tenon on four sides of a stick of wood. Removing this unnecessary metal will make it easier to begin the mark exactly where it is needed.

The second purpose is to reduce the friction between blade and wood when cutting a layout line, thereby improving control like racing tires on a fast car.

And third, it provides a convenient place to rest your fingertip to better control the knife.

If you imagine this modification can’t make much of a difference, then your lack of experience is showing. How embarrassing >~(ツ)~<

The Square

I know there are those who prefer to use a wooden square for layout work, and others who like brass ones. Both work just fine with a marking knife until they don’t. You would be wise to consider using a hardened steel square, or better yet, a precision hardened stainless steel square with your Japanese marking knife; They simply last longer and stay straighter.

There are hardened carbon steel and hardened stainless steel combination squares and die maker squares available on the market, but I think they are too bulky and too costly for making simple 90° layout lines on wood.

Matsui Precision produces a series of excellent hardened stainless steel squares that are popular in Japan and well worth the cost. I have been using them for years. Send me a note if you are interested.

The Japanese marking knife is a great tool. Once you use one, especially after making the modifications described herein, you will wonder how you ever got decent layout work done before.

YMHOS

My old marking knife was hard on my eyes and fingers, but now I know how to fix it!

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. May my square always lie to me if I lie to you.


Salt, Rice, Sake and a Prayer

Mother troll introducing her two handsome, well-dressed sons as suitors to a fairy princess. A difficult choice!

But when the fairy sang the whole world listened to him. Stephen felt clouds pause in their passing; he felt sleeping hills shift and murmur; he felt cold mists dance. He understood for the first time that the world is not dumb at all, but merely waiting for someone to speak to it in a language it understands. In the fairy’s song the earth recognized the names by which it called itself.

Susanna Clarke, Jonathan Strange & Mr Norrell

Most of the posts to the C&S Tools blog are focused on how to select, maintain and use woodworking handtools. But in this article your humble servant would like to examine the relationship between supernatural influences and construction jobsite safety from a Japanese perspective.

We will also briefly examine a traditional way to deal with supernatural beings in order to increase both safety during construction and the welfare of those who will occupy the completed structure.

Gentle Readers involved in construction, either as customer or worker, may find this article informative and maybe even helpful.

Supernatural Beings

Your humble servant has often sensed unexplainable presences when alone in deep forests, high mountains, dark caves, and open deserts where human influence is absent. These irrational feelings may spring from an overactive imagination, or perhaps the gentle ministrations of a butter-fingered baby-sitter when I was small, but I’m not alone in my perceptions because humans in all parts of the world have felt similarly about certain places on the earth such as hills, groves, and caves since before recorded history. What about you?

The peoples occupying the heavily-forested islands of Japan have, since ancient times, believed that spirits reside in trees, hills, rocks, rivers and of course the ground. Indeed, Japan’s indigenous religion, called Shinto, which can be translated as “The Path of the Gods,” is a vague belief system based almost entirely on this amorphous perception. It is no coincidence that Shinto has heavily influenced Japanese architecture and carpentry traditions.

If one believes that supernatural beings reside in trees, groves, mountains, water and even rocks, it’s not a stretch to believe that some of those beings, or spirits, are naughty and some are nice. Besides, the bad things that happen to us can’t all be blamed on Fortuna, right?

Since we cannot see these beings or spirits, and they don’t give a rodent’s ruddy fundament about what judges and lawyers do and say, how can we protect ourselves from their naughty tendencies, especially when human activities might evoke their ire?

What human activities piss-off vengeful supernatural beings in nature? Loud music? Social injustice? Wearing socks with sandals? Nah, none of those. In the case of Japan it has been traditionally held that clearing and grubbing trees and vegetation and excavating soil for construction projects is asking for trouble from the supernatural beings that call such places home. Accidents, injuries and even deaths during construction work are believed to be a direct result of such activities, and the malevolent effects of PO’d spirits can make entire buildings dangerous, unhealthy and unlucky places.

So how does one keep possibly dangerous spirits happy? A traditional approach is a ceremony called the Jichinsai.

Jichinsai Ceremony

The name of this common ceremony is pronounced jee/cheen/sah/ee, and is written 地鎮祭 in Chinese characters as used in Japan.

The first character 地 means ground or earth. The second character means “weight” as in “paper weight,” but it also means to “suppress” or “calm.” The last character is pronounced “sai” and can also be read “matsuri,” meaning ceremony or festival.

There are records of Jichinsai being performed in Japan as early as AD 690. The background of the ceremony is the belief indigenous to Japan, and found in many other locations around the world since ancient times, that spirits reside in places and even plants.

I think I participated in my first Jichinsai in Japan in 1987. I have since attended many in Japan and even a couple in the United States.

I like to think of the Jinchinsai as a ceremony to keep mischievous pixies sleepy and to hide the building and workers from Murphy’s attentions.

The Jichinsai ceremony is typically performed prior to the beginning of a construction project. Its goal is to show respect to and appease the local spirits, and thereby forestall them from seeking revenge for the contractor’s rude disruption of their happy homes.

The ceremony accomplishes these goals by providing offerings of food and booze and greeting to the spirits, showing proper respect, a bit of entertainment, and saying prayers informing them of the construction plans and asking for their protection. Basically, salt, munchies, wine and flattery followed by a polite, well-phrased request, just like a good pickup line. (ツ)

Nowadays, this ceremony has been appropriated by Shinto priests hired to conduct the ceremony, but it is neither Buddhist nor even Shinto in origin, having roots older than formal religion.

Indeed, while priests saying theatrical prayers and dressed in silk brocade robes and oh so goofy hats add to the pageantry, and they insist the efficacy, of the ceremony, in your humble servant’s opinion they add little but cost because, at its heart, the only true participants in the ceremony are the workmen who will perform the construction work, those who will live in or use the completed building, and the spirits that reside in the vegetation and ground to be disturbed. But it is human nature to enjoy and even find meaning in pageantry. If not, the Academy Awards program would have been canceled years ago for being such a boring, preachy stinker. And besides, priests need work too. 

Indeed, if only the builder conducts and attends the ceremony, that is sufficient for purposes of promoting safety for himself and his workers during the construction work, although the Owner, if he doesn’t participate, could arguably miss out on some of the blessings possibly provided by the ceremony such as his safety and prosperity in using the land and building.

A Shinto priest dressed in silk robes, wooden shoes and lacquered hat conducting a Jichinsai ceremony for a corporate construction project. A specialist subcontractor has erected the tent and provided seating and props. Notice the wooden stand with offerings of salt, foods and wine, standing bamboo at the four corners, and Cleyera Japonica cuttings below and behind. At this point in the ceremony, the Priest has sung several prayers and scattered bits of paper around. The pile of sand in the foreground is still undisturbed, but towards the end of the ceremony the Client’s representatives will poke it with a wooden hoe to let the spirits know dirt work will start soon. The step-by-step program for the ceremony is listed on the board to the right. Participants in the ceremony are required to stand, clap hands, bow, drink a drop of demon rum and make plant offerings several times. It is an extremely solemn business.

Groundbreaking ceremonies have been around for a long time in other nations too. Nowadays in the West, they have degraded to a photo opportunity for publicity hounds like politicians and business owners, but the tradition of dedicating, blessing and/or sanctifying the ground upon which a building will stand has ancient roots in Christian and Pagan traditions too. 

Nowadays most versions of the ceremony are centralized on a wooden table set up on the site where the building will be constructed surrounded by green bamboo cuttings stuck into the ground forming a square. A rope is strung around these poles and pieces of paper cut into a special pattern particular to Shinto ceremonies are hung from these ropes. 

Various offerings are placed on the table, always including at least rice, salt and sake. Some additional offerings might include products from the sea, such as fish, and products from the mountains, such as the various herbs and vegetables that supernatural beings like to munch on. Fruits are often included as well. Other than fish, meat is not included.

The general contractor usually hosts the ceremony, sets the stage, makes other arrangements and pays the costs. Of course priests don’t work for free so the cost of the ceremony is included in the contractor’s construction contract amount, although it is seldom shown as a line item. Often, however, the GC will inquire before bidding if the Owner desires a Jinchinsai to ascertain if the cost should be included or not. 

I won’t go into all the details of what goes into a Jinchinsai because it would take months of research and a book I do not have the time to write.

The following links are to YouTube videos of an actual Jichinsai with all the trimmings. Video 1 Video 2

Why Perform a Jichinsai Ceremony?

I mentioned above that I do a lot of work for international corporate Clients. Indeed, Gentle Reader no doubt uses their products daily. These are corporations that are decidedly non-religious and are careful to avoid allowing religious influence to become apparent in their business dealings. So how do they justify spending money and time on a ceremony intended to deal with metaphysical influences? The reasons, as I understand them, are twofold: (1) Peace of mind; and (2) Avoidance of blame. 

Let’s examine reason number 1 first.

After many millennia of belief, the local employees of even large international corporations have a fear of malevolent supernatural influences embedded in their DNA, so to actively reject a harmless, basically non-religious, non-controversial tradition intended to protect them may cause undue stress in some individuals.

You don’t believe me? Here’s a true story.

A Ghost Story

Some years ago my team and I were managing a two-phase construction project for a very wealthy and well-known international consumer electronics company.

Phase One included office fitout work and cleanroom construction (tenant improvements) in a leased space in a brand spankin new building located in Yokohama. Although the grade of the completed project was exceptionally high, it was just a temporary facility.

Phase Two, however, was the construction of a large, elegant, high-tech, structurally-advanced building intended for long-term operations. When completed it was without doubt the most beautiful and both technologically and environmentally advanced building in Japan, if I do say so myself.

The Client anticipated hiring hundreds of new engineers to work in both the Phase One and Phase Two spaces, but sadly hiring lagged far behind plan, so even though we had completed the construction work of the Phase One office spaces on-time and installed some nice office furniture too, it was mostly empty.

For many months after most of Phase One was complete, my team and I used the otherwise unoccupied, high-ceiling leased space as our workplace for the planning and design of Phase Two. It was a large, lonely space.

This intense project involved working late into the evening far too often. An exceptionally diligent lady on my team I will call Naoko worked many evenings alone in these empty spaces. After a few months Naoko became seriously stressed and complained about hearing strange noises and feeling like she was being watched by unkind eyes. Even I thought the place felt creepy. Soon the entire team was feeling weird and stressed.

I took Naoko’s complaints seriously because, when it comes to workplace stress, perception is absolutely reality. And so I shifted our base of operations to a less-comfortable pre-fab jobsite office sooner than originally planned to get the team out of that creepy place. Problem solved.

Indeed, there may have been something unlucky about the leased building because, besides the hiring SNAFU, the Client’s operations in the building accomplished much less than planned. Indeed, serious and very unpleasant acrimony developed among the Client’s employees that occupied it. When the new building was completed, they too moved out of the leased space as soon as humanly possible.

We later learned from the general contractor that developed and owned the office building that it stood smack dab on an old graveyard. Hmmmm.

Did I mention that the Client decided to not perform a Jinchinsai prior to construction of the leased space?

A Good Beginning

For the new building, however, the Client wisely decided they wanted to avoid the risk of not doing a Jichinsai, a decision that was welcomed by the general contractor and the thousands of workmen that were involved in its construction.

Despite having 14 large crawler cranes lifting heavy stuff and drilling deep piles, and 600+ heavy trucks carrying soil out of and concrete and materials into the extremely tight and dangerous site daily, and over 10,000 workmen for months on end, we only experienced one injury when a sheet-metal worker cut his hand on some sharp metal scrap, and one accident when a careless iron-worker managed to start a small localized fire in some urethane concrete blankets with a cutting torch.

Another worker with a well-documented history of a bad ticker had a fatal heart attack on the way home one day, but that incident was ultimately deemed unrelated to the construction work.

This safety record was a miracle in my book. Was it a direct result of the Jichinsai? Who can say. I only know that if we hadn’t done the ceremony, and a serious accident or death had occurred on the job site, the Client would have been blamed for carelessly not performing the ceremony and the work would probably have suffered as a consequence.

And this illustrates the ultimate reason for conducting a Jichinsai ceremony: Better to be safe than sore. 

The Simplified Jichinsai

There are various approaches to pacifying possibly malevolent spirits. One is the full-blown Jichinsai ceremony, of course. Another is a simpler, humbler, and less-expensive way, because, after all, what the ceremony boils down to is a sincere offering of salt, rice and sake and a silent request to the resident spirits for forbearance.

One such simplified example is quietly and routinely performed by either the general contractor or his steel erection subcontractor. They simply place a small mound of salt, another of uncooked rice, and a small cup of sake wine at the base of the first column erected, then the employees of the GC and/or the erection team offer a silent prayer. No muss, no fuss, no silly hats, but it’s still taken very seriously by the workers.

When I was a self-employed contractor, I would do something similar. Before beginning any excavation, I would politely place a small mound of salt, another of rice, and a small cup of local wine on the ground at what would later become the center of the completed building or renovation and leave it overnight. I would also lay a branch of the local vegetation, be it tree or bush, beside the offerings. Before leaving at the end of the day, I would offer a silent prayer to heaven, and whoever else might bother to listen, that the job would proceed without accident or injury to any workmen involved, and that it would remain on-schedule and under-budget.

Did it work? I don’t know, but the only serious jobsite injuries and deaths I have experienced over the years have been where a Jichinsai of some sort was not performed. Cheaper insurance you will never find.

One Beloved Customer located in the Pacific Northwest of the United States Coast recently began construction on a small but elegant outbuilding using beautiful Port Orford Cedar wood with traditional and extremely intricate interlocking Japanese handcut joints and hand-plane-finished, and natural stone foundations with fitted posts.

The photos below are of his simple Jichinsai. No accidents or injuries so far!

YMHOS

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may tree spirits drop limbs on me from a great height.

Japanese Handplanes – Part 4: Fitting Blade & Body

After tumbling down the rabbit hole, Alice discusses her options with her new friends Gryphon and Mock Turtle. After perusing this article, I hope Gentle Readers will be less discombobulated than poor Alice, less tearful than Dear Mock Turtle, and less indignant than Noble Gryphon.

A Bruise Is A Lesson… And Each Lesson Makes Us Better.

George R.R. Martin, Syrio Forel, Game of Thrones,

In this the fourth post in our series about the Japanese hiraganna handplane we will discuss how to fit the plane’s wooden body to the blade thereby improving the tool’s performance.

As is the case for most of the posts in this blog, this one too is intended primarily for the information and entertainment of our Beloved Customers, but all well-behaved Gentle Readers are welcome to partake. Bon apetit.

Why Fit Body to Blade?

Beloved Customers may wonder why your humble servant is inflicting the internet with another pointless article about Japanese planes, especially since the handplanes purveyed by C&S Tools are advertised as “ready to use” when new. Let’s address this absolutely valid concern.

As mentioned in the Part 3 of the Japanese Handplane Series, Mr. Inomoto, the daiuchi shokunin that cuts the bodies from Japanese White Oak to fit the blades forged and sharpened by Mr. Nakano, does indeed do more than just cut a gap for a blade to slot into, but fits the blade to the body so it is able to cut a decent shaving before it leaves his workshop. However, due to cost considerations and practical limits to his prophetic talents and clairvoyant insights regarding who will eventually own each plane and their preferences for the blade-body marriage, he fits the blade on the tight side, assuming the end-user will adjust the body to best suit his own purposes. Ergo the paragraph titled “Plane Philosophy” in Part 3.

I suspect relatively few Beloved Customers have given the subject serious thought, but it is nonetheless true that each owner of a Japanese plane must develop their own philosophy regarding the relationship between blade and body, and if they deem it necessary, adjust their plane body accordingly.

This article assumes Beloved Customer has decided to refine the fit between blade and body, and instructs in how to make those refinements. Are they absolutely necessary? Nah. Will they make a difference? Yes, but the degree of improvement obtained will vary from plane to plane and person to person.

Nonetheless, your humble servant recommends Beloved Customers, especially those interested in obtaining professional-level plane maintenance and usage skills, to perform the operations described in this and future articles in this series. You’ll be glad you did even if it may take some years for the benefits obtained to become evident.

So with that out of the way, let’s assemble the tools we will need to make some righteous sawdust.

Tools

The following is a list of tools recommended for this job.

  1. Wooden mallet for striking the blade and body;
  2. Carpenter’s pencil and/or marking pen;
  3. Masking tape to protect the wooden body from oily fingerprints;
  4. Vernier caliper and/or divider for measuring and comparing;
  5. Various chisels (e.g. 3mm, 6mm, 9mm usunomi paring chisels);
  6. Metal file (to be modified) or a 15~18mm wide chisel (to be modified).
The tools needed for fitting the body to the blade. The chisel next to the vernier caliper is an old Sorby chisel modified especially for working on plane beds and gifted to me by Chris Vandiver. Thanks, Chris.

Regarding the modified file or chisel listed above, this is a push scraper, an ancient tool once commonly used for precision metalwork. Your humble servant uses it to shave the bed to fit the blade. You can make this tool as wide as you wish, but please note that if the blade of either file or chisel is too wide, your shaving efforts may not produce smooth results.

You can easily make this scraping tool from a chisel or an old file by grinding a flat on the end of the file or cutting edge of the chisel square to the centerline of the blade and at an 80~90˚bevel angle. Then hone this square cutting edge and at least one of the two adjoining surfaces to 1000 grit. Voila.

If you use a file you will want to attach a handle to its tang to avoid getting red sticky stuff on your pretty wood.

If you prefer to use a regular chisel, that’s OK too, but you will find this scraper does a cleaner job with less effort.

Blade Preparation

This explanation assumes the blade is sharp and the ura is in good shape. If not, please sharpen the blade because it will of course affect the fit of blade to body.

While you are at it, check that the side edges of the blade are free of burrs or rough grinder marks which might abrade the grooves after some use. Some grinder marks may be unavoidable, but if the sides feel rough and abrasive to the back of your hand, smooth the edges a little using a sander and/or sharpening stones.

In addition, please make sure the right and left clipped corners of the blade’s cutting edge, called “ears,” are properly trimmed, meaning that they are ground large enough to reduce the width of the sharp cutting edge so it fills the width of the plane’s mouth but does not extend into the grooves, because if it does get into the grooves, shavings will become jammed between the blade and groove wasting your energy and leaving nasty scuff marks and sometimes even tracks on the planed surface. それは困る.

When sharpening a plane blade, therefore, it is important to check and trim these ears periodically. A few passes on a diamond plate or rough stone will do the job; It doesn’t need to be pretty, and the ears don’t need to be sharpened because they will never touch the surfaces to be planed.

The disassembled plane used as an example in this article, a 70mm finish plane with a Blue-label steel blade hand-forged by Mr. Nakano Takeo and a Japanese White Oak body by Mr. Inomoto Isao. An excellent tool.

Checking & Tuning the Mouth

Beloved Customers won’t need to worry about this, but Gentle Readers fettling plane bodies made by themselves or others should be careful the first time they adjust the blade’s cutting edge to project through the mouth to ensure there is adequate clearance because if the mouth isn’t wide enough to allow the cutting edge to pass through cleanly with a little clearance to spare, the blade may chip out the sole.

If there is any question about the mouth/blade clearance, the first time you extend the blade through the mouth, press the plane sole-down on a piece of clean wood while tapping the head of the blade with your mallet to make a zero clearance cut at the mouth. The supporting board will prevent the mouth from chipping. This is also standard practice when opening the mouth of a new plane body.

Hold the plane up to a light and peer through the mouth to observe the gap between cutting edge and body. The width of this gap must be greater than zero, but how wide it needs to be will depend on the thickness of the shaving you intend to cut.

Ugly tear-out can be minimized and the polish of the planed surface increased by having a tight mouth. Indeed, the tightness of the mouth and the area of the sole directly in front of the mouth applying uniform pressure on the wooden surface being planed up to the last .001 millimeter in front of the mouth is critical for exceptionally fine tear out- free cuts. On the other hand a mouth gap that is too narrow to pass the intended thickness of shaving will jamb every time, so the user must balance the width of the mouth, the desired shaving thickness, and blade projection to obtain good results.

Here is wisdom: repeatedly jamming packed chips and shavings into the mouth is not only hard on the blade, but it will damage the mouth, so before this happens too many times, you want to either adjust the mouth or your expectations for shaving thickness.

To open up or adjust the mouth, cut a hardwood guide block to use with a chisel to pare the mouth opening, and clamp it to the sole. The angle of the block will vary with the angle of the blade.

Then using an exceptionally sharp paring chisel and this guide block, take minute shavings at the mouth using skewed strokes. A paring chisel with a three-hollow mitsuura ura is ideal for this task, but any sharp chisel with a longish blade will do the job.

Body Protection

This process will involve graphite pencils, marking pen ink and fingers, so to keep the wooden body from looking dirty, please cover the top and sides with a low-tack masking tape. In this example, I used a pretty pink tape.

Adjusting the Blade to the Mouth

As mentioned above, the blade fits into and is clamped in-place by the two tapered grooves cut into the body. Sometimes the fit between the side edges of the blade and the bottom of these grooves is too tight. This can occur in a new plane if the body was improperly cut to begin with, but the most common cause is shrinkage of the body due to humidity changes.

Of course, the wooden body will change dimensions with changes in ambient humidity, while the blade won’t. If a plane is shipped from a wet climate like Japan (at some times of the year) to a dry climate like the Mojave Desert (all times of the year), for example, the body may shrink in width developing tremendous pressure on the side edges of the blade, sometimes enough to crack or split the body. Therefore, if you are located in a dry climate and acquire a plane from a wetter climate, it may be wise to remove the blade and let the body acclimatize for a week or so.

As mentioned above, the blade is tapered in width, being wider at the head and narrowest near the cutting edge. This is intentional. Ideally, you want the side edges of the blade to just kiss the bottom of the grooves where they exit the top surface of the body, and not touch the bottom of the grooves anywhere else. This type of fit will to make it easy to make minute right or left adjustments to the cutting edge’s projection by tapping the head of the blade right or left.

Obviously (and this is an important point to understand), if both of the blade’s side edges are in close contact with the bottom of the grooves their full-length, this important method of adjustment will no bueno.

Use you vernier caliper or divider to check that the the blade does indeed become narrower in width from the point where it exits the grooves at the top surface of the body and the point where the cutting bevel begins. If it doesn’t, you will need to grind in some taper. How much? Mr. Nakano’s blades typically taper the amounts shown in the photos above, but they are handmade and each one is little different.

The distance measured between the blade grooves where the blade makes contact at the top of the grooves. Please notice that this distance is slightly greater than the width of the blade at this point as shown in the photo on the right above.

In any case, please ensure the body provides adequate clearance to just accommodate the blade’s width. Mark 1 Eyeball is often good enough for this task, but a divider is better and a vernier caliper is ideal.

Make a final check by applying marking pen ink to the sides of the blade 1cm down from where the blade would normally exit the grooves at the top surface of the body. More ink is not necessary.

If some paring of the grooves is necessary to provide adequate clearance, please remove no more wood than is absolutely necessary.

Groove Maintenance

A common problem we see with old planes is cracked and split bodies caused by the tapered blade becoming shorter over the years due to repeated sharpenings, and therefore the edges of the blade exerting excessive pressure on the bottom of the grooves when a careless user mercilessly pounds the blade into the body. This sort of damage is entirely avoidable by humans, but some gorillas advocate paring the bottom of the grooves of new planes to create a gap of 2~2.5mm between the groove and blade to accommodate all the reduction in length the blade may experience over many years of service at once. To this practice, your most humble and obedient servant can only respond “Poppycock!”

Why do I object to what seems to be a logical solution? Glad you asked.

If you chisel out a big gap between the side edges of the blade and bottom of the groove, not only will you unnecessarily weaken the body by severing continuous wood fibers at the narrowest, weakest, most critical point of the body (think about it real frikin hard), but the pivoting action required to adjust the blade’s projection right and left by tapping the head right and left will become more difficult, while at the same time the blade will become less stable in the body.

I write this based on bitter experience obtained from following bad advice received before I knew better, and later being mocked by more experienced craftsmen who noticed my silly error. An embarrassing episode indeed.

Beloved Customers will of course have purchased a high-quality plane from C&S Tools, with a blade hand-forged by Mr. Nakano Takeo and Japanese White Oak body cut by Mr. Inomoto Isao, but just in case you are working on a lower-grade tool, here are some things you need to check.

The way to avoid body damage due to shrinkage of body or blade is simple: (1) Pay attention to the fit of the blade in the grooves; (3) Adjust the clearance when appropriate, and; (3) Avoid excessive use of recreational mushrooms which may dull the senses and cause chronic tool neglect.

In other words, when you notice the blade becoming tight in the grooves, simply pare the bottom of the grooves a nat’s mustache hair deeper. Don’t get carried away because a little contact is a good thing!

Our 6mm and 3mm usunomi paring chisels are ideal for this job. but standard oiirenomi chisels can accomplish the task too.

Another option is to grind the sides of the blade making the blade a little narrower in width.

Beloved Customers have the choice of learning from your humble servant’s stupid mistakes or from their own. Of course, I suppose there’s always the default option too many lost and wandering souls select of neglecting to learn anything at all…

Fitting the Bed to the Blade’s Back

Assuming Beloved Customer has completed the checks and adjustments in the previous sections, the general steps for fitting the bed to the blade are as follows:

  1. Begin by rubbing the back of the blade from where the cutting bevel begins to the end of the steel lamination with your carpenter’s pencil giving it decent coat of graphite. Marking pen ink or Dykem works too.
  2. Insert the blade into the grooves and tap it with your mallet (not a metal hammer!) until the cutting edge is nearly projecting from the mouth. You may need to really wack the blade hard 5~10 times to accomplish this the first time.
  3. Next remove the blade by holding the plane in your hand and alternating strikes on the right and left sides of the chamfer on the body behind the blade’s head. Don’t strike the flat end of the body! The blade should wiggle out after some less-than-gentle persuasion. If your plane doesn’t already have a pretty 6~8mm wide chamfer cut on this edge, please make one.
  4. Examine the bed. You will notice how the areas in contact with the blade are now marked with graphite. We need to pare or scrape down these contact points to achieve a more uniform contact.
  5. Use your chisel or scraper tool to carefully shave down the high spots marked with graphite. Cut/scrape only those areas marked with graphite. Before you begin making sawdust, however, please be careful to not remove any wood from any of the three surfaces inside each side groove for now. You need to sneak up on the final shape of the bed like a kitten stalking a grasshopper, with eyes wide open, gently and a little bit at a time. It would be a serious mistake to try to make a perfect fit after only a few passes.
  6. Repeat steps 2~5. You may need to do this dance 10 times to get it right. You won’t need to apply more graphite each time, just rub the back with a piece of cloth to redistribute the graphite. Or you can use your carpenter’s pencil again. With each iteration, the graphite marks left on the bed will increase in number and become larger. You want to be able to seat the plane blade with only three or four medium strikes with your mallet, and make fine adjustments with just a few more. At no time should your plane squeal a complaint.
  7. When the blade can be easily seated with 3 or four medium wacks of your mallet, use a metal file to lightly smooth out the rest of the bed. Perfection is neither attainable nor should it be sought.
The bed before applying graphite and any shaving. Mr. Inomoto Isao does a nice job, so contact is good, but still tighter than I prefer. The No.13 is a mark he made to keep blade and body matched. Notice the “tsutsumi” shelf cut at the bed just inside the mouth. This is a nice, pretty detail that aids in preventing the blade from “sniping” the ends of narrow boards, but sometimes it gets in the way, and after much use, it becomes so thin it must be removed. It is neither necessary nor sacred.
The back of the blade has been rubbed with a graphite pencil, and is being tapped into the body. It takes some forceful strikes to get it into position. Notice the purty-pink low-tack masking tape applied to the body to help keep it free of graphite fingerprints. My planes seem to appreciate brighter, feminine colors.
Graphite marks left on the bed from the first insertion of the blade. Not terrible, but contact could be better.
Shaving the bed with a scraper chisel the first time
Shaving the bed with a scraper chisel the second time
The bed after shaving it the third time.
The completed bed following final cleanup with a file. The blade can be inserted with three medium mallet strikes, and fine adjustments made in 3~4 strikes. The blade does not tend to twist out of alignment. Notice the graphite marks left on the tsutsumi shelf where the blade has contacted it.

The Peppermint Twist

Now that the bed is fitted to the blade, we need to return our attention to the grooves.

If one groove is pinching the blade more than the other, the blade will want to twist out of alignment. This can be very irritating.

The surfaces inside the grooves touching the ura and back of the blade should be clean and straight. In any case, unless it causes a serious performance problem, it’s best to leave these surfaces alone for a while because after inserting and removing the blade several times the fit may improve automatically.

If the blade continues to twist out of alignment, however, determine where the high points are on the surface of the groove touching the blade’s ura. You can do this by peering into and through the mouth while shining a light into the groove.

Once you have identified the high spot(s) glue a piece of fine sandpaper to a thin stick of wood and sand it down a little bit at a time between inserting and removing the blade frequently to check the fit.

Don’t sand down the surface inside the groove which contacts the blade’s back unless absolutely necessary because this will effectively open up the mouth, something we want to avoid for as long as possible.

With this, your plane’s hard, sharp blade and soft wooden body should fit together like hand in glove. It may sound like a lot of work, but it usually isn’t. In fact, besides prepping the blade, the whole process can usually be completed in less time than it takes to read about it.

So far in this series I have provided a lot more detail and explanation than I have ever seen in writing elsewhere. It took me many years of fumbling in the dark, much consultation with older, more experienced craftsmen, no few curses and ungentle slaps to the back of the head, and numerous expensive mistakes to learn these things. I hope Beloved Customers profit from them.

In the next post in this ongoing adventure towards the perfect Japanese handplane we will shift our attention to fitting the chipbreaker (uragane 裏金) to the blade.

See you again soon.

YMHOS

Alice asking advice of a caterpillar sitting on a magic mushroom, smoking magic mushroom.

Other Posts in the Japanese Handplane Series:

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may the ears of all my plane blades become clogged with wax.

Japanese Handplanes – Part 3: The Blade

A beautiful and even poetic plane blade forged by the famous Chiyozuru Korehide. The carved inscription reads ”Shin, Un, Mu” meaning “God, Cloud, Dream.”

The best steel doesn’t always shine the brightest.

Joe Abercrombie, The Blade Itself

In this the third post in our series about the Japanese hiraganna handplane we will focus on iron and steel and discuss some unique characteristics and even some philosophical aspects of the hiraganna blade. Why? Because to become proficient at using and maintaining a tool, one must understand it more than just superficially.

In addition, we will briefly examine the story of a single plane blade made for a famous carpenter by a famous blacksmith.

The Shin Un Mu Blade 神雲夢の刃

The plane blade pictured at the top of this article was forged 6 years after the end of World War II by a famous Tokyo blacksmith named Chiyozuru Korehide for a famous Tokyo carpenter named Mr. Nomura Sadao. The engraving on the back by Chiyozura states the blade (and matching chipbreaker) was made by him for Nomura Sadao and completed on June 4, 1951. Chiyozuru charged Mr. Nomura ¥10,000.

You will notice that it looks different from most plane blades in that it lacks the beveled “ears” at the right and left corners of the blade’s cutting edge commonly seen in Japanese plane blades.

The beveled corners absent from this blade are necessary with ordinary blades to prevent the cutting edge from extending into the grooves on each side of the blade opening used to retain the wedge-shaped blade in-place. Without the bevels, shavings become jammed between the groove and blade leaving unsightly and inefficient marks and tracks on the surface of the wood being planed. More on this below.

The blade in question, however, has rabbets cut into the jigane at the left and right edges of the blade so the ura area is thicker than the sides which fit into the retaining grooves, and the cutting edge, therefore, does not intrude into the grooves, making beveled ears unnecessary. This is a very logical solution, although it was not actually invented by either Chiyozuru or Mr. Nomura. Apparently, Mr. Nomura first saw the design at a school. He then made a wooden full-scale model and asked Chiyozuru to forge it for him.

While it is an elegant solution to a real performance issue, it is much more difficult to make this style of blade than the conventional one, and so never became popular.

On the subject of materials, Chiyozuru is well known for preferring to use imported steel, mostly from England, instead of traditional domestic Tamahagane steel. Although the source of the soft jigane is uncertain, there can be no doubt the steel lamination is made of British high-carbon steel.

Gentle Readers are no doubt aware that Japan has always been a land of many man-made and natural disasters, earthquakes and widespread fires being especially common. To protect this important blade from being lost to posterity, as were so many valuable things during the war, upon his retirement Mr. Nomura entrusted the blade to the Takenaka Carpentry Tools Museum located in Kobe, Japan.

Ironically, a large earthquake struck Kobe on January 17, 1995 killing over 6,400 people and tearing the city a new one. Fortunately, while the museum’s exhibits were jumbled up, this blade was not damaged.

Upon the relocation of Mr. Nomura to the big lumberyard in the sky, his heirs formally donated the blade to the museum where it remains to this day.

The blade has four Chinese characters engraved into its face, the meaning of which is a bit of a mystery. From top to bottom they read 神雲夢, pronounced “Shin, Un, Mu” which translates directly into English as “God, Cloud, Dream.” No doubt there is some deep poetic meaning being expressed through these three characters, but the intended meaning is far above the poor understanding of your humble illiterate servant.

Interpretations from Beloved Customers and Gentle Readers are welcome.

Definition of Fettle

While we are on the subject of literacy, I would like to clarify the meaning of a word pertaining to working on tools, and especially planes.

Gentle readers have no doubt heard the word “fettle” used in the phrase “fine fettle,” usually referring to someone being in good health or physical condition. But it has other, older meanings.

In the British dialect, it means to “set in order,” or “get ready,” from Middle English fetlen to shape, prepare; perhaps akin to Old English fetian to fetch.

Your humble servant uses fettle as a verb, mostly when truing a plane or other tool, but also for adjusting it.

Never let it be said that the Gentle Readers of the C&S Tools blog are less than exquisitely erudite and edumacated.

Blade Details

Misunderstandings abound and deep, pungent rivers of BS often burst their banks when the details of the Japanese hiraganna plane’s blade are discussed; Buckets, mops and even garbage pumps are necessary to clean up the mess. I despair: What to do, what to do?

While it appears to be a simple, crude, even haphazard component to the uninformed, the design of a well-made blade is subtle and its execution elegant. I am confident Gentle Readers willing to forego both the temptations of ridiculous rumor and magic mushrooms for a time will quickly understand. So without further ado, let’s turn on the pumps and get our mops moving.

Laminated Construction

The blade is made by forge-weld laminating a piece of hard high-carbon steel to a larger piece of softer low/no carbon steel/iron. These details are discussed in more detail in the two posts linked to below. It is important to understand these details if Beloved Customer intends to become skillful in using and maintaining Japanese planes.

Sharpening Part 8 – Soft Iron 地金

Sharpening Part 9 – Hard Steel & Soft Iron 鍛接

The Ura

The blades of quality Japanese chisels and planes have a hollow-ground area on the blade. In the case of plane blades, it is located on the surface your humble servant calls the “face,” which is oriented upwards when installed in the body. An accurate understanding of this structural detail is essential to using and maintaining the Japanese handplane. We discussed this detail in a previous post linked to below. Please review this post if you haven’t done so previously.

Sharpening Part 10 – The Ura 浦

We discussed how to perform periodical maintenance on the ura in an earlier post. Oh joy!

Another plane blade by Chiyozuru Korehide engraved with many of the brands he used during his career. It has a sweet, sculptural ura.

Blade Retention

The blade of the Japanese handplane is held firmly in-place by the wedging action of the blade in the tapered grooves cut into each side of the mouth opening. This arrangement eliminates the dedicated wedges, usually made of wood, used since at least Roman times to retain the blades of Western planes. It also makes irrelevant the widgets and linkages common to modern planes such as the Bailey-pattern, considered by many to be the pinnacle of plane design in the West. Simple is best, don’t you think?

A common misunderstanding about Japanese planes is that pressure between the wooden body and the back of the blade is necessary to both lock the blade into the body and to eliminate chatter resulting from blade vibration. In response, your humble servant can only increase the speed of the garbage pump and say “poppycock!”

Except in the case of a poor quality body, or one damaged through improper setup and maintenance, the friction acting on the right and left sides of the blade generated by wedging action in the grooves must be sufficient to hold the blade in-place without any pressure on the blade’s back.

And unlike the potato chip-thin blades common to many Western planes, the quality Japanese plane blade of the sort we carry with its relatively thick, laminated construction may have a few female characteristics, such as beauty and elegance, but despite fitting into a truly tiny mouth it simply will not chatter (as you know, it’s chisels and squares that love to gossip).

While some degree of uniform contact between the wooden block and the back of the blade is desirable to steady the blade in-use, many fit their blades (or perhaps “neglect to properly fit their blades” would be a more accurate description) to develop high pressure between blade and bed, making it difficult to adjust the blade and distorting the body unnecessarily. In extreme cases, this pressure can even push out the sole, preventing the plane from working entirely, a situation that has shaken many a poor woodworker to the core! Pixie involvement cannot be dismissed.

We will discuss this subject more in future posts.

Lengthwise Taper

A casual observation reveals that the blade is tapered in thickness along its length, being thickest at the head, and thinnest at the cutting edge bevel. The purpose of this taper is simply to wedge the blade into the grooves in the body. Please note that this wedging action does tend to cause the body to deflect to some degree, something which must be taken into account when fettling the sole, a subject we will discuss in a future post in this series.

Transverse Taper

The blade is also tapered in its width, being widest at the head and narrowest at the cutting bevel.

Ideally the side edges of the blade are in intimate contact with the grooves only where they exit at the top surface of the body, but should normally have no contact in the grooves elsewhere, making it possible to adjust the blade’s projection through the mouth to a uniform distance by gently tapping its head right and left a small amount.

Curved Back

Finally, please observe that the back (vs. the ura) of a quality blade is not flat, but is slightly hollow-ground centered around the centerline of the blade’s length. The amount of this hollow should be more-or-less uniform over the blade’s length.

One purpose of this detail is to lighten the blade’s weight, but more importantly it helps keep the blade from twisting out of alignment in-use. If you have ever made a wooden plane body to fit a blade with a flat back, you may have experienced the irritating tendency of the blade to twist out of alignment under heavy planing forces. This is typically not a concern with the Japanese design because of the curved back detail, so long as the body’s bed is well-fitted to the blade.

Since each blade and its wooden block are a little different, and not yet in perfect accord when new, fitting the body to the blade is one of the first things one must do to a new plane. This fettling operation will be the subject of a future post.

A plane blade by Mr. Ogata. Notice the curved back. Notice also the trimmed and beveled “ears” at the right and left corners of the cutting edge.

Plane Philosophy

Traditionally, everywhere planes were used around the world, a craftsman would commission or purchase the metal parts for his plane and cut the wooden body himself.

In recent history in Japan professional plane body makers called “daiuchi shokunin” 台打ち職人, which translates directly to “plane-body beater” (I kid you not) have become common. These craftsmen fit blade to body making a nearly complete retail product. The end-user, however, is still expected to adjust the fit to his preferences.

Many of these ostensibly completed planes are sold in a “sugu tsukai” 直ぐ使い condition, meaning “ready-to-use.” As witness of this, such planes usually have a wood shaving resting in their mouths when sold. However, the fit between blade and body is intentionally too tight. This is where philosophy comes into play.

There are regional preferences in Japan when it comes to tools, including sickles, saws, axes, adzes, chisels and of course plane blades. In far Eastern Japan, especially the Tohoku area and Hokkaido, thicker, heavier plane blades are preferred, whereas in Tokyo and Western Japan, thinner blades are traditional.

But while discussions of these differences make the hearts of historians go pitter patter, they are irrelevant to persons living outside Japan, so we will ignore them for now.

There are two general, practical approaches to blade size and fit. Carpenters tend to like stiff, thick blades that fit very tightly into the body because they tend to retain their settings better in the rough conditions of a construction jobsite. The downside to the thick blade is that it’s heavier, it takes longer to sharpen, and it’s more difficult to make fine adjustments to.

Craftsmen that do finer, more precise work such as joiners, sashimonoshi, furniture makers and cabinet/tansu makers prefer thinner blades that are quicker to sharpen and easier to frequently adjust to make fine, precise cuts.

We have Mr. Nakano forge the blades for our planes more in the Tokyo style: thicker than some but thinner than most.

Not knowing who will purchase the plane, unless directed otherwise most daiuchi shokunin cut tight-fitting bodies more suited to the carpenter, and assume the user will adjust the blade/body fit to their preference. This is a great idea, and probably the only practical solution, but the reality is that too often the pressure on the back of the blade is so high it ends up creating problems for the user unless corrected.

Too many inexperienced users of Japanese planes, especially amateurs located overseas, learn how to use Japanese planes without knowledgeable supervisors or fellow workers near at hand to notice their mistakes, wack them upside the head, and tell them how to correct their errors (welcome to the gentle world of the Japanese craftsman), and consequently never really figure out how to setup, fettle and maintain Japanese handplanes. I think this is one reason why so many Western woodworkers who give Japanese planes a try fail to ever get satisfactory performance out of their planes and eventually become frustrated.

While your humble servant is eager to provide Beloved Customers all practical support and encouragement, the guidance he can provide is limited by distance, the written word, and the undeniable fact that he is a gentleman of great refinement and exquisite sensitivity (She Who Must Be Obeyed has been known to disagree, but what does she know?).

Therefore, upon making a significant mistake, Beloved Customers must instead call themselves rude names and slap their own heads to aid learning retention. May I suggest “Blockhead” as an appropriate self-imprecation in the case of planes? (ツ)

Conclusion

In this post we considered some of the unique design features of the Japanese hiraganna handplane’s uncompromising and bitterly sharp iron and steel blade.

We even examined a historically-important, unusual, and exceptionally beautiful blade made by a famous blacksmith for a famous craftsman with curious engraving of unfathomable meaning. You can’t make this stuff up.

In the next adventure we will turn our attention to the body of the Japanese handplane, the softer, gentler, wooden component with the mouth that directs and controls the work of cutting.

And I promise we will make some sawdust.

YMHOS

Chiyozuru Korehide (1874~1957), the blacksmith of the blade shown above.

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone using the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may my plane blades chatter and gossip unceasingly!

Other Posts in the Japanese Handplane Series:

Sharpening Japanese Tools Part 30 : Uradashi & Uraoshi

And now at last it comes. You will give me the Ring freely! In place of the Dark Lord you will set up a Queen. And I shall not be dark, but beautiful and terrible as the Morning and the Night! Fair as the Sea and the Sun and the Snow upon the Mountain! Dreadful as the Storm and the Lightning! Stronger than the foundations of the earth. All shall love me and despair!

J. R. R. Tolkien

This article is a continuation of, and probably the conclusion to, our “Sharpening Japanese Tools” series. The last post was one year ago and gave an example of how to employ the lessons taught in the previous 28 posts. At that time, your humble servant promised to discuss the subjects of this post at a later date. It’s later.

Why the delay? Simply because I am an excessively compassionate sumbitch who wanted Beloved Customers who hadn’t already figured out plane blade sharpening on their own to become proficient at regular sharpening operations before worrying about something as bizarre as wacking hard steel blades with hard steel hammers. After all, in the words of Miss Benatar, it’s sometimes a heartbreaker.

But now with the blog teetering on the loose and crumbly edge of the rabbit hole that is the Japanese handplane, we have the choice of either gliding gracefully into its depths or clumsily tumbling down ass over tea kettle (oh my!). Alas, we can tarry no longer.

With his article we will begin our graceful swan-like journey by studying a matched set of operations Beloved Customers need to master to become proficient at maintaining Japanese woodworking blades, one called “Uradashi,” and a related operation called “Uraoshi. If you already have these skills, accept my highest praise. The target audience for this post, however, is those that don’t have experience with uradashi and uraoshi as well as those that want to review and improve the skills they already have.

So spread your wings and fly, my brave cygnets!

Definitions

Beloved Customers should already be aware of the the hollow-ground “uratsuki,” typical to Japanese chisel and plane blades. If not, please review the article at this link.

Uradashi is pronounced oo/rah/dah/she and written 浦出し in the Chinese characters as they are used in Japan. These characters translate directly to “push-out the ura.”

Uraoshi is pronounced oo/rah/oh/she and written 浦押しwhich translates directly to “press the ura.”

These two maintenance operations are performed to restore the blade’s cutting edge to useful condition when the thin land at the cutting edge is almost worn out. We will discuss the why and how below.

Long-term Strategy

Before we start pecking on steel, let’s consider our sharpening strategy.

Professional-grade blades are not only expensive, they are difficult to make, hard to find, and require an investment of time and effort from the user if they are to deliver high-performance results over many years. To minimize the required expenditure of time and effort, and to maximize the results delivered, we need more than just technique, we need a maintenance strategy.

In previous posts in this series we have discussed multiple strategies, some physical, some psychological, and even a few supernatural ones. The following is one I strongly urge Beloved Customers to adopt:

  1. Get the ura in good fettle, and then;
  2. Avoid working the ura on anything but one’s finest-grit sharpening stone thereafter, (with the exception of uraoshi following uradashi, of course).

Simple, no?

The ura is formed by hollow-grinding a lamination of extra-hard high-carbon steel (at least in the case of C&S Tool’s chisels, planes and knives). Because it is hard layer of steel is time-consuming to abrade, a wise craftsman will work to keep the ura as deep as possible, and the flat lands surrounding the hollow-ground ura as narrow as possible, as long as possible, thereby minimizing the area of hard steel that must be abraded with each sharpening.

But no matter how careful we are to preserve the ura, sharpening the bevel makes the blade incrementally shorter, so the day will come, at least in the case of plane blades, when the land at the ura immediately behind the cutting edge, called the “itoura,” (pronounced ee/toh/oo/rah, meaning “ thread ura” ) becomes as thin as a thread. Once it disappears, the blade will no longer function. This is the only drawback to the Japanese ura feature, and can only be solved by bending brittle steel.

Bending Hard Steel

The goal of uradashi is to cause the lamination of hard steel at the cutting edge to bend towards the ura so that when we subsequently abrade the bent portion of the ura the itoura land will be restored.

Now if you think about this for a second you will realize that trying to bend a thin plate of steel hardened to Rc65~66 without snapping it is a fool’s errand. In the case of Japanese blades it is possible to accomplish but only because of the thicker, cushioning layer of soft low-carbon/no-carbon iron, called the “jigane,” to which the hard steel layer is laminated.

Your humble servant struggled at first with uradashi, in part because every explanation I read about the process in both English and Japanese was written by people who either didn’t really know what they were talking about, or were too lazy to explain it well. Some years, several broken blades, and much heartbreak later I finally figured it out. Better information is available nowadays, but there is still plenty of BS out there to shovel.

The first key point to understand and always remember is that uradashi is not about using a hammer to bend the hard steel layer; Never ever ever never touch this steel with your hammer! I forbid it on pain of 20 lashes with a wet noodle.

Instead, the goal is to peck on the soft iron jigane layer of the laminated blade at the bevel, as described below, expanding it so the hard steel layer laminated to it will curve in the direction of the ura without snapping or cracking. Please read the previous three sentences again, offer a prayer of remembrance to the gods of handsaws, and click your heels three times (ruby slippers are not mandatory(ツ)).

The second key point you need to grasp around the neck with both hands and dig your Jimmy Choos deep into is that it is indeed a fool’s errand to try to bend the soft iron lamination by the power of your mighty arm, Oh Lord of Thunder. No, we must be as clever as Loki.

So, how do we cleverly do this job, and what tools should we use?

The 60mm blade used in this example forged by Mr. Uchihashi Keisuke from Swedish K-120 steel. The brand name is “Keisaburo.” An excellent blade and still functional, but the itoura is getting a little skinny.

Tools

You will need the following tools to properly perform uradashi and uraoshi on a blade:

  1. A small hammer. Great force is neither necessary nor useful, but you must be able to control this hammer very precisely, so the lighter the better. One with a pointy end like a funate or a Yamakichi or the corner of the thin end of a Warrington hammer is ideal because it focuses maximum pressure on a small area, deforming the jigane efficiently, and it is also easy to see where the hammer will impact providing better control. And control matters a lot because if you miss and strike the hard steel at the cutting edge it will be damaged and bitter tears will flow. Consider yourself duly warned, Oh Might Thor;
  2. An anvil of sorts. This can be any piece of steel with some mass and with a rounded-over corner. A piece of railroad track is great. I use the face of a small sledge-hammer clamped in my vise. A sharp corner is not good, so grind or file one and then smooth it. A piece of thin postcard material glued to this rounded corner help keeps the blade from slipping;
  3. A small square or straightedge;
  4. A marking pen or scribe to mark the “target area” on the bevel;
  5. A rough diamond plate/stone or a mild-steel kanaban plate + carborundum powder;
  6. Parking pen or Dykem for coloring the ura’s lands;
  7. Regular sharpening tools (stones, water, etc.).
A small sledge hammer used as an anvil by clamping it in a vise with another clamp as a stabilizer.

Target Area Layout

Let’s begin by laying out the target area on the soft iron jigane at the blade’s bevel with a marking pen. Or you can scratch lines into the jigane with a metal scribe. This target area will indicate the area you will peck with your little hammer producing many small dents. You must not strike outside this target area even if tempted with donuts.

The striking area marked with marking pen.

The dents you will make with your little hammer need to be limited to a band on the jigane parallel to the cutting edge and beginning 2~3mm from where the jigane lamination begins extending to the end of the jigane lamination at the blade’s back, in the case of plane blades, or the face where the brandname is engraved in the case of chisel blades. Make a line with your scribe or marking pen the full width of the bevel at this distance from and parallel to the cutting edge. Everything above this line in the direction of the blade’s back, in the case of plane blades, or the face where the brandname is engraved in the case of chisels and knives, is the primary target area. Make sure you get this right.

The dents need to extend across the full width of the jigane layer, except where the corners (ears) have been ground to a bevel at the right and left end of the blade, so the right and left limits of the target area are delineated by the ears.

Although we need to tap the full width of the blade to avoid stress concentrations, there is nothing to be gained by trying to bend the far right and left corners of the blade, so we want to focus approximately 2/3rds of our hammer impacts and the resulting dents near the center 1/3 of the blade’s width. Mark the right and left limits of this central area on your blade with a marking pen or scribe.

The Grip

If you are right handed, hold the blade in your left hand with your index finger extended and pressed against the ura parallel with the cutting edge, and about 5~10mm away from it. Press down with your thumb on the blade’s back clamping the blade between your thumb and the side of your index finger. Your other fingers should support the blade from the ura side.

This shows how to hold the blade on the anvil.

Your index finger will be the fence that keeps the blade in proper alignment during the tapping-out process.

Next, we need to figure out how to align and move the blade on the anvil, as well as where to place hammer blows in relation to the blade and anvil.

This photo shows the grip without the blade in the way. Notice how the index finger is touching the anvil. The blade is shifted right and left using the index finger as a fence to keep blade and hammer under tight control.

Manipulating the Blade on the Anvil

Place the blade’s ura on the rounded corner of your anvil. You may want to tape or glue a piece of thin cardboard, postcard, or manila file folder to the anvil’s corner not so much as a cushion but to help prevent the blade from slipping, but this is not mandatory.

Adjust the distance between your extended index finger and the cutting edge as necessary so your finger is touching the anvil stabilizing its position, and so you can slide the blade to the left and right indexing off your finger to keep the target area in proper alignment.

Next, while still in position facing your anvil and with hammer in hand, move the blade aside and tap the rounded corner of your anvil with your hammer lightly. Memorize this location and your position because every tap from now on must be aimed at this same exact spot on the anvil.

The Tap Dance

The time has come to begin the dance.

Reposition the blade on the anvil and use your little hammer to tap the soft jigane layer at the bevel (only the jigane!) in the target area you marked earlier making a row of small dents in it.

These small dents don’t need to be pretty or uniform. Be patient because you may need to make hundreds of pecks, each one quite precisely.

Here is the key point to understand: You want each little dent to cause the jigane to deform and expand in length and width a tiny bit, gradually, until a significant degree of deformation accumulates. The hard steel layer, however, will constrain the jigane layer from expanding, causing the blade to bend, and causing the hard steel layer to deflect and curve towards the ura, bending it without breaking it. It doesn’t seem possible at first, but I promise it will happen, so please be patient.

The trick then is to use the grip described above and use your forefinger to index the blade against the anvil while moving your hand, along with the blade, a tiny bit right or left with each strike, with the each point of impact firmly supported on the anvil, in-line with the hammer blow, thereby squishing the jigane between hammer and anvil. In this way, since the hammer is always aimed at the same exact point on the anvil, you don’t need to worry about realigning it with each blow, removing several difficult-to-control variables from the tap dance at once.

Remember, keep the hammer and anvil precisely aligned, and move the blade left and right, not the hammer. It helps to touch the inside of the elbow of the arm using the hammer against your side in a fixed location to help maintain a consistent hammer swing and distance. Until you have mastered consistency, speed is risky.

Another key point to understand is that, unless the point of your little hammer’s impact is not directly in-line with the point where the ura on the opposite side of the blade is touching the anvil, the force of the hammer’s impact will tend to cause the unstable blade to jump and wiggle around instead of deforming the jigane. This wastes time and energy and makes it difficult to make precise taps.

Here’s a video of Eleanor Powell tapping away with great control, and with the aid of her faithful Fido. I don’t recommend including a benchdog in your tapping-out routine other than as a deterrent to any pernicious pixies lurking in your workshop eager to cause you to miss with your hammer and chip your blade. Evil pixies!

Here’s a video of Sarah Reich tap dancing with every strike landing precisely in the target area. I need to get a pair of shiny red lycra pants like her to go with my most excellent aluminum foil hat with the curly copper wires and red fringe. Do you think they would make my butt look huge?

Remember, force is neither necessary nor useful. The goals is to make many precisely aligned tiny taps producing many small deformations in the target area, with no impacts on the hard steel layer.

Dent Removal

We talked about “dents” above. If you are using a round-faced hammer, those dents will be little crescents. If you use a hammer with a tiny striking face on one end like a Yamakichi or Funate, that tiny face will dig into the metal making ugly little peck marks instead of pretty little crescents. I have used all varieties of hammers but prefer the ones with pointy ends because they impact face is small and, it seems to me, easier to control. Six of one half-dozen of the other.

But remember that we will abrade away all those dents/craters after a few sharpening sessions, so appearance is of zero importance.

The Goldilocks Itoura

The goal, of course, is to bend the blade at the ura land just behind the cutting edge enough to create a useful, flat ura. But how wide should the itoura be when the process is complete? Among plane connoisseurs a narrow itoura is, like a willowy super model, considered a thing of beauty. By narrow I mean some where around 0.50~1.0mm.

A narrow itoura does indeed look sexy, so much so that fashion-conscious plane blade blacksmiths make a skinny ura a point of pride. And, in fact, a bulimic itoura makes it easier and quicker to sharpen the blade because the square millimeters of hard steel one must abrade/polish is minimal compared to a wider itoura.

The downside to the super-model itoura is that it wears out sooner, making it high maintenance. Now, I’m not suggesting that if your plane blade has a super-skinny itoura it will demand weekly spa visits, twice monthly trips on a G700 jet to the Vienna Opera, annual ski holidays in Verbier, and bi-annual boob jobs, but there is no doubt you will need to do the uradashi tap-dance more often. Shiny lycra pants are optional, but ooh sooo sexy.

On the other hand, a wider itoura of 3~4mm has some advantages too. It’s easier to fit the chipbreaker (uragane), and you don’t need to do uradashi/uraoshi as often. Much wider than this, however, and I find it can be difficult to get a screaming-sharp edge at times. Moderation in all things, I guess.

I don’t know how to describe when to stop tapping-out the ura to obtain a good width for your itorura because every blade is a little different, but after doing it a few times you will develop a sense of when enough is enough. However, to develop that sense you should make frequent checks on your tapping-out progress by placing your handy dandy straightedge or square right on the itoura parallel to the cutting edge and sighting between the blade and the straightedge/square with a strong light shining at the gap. You will be able to see the itoura gradually bulge upwards at the center. Even a little bit of a bulge will give you a useful itoura, so don’t get carried away.

Uraoishi

Once the tap dance is done, we need to grind down the ura to form a new itoura.

The traditional method is to use the mild steel kanaban lapping plate mentioned above, although any true lapping plate will work. One sprinkles a small amount of carborundum powder on the plate along with a little water, and works the ura side to side grinding down the bulged area to make a flat.

The problem with lapping plates and carborundum powder is that not only is it a messy process, but unless you are careful to keep the right amount of wet grit on the plate, the results tend to be a tad irregular. I recommend using diamond plates because they produce more consistent results quicker.

Whether you use a kanaban lapping plate or a diamond plate, it is important to focus pressure on the thin area where you need the itoura to develop. Pressure anywhere else is not helpful, but only wears out the itoura prematurely.

Here is wisdom: When they first attempt uraoshi most people try to stabilize the blade by applying uniform pressure across the back of the blade. This seems to makes perfect sense, but it always results in grinding a nasty little trench in the ura where it touches the extreme edge of the kanaban or diamond plate. Remember, the uraoshi process tapped out a bit of metal right at the cutting edge, and mostly at its center. This is what you need to abrade, NOT the right and left lands of the ura, and certainly no more than 3~4mm from the cutting edge. So carefully focus the pressure you apply during uraoshi only on the thin area where you need to restore the uraoshi.

Some people like to apply a thin strip of paste wax, perhaps 3~4mm wide, on the edge of their kanaban or diamond plate to prevent it from digging ugly trenches in their beautiful and delicate side lands. Others like to apply a thin strip of mylar tape at the same place for the same reason. These techniques all work, but professional sharpeners don’t use them because they know how to apply pressure correctly.

A quick touch of the blade on the diamond plate shows where the black marking pen ink has been removed, and the highest spots on the bent itoura.

After the itoura has been restored (perfection is not necessary), polish the blade using your normal sharpening routine.

The restored itoura.

The bevel after working it on the diamond plate and stones. The remaining peck marks will disappear entirely after a few sharpening sessions.

Chisel Blades Versus Plane Blades

Uraoshi and uradashi are operations typically, but not exclusively, performed on plane blades. About the only time chisels need to have uradashi performed is to restore the itoura after the blade receives major damage, like a big chip. A sad event all users of Japanese tools experience from time to time

There is a structural difference between plane blades and chisel blades one must understand when considering performing uradashi on a chisel blade.

Plane blades have a steel lamination that is more-or-less uniform in thickness because that’s all that’s necessary. Chisel blades, on the other hand, are subject to much higher bending stresses than plane blades, so to prevent yielding and failure, traditional chisels are forge-laminated with the steel lamination wrapped up the right and left sides of the blade, forming something akin to a structural steel U-channel, producing a higher moment of inertia, and therefore greater strength and rigidity,

Because of this additional strength, chisel blades are more difficult to bend at the right and left sides using uradashi techniques compared to plane blades. Indeed, they may break if you try.

Since you can only hope to safely bend the steel lamination in areas away from the more rigid sides, uradashi operations on narrow chisel blades will go as smoothly as throwing a cat through a screen door. I wouldn’t even try it on any chisel narrower than 24mm. Beloved Customers have been warned.

If you feel compelled to attempt uradashi on a chisel blade, my only advice is don’t peck within 3mm of the right and left sides.

With this article, our Sharpening Japanese Tools Series is complete (probably). I hope it has been helpful. If you’ve had the patience to read it all, and the clairvoyant ability needed to understand most of it, then you know a heck of a lot more on the subject of sharpening than I did when I started the journey. At least you have received some great ideas for sexy new additions to your simply mahvelous woodworking wardrobe!

YMHOS

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may Iron Pixies pass gas in my cornflakes every morning.

Links to Other Posts in the “Sharpening” Series

The Forgotten Sumitsubo 忘れ物の墨壺

The Forgotten Sumitsubo

Remember me when I am gone away,
Gone far away into the silent land;
When you can no more hold me by the hand,
Nor I half turn to go yet turning stay …

Christina Rossetti

The tool pictured above is a very old “split-tail” variety of “sumitsubo.”

Versions of this tool are used in many trades worldwide to mark a straight layout line on material being worked. In the West, the line is coated in chalk to produce a “chalkline” when snapped, but in Japan a silk line wound on the spool near the tail of the tool is soaked in ink as it passes through the “pond” near the pointy front of the tool to produce the same sort of layout line.

This particular tool is unusual not only because it is one of the best-preserved examples of sumitsubo in existence, but also because it was discovered during restoration work on the 27m tall Nandaimon gate of Todaiji temple in Nara Japan in 1879.

Since its discovery it has become famous as the so-called “Forgotten Sumitsubo.”

The reason for the unusual name, indeed the very reason it has survived in such a good state of preservation, is that Todaiji Temple’s Nandaimon gatehouse where this sumitsubo was found perched peacefully on top of a beam high in the structure was built in the year 1199, so it is likely this sumitsubo had remained there undisturbed for around 680 years, a long time for a wooden tool.

Was it really forgotten? I like to think some carpenter left it there on purpose to look after his work. But that’s just me…

Related image
Front elevation of the Nandaimon gate of Todaiji temple, Nara, Japan. The deer of Nara are like pigeons. The stall to the left is selling “deer crackers” for tourists to feed them.
The eaves of Nandaimon Gate
Related image
Looking up into the structure of Todaiji’s Nandaimon Gatehouse
Cross-section sketch of Todaiji’s Nadaimon Gate

So, if you ever misplace a tool at a jobsite, instead of fretting about it, just imagine that someone, someday, will find it hidden inside the building 700 years later and reverently put it in a museum. Certainly more romantic than any other more likely option. (ツ)

YMHOS

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. May the two guardian kings above refuse to let me shower alone.

Japanese Handplanes Part 2 : Blade Adjustment

I warn you, if you bore me, I shall take my revenge.

J.R.R. Tolkein

Your most humble and obedient servant has received many requests over the years for explanations about how to setup, adjust, maintain and use Japanese planes. It’s a big subject, enough to fill volumes and volumes, and an important one to woodworkers, but I will try to explain in enough generality that new guys can follow, and in enough detail that professionals may glean something useful.

In this series we will discuss how to adjust a Japanese plane so it works well, how to tune it to increase performance, how to treat the body to reduce warpage and keep it looking good, how to deal with normal wear and tear, how to periodically tap out and dress the ura during sharpening, and of course how to use a Japanese plane.

This last subject is extremely simple but one many amateur users of Japanese planes and most users overseas get wrong. It happens so frequently that I am confident the improvement in Beloved Customer’s personal performance with Japanese planes will improve dramatically from this last subject alone.

The problem with Japanese planes is that, while they are simple tools, they are at the same time more sophisticated than appearances suggests. Dealing with these subtle details without properly understanding them leaves many as confused as a ball of yarn among a dozen big-eyed kittens, so to avoid having too many strands running all over the place, let’s start with the basics, namely how to adjust them. For purposes of this discussion, we will assume our plane is in good fettle to begin with.

Terminology

Your humble servant will not attempt to teach Gentle Readers all the Japanese terms for every part of the hiraganna plane but will try to use standard English language terms wherever possible instead. Indeed, since the plane is a relatively recent tool in the Japanese woodworker’s toolbox, and has a much longer archeological history in the West, it seems silly to use more Japanese words than absolutely necessary to describe something that did not originate in Japan, and can easily be described in English.

I am not a government employee or a legal expert, and so see no need to make things more confusing than necessary. I humbly apologize in advance if this approach offends any purists or employees of the IRS.

The standard handplane in Japan, the one intended to create and/or smooth flat surfaces versus rabbet, chamfer or molding planes, just to name a few, is called the Hiraganna. This word is written 平鉋 in Chinese ideograms and pronounced hee/rah/gahn/nah, without emphasis on any part of the word.

The first character 平 means “flat.”

The second character 鉋 is comprised of two standalone characters combined to make a single character, a common practice in the Japanese language. The one on the left side, 金, means gold or metal, while the one on the right, 包 means “to wrap.”

The character for kanna was not invented in Japan but is said to have been used since the Táng period AD618 – 907 in China, although the tool it represented at the time was a scraper of sorts and not a handplane.

Preparing the Body

Although this is not an issue in the case of the planes C&S Tools purveys, Gentle Readers will want to inspect their plane, and perhaps make a few modifications to the body before playing with the blade too much.

Striking Chamfer

When removing the blade or reducing the cutting edge’s projection through the mouth, we need to strike the body on the corner between the flat end of the plane’s body and its top surface, so we need a chamfer at an approximately 90˚ angle to prevent damage to the body. How wide? 3~5mm is a good range. While you are at it, cut off the corners formed at the right and left sides of this chamfer.

This is a one-time operation.

Sole Chamfers

You need a chamfer on the right and left sides (long direction) of your plane’s sole.

These chamfers have two purposes. First, to prevent the edges of the sole from chipping. Second, to make a gap for your fingers to grip when lifting up the plane.

As the sole wears, Beloved Customers and Gentle Readers will need to be refresh these chamfers from time to time, so further explanation is necessary.

Some people promote big, wide 45˚ chamfers at these locations. Your humble servant has even seen country bumpkins cut these wide chamfers and then cut grooves leading from the sides of the mouth to these chamfers for shavings to escape into. Codswallop!

The thinnest, weakest portion of any wooden plane’s body is sidewalls at the mouth. This is also where most warpage originates, so please don’t weaken it more than is absolutely necessary. In addition, wood removed from the sole by cutting overly-large chamfers reduces the bearing area of wood on the surface being planed accelerating wear on the sole. Keep these chamfers narrow at 3~5mm and a max angle measured from the sole of 25~29˚ More than this is unnecessary and possibly harmful.

A chamfer is not necessary at the trailing end of the sole so long as you have the self control to not strike the sole with your mallet.

Do not cut a chamfer at the leading edge of the sole as it will guide sawdust and shavings between the sole and the surface you are planing.

Top Chamfers

Apply a small chamfer on the front and side edges of the top surface, just enough to prevent chipping. 45˚ chamfers are fine, but a roundover (bozumen 坊主面 which translates to “Priest’s edge,” probably in reference to the bald head of Buddhist priests in Japan) is a friendlier, more elegant edge treatment, IMHO. Your choice.

Hammer or Mallet

In order to use a plane of any kind, one must remove the blade to sharpen it, and then re-install the blade and adjust its projection from the body’s mouth to produce a wood shaving of the desired thickness.

Like most wooden-bodied planes, one adjusts a Japanese plane by striking it with a hammer or mallet. To drive the blade further into the wooden body (called a “dai” 台 in Japanese) when installing the blade or when increasing the depth of cut, one taps the head of the blade down into the wooden body. Pretty straightforward. But like most things in life, there are both clever and stupid ways to get even simple jobs done. Let’s consider some of the clever ones, shall we?

The wacky ones can be very entertaining, I know, but I think I’ll leave those for the tool abusers on GooberTube.

You can use either a metallic hammer or a mallet made of wood, plastic or even rawhide to tap the blade or dai during these operations. They all work just fine, but there are long-term consequences to this selection you need to be aware of.

In Japan a steel hammer is traditionally used by carpenters to adjust planes. Without a doubt it’s convenient and effective, but there are some serious downsides to using a steel hammer you may not realize. Those include:

  1. A steel hammer always mushrooms the blade’s head;
  2. A steel hammer always dings the blade’s pretty face, and most critically;
  3. After many strikes, steel hammers will often crack and even split the wooden body (dai).

A deformed and ugly blade may not be a tragedy, but a split body is an expensive and time-wasting catastrophe, especially if you are a professional that needs his planes to keep cutting.

What did this brightly-polished plane blade do to deserve such barbaric abuse?
All the worst consequences of using a steel hammer on a plane are condensed in this one photo. Notice the mushroomed head of the plane which the owner has probably already ground down several times. We can’t see the blade’s face, but notice how the chipbreaker’s face is all dinged up. And I guarantee you the blade is even more damaged. And of course, the split dai. Tragic! What did this poor innocent little plane do to deserve such barbaric treatment?! And how much of this plane’s useful life did the owner waste?

There may be Gentle Readers who will say: “But I’ve seen Japanese craftsmen using steel hammers to adjust their planes, so it can’t be wrong.” The first part of this observation may be true, but the last bit isn’t. The undeniable truth is that steel hammers have created many ugly, dinged, bent, and mushroomed blades, as well cracked and splintered dai, mostly unnecessarily. Some carpenters are especially abusive of their poor planes, sorry to say, but not all Japanese craftsmen are so inured to the suffering of their tools.

C&S Tool’s planes don’t deserve such violent abuse, so we recommend Beloved Customers use a wooden mallet to adjust them. Without exception. A plastic or rawhide mallet with a wooden handle will work just as well.

Removing the Blade and Chipbreaker

Both the blade and chipbreaker are removed by tapping the chamfered corner of the block behind the blade with a mallet. We discussed this chamfer above.

It is of course possible to loosen the blades by tapping the flat tail end of the block, but there is a risk of striking the bottom edge and deforming the sole. Best avoided altogether.

The physics work best when the mallet impacts are applied in a direction more or less parallel with the blade.

Your humble servant prefers to make this striking chamfer wide to minimize deformation of the body, but this is a personal preference. If your plane’s body is not chamfered, creating it is is an important first step.

The chipbreaker (uragane) must be removed before the blade, but you need to be careful to prevent two unfortunate things from occurring during this process. The first thing to avoid is the chipbreaker jumping out of the block providing Murphy the opportunity for gleeful mischief.

The second thing to avoid is the blade backing out of the body further/faster than the chipbreaker causing the chipbreaker to ride over the extreme cutting edge dulling it. This point is one newbies often overlook until they wonder why the pretty cutting edge they just sharpened is dinged even before they begin cutting.

How does one keep blade and chipbreaker under control? Your humble servant recommends pressing a forefinger onto the chipbreaker and applying pressure upwards when removing it. Do the same on the face of the blade when its turn comes/ as shown in the photos below.

When removing the chipbreaker, apply pressure towards the blade and upwards with your index finger to monitor its movement and help maintain control. It is critical that the chipbreaker moves upward faster the than the blade to prevent the chipbreaker from contacting the sharp cutting edge dinging it.
While applying upward pressure with the index finger on the chipbreaker, tap the chamfer behind the blade to cause the chipbreaker to move up and out of the body’s mouth. BTW, please make it a habit to not strike the center of the chamfer, but instead alternate strikes between the right and left sides of the chamfer to ensure the body will provide long service.

Once the chipbreaker is loose, remove it and go back to tapping the body to loosen the blade further. Continue to apply light pressure to the blade’s face to better monitor the blade’s movement, and to prevent it from jumping out of the body.

The plane used for this example is an extra-wide 80mm finish plane with a blade forged by Yokosaka Masato. The oasaebo steel rod which retains the chipbreaker in-use can be seen tightly installed across the mouth. This is typically never removed over the life of the plane. In the center are the blade and the chipbreaker (uragane). A very nice blade hand-forged from Shirogami No.1 high-carbon steel. To the right is the mallet your humble servant uses for plane adjustments. Notice how the head of the blade is not mushroomed, its pretty face is free of the dents and dings, and the body is free of the dents, cracks and splits that often result from using steel hammers.

Adjusting the Chipbreaker (Uragane)

The chipbreaker is a recent addition to the Japanese plane. In earlier centuries, they had only a single-blade. Unlike the Western Bailey-pattern planes that incorporate the chipbreaker into the linkage necessary to adjust the blade, hiraganna planes work just fine without the chipbreaker. Indeed the chipbreaker’s only role is to reduce tearout, so when tearout is not a concern, removing the chipbreaker will reduce the force necessary to motivate the plane and may even produce a smoother cut.

The chipbreaker of a new plane often needs to be fitted to the blade and body using files and stones, but that is a subject for a future article, so to keep things simple, we will assume the chipbreaker is in good shape and is happily wedded and bedded to its blade.

Gentle Reader is no doubt wondering how to adjust the chipbreaker with the large head of a mallet. The answer is to use the butt of the handle as shown in the photo below. Just hold the mallet’s handle in a fist with the head upward and bring the handle’s butt down on the the chipbreaker. Easy as falling off a log, as my father would say. The connection between the mallet’s head and handle must be quite solid, of course. These mallets are easily made.

Using this technique, your plane blades will look beautiful, and your dai will give many years of reliable service. And although they only have tiny mouths with just a single, shiny, silver tooth, if you look carefully you will sometimes see their clever little smiles.

Using the end of the mallet’s handle to adjust the chipbreaker. Notice that, once again, the index finger is use to monitor the chipbreaker’s movement and to keep it under careful control. To ensure the chipbreaker will do its job, its edge should ultimately be adjusted to be in very close proximity to the cutting edge (>0.002″ (0.05mm). This distance will vary with your plane and the wood being cut, and will require experimentation and fiddling to get right, but with practice, this process will become automatic and intuitive. Be careful to prevent the chipbreaker passing over the cutting edge as this may dull the blade causing Gentle Reader to say undignified things and the iron pixies skulking in your workplace to howl with glee.

To remove or back-out the chipbreaker, one strikes the dai as if loosening the blade, but with a finger on the chipbreaker to keep it from dragging over and perhaps dulling the blade’s cutting edge.

When adjusting the chipbreaker, sometimes the blade will shift position too, so a back and forth adjustment of blade-chipbreaker-blade is sometimes necessary. The tighter the fit of the blade and chipbreaker in the body, the more fiddling is required, so craftsmen such as joiners, sashimonoshi and cabinetmakers that routinely make fine, precise cuts and sharpen frequently tend to prefer thinner blades that fit into the body with less force and are easier to adjust than do carpenters who perform less refined work.

We will delve into this aspect of handplane setup in our journey ass over teakettle down the rabbit hole in a future post.

Adjusting the Blade

In order to take a clean full-width cut, the blade must project from the mouth the appropriate amount, and evenly across its width. In other words, it must not project too far, nor too little, and one corner of the blade must not be projecting more than the opposite corner.

To evaluate the blade’s projection through the plane’s mouth, hold the plane upside down to a light-colored uniform background and look along the plane’s sole. The correct projection will be a thin line of uniform height across the width of the sole. If one side of the blade is projecting more than the opposite side, the blade is either skewed in the body, or it is shaped skewed.

If the blade is skewed, tap the head to the right or left with the mallet. If, however, a few taps fails to make the projection uniform, the blade’s cutting edge must be reshaped.

Please be aware that continued lateral pounding on the blade will not improve the situation and may damage the wooden body.

Most planes allow a little bit of wiggle room for the blade, but sometimes, especially if the body shrinks in width due to reduced ambient humidity, the notches in the side of the mouth may need to be pared slightly deeper, or the blade ground narrower, to provide this right/left wiggle space. Be very careful, however, to avoid paring these grooves more than a thin shaving or two wider because removing wood at the grooves directly and irrevocably weakens the weakest point in the wooden body.

Looking down the sole to ascertain the blade’s projection, the black line visible at the top of this photo. A light-colored, uniform background is helpful for this. In this case, two adjustments are necessary. The first problem is that the blade is projecting too far. This is easily resolved by tapping the chamfer behind the blade, something that, with practice, can be done while the plane is held upside-down in this position. The second problem that must be resolved is the skew evidenced by the blade’s projection being much greater on the left side of the photograph.
Adjusting a skewed blade by tapping the blade’s head laterally. If a few taps will not correct a skewed blade, it probably needs to be reshaped to correct a skew that developed during sharpening.
A much smaller, useful projection with just a tiny bit of residual skew that must be corrected. When taking extremely fine finish cuts, the ability to determine the blade’s projection sometime seems more clairvoyant than simply optical.

To test the projection of the blade, and ensure skew has been removed, hold a a short, narrow piece of softwood such as pine or cedar in your hand and run it over the cutting edge, first on one side of the blade, then the opposite side, and finally the center, and observe the shavings (if any) produced. They will tell you the truth. Be careful not to shave your fingers unless they have become hairy (ツ).

Even experienced craftsmen betimes become gutted, gobsmacked, and guragura upon discovering their otherwise perfect plane blade has become skewed and is projecting too far on one side to be adjusted for a good cut without resharpening it. Of course, the culprit is almost always pernicious pixies, but a wise Beloved Customer (are there any other kind? Nah!) will be careful to follow Petruchio’s example and tame the skew. And don’t forget to use a hardened stainless steel straightedge to check the blade for square when sharpening.

Striking the Body of the Plane

Your humble servant does not want to seem repetitious, but just so there is no confusion, I feel compelled to review a point or two before we end this discussion.

When backing out or removing the blade, make it a habit to strike the chamfered edge of the dai behind the blade alternating between the right and left sides instead of dead-center.

Also, angle your strikes so they are more or less parallel to the long axis of the blade. With a little practice this will become second nature. The reason for this action is simply that it is both more effective and at the same time helps to keep the dai in one piece.

Please, never strike the flat tail end of the plane’s body, but only the chamfered top edge of behind the blade. Too many people who strike the flat end of the tail get carried away and end up damaging the sole.

If you examine your plane you will notice that there is actually very little wood holding the plane’s body together in the mouth area. Indeed the only continuous wood is at the sides, and it is only as thick as the distance between the bottom of the blade grooves and the exterior sides of the body. Not a lot of meat.

If we strike the body’s tail in the center, the body, being relatively unsupported in this area, must flex creating stresses, sometimes enough to crack, sometimes even enough to split it. This sort of damage is common, but almost entirely avoidable because, if we strike the right and left extremes of chamfered edge behind the blade, stresses will be carried through the stronger sides reducing the chances of cracking and/or splitting the tail. You can feel and even hear the difference if you pay attention.

If you don’t care how your plane looks, and prefer replacing or fixing their wooden bodies instead of using them, by all means disregard this suggestion. You might want to get some extra bubble wrap to keep yourself entertained while the bolt and epoxy repair to your plane’s broken body cures.

Damage to the body or blades of C&S Tool’s planes caused by the incorrect use of metal hammers will void the tool’s warranty.

Plane Storage

When you purchase a plane, the blade is already installed in the body, although the cutting edge is usually recessed inside the mouth to protect it. The first step, therefore, is to remove the blade and examine it.

If you live in a low humidity area such as Nevada or Arizona in the USA and purchase a plane from a part of the world with high-humidity at times, such as Japan, it is wise to remove the blade and set the plane aside for a few days to let the body become acclimatized, especially if you plan to use the plane in a space with central heating and cooling which may cause the wooden body to shrink in width

If you plan to store your plane for several years in a dry climate, or in a space with central heating and cooling, we recommend you remove the blade and chipbreaker, oil them, wrap them in aluminum foil, and store the body and blades together but without being installed in the body to prevent the blades from restraining the body’s shrinkage causing it to crack. Just to be safe.

In the next post in this adventure we will discuss how to modify a Japanese plane’s body to make it easier to use.

And please remember the wise words of the Sage of Possum Lake: “Remember I’m pullin’ for ya–we’re all in this together.”

YMHOS

The end view of an amazing nagadai plane body by Inomoto-san made from a piece of Japanese White Oak combining “Oimasa” grain orientation and the highly-desireable ripple grain. In oimasa orientation, the dense, tough, light-colored medullary rays are oriented towards the sole, making the sole wear slower. Using plain-sawn wood will direct even more of these rays to intersect the sole further reducing wear, but at the same time would increase the tendency of the sole to warp. On the other hand, orienting the annual rings vertically in a “quartersawn” configuration would maximize the body’s stability, but at the same time would cause the sole to wear quicker while making the body less resistant to cracking and splitting. Oimasa orinetation shown in this photo is a compromise intended to reduce warping without reducing strength and to improve the sole’s wear resistance. Ripple-grain white oak is not only more beautiful, it contains more of the harder Winter wood making it both more wear-resistant and more stable than ordinary white oak.

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