The Japanese Gennou & Handle Part 8 – Head Style & Weight

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A comparison of two styles of hand-forged gennou heads. Top: A Yamakichi gennou head by Hiroki. Bottom: A classical ryouguchi head by Kosaburo with the antique “swollen eye.” Both handles are made from American Osage Orange, an excellent wood for hammer handles. The top handle still exhibits the neon yellow color typical of OO, while the bottom handle has been exposed to sunlight for a few weeks and turned a nice but unusual brown color.

Better a bald head than no head at all.

Seamus MacManus

In the previous post in this series about Japanese hammers we examined a feature found in all modern hammer heads: the essential, unblinking unseeing eye. In this post we will touch on the style of heads recommend for using with Japanese chisels. We discussed this subject in this post as well.

Gennou Head Shapes

The most common head shapes commonly available in Japan nowadays are: ryoguchi, daruma, funate, yamakichi and various hybrids thereof.

Ryouguchi

Ryouguch is the most common style of head, at least in Eastern Japan. It has two faces: A flat one for striking chisels and nails, and a slightly domed opposing face for kigoroshi and setting nails below the surface of boards.

While a simple design, this style of head has a relatively high moment of inertia, making it is more stable than other styles and therefore less likely to twist out of alignment during the swing, or twitch upon impact, a positive thing if you are a card-carrying member of NBA (Nail Benders Anonymous). (ツ)

Face designs in this style vary widely including round, oval, square, rectangular (usually with corners removed for a more octagonal shape) true octagonal, and the “Ichimonji” style with roundish sides and a flat top and bottom. We prefer the rectangular shape with cut corners best, but one style is no better than another. We don’t recommend, however, faces with 90 degree corners as the corners are counter-productive during kigoroshi operations and are structurally weaker.

If you are worried about pulling nails, we encourage you to use a nail bar to reduce the number of broken hammer handles wandering the world sad and lonely as a cloud.

A 200monme/ 750gram/ 26oz Modern-style ryouguchi gennou by Kosaburo. Notice the symmetrical shape, slightly flared ends, and the polished “hachimaki” band near each striking face.

The Daruma

Named for a famous buddhist priest of oval stature who lost both arms and legs through excessive meditation in his quest for “satori,” an intensely spiritual obsession that no doubt consumes the attention of some of our more enlightened Beloved Customers, the daruma (pronounced dah/rhu/mah) style gennou head is a stubbier version of the ryouguchi gennou, always with a round face.

This style of head is more popular outside of Japan than it is domestically, for reasons your most humble and obedient servant fails to understand. From a physics viewpoint, at a given weight it is less stable than any other style of gennou, but because it has a bigger face, and is intended to be used at constantly differing angles such that stability is not so much a virtue, it is preferred by carvers. Joiners like it too for cutting repetitive mortise and tenon joints, but it is not favored by most trades and may invite remarks at jobsites from other workers about the owner being unable to find his derriere with both hands and a GPS. That said, your humble servant frequently uses daruma heads for cutting precise mortise joints. Wait a minute…. where did I set down that darn GPS tracker….?

An 80monme/ 300gm/ 11oz daruma head with an rock maple handle.

The Funate

A funate gennou with bubinga handle.
The tail of a funate gennou. This point can be sharpened for creating pilot holes for nails when shipbuilding, or left as a rectangle of starting and setting nails. The face is slightly domed, but still flat enough for striking chisels. A good multi-purpose head that favors nails more than chisels.

The funate gennou is closer in appearance to Western hammers with a skinnier neck behind the striking face, but without the split-tail “piano chisel” a foreman from my misspent youth named Jack Frost called the claw on his 28oz waffle-face framing hammer. It is more commonly seen in the Western Japan than Eastern Japan where I learned Japanese woodworking.

This gennou is useful for finish work involving nails and for tapping-out plane blades, but less useful for wacking chisels.

The Yamakichi

Yamakichi was the name of a gennou blacksmith working in Fukuoka on Kyushu Island that originated this style of head and gave it his name. “Yama” 山 means “mountain” and “kichi” 吉 means “luck” or “lucky.” Kosaburo introduced this style to Tokyo in response to customer demand and with Yamakichi’s permission, we are told, improving the design somewhat.

This style is a heavy-duty stubbier version of the funate with a slightly domed face and a kinda sorta pointy tail, perhaps better suited to driving/setting nails than the ryouguchi head, but certainly better for striking chisels than the funate style.

Better with nails than the ryouguchi style, this head makes an excellent all-round hammer for working in the field, and can even handle tapping-out and kigoroshi tasks.

The design has a unique and interesting appearance which reminds this humble scribbler of a 1956 Ford F100 truck in that, while neither sleek nor smooth, it has a sculptural quality not seen in the other styles that “grows on you.” It feels good in the hand.

There are other in-between head shapes, but these are the four basic styles generally available for woodworking today.

Another view of the Yamakichi gennou pictured at the top of this article after the color has mellowed through exposure to sunlight. This is 300monme/375gram/ 11oz head by Hiroki has an American Osage Orange handle. (The decorative twine was added at the tool’s request. It has a thing for the color red).

Weight

The subject of gennou head weight was examined at some length in a previous post.

Regardless of the type of gennou head you select, weight is a critical factor that will depend on what you plan to hit, your height above the thing you are hitting, how hard you need to hit it, and how precisely you need to hit it. Your own practical experience is the best basis for selecting the genno weight for a particular job, but some guidelines can be suggested.

To begin, the traditional measure used for gennou in Japan is the “monme,” with 100 monme equaling 375 grams or 13.2 ounces (1 ounce = 28.35 grams). 

The standard middle-of-the-road weight for genno used by carpenters in Japan is 100monme (375grams/ 13.2 ounces). The most common hammer used for finish carpentry in the United States weighs 16oz = 120monme, a size commonly available in gennou too. So if you are going to buy your first gennou, and you intend to use it for general finish carpentry or furniture making, a 100 or 120 monme genno is a good place to start. 

For finer work, an 50-80 monme (11-7 oz) to gennou is a good choice. If you intend to make furniture or joinery, one in this weight range is a must-have.

For cutting deep mortises in heavy timbers with large chisels, as in timber framing or boat work, a 200monme (26oz) hammer is frequently used, but 250 (33oz) and even 300monme (40oz) heads are available. I own and use them when necessary. Some factors to consider when selecting a heavy gennou are that with greater weight comes greater impact force, and greater penetration, but heavier gennou are more tiring to swing and harder to control precisely.

Other factors to consider are the width of the chisel blade being used, since a wider blade requires more force to cut to a given depth, and the hardness/toughness of the wood being cut. Only experience can tell Gentle Reader what weight will work best in a given situation. Just be aware that, unlike bobby socks and government health care, there is no such thing as one-size-fits-all.

Conclusion

We hope this article has answered some of Gentle Reader’s questions on the subject of selecting a gennou head. If you have additional questions or need clarification, please use the “Leave a Reply” form below.

In the next post in this metaphysical adventure series we will discuss the differences between mass-produced and hand-forged gennou heads. We will look at woods suitable for making handles, and gennou design in much greater detail in future posts, promise.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. Please share your insights and comments with everyone by using the form located further below labeled “Leave a Reply.” We aren’t evil Google or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Japanese Chisel Setup: Additional Notes

A properly setup and hard-used set of excellent mukomachi mortise chisels by Kiyotada. Guess which ones have seen the hardest use over the years and benefited most from proper setup. The blades and handles are all shorter than when new, but without proper setup it is unlikely some of these tools, all of which are at least 30 years old, would still have their original handles, which they do.

Honesty and transparency make you vulnerable. Be honest and transparent anyway.

Mother Teresa

Introduction

Since we wrote the tutorial (located here) describing the advanced procedures we recommend for setting up Japanese chisels ten years or so ago, we have frequently received questions from Gentle Readers about the fact that the chisel setup procedures described therein differ in important ways from those taught by most retailers of Japanese tools in the USA and Europe, as well as those expounded in videos on NoobTube, or posted on the woodworking internet forums.

In response to these questions, we recently added a few paragraphs at the end of the tutorial in question which we are including in this post to dispel confusion among Gentle Readers that have not had the opportunity to read the article.

The Question

The most common question is: “Why does your description of how to setup Japanese chisels vary so much from those given in online videos and the woodworking forums?”

A knee-jerk response to this question might be that the questioner should take a big, heaping spoonful of that online advice, then hold their nose and swallow it down, yes, all the way down, …. keep swallowing now, then judge for themselves if it is sugar or BS. As the saying goes: “the proof is in the pudding,” or was it “laughter is the best medicine?” We forget. In any case, while such a hasty reply would be entertaining, it would also be crude and unrefined, and since we are nothing if not always gentle and elegant, we will instead try to provide a more palatable explanation.

The Long Answer

Yes, Virginia, we have seen the various online videos about setting-up Japanese chisels. The creators of most of them are simply parroting instructions that some long-gone employee of a Japanese wholesaler, someone who had never used a chisel professionally, heard from another guy working at a chisel factory assembling thousands of chisels everyday as quickly as possible from cheap parts, some of which may have been imported from China.

Some Gentle Reader may be saying to themselves: “Wait just one frickin minute there! What do you mean, “made in China!?” Please, take a deep breath, smell the napalm, and realize that many of the components assembled into products in advanced countries are actually made in China at low cost. Poor quality is the natural consequence of procurement policies aiming to maximize profits above all else. The components used in C&S Tools’s chisels, however, are all made in Japan of quality materials and to reasonable tolerances.

Here’s the problem: Imagine a chisel handle and/or crown manufactured to such careless tolerances that one must beat the heck out of the handle with a hammer (kigoroshi) to crush and break the wood cells to reduce the handle’s diameter enough so the poorly-matched crown will fit. With this still percolating in your head ask yourself two questions: (1) What sort of attention is being paid to quality control that these two simple parts aren’t manufactured to better tolerances? And (2), will crushing the hardwood handle’s cells improve or harm its durability and/or longevity?

Or imagine, if you possibly can (difficult, we know), a handle and its crown or ferrule so poorly matched that one must swell the wood with water to get the crown or ferrule to stay attached long enough to ship the chisel overseas. Is your mind boggled yet?

Do you suppose poor tolerances or ham-handed setup techniques make for a better chisel, one that will provide good long-term service in the real world? Sadly, this is the grade of chisel with which the PooTube “Creators” and the so-called “experts” on the orc-infested forums have hands-on experience.

The manufacturers of these hardware store-grade tools provide zero warranties. Their products disappear into anonymous overseas markets where consumers are accustomed to being deceived as a matter of course, and the quality of most of their competitor’s products in the local markets, essentially sharpened Chinese-made screwdrivers, are of even poorer quality, so there is no backlash, only profits.

If any of this sounds to you like proper quality control or good value for the consumer, then there’s some swamp land located next to an abandoned plutonium extraction plant in North Korea, shovel-ready for resort development, that’s for sale at an amazingly low price. We read about it on an internet forum, so it must be true. All you have to do is send US$3,000 in small bills via FedEx to a private P.O. Box belonging to Prince Musa Adebayo in Abuja, Nigeria. It’s a limited time-offer, so you’d better hurry. ( ͡° ͜ʖ ͡°)

Most of our Beloved Customers are not new to Japanese tools. They have bought the sizzle before, found it rancid, and come to us for honest handmade tools that meet the rigorous demands of advanced Japanese professional woodworkers.

The Short Answer

Let’s wrap this up by concisely answering the original question.

First, the setup techniques we recommend are different because the tools our Beloved Customers need to setup are different from those to which the “Creators” on Gooble’s PhewTube and the trolls on the internet forums are accustomed. They are made by true craftsmen, not unskilled factory workers using mass-produced components, much less mass-produced Chinese components. Our craftsmen are Japanese gentlemen living and working in Japan using crowns, ferrules, and handles made by them to reasonable tolerances, and the highest-quality hand-forged blades, also made by real Japanese blacksmiths working in their own smithies. Kigoroshi and water soaks are not necessary to setup these chisels, and will in fact harm them.

Second, because our Beloved Customers selected C&S Tools, we assume they are more advanced than the easily-deceived amateurs that typically buy hardware store-grade mass-produced chisels, and therefore actually want to do initial setup in accordance with the highest standards, not the lowest. It’s their choice, of course, but it would be grossly irresponsible of us to advocate lesser techniques like those of the GooberLube posers or the slimy denizens of the internet forum troll pits.

And third, unlike the wholesalers and distributors that peddle hardware store-grade tools overseas at inflated prices, we take our warranty seriously, and therefore actually care about the performance and longevity of the tools we sell. Accordingly, we need our Beloved Customers to set them up properly using the advanced techniques in our tutorial because we have a reputation to protect and a direct financial interest in customer satisfaction.

Five Potential Solutions

We hope the foregoing explanation clears up the original question. In addition, the following list describes five potential solutions to the other problems we touched on above. Sorry, but you’re on your own in the case of Prince Musa:

  1. Purchase only high-quality tools made to reasonable tolerances from quality materials by genuine professional craftsmen and blacksmiths that have long-term relationships and reputations that might be damaged by shoddy quality, not factories;
  2. Buy chisels and other edged handtools only from retailers (like C&S Tools) that both offer and honor a full international warranty on materials and workmanship, one that doesn’t require you to expend additional funds to benefit from. Good luck finding anyone else;
  3. Beware the often well-intentioned posers on Yoogle’s GooTube (or is it Toogle’s YouGube? We forget) who specialize in spinning an ounce of BS into 7 minutes of visual entertainment, all without any responsibility for the accuracy, completeness or honesty of their representations;
  4. Beware the chittering of the pustulous trolls and execrable orcs scuttling about in the fetid darkness of the internet forums;
  5. And last but not least, always remember the most reliable litmus test for veracity: Money Talks and BS Walks (see point 2 listed above).

Or, you can always try the spoon test described above: Bitter lessons teach surest. (ツ)

YMHOS

A properly setup and hard-used 10-piece set of oiirenomi chisels by Kiyotada. Guess which ones have seen the most use? All the handles and most of the blades are significantly shorter than when new, but the handles are entirely undamaged, proof that proper setup pays dividends. I need to tap-out some of the blades again.

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and won’t sell, share, or profitably “misplace” your information.

© 2020 Stanley Covington All Rights Reserved

Toolchests Part 7 – Key Performance Criteria Solutions 2: Sealing, Insulation, Security, Portability & Tiedown

Bernini’s David, completed in 1624. I have seen all three of the famous David sculptures in-person, but this is my favorite because David is not depicted as a static, obviously posed, formulaic study-in-marble or bronze of the human form as he is by the other masters. Instead, Bernini used his chisel to tell a dynamic story of a young man staring intently into his enemy’s eyes as he winds up to deliver a sling stone to his fuzzy forehead, a single, unlikely rock that changed world history forever. Although Bernini portrayed the face of a shepherd boy risking all in front of two opposing armies, this determined visage could just as well be that of a surgeon, a baseball pitcher, or a woodworker, of course.

Three things are needed for success in painting and sculpture: to see beauty when young and accustom oneself to it, to work hard, and to obtain good advice.                        

Gian Lorenzo Bernini

In the previous post in this series about toolchests we examined solutions to two of the Key Performance Criteria I established when planning my toolchest, namely durability and longevity. In this post we will examine the solutions to three more performance criteria: Sealing, Insulation, and Security. It may be long, but I hope our Gentle Readers will at least find it diverting.

Sealing & Insulation

Sealing the toolchest tightly and insulating it are important factors to consider when planning a toolchest, as mentioned in previous posts in this series, because a leaky chest can allow cold air, dust, and insects access to the tools stored inside it, potentially soiling, corroding, and damaging them. There are several details one can include in a toolchest design to minimize this problem. Some of the measures I employed are explained below.

The Lid

Front elevation of the toolchest. Please notice the depth of the lid, and the 3 raised floating panels in the frame & panel lid. Odd numbers are considered more fortuitous in Japan than even numbers. The chest rests on a wheeled torsion-box base, but it is not affixed to it. Please also notice the simple, old-fashioned half-inlet chest lock, easily defeated but easily repaired.

The role of a toolchest’s lid in sealing and insulating it over many years cannot be overstated. Unfortunately, many historical examples eventually failed miserably either through poor design or poor execution. I was determined to avoid those failures.

As I mentioned in previous posts, chests in museum exhibits and books all look great, many having been at least partially restored, but if Gentle Readers want to get a sense of how chests fail, they should also inspect the busted examples in antique stores and restoration shops.

The first common failure I found when inspecting antique chests was a poor seal at the lid. This is almost universal. It frequently stemmed from a poorly-fitting lid, one that probably fit nice and tight when new but warped over time. In other cases, the lid had cracked and split like the seaman’s chest in the photo at the end of Part 2 of this series. Another common problem was due to what could only be an intentional gap on the hinge side of the lid. And then there were the gaps caused by thin, narrow and weak iron hinges secured by short wood screws bending, wearing and/or loosening. So how to avoid these problems?

Let’s look at wood first. A policy that has served me well over the years is to always assume that a solid board of more than a few inches in width will eventually warp if left to its own devices. Of course, in the real world this is not always the case, but I’m a belt & suspenders & safety harness kinda guy. Besides, remember the 200 year useful life-cycle objective.

I also assume that a board more than a few inches wide will eventually split, or cause damage to another board in the assembly, if overly constrained from responding to both normal seasonal changes in humidity and the unnaturally dry conditions created by air conditioning systems inside modern buildings. Am I overly cautious? Perhaps more so than captain Edward Smith of the RMS Titanic was on a cold night in April 1912.

The historical record represented in the museums and antique stores I visited support this assumption in the long-term, especially when one considers the effects of AC and central heating systems lacking expensive humidity controls. Therefore I designed and constructed the lid so it included no constrained boards more than 2-13/16″ inches in width. In addition I also reinforced the lid from warping as a unit to prevent it from self-destructing during the planned 200 year useful lifespan. Not that hard to achieve with a little thought and a few sharp saws and chisels.

The lid is comprised of two main components: A horizontal top which is joined to the lid’s vertical sides. The top is frame and panel construction, a technique which allows the cabinetmaker to build wide, stable surfaces using a joined framework of narrower pieces of wood with free-floating panels set in between. The framing pieces are narrow enough to accommodate cross-grain construction at the joints safely. The larger panels are too wide to permit cross-grain construction without eventually failing, so they are not glued to the frame members, but are free-floating so they can expand/contract with humidity changes without cracking, splitting or breaking the frame. Gentle Readers who have never done F&P work before should learn how. It is a skill every self-respecting maker of solid-wood casework or joinery must have.

Side view of the toolchest. Once again, please notice the frame & panel construction of the top and depth of the lid, a detail which provides great strength and stability to the normally failure-prone lid. A hardened lifting/tie-down ring through-bolted to the sidewall is also visible, as is the end view of the torsion-box base with urethane wheels which makes it possible to move the toolchest over level surfaces and up loading ramps when full of tools without damaging floor finishes.

The top’s frame consists of 6 pieces of wood 30mm (1-3/16″) thick by 70mm (2-13/16″) wide. Four perimeter pieces are joined at the corners using pinned (wooden dowels) dovetail bridle joints to form a rectangular frame 1,015mm (39-15/16″) x 595mm (23-7/16″). Two pieces of the framing wood divide the long dimension of this rectangle into 3 equal-sized spaces filled with 21mm (13/16″) thick free-floating raised panels using a tongue and groove joint. Both tongues and grooves are coated with Briwax (beesewax and naptha) to prevent glue squeeze-out and paint from gluing the panels into their grooves, something that happens frequently and almost always causes the panels to crack and even split. I just hope that future generations are wise enough to not refinish the chest by glooping paint on these joints effectively gluing the panels in-place eventually destroying the lid. Much excellent antique woodwork has been destroyed by careless painting.

Given the thickness of the frame, the sturdiness of the corner joints, and the quality of the wood, the lid is an extremely stable construction all by itself, one that has not warped or cracked in 25+ years. Good enough, perhaps. But wait, were are my suspenders?!

This top is attached by glue and wooden pins to a vertical four-piece perimeter framework that extends downwards an additional 130mm (5-1/8″) making the total external depth of the lid 160mm (6-5/16″). Theses four vertical boards are also 30mm (1-3/16″) thick, joined at each of their four corners by 7 pinned through-dovetails. Even if the glue fails someday, the pins will keep the dovetails locked in-place. This construction makes the lid assembly extremely rigid and resistant to wracking and prevents the top and sides from warping. This lid assembly has never warped, stuck, bound or even squeaked. Not once.

Besides providing stability and a gap and crack-free seal, this construction creates the space I required to house many heavy tools inside the lid as well as the structural strength to handle the load without noticeably flexing or twisting. This is directly related to Performance Criteria No. 4: Accessibility.

A wide, bold surface like this lid with exposed joints just begs for the addition of engraved metal plates and hand-forged straps of the sort easily obtainable in Japan. I freely admit that decorative hardware would really look cool, but I managed to avoid the temptation because history shows that, if firmly affixed to the wood, metal plates and straps tend to constrain the wood’s natural expansion and contraction often eventually opening joints and cracking wood totally defeating the purpose of the elegant frame and panel construction. None of that nonsense for me, you wascally wabbit.

Front and top view sketches of the toolchest with minimal dimensions. All the drawings will be available for free download in a future post.

The Seal Between Lid and Case

Chests made in the tradition of Western countries often have an interlocking lip between lid and base which more or less seals three sides, but which leaves a gap at the hinge side where dust, humidity, cold air, fungi, insects and pixies can enter. That’s nonsense. But what are the realistic options?

One well-published toolchest has the hinges supported on corbels attached to the exterior back wall of the chest. I think this is a clever solution, and one I considered, but ultimately rejected because it increases the toolchest’s overall width by the corbel dimension without increasing internal storage space. I of course considered rubber gaskets, and even magnetic refrigerator gaskets. Either would have sealed well at least until the unavoidable day of reckoning when the rubber and plastic oxidized, cracked and crumbled. They won’t last 200 years anymore than Cher’s beauty will. Oops, sorry. Too late.

The solution I eventually settled on was a detail common to Japanese casework, namely a lip applied to the inside of the lid where it meets the lower case. While not quite airtight, this lip does ensure the lid and case are precisely aligned when closed, that there is no gap at the hinge side, and that very little cold air, dust, fungi, bugs, or even anorexic pixies can infiltrate the toolchest once closed. I used a tough, fibrous, exotic hardwood for this lip that has held up well. The seal is so good that, even with 25 pounds of tools mounted inside the lid, I can drop the lid from full-open and the air-pressure created by this tight seal will make the lid close slowly without a sound. I have not had to replace it in 25+ years, but it would be easy to do if necessary.

This simple detail, combined with the natural thermal properties of the 30mm thick wooden sidewalls and lid, satisfied the criteria for insulation too.

Hinges

We discussed a few methods involving wood to prevent drafty lids above. Next let’s examine metal hinges.

Another failing of antique chests common to all the traditions I was able to investigate was inadequate and/or poor-quality hinges. When hinges are lose and sloppy when new, or become loose and sloppy over time due to wear and/or corrosion, or when the tiny often poor-quality nails, staples or screws used to attach most hinges loosen and become “idiots” as they say in Japan, the lid won’t align with the case and/or a gap develops between lid and case. Secondary damage results. Dirt, air, bugs and pugilistic pixies infiltrate. It’s the beginning of the end.

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Another look at that horrendous pixie infestation in a toolchest with a leaky lid located in a clothing-optional workshop. Bad hinges, no doubt. How embarrassing!

Traditional blacksmith-forged iron or steel hinges with decorative engraving or hammer marks are extremely attractive, but they just don’t meet my performance criteria. To begin with, iron/steel always rust. Rust then expands, becomes abrasive, and wears off destroying tolerances, a nasty cycle. Handmade hinges look cool, but tolerances are poor. And most importantly, traditional hinge pins are short and small in diameter with tiny bearing surfaces that wear quickly, and since their ends are peened, they cannot be removed easily. That would never do.

Instead of installing pretty traditional hinges or the cheap hardware-store hinges most people use for chests, I chose to use five solid-brass commercial door hinges with removable steel pins, made possible by the 30mm thickness of the case walls. I give them a dab of oil every couple of years. There is a reason modern door hinges can endure a lot of wear and abuse, and it has nothing to do with historical accuracy, I promise you.

I inset both leaves of these hinges and attached them using 2″ long grade-8 stainless steel screws (made in the USA not China) after dripping glue into the holes. They have not loosened or even developed a squeak in 25+ years.

The long strap hinges used on American and British chests may look sexy, but they often cause the lid to crack and split. Think about it.

Security

More often than not, quality chests have historically had locks of one sort or another installed. If you, Gentle Reader, decide your toolchest needs a lock, you should develop a security strategy early in the design process. Here’s mine.

As part of my day job I have talked with a lot building security experts when planning restricted-access facilities for Clients that have a lot to lose if their corporate secrets are stolen. I’m not suggesting you need 10-lb locks with biometrics, multiple layers of 1/2″ hardened plate steel doors, contact switches, keypads, cameras backed-up in Colorado, or armed guards. But I can share with you something I have learned applicable to cabinetry.

A lock won’t dissuade a determined thief with a crowbar for even a minute, but it may help keep an honest man honest.

But thieves are not all we need to worry about.

Ever have one of your adoring children or your loving spouse (yes, the one that thinks you have too many tools already and should buy new kitchen counters instead) borrow a tool, or even worse, lend it to a friend or neighbor without telling you? How often did that tool find its way back to its proper place in your toolbox or workshop?

How often has one of your precious, carefully-sharpened chisels ended up being used as a combined paint can opener and stirring stick only to spend the following months or years smeared with paint, humiliated, alone, forgotten, sadly weeping behind old paint cans in your neighbor’s garage? Besides the indignity of paint spots (chisels are often vain, you know), imagine the emotional trauma the poor thing suffered. Not to be bourne….

To help preclude this sort of trauma, Gentle Readers have three choices when it comes to casework locks. The first is to use standard locking hardware that requires a modern keyed lock with a tumbler. These work pretty well, but most look ugly in handmade casework. Appearance aside, the real problem is that, given time and privacy, and lacking lock-picking skills, a determined thief will simply break wooden casework with a crowbar. We see this sort of damage in modern cabinets frequently. It’s expensive to repair.

The second choice is to use heavy bars, locks and chains. I use this technique when I ship my toolchest by first padding the chest with plywood and blankets and then running a 10mm hardened-steel chain (chain-hoist chain) around the chest through the hardened-steel lifting eyes on both ends crossing underneath and on top of the case. This I secure with a heavy, high-security padlock underneath the rolling base. Bolt cutters won’t cut the locks or chain, but a largish hydraulic bolt cutter could. Likewise, an angle grinder could get through given some time, noise and sparks. This is a lot of trouble both for me and the thief, but it will absolutely stop a pilferer with a crowbar. 30mm thick sides and lid, remember. But it is not at all practical for routine access to the tools inside.

A half-mortise chest lock. A classic.

The third method is to install a lock that is convenient to use but easily defeated so a determined thief won’t destroy the chest in the process of bypassing it. A strange approach, I know, but it is logical and practical. The locking system I selected is a simple, old-fashioned brass half-mortise chest lock. You could pick it with a hairpin if you know how, or pop it open with a clam hammer. It’s quick and easy to lock and unlock, and it deters rugrats, wives, casual pilferers and even pernicious pixies, all while looking classic and unobtrusive. If a determined thief has the opportunity, he can easily break the lock and get in. The upsides are that he can do it without destroying the chest, and you will know he did it. Not ideal, but nothing ever is.

Portability

The portability criteria I established during the planning phase required the toolchest be light enough in weight to be carried up stairs by two men when empty. It had to also be easily moved over flat surfaces by one man with a full complement of tools inside.

Gentle Readers may recall the following image of a Japanese kuruma dansu from Part 2 in this series. This tradition served as inspiration for my design.

アンティーク家具 古民具 骨董 江戸時代 味の良い車長持ち(時代箪笥)

In Japan this type of chest is called a “kuruma dansu 車箪笥,” which translates to “wheeled chest.”

You may wonder why anyone would need wheels on a piece of casework intended for interior use. The reason is simple practicality: Japan has a long history of urban fires that destroyed entire cities on a regular basis, but the addition of wheels to casework made it possible to quickly roll them out before the house burnt down, thereby saving valuables. Try doing that with a wall cabinet! Or try doing it over unpaved streets with tiny fragile casters screwed to the base of a loaded chest.

Wooden wheels are cool and mecha retro, but I rejected them for two reasons. First, they have solid axles, and if rolled around much both the wheels and the floor will be damaged, a lot, especially if grit and small stones become embedded in the wood. Not practical.

The second reason is more complicated. To begin with I wanted to be able to remove the wheels at times to comply with the maximum height criteria I had established in order to move the chest up narrow Asian stairs. Even with the current design, I need to remove the lid to get it up some stairs, including the house I currently live in.

The wheels in a kuruma dansu not only add a lot of fixed additional height, but that height is volume I would prefer to have inside the chest for tool storage instead of being occupied by an integral undercarriage, wheels and axles. But by using a detachable torsion box base with modern extra-heavy-duty lockable industrial casters with urethane tires, ball-bearings, and crazy pivots (free to rotate around a vertical axis), I was able to raise the chest further above the floor to improve access, satisfy the maximum height and portability criteria, and secure more interior space. If the casters go bad, I can replace them easily without impacting the chest in any way, unlike some examples where the casters are screwed to the bottom of the chest.

Besides, there have been a few years when the toolchest spent time in state (in full view) in our living rooms, and while my wife is Japanese, she simply doesn’t like the appearance of kuruma dansu. Go figure. During those periods, I simply removed the wheeled torsion box and rested the chest directly on the floor. My wife placed a colorful cloth noren over the chest with a flower vase on top. Some of her lady friends from church who visit occasionally liked it enough to ask if I would make chests for them.

Tie-down & Lifting

The performance criteria for tie-down and lifting were as follows: “Can be secured to the walls or floor of a shipping container or moving truck, and lifted by crane quickly and easily and without employing complicated rigging or straps touching the wooden surfaces.”

As seen in the picture above, a hardened steel ring is through-bolted to each endwall of the toolchest. These are not reproductions or homemade rings, but certified load-rated hardware that serves three purposes. First, they make it easy to secure the toolchest to the side or floor of a container or truck. This capability is very important in the case of a toolchest that must make international moves frequently. If you think it would be easier to just have the movers throw blankets over the chest and strap it down, you’re absolutely right. The problem is that the likelihood of those conscientious, patient and gentle professionals that load conex boxes and trucks properly positioning the toolchest so it won’t shift, and then tightening the straps or ropes (if they even bother to use straps or ropes) so they don’t loosen, or scratch and abrade the toolchest, are slim and none, and Murphy always makes sure Slim is drunk on moving day.

The second purpose of these rings is to make it easy for two men to carry the chest by looping straps through each ring and over a 2×4 passed over the chest and placed on each man’s shoulder. This too is a traditional Japanese method of transporting heavy boxes, and is directly related to the “Portability” criteria discussed above.

And third, if I need to chain the chest closed to prevent pilfering, as I do when it is stored in a warehouse, I can pass a hardened chain through the rings, over the top and secure it with a padlock under the base without fear of the chain being slipped off, as described above under “Security.”

Sorry this article was so long. Perhaps these scribbles will suggest some solutions to our Gentle Reader’s tool storage systems.

In the next post in this Homeric tale of mystery and adventure we will take another look at hinges and examine the tools mounted inside the lid.

YMHOS

芹沢模様 のれん 縄のれん文
A dyed cloth noren, traditionally hung in door openings in Japan to provide decorative privacy while allowing airflow during hot months. Also makes a most excellent toolchest cover when company visits.

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and won’t sell, share, or profitably “misplace” your information. May I swallow a thousand needles if I’m lying.

The Japanese Gennou & Handle Part 7 – The Unblinking Eye

Tempo is all, perfection unattainable,
as at the top of the swing… …there’s a hesitation, a little nod to the gods that he is fallible. That perfection is unattainable.

“The Golf Swing” by Roy McAvoy

The Japanese gennou is outwardly the simplest of hammers comprised of just a differentially-hardened steel head attached to a wooden handle without wedges, pins, epoxy or rubber. But as simple as it is, there are several factors that drive this tool’s performance. One critical factor is its “eye.”

The Unblinking Eye

Since ancient times, hammer handles have ended in a “tenon” designed to fit inside a rectangular through-mortise hole in the hammer’s head called the “eye,” in English, and “hitsu” in Japanese. In Western hammers and the majority of Japanese hammers the interior walls of the eye are angled so that a wedge driven into the end of the handle will splay the tenon keeping it from slipping out of the eye. This connection works as well as can be expected, if the eye is deep and tolerances are acceptable, but Japanese gennou heads are compact and their eyes are not deep, so a better solution is called for. 

The downside to securing the head with a wedged tenon is that the wedge will frequently cause the handle to split weakening it considerably. Also, a wedged connection seldom has uniform contact and pressure inside the eye and may therefore loosen as the wood wears from impact forces. In addition, uneven pressure between tenon and eye may induce unpleasant vibrations in the handle, a phenomenon you have not doubt experienced without realizing it, like an itch on the back of the neck from a mosquito bite.

A tight, high-friction, uniform-pressure fit between the eye’s walls and the tenon keeps the quality Japanese gennou head in place and working efficently. Straight, parallel, square, clean walls are therefore critical.

Inexpensive mass-produced gennou and hammers typically have eyes with poor tolerances hidden by the handle tenon and sometimes concealed under resin caps. The heads and handles of such hammers and gennou seldom remain securely attached if used heavily long-term. Experienced Japanese professionals, therefore, have traditionally preferred to buy just the head without a handle so they can inspect the quality of the eye before laying down any money, and then make the handle themselves. This is consistent with the frugal craftsman ideology once common throughout the civilized world wherein the craftsman would make as many of his own tools as possible, often in imitation of his master’s tools and using metal components forged by the local blacksmith, all to be completed by the conclusion of his apprenticeship and graduation to “journeyman.”

This explains the demand in Japan for high-quality relatively expensive heads such as those hand-forged by Kosaburo or Hiroki. Not only are they properly shaped and consistently heat treated, but they have precisely dimensioned eyes that will not only hold onto the tenon a long time and reduce unwanted vibrations, but will save the owner a ton of effort both truing the eye and replacing failed handles later. And since the gennou is an heirloom tool, the extra cost of such a head is not wasted.

Four hand-forged gennou heads: L~R 375gm Kosaburo Classic; 100gm Hiroki Modern; 338gm Hiroki; 300gm Hiroki; 25gm Hiroki. All differentially hardened. All made entirely by only power-hammer, forge, and grinder by hand. Dies, presses, mills, CNC equipment, EDM equipment were not used to shape these heads or form these eyes.
Mr. Aida studied under Kosaburo. Although their styles are different, most notably the lack of a polished “hachimaki” headband in Hiroki’s products and the very different oxidized forge skin, both blacksmiths made/make precise eyes.

Since so much relies on the connection between the handle’s tenon and unseeing eye, let’s examine it and correct any deficiencies revealed.

Examining the Eye

The first step in inspecting a gennou head is to check the eye because if this is wrong, then the head will not only be difficult to make a handle for, but it will be unstable during the swing and skittish on impact, intolerable failings in a tool we need to use with speed and precision unconsciously.

Just sight down the length of the head’s body with the eye in view. The eye should be of uniform width over its entire length, and the sides parallel, of course. It should also be centered in the body and not skewed. The narrow end surfaces of the eye should also be straight and square to the sides. Mass-produced gennou heads typically fail this examination to some degree, and even some expensive handmade heads will too, sorry to say. Be sure to inspect both the top and bottom surfaces of the head.

560gm Kosaburo Classic-style gennou head. Old-stock with surface patina. This is how all Japanese gennou were shaped prior to around 1890. The swollen area around the eye was created by the pressure of the mandrel being hammered into the yellow-hot metal to form the eye. This bulge was also once common in European and American hammers.
560gm Kosaburo Classic-style gennou head.
560gm Kosaburo Classic-style gennou head.

Next you need to inspect inside the eye. Use a flashlight to check the interior walls are straight, parallel, square, free of twist, and without significant bumps, bulges or gouges. You may need to make a tiny square from wood or metal to perform these checks. There are special machinists squares and depth gauges that are ideal for this purpose. An accurate vernier caliper will prove useful.

Ofttimes the eye’s walls are intentionally sloped inwards from both ends so the center of the eye is narrower than either opening. This geometry is intended to compress the tenon as it is driven through the constriction locking the tenon into the eye. The crushed tenon is then supposed to expand afterwards, essentially relying on kigoroshi to bind the tenon in the eye. This geometry does work, kinda sorta, if a wedge is driven into a sawkerf cut into the tenon. Gennou heads with this style of eye are much easier to produce and are intended for mass-production beaters. Such head/handle combinations may exhibit strange harmonic vibration, which you may or may not be able to detect, and since pressure on the wooden tenon is not uniform, swelling/shrinking of the tenon with seasonal humidity changes will always cause the head to loosen over time.

If a gennou head is secured to the handle with wedges, it may be because the eye is sloppily made, or just because that is what amateurs are accustomed to seeing, but a quality gennou head fitted to a proper handle does not need wedges to secure it no matter what Fat Max says.

Correcting the Eye

As the erstwhile golf poet Tin Cup taught the World: “Perfection is Unattainable,” so I don’t encourage anyone to go OCD over the hole in a hammer head, but if you are patient, you can use small files to true the unseeing eye to the best of your patience and ability. This may be a tedious job because only small files can be used, and that within a narrow space both difficult to see into and with little room to develop leverage.

Related image
Kevin Costner as Tin Cup testing various apparatus to correct his golf swing which he laments “feels like an unfolding lawn chair.” Woodworkers too are susceptible to the allure of commercial mechanical fixes such as honing jigs and sawing jigs.

Please be careful when filing to avoid making things worse. Remember, flat, parallel walls free of twist with clean sharp corners are the goal. Once you have trued one poor quality eye you will understand the value of a high-quality premium gennou, which has nothing to do with finish or decoration.

If your gennou head has a constricted eye, please file all four walls straight.

Whatever you do, don’t leave the walls curved outwards so that the eye is wider at any point inside than at its openings, because the handle can never be properly fitted to such an eye and will always work loose.

Make a Layout Tenon

Once the eye of your gennou is true, cut and plane a piece of softwood that perfectly slip-fits into and through the eye with 3 or 4 inches protruding out both sides. Draw lines on the stick where it projects from both ends of the eye. We will call this stick the “layout tenon.” Save it to use later in the handle-making process.

In the next post in this series on making a handle for the Japanese gennou hammer we will look at selecting a gennou head.

YMHOS

A 750gm Kosaburo Modern-style head with a Japanese black-persimmon handle. This was the first Kosaburo head I purchased over 30 years ago. A good friend and a lifetime tool.

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Toolchests Part 6 – Key Performance Criteria Solutions 1: Durability and Longevity

It is not down on any map; true places never are.

Herman Melville, Moby-Dick or, the Whale

In the previous post in this series we discussed the need to develop Key Performance Criteria when planning a tool storage system, some of the pitfalls to avoid when making KPC’s, and then listed the KPC’s I developed for my toolchest, not as an example to imitate but just for reference purposes. In this post we will examine some of the solutions I arrived at regarding how to incorporate those KPC’s into a practical design. I hope it proves informative, or at least amusing.

Durability

A toolchest should be tough as a whale because a fragile one endangers the tools we trust it to protect. Those Gentle Readers for whom durability is not a high priority should stop reading now and go back to the important task of popping bubble wrap.

When I was researching this performance criteria, I bought books and visited libraries reading everything I could find on the subject. I visited museums and was told to get up off the floor and “move along now,” by security guards more than once. I just wanted to see underneath….

I visited antique stores and the workshops of professional antique restorers and grilled them about what materials and construction details withstood the tests of time best, learning much that wasn’t written in the books.

I incorporated some of the things I learned through this investigative process into the design and construction of this toolchest, so let’s examine a few related to durability and longevity.

Wood Selection

I grew up making cabinetry and casework with my father from readily available commercial materials such as 3/4″ plywood. We would mill solid wood parts to match this standard dimension even though trees don’t grow in quarter inch increments. While the material of choice has shifted from plywood to MDF in recent years, this is still standard procedure in commercial situations. However, since my toolchest was not to be a commercial product for a Client with no understanding of quality casework beyond external appearance, but rather custom casework for my personal use, I tossed those standard procedures out the window and started with a blank page.

My examination of the available literature, museum exhibits and antiques available to me at the time combined with some structural analysis revealed that durability is heavily influenced by the mass and the strength of the wood. This seems like a common-sense conclusion, but it flies in the face of conventional toolchest design, as you will see.

Many advocate making chests from lightweight, inexpensive woods such as sugar pine, poplar, cedar or cypress, and to dimension the walls thin to minimize cost and weight, and to maximize interior volume. This is the traditional approach for chests used by common folk, but anticipating the abuse my toolchest was likely to experience, and considering my longevity goals and the fact that I would never need to carry it far by shank’s mare or mule, I eschewed this philosophy and decided to use stronger more durable wood and thicker, with weight a lesser priority.

One of the so-called “Genuine Mahoganies,” Honduras Mahogany is very resistant to rot and termites although some beetles will eat it if they can find it. We will look more at the sensory capabilities of bugs in another post in this series. HM is strong, not too heavy, easily worked, glues exceptionally well, and is phenomenally stable. Along with Cuban Mahogany, it has been the most desirable wood for luxury furniture in the Americas and Europe for centuries. 

This wood is difficult to obtain in the United States nowadays because of import restrictions prompted by environmental destruction through over-harvesting, but at the time, it was readily available as S2S clear lumber in the People’s Socialist Republic of Northern California. 

HM’s coloration varies from tree to tree. The coloration of the HM I purchased was not the most desireable dark red, but the less-expensive, less-dense orangish variety. However, I splurged and used ribbon-figured HM for the tray sides.

I used no “secondary woods” except for the 5mm plywood non-structural loose dividers in the sawtill. No need to be a cheapskate.

Wood Thickness

One purpose of my research was to gain an understanding of the typical failure modes of chests. You don’t see busted, bug-infested, rotted-out examples exhibited in museums or written about in books, but there are lots of old broken-down chests in antique stores, and restorers are always working on them; I strongly encourage you to venture away from the internet into the dark and foreboding world of reality to examine them with your own eyes and hands to determine the challenges they faced during their lifetimes.

One very common failure mode is ruptured corner joints resulting from what appeared to be drops and impacts. Another common failure mode is cracks, gaps and warped lids resulting from differential expansion/contraction inherent in wood. So I needed to develop solutions to these traditional failure modes.

In a dovetailed chest, impact forces from drops frequently cause corner joints to fail, so the solution I employed was to use plenty of dovetails, and to make the side wall material thick enough to provide adequate surface area for glue to bond and impact energy to be safely dissipated without causing the carcass to rupture.

Obviously (or maybe it is not obvious to some) thicker walls increase the amount of long-grain to long-grain contact area at a dovetail or fingerjoint corner joint by more than the square of the thickness. A simple calculation showed the sides had to be much thicker than 5/8” to achieve the impact resistance and glue strength I needed, so I went with 1-3/16” (30mm) thick sides. And instead of using a lightweight softwood like pine, a weak but delicious wood upon which bugs and fungi dine with gusto, I went with the much stronger and more rot/bug resistant Honduras Mahogany in a medium density as noted above. This proved to be a wise decision as evidenced by the results of multiple drops and several forklift encounters during my travels. And due to its dedicated wheeled platform, the additional mass has not been a problem so far. This was never intended to be a truck-bed toolbox.

Of course, most drops and forklift kisses impact the base first, and if the bottom corner connections fail all is lost, so I made the base (skirt) of tough 40mm thick high-density mahogany, dovetailed the corners, and pinned/glued it to the chest’s sides. These four pieces and the assembly they comprise is the densest, toughest component of the chest. It is scratched and dinged but this is only cosmetic damage, so I feel the base has done everything I needed it to do, at least so far.

I doubt 3/4″ sugar pine sides or a 5/8” ~ 7/8” thick poplar base would have survived the first drop from a moving truck bed, let alone that incident in Bangkok when what must have been a deranged peg-legged forklift driver pushed the tool chest into the conex box with his fork tips while shrieking “From Hell’s heart I stab at theeee!” The madman damaged the toolchest but neither pierced nor cracked it. After that, I rechristened it “Moby Dick. “ Harpoon sockets and grog were not involved.

Related image
“…to the last I grapple with thee; from hell’s heart I stab at thee; for hate’s sake I spit my last breath at thee.”

Differential Expansion & Contraction

Changes in humidity make wood expand and contract. You can ignore this natural tendency, as the plastic puppet people that love MDF do, or even fight it if you enjoy humiliation, but given enough time you will lose. Better to plan for it if your longevity goals are 200 years. If, however, longevity is not important to you, please stop reading this article immediately and get back to popping bubble wrap.

Avoiding damage caused by differential expansion and contraction of wood is a problem humanity resolved centuries ago using well-known, but oft-ignored solutions. Some of those techniques are to use mechanical connections (e.g. dovetails, mortise and tenon joints, etc.) without relying solely on glue, avoidance of wire nails, avoidance of wide cross-grain joints, avoiding steel straps hard-connected cross-grain, and using frame-and-panel construction when wide cross-grain joints would otherwise be impossible to avoid, to name some primary solutions.

My design uses few metal fasteners, just stainless-steel screws to attach the lid’s hinges and tray shelves, brass screws to attach the brass lock and recessed tray pulls, and 4 steel bolts to attach the lifting eyes. No metal straps are used.

My toolchest employs a floating frame-and-panel lid with deep sides made from solid Honduras Mahogany. I’ll go into this more in future posts.

The chest’s bottom is also frame and panel construction in solid mahogany. Frame and panel construction was used for all tray and drawer bottoms. No engineered wood materials such as plywood, MDF, LVL, OSB or veneer were used.

All glued joints in my toolchest are dovetails or pinned dovetail mortise and tenon joints, and trenails. If the glue fails, which it eventually will in some places sure as eggses is eggses, the mechanical joints will still hold together. I did not use nails, screws, staples, biscuits, splines or loose tenons as structural fasteners.

Fungus, Insects and Rodents

As noted above and in Part 3 in this series, wood as a material may be economical, easy to work, have decent insulation performance, and make our collective hearts go pitter-patter, but we cannot safely ignore the fact that some fungi and insects love to eat wood, and rats and mice will chew holes in it. How can we adapt our toolchest design to deal with “the crud,” creepy crawlies, and critters? A few possible solutions are listed below:

  1. Select a wood that is naturally unpleasant to chew without using toxic levels of hot sauce. God made some woods yummy, and others noxious. The later typically lasts longer;
  2. Use thicker wood to make the toolchest strong and tough. This will also make it more difficult for rodents to chew holes in it.
  3. Make the wood unpleasant for fungus and bugs to eat and rats to chew through the miracle of modern chemistry available in either commercial or homemade wood preservatives;
  4. Seal all raw wood surfaces, both inside and outside the toolchest, so fungus spores will find it difficult to take root, and insects less likely to detect the savory smells of yummy wood (that is how they find it, you know);
  5. Elevate the bottom of the chest above the ground/floor so there is an “air gap” preventing direct moisture transfer from below thereby keeping the wood’s moisture content at levels less than those preferred by fungus and bugs;
  6. Design the base details so some air circulation underneath the chest is possible to reduce fungus growth and make cleaning possible:
  7. Place vaporized fungus and insect repellent (e.g. moth balls or toilet cakes) inside the toolchest further minimizing delicious woody smells that attract insects while at the same time creating an uninviting or even hostile environment for their kiddies;
  8. Combine all seven of the solutions listed above, which is what I did. You know me: Belt, suspenders, and safety harness.

We will talk about these solutions and other factors that informed the design of the toolchest in future posts.

I encourage you to give similar consideration to the design of the furniture and casework you build for your own use, at least if, like me, durability means more to you than the joy of popping bubble wrap.

In the next post in this series about my toolchest, we will consider some potential solutions to the remaining Key Performance Criteria you may want to consider when designing your toolchest.

Call me Ishmael.

“Talk not to me of blasphemy, man; I’d strike the sun if it insulted me.”

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information. Honest.

Kireaji 切れ味

‘Be careful you don’t cut yourself. The edges are sharp enough to shave with.’
‘Girls don’t shave’, Arya said.
‘Maybe they should. Have you ever seen the septa’s legs?”

George R.R. Martin, A Game of Thrones

I mentioned in a previous article my belief that a love of sharp tools is embedded in the Japanese people’s DNA. I am convinced this is by no means limited to the people of these mountainous green islands. I know it is deep in mine too, and it may be in yours.

Whether they were made of bone, flint, copper, bronze or iron, humans of all races and all locations worked with axe and adze, chisel and scythe, sword and dagger to keep body and soul in close proximity for many thousands of years before written language was invented or Microsoft products crashed. Our reliance on and love of sharp tools is still part of our DNA, to one degree or another, and for good reasons.

The words we humans make and use give insight into our deeper natures, so a very brief lesson regarding a single word in the Japanese language, one that is an intentional, defining characteristic of our tools, and one you will not find in any textbooks, may be illustrative of this point.

Cutting Flavor

The word your most humble and obedient servant has in mind is “kireaji” 切れ味 pronounced “ki/reh/ah/jee. This word is comprised of two Chinese characters. The first of the two ideograms being 切 , which is pronounced in its un-conjugated form as “setsu” or “kiru,” meaning “cut.” This is an interesting character. People who study these things say it is an ancient combination of two characters. The small one on the left looks like the character for the number seven 七, but actually it represents a vertical and crosswise cut in the shape of a plus sign 十. The character to the right, 刀 , is pronounced “to” or “katana” and means “sword.” So “kiru” means to cut with a sword or blade.

The second character in the word is “Aji,” 味 meaning “flavor.” Combined, these two characters mean “cutting flavor,” but the resulting word has nothing to do with the human sense of taste and everything to do with the feeling transmitted to the user when a blade is cutting. This word is used in reference to all cutting tools from axes to swords to razors, and certainly for knives, chisels, and planes.

In the English language, the closest word we have is “feeling of sharpness,” I suppose, but it isn’t the same. The act of cutting, in the Japanese tradition, is a sensory experience, one that can be pleasant, in the case of a well-designed sharp blade, or unpleasant in the case of a clumsy dull blade. I think you now have a sense of what the word kireaji means, and how how it feels. Do you understand why it is an important word when talking about tools?

When we speak with our blacksmiths and sharpeners about the tools they produce, the kireaji we expect of their products is always part of the discussion. A blade can have a good kireaji (良い切れ味, an indifferent kireaji (どうでもいい切れ味)or a “distasteful” kireaji (不味い切れ味). It can be “brittle” (切れ味が脆い)or it can even be “sweet” (切れ味が甘い)meaning soft as a spoiled child. We always insist the first meaning be applicable because anything less is failure. Even if some of our customer’s tastes may not be refined enough to discern the difference, ours are.

We work closely with our blacksmiths and sharpeners to make sure they understand our requirements for sharpness. And just to be sure, we constantly test their blades to ensure compliance. If you buy a tool from us that has an especially sharp edge and looks like it may have been used lightly, please understand this is part of our QC efforts and not a return or a reworked reject.

If you know of other languages that have a similar idiom, please let us know in the comments section below.

Like the flavor of fine wine, rich chocolate or gourmet donuts (mmm donuts), the kireaji of cutting tools varies with materials, blacksmiths, and specifications. At C&S Tools we are not satisfied with outward appearance only, but take our products to a different level by making kireaji the very highest priority. This makes C&S Tools almost unique among retailers of edged tools.

Does kireaji matter to you?

Bon appetite!

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. Please share your insights and comments with all our readers in the form located further below labeled “Leave a Reply.” We aren’t evil Google or incompetent facebook and so won’t sell, share, or profitably “misplace” your information.

Toolchests Part 5 – Defining Key Performance Criteria: Avoiding The Whirlpool of Indecision

Byodoin temple in Kyoto, Japan

To fail to plan is to plan to fail.

Anon

In the previous four parts in this series about toolchests we examined some aspects of the history of toolchests, as well as the goals, objectives, pros and cons that informed the design and construction of my toolchest, and which any effective design should at least consider.

In this post we will examine some of the design criteria I arrived at after several years of cogitation, and some pitfalls common to the design process you may want to avoid. I hope this discussion will be helpful when you, Gentle Reader, are planning your tool storage solutions.

Background

The subject of this series of posts is a toolchest I made by hand over 26 years ago when living in San Mateo, California.

The basic idea for my toolchest was born many years ago when I found an old British book on woodworking with drawings for a unique toolchest while browsing the darker reaches of the University of Tokyo’s library.

My profession has taken me to many locations around the globe, but even if I don’t use my tools to earn a living anymore, I still need them nearby for the sake of my mental health. I take this toolchest with me when I am working away from home, sometimes in foreign countries and for years at a time. It contains most of the tools I need when working wood by hand. Therefore, the design was heavily influenced by logistical and environmental factors. 

It has English roots, as do I, but it is neither a reproduction of a historical toolchest, nor a slavish imitation of someone else’s. It is also not a haphazard conglomeration of details cherry-picked from books and the internet because they look cool or some internet guru (this was before the internet) did a video on NoobToob. It took me literally years to research, refine, and complete the design, and although it is based on an old British source, I incorporated details from Japanese casework I felt would help me achieve my performance objectives. 

Avoiding the Porcelain Whirlpool of Indecision

Anything of any difficulty worth doing well requires a plan, but a beautiful plan does not spring forth from the mind perfectly shaped. It typically begins with just a framework, or more often, pieces of a framework, to which we attach, over time and through deliberation, the decisions that culminate in a plan. Experience matters during this process, but research and careful deliberation can often compensate for a lack thereof. Let us consider a few aspects of planning in the real world that should influence a toolchest design.

In my day job I manage the planning, design and construction of new commercial buildings and interior fitouts (tenant improvements) in Japan, and while the dollar value of a toolchest is much less than a building, I believe the same planning principles can be applied.

Every building project must have a plan, sometimes called a “program” or “design brief,” that describes in writing what the Client requires the completed construction project to accomplish. This document does not include project-specific design drawings, because those aren’t necessary or even useful at first, but it still drives the architectural, structural and MEP (mechanical, electrical, plumbing) design. Architects, engineers, consultants and I can help a Client develop this planning document, but ultimately the Client pays the money and lives with the results so the decisions are his to make. This aspect of planning can be difficult for anyone, especially those that are inexperienced, insecure, or too proud to admit they don’t know it all.

What many inexperienced Clients don’t realize is that, even though they may not be able to get their minds around the hundreds of decisions that must be made, and frequently fail to make them at all, abandoned decisions will still be made, but by default or happenstance instead of intelligent choice. Sometimes the default decisions are justified as “tradition.” How convenient. How slothful. I call this “design by neglect.”

If a reasonable person manages to struggle through a project, that experience will typically improve his decision-making capabilities greatly. However, occasionally a Client suffers from a mental defect I call “Spiral Decision Neglect Syndrome.”

A sufferer of SDNS may imitate but cannot learn. He will not only fail to make critical decisions, but he will become angry when he discovers he lacks the ability and/or the courage to make them, always a sure sign of shame. To conceal his poor ability and protect his pride, this person will remove those capable people around him that could have helped and replace them with yes-men. From that instant the design process will follow an inescapable spiral path into the slimy depths of the porcelain scrying bowl to the fate that awaits all turds. I’m sure you have known people like this and seen the stinky spiral of failure that surrounds them as they rise in the corporate world. But I digress.

The wise person will acknowledge they don’t have all the answers at first (no one does), but will be diligent enough to work for the answers, having faith they will find them. They will also document the criteria that will drive the decisions that must be made so the design does not veer off into the weeds. I call this process “Defining Performance Criteria.” Please note that Performance Criteria typically describe what a thing must do or not do, not so much what it will look like.

Planning Techniques

But what if you don’t have experience, or lack confidence in your planning and/or design abilities? Welcome to the club that includes most of humanity: “Admission is free, please pay at the door. Pull up a chair and sit on the floor.” Here are my suggestions:

  1. Do research, including reading accounts of both traditional and modern solutions, and personally inspect as many physical examples as possible. Antiques can be very educational. Modern cabinetry can be enlightening;
  2. At the time you begin your research, buy a quality, dedicated paper notebook or artist’s sketchbook and fill it with notes of your research and observations, along with hand-sketches, clippings and photographs of your research. Let it ramble. Allow time for all this to percolate in your mind. It’s fine to transcribe this notebook to digital format and store the text along with photographs on your computer or cloud, but don’t abandon the paper notebook: it’s the roadmap that traces your progress;
  3. Determine your Key Performance Criteria (“KPC,” more on this below);
  4. Make a sketch of your tool storage system on paper in pencil. Not in Sketchup or AutoCad because you don’t want it to be pretty and finished-looking too early, but rather organic and flexible. Ugly is OK too, as my mother always told me as a child (ツ). Too many people deceive themselves with perfect-looking digital drawings early in a design process; Just ask any architect or commercial contractor over 60 years old and they will confirm what I mean;
  5. Determine internal and external dimensions, adding numbers;
  6. Rework the drawing until it meets your KPC, or rework your KPC to match reality. Perhaps a cardboard mock-up will be helpful if you have difficulty converting lines on paper into a 3-D image in your mind, as many do (this is a skill that can be learned and is worth developing, BTW, and mock-ups can help, a lot);
  7. Get the opinions of independent third parties you trust;
  8. Repeat steps 6 and 7 until you are satisfied allowing time between each iteration for your brain and eyes to reset. Perfection is unattainable;
  9. Make a final drawing by hand or in digital format. Perfection is unattainable;
  10. Buy wood and hardware and start making sawdust. Don’t worry about getting it wrong, just get it made. Perfection is unattainable.

Don’t give a thought to appearance until after Step 7. It is human nature to focus on appearance when beginning a design, but that is counter-productive. To the contrary, a wise man will formulate his Key Performance Criteria (Step 3) long before considering the project’s appearance, because the KPC comprise the key supports in his planning framework. He can then do research and formulate possible solutions in harmony with them, and in due course after careful consideration, make the myriad necessary decisions before the onset of “design by neglect.”

If the process seems overwhelming, break it into little pieces that are not, and knock them off one-by-one.

Part of the planning process must include a thorough understanding of both historical needs and traditional solutions, but with a sharp eye to avoid past mistakes, while at the same time seeking solutions that meet your specific needs instead of the traditional needs of others. Monkey see monkey do may work for monkeyshines, but it is a piss-poor plan for bespoke casework, in other words.

How do I know this process works? I learned it from world-class architects. Spend a few million dollars of other people’s money on architects and designers over 30 years and you too will be convinced. But don’t take my word for it, look at history: the process described above is older than the pyramids of Giza; It helps you think; It makes you think. If you do it, your design capabilities will dramatically improve.

Key Performance Criteria

The following are some of the Key Performance Criteria I developed when designing the toolchest in question. If you are thinking about making a tool storage system, be it cabinet, toolchest, or pegboard, you will need similar criteria, whether you realize it now or not. Please observe that most of the items in the list below do not describe how the toolchest will look but rather what it must accomplish, so function dictates form. Notice also that, while it includes no dimensions other than the designation of the longest handsaws, it could well include actual overall dimensions, but those can be determined later.

  1. Internal Dimensions: Long enough to house a self-contained sawtill with several 26” Disston No.12 handsaw inside along with other essential hand-powered woodworking tools (no powertools), and as wide as practically possible;
  2. External Dimensions: Narrow and short enough to fit through Asian residential doors and up narrow stairways;
  3. Depth Dimension: Deep enough to contain three sliding trays in the upper portion of the interior, all dimensioned to accommodate specific tools, and two chisel boxes stacked on top of each other in the lower portion below the sliding tills (the “dungeon”). And not so deep one can’t easily reach to the farthest, deepest corners without having a 14 year-old girl’s flexible joints;
  4. Tool Access: Tools used frequently to be quick to locate and easy to remove and replace without bending, kneeling, or shifting trays around;
  5. Durability: Tough enough to survive international moves, and loading and unloading from trucks, ships, and containers by drunk, one-eyed tweakers using malevolent Cyberdyne Systems forklifts and predacious pallet jacks without being punctured, racked, or spilling the contents. Short-term toughness and strength, in other words.
  6. Longevity: Must last for many generations of constant use (minimum 200 years) in indoor situations without experiencing warping, structural degradation, rust, rot, or damage from insects and vermin. This criteria depends on the durability criteria listed above, but instead of just surviving short-term knocks and dings, it includes surviving long-term damage from within due to design failures and/or long-term infestation;
  7. Sealing, Insulation & Security: Seal tightly in all temperatures and humidity without the lid racking, warping, gaping, cracking, or binding, and while protecting the contents from temperature swings, condensation, dust, bugs, rats, sticky-fingered pixies, and Darwinian shrinkage (pilfering);
  8. Portability: Light enough to be carried up stairs by two men when empty. Easily moved over flat surfaces by one man with a full complement of tools inside;
  9. Tie-down and Lifting: Can be secured to the walls or floor of a shipping container or moving truck, and lifted by crane quickly and easily and without employing complicated rigging or straps touching the wooden surfaces (straps and ropes tear things up); 
  10. Appearance: Attractive and workmanlike in appearance with some subtle decorative details. No inlay or extravagances.

When planning your tool storage system, you will either develop your own key performance criteria, or fall into the trap of “Design by Default.” Hopefully you will avoid the smelly pit of SDNS.

The criteria you decide on will be different from mine, but similar, just as your tools are different from mine but similar. However, I hasten to add that it would be a mistake to design a toolchest solely around the tools you own and use right now since those tools will change over the years. As someone who has plenty of “planning experience” (also read “made lots of mistakes”) I assure you that “Future-proofing,” meaning to provide “flexibility” and “adaptability” to deal with future changes in the tools you will store and the way you will use them, is always superior to an inflexible storage plan. For instance, while it is necessary to design rigid provisions for tools stored inside the lid to keep them from falling out, in most cases French-fitted trays are not an efficient long-term solution IMO.

While I have tremendous respect for successful ancient designs, the concept of imitating traditional details and features just for the sake of “historical correctness” was never a consideration for me because, like outhouses, straw roofs, blood-letting and ducking stools, some modern alternatives are superior to tradition.

German postcard depicting a ducking-stool being used to punish a baker accused of making his loaves too small. Would that such public persuasion could be dealt to every politician caught lying or public employee that takes bribes. I think the world’s lakes and rivers would overflow with ducking chairs greatly improving society.

In the next post in this series we will examine the durability and longevity criteria and the solutions I employed. We will also take a stab at the other criteria listed above in future posts.

YMHOS

Other Posts in this Series:

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information. Promise.

Safety Rules & Habits for Edged Handtools

The chisels, knives, and planes we sell are all hand-forged by ancient smiths. There may or may not be dwarvish ancestry in one or two cases, but without exception our blacksmiths make blades with unsurpassed crystalline structure that cut like Satan’s scalping knife.

The Psychology of Steel

It’s important for those of use who use such sharp handtools to understand how they think. Allow me to put on my metallurgical psychologist’s hat for just a moment to expound. FYI this hat is a highly-polished brass skullcap engraved with runes of power and decorated with multiple rings of tiny silver bells suspended from stubby brass rods attached to the cap. The bells make a very pleasant tinkling sound. Much glitzier but more dignified than the aluminum foil cap with projecting curly copper wires I use to protect my mind from the brain-rays of alien used-car salesmen. But I digress.

High-quality blades are especially single-minded and simply live to cut wood. If you don’t believe me, just ask them. You will hear the chirping and tapping sounds they make when they are happy, if you listen carefully. And the shavings and chips that fly from their milky silver edges will attest to the fun they are having. They love cutting wood best of all, but the problem is they will try their darndest to cut anything they can latch onto. It’s just their nature; something we must understand if we are to prevent the servant from becoming the bloody master in the blink of the eye.

First Real Injury © 2007 Sauer & Steiner

Safety Rules vs. Safely Habits

Everywhere we look nowadays there are rules and busybodies busily enforcing them. They don’t call it the “nanny state” for nuttin. Safety rules can be helpful but don’t do us any real good unless we we eventually turn them into those unconscious actions commonly called habits. Like never pointing the barrel of a rifle at anyone anytime even by accident, or putting on the car’s brakes before the vehicle crashes through the storefront, the potential consequences are just too severe to leave them as empty rules.

I don’t want to sound like a nanny, but as someone who has made one, perhaps even two stupid mistakes in his lifetime, I would be derelict in my duty if I did not point out one rule and a few wise safety habits worth developing especially to those of our Beloved Customers that purchase our chisels and knives and want to continue to have more than just an emotional attachment to their fingers, hands, toes and feet.

The Big Safety Rule: Don’t Let Them Bite You

The most important cutting-tool safety rule you need to follow is: Don’t let them bite you!

Sharp wide blades can sever a lot of nerves and tendons in the blink of an eye. A deep injury won’t even be painful if your blades are sharp, at least at first, but the damage may be impossible to repair fully and too often is life-changing, and never in a good way. So the application of this rule is simply don’t give cutting tools an opportunity to do mischief.

Safety Habit One: Never Cut Towards Yourself or Anyone Else.

OK, now that the big safety rule is on the table, let’s break it down into three basic safety habits. First, never ever ever never cut towards yourself or anyone else.

An example. A universal mistake everyone, without exception, makes at least once is to hold down a piece of wood with the left hand while cutting it with a chisel or knife motivated by the right hand towards the hand holding down the wood (in the case of right-handed people). They slip, or the chisel or knife jumps out of the cut, or the chisel or knife is dull and they lose control, or they apply too much force, or don’t allow enough distance to slow the tool down after the cut should end. Whatever the cause, in the next instant the wood quickly changes a pretty crimson color, and the left hand feels strange. So please, never ever ever never allow your hands to get in this situation. Assume I’ve now yelled this warning into your ears 50 times and hit you with a wooden mallet with each cockroach-killing screech to make the lesson sink in. It’s that important.

Safety Habit Two: Reject All Distractions While You Have a Cutting Tool in Your Hand


Another common mistake everyone makes from time to time is to allow a distraction to control us while holding a chisel or knife. For instance, trying to juggle a can of beer and a chisel at the same time may place your nose or eyeball at risk (alcohol is such an uplifting beverage); Or scrambling to answer a cell phone call without setting the chisel down first may result in the sudden appearance of an inconveniently leaking red nick in your neck that doesn’t quite compliment the fashion statement being made by your hand-embroidered woodworking robes.

Case in point: Many moons ago before my beard turned white I was cutting mortises using a sharp chisel at my workbench, using the time-honored butt clamp, of course, when a yellow-jacket wasp (of which I have an uncontrollable phobia ever since a frantic encounter as a small child with a hornet’s nest in Grandma’s attic), landed on my leg. In a blind panic I swiped the wasp off my left thigh with my left hand, which by total coincidence was also holding the chisel. 40 years later I still have that big unsightly scar that ended my promising career as a bikini model before it really got started, robbing the world of great beauty (ツ)。


Professional woodcarvers all know somebody with deep, crippling injuries to nerves and tendons in hands or legs from using carving tools improperly or while distracted. Not a few have lost whole hands. The wise ones wear kevlar or steel mesh gloves when they must secure work with a hand while using chisels or knives. While I don’t condone it, professional woodcarvers must sometimes violate the rules just to get the job done. These safety gloves are good for preventing slicing cuts, and help to reduce the severity of injuries in all cases, but may not stop a knife or chisel from stabbing you if it is motivated, so please don’t violate the first rule just because you’re wearing fancy gloves.

The solution? Set your knives and chisels aside in a safe manner and location before you do anything other than cutting wood. In other words, have the self control and situational awareness to reject all distractions.

Oh yea, and please don’t drink and drive chisels.

Safety Habit Three: Always Set Your Tools Aside in a Safe Place and So They Can’t Move

This final safety habit is related to number three in that distraction often causes us to violate it. In this case the hazard is a chisel or knife falling from a work surface, at which point Murphy rolls up his sleeves, licks his eyeball with his long purple tongue, and skillfully guides the tool cutting-edge first towards ankles, feet and toes. In Japan were work has traditionally been performed while sitting on the floor, a common problem is accidentally kicking a chisel. Of course, the chisel doesn’t appreciate such boorish behavior and will bite back.

I don’t know about you, but I don’t wear thick leather steel-toed work boots in my workshop. I prefer flip-flops or crocs without the heavy and dreadfully unfashionable steel accessories. Problem is flip-flops are not tough enough to prevent a 200gram atsunomi falling cutting-edge-first from a height of 70cm from severing a toe, so I am careful to not give Murphy the opportunity to place his bomb sight on my “little piggies.” I encourage you to always be aware of both Murphy and pernicious pixies and never put yourself at their mercy.

The solution? Be careful of where and how you set your tools down and make good practices a cast-iron habit. Don’t leave them hanging over the edge of your workbench, or balanced on top of other tools where a bump from a strolling bench kitty or vibration from a hammer impact might knock them off. If you have several chisels or knives on your workbench at the same time, use a chisel box. Another effective solution is to make a tool rest by cutting some notches in a stick of wood, place it in a safe location on your work surface and rest the tool’s blades in those notches to keep them organized, to protect their cutting edges from dings, and most importantly, to prevent perfidious pixies from pushing or rolling tools off your workbench and Murphy from dive-bombing your wiggly pigglys. This is especially important if children have access to your workplace or you have a bench cat swanning around demanding snacks and ear-rubs.

How to Develop Good Safety Habits

Everything we have discussed so far is only hot air and electrons unless you manage to actually ingrain wise safety habits into your soul. I don’t know how it works for you, but the steps below is how it works for me. Perhaps it will help you develop good, automatic safety habits.

Step 1: When you have an accident (and you will), stop working and figure out how it happened, and what you could have done to avoid it. Hopefully it won’t be while waiting for X-ray results after an iron worker drops a bunch of steel decking cutoffs on you from 14 stories above.

Step 2: Every time you find yourself in a similar situation, stop and think if it is possible the same bloody thing could possibly happen again, and what you need to do differently. For instance, figuring out a clamping arrangement that keeps your left hand out of the path of travel of a bloodthirsty paring chisel is something worth taking a few seconds to do.

Step 3: Remember the pain and embarrassment of the original accident to help you make the process of thinking through potential ouchy incidents, and then using the solutions you developed automatic. In this way a good habit is born. This process may not work for you, but it does for many.

I can also share a bit of superstition with you. Everyone nicks themselves occasionally when using sharp tools. I know I do. When this happens, I place a tiny smudge of the red stuff on the tool that bit me, and on any other cutting tools that have yet to nick me, and let it dry. I’m pretty sure this quashes their curiosity about how I taste in advance. At least I think that’s what they tell me when I am wearing my metallurgical psychologist’s hat (ツ)。

There is one thing I can promise: you will find a severed tendon or damaged nerves in a hand or foot to be more than just inconvenient. And if, like me, fashion is your life, scars may tragically preclude your picture from ever appearing in the Swimsuit Issue of Sports Illustrated. Such a loss!

Be careful. Develop good habits and make them automatic. Don’t let your tools bite you or anyone else, even if they beg with those big puppy-dog eyes.


YMHOS

The Japanese Gennou & Handle Part 6 – The Ergonomic Anaya 穴屋

Don’t force it, get a bigger hammer

Arthur Bloch

The handle that is the focus of this series of posts is an interpretation of the gennou handle developed over several centuries by the anaya carpenters of Japan. In this post I would like to touch on some of their history and the ergonomic factors that drove their subtle innovations.

Historical Background

The word Anaya (穴屋) translates to “hole maker,” a type of carpenter that was common in Japan before the general availability of portable electrical mortisers. These craftsmen had their own guilds in major urban areas and specialized in cutting mortises in beams and columns for wooden structures. They didn’t do layout. They didn’t dimension timbers. They didn’t saw tenons. They didn’t do assembly or erection. Their only tools were the chisels and hammers they used from sunrise to sunset to cut mortises as quickly and accurately as they could.

Anaya did piecework, meaning they were paid according to the number of mortises they completed each day, not by the job or an hourly rate. Each individual Anaya was in direct competition with his fellows for speed and efficiency, so they were serious about the performance of their tools.

Consistent with the Japanese obsession with constantly making minor improvements to their tools, Anaya were forever asking blacksmiths to make them custom chisels and hammer heads reflecting their latest opinions. There are records of more than one chisel blacksmith, including the famous Chiyozuru Korehide, refusing to make chisels for Anaya because of their persistent, obsessive demands.

The gentleman that taught me how to make gennou handles 30 something years ago is now in his late 90’s. He was a young man back when the anaya trade in Tokyo was still burgeoning, and he learned from the best in the business. 

Ergonomic Factors

Following are four ergonomic principles related to hammers in general and gennou in particular you should keep in mind when planning your handle. These principles are applicable to not just Japanese gennou, but to all varieties of hammers swung with a single hand. You need to understand them before you design your gennou handle.

  1. Handle Length: Every person’s combination of bones, tendons, muscles and work habits is different. Therefore one size of handle does not fit all; There is a handle length that best fits your body, the way you work, and the type of work you do.  
  1. The Grip: For the reasons stated in No.1 above, one grip style does not fit all; There is a handle shape with dimensions that best fits your body, the way you work, and the type of work you do. 
  1. The Knuckles: The human body operates a hammer or gennou most effectively when the plane of the head’s striking face at the instant of impact is oriented in line with the surface of the finger knuckles of the hand holding the hammer. 
  1. Head Angle: When swinging a hammer, the hand naturally moves ahead of the hammer’s striking face. Therefore, instead of being in line with the arc of the swing, the head’s centerline will typically end up cocked out and away from the arc of the swing, assuming the handle is straight and hung (installed) with its centerline perpendicular to the head’s centerline. As a result:
    1. The hammer’s face is unlikely to strike the nail or chisel squarely; 
    2. The center of mass of the head will most likely not be in alignment with the intended axis of travel of the nail or chisel on impact; 
    3. The nail or chisel will therefore be kicked out of the desired axis of travel; 
    4. Precision will suffer, and;
    5. Time and energy will be wasted.

Before you design your handle, I highly recommend you thoroughly understand these four essential principles. If you doubt their validity, investigate them yourself. Google will not suffice. There are a couple of tests described in Part 13 of this series you can perform to verify them. In the meantime, here is a homework assignment: Figure out a way to determine if your hammer’s face is striking the handle of your chisel squarely, or if it is cocked. Let me know your conclusions in the comments below.

The positive impact of incorporating these ergonomic principles into your handle design, as well as the negative impacts of ignoring them, can make a big difference in your performance and work efficiency. In future posts we will show you how to deal with these ergonomic factors to design and make a gennou handle perfectly suited to your body and the way you work.

But before our tumble ass-over-teakettle down this particular rabbit hole loses every semblance of dignity, in the next post in this series we need to examine a critical but oft-ignored part of any hammer : The Unblinking Eye.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions 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 or incompetent facebook and so won’t sell, share, or profitably “misplace” your information. Promise.

Previous Posts in The Japanese Gennou & Handle Series

Part 1 – Introduction

Part 2 – Ergonomics

Part 3 – What is a Gennou?

Part 4 – The Varieties of Gennou: Kataguchi, Ryoguchi & Daruma

Part 5 – Kigoroshi

The Japanese Floor Workbench (Atedai 当て台) by Dominic Campbell – Part 1

The Shokunin’s art is difficult, if not impossible, to separate from his work space, his tools and his equipment. The craft is not apart from his life so much as it is a heightened detail of life.”

Toshio Odate
My workspace, and newly finished workbench. Credit: D. Campbell

Foreward

Today’s article is a guest post by Mr. Dominic Campbell, a friend and deeply Beloved Customer residing in Old Blighty who, when he needed a workbench, decided to make a traditional Japanese atedai, a solution I too am very fond of, even if my knees aren’t anymore.

This is the first in a two part series about his atedai Dom was kind enough to share with us. This first part is about the design and construction of the atedai in question. The second part will be about how to use this excellent tool. Enjoy!

Stan Covington

Introduction 

I began woodworking, I guess, like a lot of the readers of this blog, with some hand-me-down western tools, and a pair of cheap, flimsy, store-bought sawhorses. A lack of space, the inclement British weather and my lack of any form of work holding made sawing and other simple tasks difficult and frustrating.

I then stumbled across a video of a Japanese craftsman working in a very similar manner, yet with far superior results… I had to know what this guy knew. While reading, practicing, and absorbing as much information as I could ( some would say falling down the Japanese woodworking rabbit hole), my work developed, and I built up my skills to a point where I felt the need for a dedicated workbench. Using Japanese tools for 95% of my work, I have found they work best as part of a system, and so decided on a Japanese floor workbench AKA an Atedai (/ah/teh/dai 当て台). This kind of workbench lends itself to a very flexible workspace. It can be adapted to use standing up, and easily stored out of the way conserving space when necessary, an important part of the Japanese tradition.

Much of my own work is kurimono (刳物), or carving from solid blocks of wood, as well as a bit of sashimono casework (指物) and tategu joinery work (建具), including kumiko-zaiku (組子細工). I tried to make one bench that would work for all of these specialties, but with an emphasis on the heavy chisel work needed in kurimono. 

The first trays, called Wagatabon (我谷盆), I made with my new workbench. All carved from solid blocks of walnut. Credit: D. Campbell

After keeping Stan up to date with my progress on the workbench build, and showing him what his tools had been up to, he asked if I wanted to share my thoughts on this style of workbench.

And so, in this mini-series, I hope to show you, Gentle Reader, a method of working, and work holding that may, or may not, be of immediate practical use to you, but that is interesting, and provides some food for thought, nonetheless.

Atedai Construction

Before we look at how to use an Atedai, we first need to build one, and although the construction of the Atedai is simple at first glance, there are a few important considerations and details to keep in mind.

It must also be said here that all workbenches are as varied as the people that use them, and this is no different for the Atedai. The type of work you do, the materials you work with, the training received, how tall you are, how you intend to use it… the list is endless…will all dictate your bench’s dimensions, design details and final appearance. It is not uncommon for craftsmen to have several atedai on-hand depending on the task undertaken. In this post I will focus on just a single way to get the job done.

A craftsman caressing his atedai’s top. This picture was taken by his wife who wished he would give her as much attention. But what would she say if he beat on her with a hammer? Be careful what you wish for. (SRC)

The Work Surface

The work surface is the heart of any workbench, and it is no different here. We mostly have the same considerations too: single slab, or laminated? What species of wood? How long? How wide? How thick? What height? Will it be flat or angled? There are no right or wrong answers, within reason, and is often a case, the final selection will depend on what you can get hold of, what you like, and the type of work that you do (you can start to see why craftsmen often have a number of benches in their workshops – they are easy enough to make, and store easily out of the way, taking little space, so why not?).

My own bench top is a 57″ x 17″ x 3.5″ sycamore slab (and 7″ high with the legs in). This is quite long for the work I do, but it gives the bench good weight/inertia, and is useful for the occasional long beam I have to work. It was not, however, easy to get flat, nor is it easy to keep dead flat along its entire length and width. You pays your money and you takes your chances…

An old beechwood atedai (SRC)

Four laminated atedai in a woodworking classroom stacked off to the side. Notice they are stacked on their left edges and not their right. This is because the right edge is used for shooting and must be kept clean and free of grit. (SRC)

A Few Observations

There are a number of possible answers to the questions posed in the previous section, and so I thought it would be useful to briefly explain my thoughts behind the selection and preparation of my work surface in order to give some insight into the kinds of questions you should be thinking of.

With regard to construction, you have to weigh up the pros and cons of each approach, and make a decision that works for you. A laminated top will tend to be a bit more stable, whereas a solid top could be liable to warping a bit more. A solid slab is a bit more traditional, can be made to move a bit less through certain techniques (as we’ll see below), and is quick and easy to put together – i.e. you buy it, and apart from surface prep, the top is basically done. That said, big slabs can be harder to find (depending on where you are), and can be expensive. I actually found it easier to find a slab, than it was to find smaller stock of the same woods…. most lumber yards near me won’t give small orders the time of day… it was either construction pine, or a big hardwood slab. I hope you have better options!

In terms of wood choice, most woods commonly used to make workbenches will work fine. Too soft and the atedai will be easily damaged, but too hard and the atedai may damage your work (especially if using softer woods), and become slippery. Woods with contrasting hardness between winter/summer growth like douglas fir can work, but problems can arise especially if you shoot a lot on the surface, as the winter wood and summer wood can wear down at different rates leaving ridges. I went with Sycamore (Acer pseudoplatanus – actually a kind of maple) as it has a fine grain, is medium hardness, and I could get hold of it in the right dimensions for less than £100… all important considerations!

To make sure my top was as acclimatized as possible, I left it for about 5-6 months in the workshop where it will be used (it was air dry when I bought it, but I don’t know for how long). My shop is an unheated 1 car garage, and not climate controlled (I use a small dehumidifier, however), so I expect some movement. That said, I wanted to give it the best chance of settling in before I started flattening the top, and doing the joinery for the stops and legs.

When I got hold of the slab, it had quite a bit of cup and twist – one potential downside of using big slabs – and it took some hard yards to make it flat and twist free. I left the underside untouched as much as possible – to retain as much weight as I could in the bench – planing only where the legs would go, plus a bit on either side. Preparing a big slab, unless you have an industrial sized planer, is a hand tool job, so prepare yourself for a work out.

The sides of my bench are 90° to the top, with special attention placed on the right hand side when sitting at the working end. This is traditional with atedai because the user indexes a plane vertically against the right hand edge of the top to quickly shoot the edge of boards to 90° , although I prefer to use shooting jigs to help when 100% precision is needed. You can also attach a length of wood to the right hand edge to form a support ledge for the plane when shooting.

As you can see in the pictures, this slab has a few knots scattered about, which I stabilized with CA glue, and planed flush. This has worked well so far, but if the knots come loose in the future, I will cut them out and patch them.

With regard to dimensions, the general rule of thumb is that if you work wider boards you tend to need a wider bench (although you can up to a point plane wide boards on the narrow bench, it can be hard to use the bench as a reference surface to check for twist). However, too wide is harder to keep flat, is heavy, and is more expensive. 

Too short a bench makes it harder, if not impossible, to plane longer stock. But again, too long is heavy, expensive, and harder to keep flat (can you see a trend here?). It is also impractical, unless you are Stretch Armstrong, as you can only plane as far as you can reach while sitting or kneeling. That said, you can (as you will see in Part 2) put a floor bench on saw horses (or your normal workbench) to use standing up to increase your reach, in which case a longer bench can help cover long stock prep too.

A zabuton cushion for use while sitting on the floor (SRC)

The final question regarding dimensions is total height, a combination of top thickness plus the legs. Most people use an atedai while sitting on a zabuton cushion placed on the floor like the blue one shown in the photo above. In this case, the bench top should be low enough to hit your knee so you can stop it from sliding, but high enough that your plane will not hit your knee (ouch!) when planing or shooting down the middle of the stops. Somewhere between 4-7 inches high normally work well, with a slab thickness of between 2-4+ inches, YMMV. If in doubt, go higher – you can always reduce the height slightly later down the road.

Another consideration is perhaps unique to the Japanese atedai, namely whether or not to build the top with a slope. Some craftsmen prefer the bench to slope down towards the end they sit at for ease of planing, but I prefer a flat surface. It’s a better all-rounder, and it’s easy enough to jack up the far end temporarily if desired.

To slow down any movement, I sealed all end grain surfaces (using Osmo End Grain sealer) on the completed workbench (top, legs, and stops). All of this combined (plus dovetailing the legs, as explained below) has worked well to stabilize the top, and movement has been minimal, although it’s always worth checking before any fine joinery task… little and often is a good idea for keeping a bench flat. 

The end grain sealing is all the finish I have applied to this bench. I left the top with the planed surface in order to keep it from becoming too slick. As I don’t use a lot of glue or finishes in my work, I didn’t apply anything else to the surface, but a light coat of oil can help things from sticking too much if needed, however.

The Legs

Now back to the construction of the atedai, we come to the legs, or battens, which should be thick and solid – in my case 4×4 inch sycamore attached to the top with sliding dovetails. 

You can simply toe-nail, or similar, the legs in place if you wish, but the sliding dovetail helps to keep the board flat and is, IMHO, a much more elegant, long term, solution. It is not uncommon in Japan for these benches to be passed down from master to apprentice, so I built mine too with longevity in mind. Sliding dovetails can also help knock the bench down for storage or transport, if that is something that you will need.

This bench was made entirely with hand tools. The double tapered sliding dovetail is hard to achieve using machines. Credit: D. Campbell (tools by C&S Tools)

After talking to Stan, I went with a double tapered sliding dovetail, which helps the legs fit extremely tightly (while also being much easier to slide in place), and helps resist humidity fluctuations, bangs and vibrations better than a standard tapered sliding dovetail – all important advantages for a workbench. 

The double taper in this case refers to a taper not just in the width of the dovetail (as is normal), but also in the height of the groove along its length, with the leg tapered to match. This connection can be achieved in any number of ways, in my case with plane and kotenomi. The tapers on my bench were around 1cm in width, across the board, and 0.5cm in height – this still made for a pretty tight fit. 

My legs right now are just a bit proud of the edge of the top while it settles in, so I can knock them in further later if needed. Their slight projection doesn’t interfere with shooting with a top that is 3+ inches thick however, so they aren’t causing any headaches being a little proud…

The Kote Nomi, or Trowel Chisel, excels at this work and is a joy to use. Credit: D. Campbell

As a final touch on the legs, to give the bench the most stable footing possible, it is wise to relieve the middle of the legs slightly – just enough to keep it clear of the floor. Also, some thin rubber, cork, or in my case, part of an old chisel roll, help to prevent the bench from sliding around. You don’t want to use anything too thick however, as that will absorb too much shock, reducing the efficiency of your hammer blows when chiseling.

A view of the underside of the atedai showing one leg tightly inserted in a self-locking double-tapered dovetail. The legs are slightly relieved in the centre to prevent high-centreing on uneven surfaces. Non-slip feet are optional – just don’t make them too thick. You can see where I have left the underside rough-sawn to retain as much weight as possible. Credit: D. Campbell

The Stop(s)

The work you do will determine what kind of stops you need. Sashimono-shi tend to use much thinner stops, while those using the bench for kurimono, or hollowing work, will often (but not always) use more substantial stops to stand up to the forces involved, often with just one stop across the entire width of the board. Again, it’s horses for courses.

Back then, to our good old friend the sliding dovetail. In my case for the stops, I used a regular stopped sliding dovetail. I didn’t taper the stops at all, as I wanted to make sure they stay in place firmly – a sideways knock on a tapered stop will send it flying too easily for my liking.

Completed stops. You will get plenty of sliding dovetail practice while making an Atedai. Credit: D. Campbell

My stops are quite substantial, much bigger than I have seen sashimono-shi use, but stop short of a full width stop, in order to leave room for morticing longer stock (see part 2, coming soon, for the venerable bum clamp), as well as a gap for shooting. If you decide to make your own atedai, you will need to consider what work you will use it for, and plan your stops accordingly.

One useful feature of the stops is that being dovetailed, you can make several and interchange them, or remove them completely, depending on what you are doing. These benches really are incredibly versatile, and are completely custom to the work you do – a joy to use.

Summary

The finished Atedai, ready for action. Credit: D. Campbell

And there you have it. Four sliding dovetails and you have yourself a workbench that is ready to go to work.

I hope, in this post, to have given you some insight into how to build an atedai workbench for yourself, and some of the considerations you must think about if you do. They are simple benches, but there are a few important considerations to think about before you decide to make one. If you have any questions, just leave a comment below, and Stan or I will do our best to help.

In Part 2 of this mini-series I will show you how you can actually go about using such a workbench, some further customizations that one can make, and some examples from other craftsmen to help inspire you – I hope you’ll join us. 

Yours in wood,

Dominic Campbell, Kent, UK