Carving a wagatabon container using an uchimaru gouge
“A good tool improves the way you work. A great tool improves the way you think.”
Jeff Duntemann
The Uchimaru Nomi is a gouge, very much like those seen in the West
The name is composed of 3 Chinese characters (kanji): 内 pronounced “uchi “which means “ inside” or “interior,” 丸 pronounced “maru” which means “round,” and 鑿 “nomi” which means chisel.
This gouge has a blade very similar in cross section to its Western counterpart, but unlike Western gouges, it is made of laminated steel, has the combined tang and ferrule construction typical of Japanese chisels, and a crown to reinforce the handle and protect it from violent hammer blows. These are strong chisels used by carpenters to carve large-scale architectural components, and sculptors.
They come in different sizes and sweeps, although not as many as the Swiss make. Some are the size of typical oiirenomi bench chisels; others are the size of the larger heavy-duty atsunomi.
As you can see, these blades are are not hollow-ground.
The relatively hard layer of steel which forms the cutting edge is often subjected to more lateral forces when carving than their straight-bladed cousins, and are sometimes damaged as a result. Professional carvers will hold the thin cutting edge over a small candle flame to reduce the hardness over a small area to reduce this tendency. Your humble serrvant is not recommending this practice, just conveying information.
The technique used for sharpening Japanese gouges is identical to their Western counterparts. To sharpen the outside bevel, typically one will use dedicated sharpening stones with grooves worn into them that are slightly greater than or equal to the radius of the gouge. One removes the burr and polishes the inside curve by using a short stone with a radiused edge.
A piece of leather charged with polishing compound can be used to put a final polish to the bevel. One can also bend this piece of leather to polish the gouge’s inside surface. Easy peezy.
Standard sizes are 9mm, 12mm, 15mm, 18mm, 24mm, 30mm, 36mm, and 42mm.
There are also uchimaru gouges made as paring chisels, with longer blades and handles, slimmer necks, and without crowns.
If you need a gouge that that can hog a lot of wood, will take an exceptionally sharp edge and will maintain it a long time, then this is a tool you should consider.
In the next post, we will look at a different type of gouge, one you may not have seen before.
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. May I gag on a hairball if I lie.
“Along with the milk of my nurse I received the knack of handling chisel and hammer, with which I make my figures.”
Michelangelo
In a previous post, we looked at various types of oiirenomi (bench chisels) and mortise chisels. In this post we will examine a type of tatakinomi called the “Atsunomi.”
DESCRIPTION
The ”Atsunomi, ” written 厚鑿, translates to “thick chisel.” This is the largest variety of tatakinomi readily available nowadays and is almost identical in design to its more petite oiirenomi sisters, but being larger, longer, heavier and stronger it is able to transmit and endure the impact forces of heavy hammer blows from sunup to sundown to cut a lot of wood. Indeed, I can remember times when the handles of my atsunomi in the photographs on this page became seriously hot after long hours of heavy hammer blows.
The 24mm chisel in the photograph below was the first atsunomi I owned, and has seen hard use with heavy hammers, but has held up well.
24mm Atsunomi by Kiyotada (Japanese White Oak handle)
If I can liken the bench chisel or oiirenomi to a 1/4″ cordless drill, then the atsunomi is a 9 amp 1/2″ corded drill (when combined with the right steel hammer). Serious business indeed.
APPLICATIONS
The atsunomi is ideal for heavy work such as timber framing and wasting large amounts of wood quickly. However, carpenters are not the only trade to use them. Many professional craftsmen in Japan, even those that never work on construction sites, prefer to use atsunomi even for delicate work because of their relatively longer blades, greater durability, and cost-effectiveness.
Because of its greater size and weight, the atsunomi is not as nimble as the smaller varieties of tataki nomi and demands the user to have greater strength and skill. But on the other hand, it’s very stable in the cut, and wastes wood with impressive gravitas.
A comparison of a 42mm oiirenomi (top) and a 54mm atsunomi (bottom) by Kiyotada. The atsunomi is longer, thicker and stronger in every way.
As with all tataki nomi, the handle is big enough to use with one hand, but not two. Atsunomi always have a mild steel katsura crown installed at the end of the handle to reinforce it and prevent it from splitting under hammer blows.
Standard widths for atsunomi are: 12㎜, 15㎜, 18㎜, 21㎜, 24㎜, 30㎜, 36㎜, 42㎜, 48㎜, 54㎜.
There are several varieties of atsunomi, some with very wide blades and others with very long necks, but I will not go into that level of detail in this post.
In Part 9 of this saga of romance and derring-do, we will examine the Uchimaru Nomi.
YMHOS
48mm Sukemaru atsunomi w/ Japanese white oak handle. A serious tool for serious work
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone using the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie, may all my chisel’s uras dissapear.
“You can complain because roses have thorns, or you can rejoice because thorns have roses.”
Tom Wilson
Nihon Mukomachinomi. Definitely in the Miki City style
This tool is a specialty mortise chisel with two blades for cutting twin mortises at the same time. It was developed specifically for cutting mortise joints in wooden stiles and rails for doors, shoji, cabinets and other joinery.
DESCRIPTION
Interestingly, double or twin tenons are not called ” nihon hozo” (hozo means ” tenon”) but “ nimai hozo “ (二枚ほぞ) with “ni “ meaning 2. In this case the number is combined with the counter “mai “ used to count flat things like a sheet of paper or tenons. Japanese is almost as messy as English… Your humble servant blames those pesky Buddhist priests for the complications involved in reading and writing Japanese, but I’m not sure who to blame for English.
The name is a variation of the name of the standard mortise chisel ” mukomachi nomi” in my previous post, and no, I still don’t know what it has to do with ” waiting over there.” In front of this is added ”nihon” (二本) with ” ni” meaning ”2” and ” hon” being a counter for longish things, like pencils or trees, or in this case, blades. The word is pronounced ” knee hone.”
Allow me to wander off the path a bit and talk about the Japanese language since you might find a few details interesting. If you don’t feel international today, please feel free to jump over the next few paragraphs.
The nation of Japan is called “Nihon” or “Nippon “ in the Japanese language and is written with the two characters “Ni “ 日 and ”Hon” 本 sometimes pronounced “pon.” Yes, the same pronunciation and one of the same characters used in nihon mukomachi nomi. Besides being a counter for pencils and trees and longish things, it also means ” book” and ” source. ” The word for the nation of Japan means “The source of the sun,” a jab by the Japanese at an arrogant Chinese emporer some millenia ago.
Spoken Japanese is not that difficult for English speakers to figure out, but the reading and writing are crazy difficult because of the vast quantity of Kanji, the multiple pronunciations possible for most of them, and the multiple meanings attached to many.
Elementary children are required to learn 1,006 kanji characters along with the various meanings and pronunciations. In total, a minimum of 4,272 characters are used in newspapers and magazines and must be learned before graduating middle school. Most educated people in Japan can read well over 6,000 of the over 13,000 registered kanji in Japan. Universal literacy requires a lot of study and memorization at a young age. This should give you an idea why education is so highly valued in Japan.
When I was a young missionary in Japan in the 1970’s, I spent several months stationed to Ehime prefecture in rural areas of the island of Shikoku, back when many farmhouses in that locale still had thatched roofs, no glass windows, and no electricty. Many of the older residents had spent their entire lives on their little farms and could not read or write, and had never seen a brown-haired blue-eyed foreigner before.
But the children in these mountain villages were always excited to see a foreigner and would swarm around and ask us where we were from. My standard response to this somewhat rude but innocent question was to point down at each of my legs and count them saying ”One leg, two legs. I’m a Nihonjin.” The “nihon” I was was jokingly referring to was the same as the mortise chisel which is the subject of this post, not Japanese Nationality which is pronounced identically.
Now you know a stupid pun in Japanese, so never say you didn’t get your money’s worth at this blog!
The twin-blade mortise chisel is exceptionally difficult to make, and even new ones require the owner to perform a significant amount of tuning to convince them to perform well. They have never been common, and I am not aware of anyone forging them now.
APPLICATIONS
The twin tenons this chisel specializes in cutting are almost twice as strong as a larger single tenon, and are the preferred joint for high-stress wooden connections worldwide, especially joints in doors and windows. If you haven’t tried them before, you should. They look pretty cool as through tenons too.
Twin tenons have three advantages that justify the extra work. First, while they may have the same or even less cross-sectional area, they have more surface area than a single tenon in the same space, creating greater friction when assembled, if properly cut, creating a joint that is much more likely to stay assembled when stressed.
Second, this larger surface area also means a larger glue area, a big advantage with the right glue.
And finally, twin tenons are much more resistant to twisting, an huge advantage for highly stressed joints in operable doors and windows. This is their biggest advantage and is nothing to sneeze at. If you want a door to last, always use twin tenons, at least at the bottom rail.
Sokozarai chisel used to clean and shave the bottom of mortises
I purchased one of these chisels many years ago. They are difficult to tune. But even after all that work, the gentleman I learned tategu work from many years ago was not impressed with my clever tool insisting that a regular mortise chisel does a better job. There is an obscure structural reason why this makes sense, which I will not delve into here, but I did not ask Mr. Honda at the time for an explanation because it would have been improper to question a master who had been a professional joiner at his level for 60 years.
I can’t get these chisels made anymore, and know of no blacksmith that makes them nowadays. The time is not far away when handmade tools will not be available except as collectors items.
YMHOS
If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my mortise chisel split asunder!
Japanese mortise chisels are called “Mukomachi Nomi” 向待鑿. I am unsure of the origin of the name, but the Chinese characters can be read as meaning “wait over there.” A curious name, it may refer to the shape of the transition from blade to neck, called a “machi” which is unique in Japanese chisels. Your humble servant will simply call them “mortise chisels.”
DESCRIPTION
12mm Mortise Chisel – Sukezane (Ura View)
Mortise chisels are single-purpose tools for cutting rectangular holes in wood for mortise and tenon joints, the oldest recorded wood joint known.
Unlike other Japanese chisels, and even Western mortise chisels, the sides of the Japanese mortise chisel are shaped square to the “flat” instead of being angled slightly less than 90 degrees. The surfaces of the sides are of course straight along their length, but are either flat or slightly hollow across their width.
Other varieties of chisels have sides angled inwards to prevent the chisel from binding in the cut. This is less than ideal, however, when cutting small mortises because it allows the chisel to twist inside the mortise scoring the sides and reducing precision. The Japanese philosophy is that the blade’s sides should shave and clean the mortise at the same time it is cutting it so the sides don’t require additional cleanup with a paring chisel. Its a matter of precision and efficiency.
The straight flat sides of the mortise chisel have a relatively larger surface area that can create a lot of friction in the cut making extraction difficult in some cases, so the standard maximum width is 15mm.
Many advocate using double bevel cutting edges for Western mortise chisels. I have no problem with double bevels for atsunomi used to cut wide, deep mortises because the double bevel tends to kick more waste out of the mortise hole than a single flat bevel, although double bevels are more trouble to sharpen. But in the case of the standard Japanese mortise chisel, I recommend using a simple flat bevel for two reasons:
The first reason is that, since sharpness is critical for precise work, and a flat bevel is quicker and easier to sharpen, a flat bevel is more precise.
The second reason is that a flat bevel tends to stabilize the chisel in the cut more than a double bevel blade can, keeping it from twisting out of alignment and gouging the sides.
The mortise chisel is a specialist chisel for joinery, cabinetmaking and furniture work. It is not generally used by carpenters. Craftsmen that routinely use mortise chisels work to much tighter tolerances than most woodworkers, so a professional-grade mortise chisel must be forged and shaped to tighter tolerances than other chisels.
I only have one blacksmith with the skills and attention to detail required to make mortise chisels to my specifications. He thinks I’m a prissy pink princess. I think he’s a stubborn old fart. We’re like an old married couple（ツ).
If you need to cut lots of precise mortise holes quickly, then this tool will definitely improve your results and increase your satisfaction. It may not be the most handsome chisel in your toolchest, but you will come to rely on it more than any other for quality joinery work.
Standard widths for mortise chisels are 3mm, 4.5mm, 6mm, 7.5mm, 9mm, 12mm, and 15mm, but Sukezane won’t make 15mm mortise chisels for me anymore, dagnabit.
More than any other, mortise chisels are subtle, intelligent beasties, or at least they can be. I will talk more about what to look for in a good mortise chisel, as well as how to realize their Einstein-like focus to help you do better work, in future posts.
If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may mortise chisels all turn to rubber.
“Life is not a matter of holding good cards, but of playing a poor hand well.” – Robert Louis Stevenson
So, you finished building that fine cabinet, or 8-panel entry door, or carved balustrade and the day has come to install it at the jobsite. Will you need to cut a bit of gypboard or lath-and-plaster while installing it? Might your chisel get jammed against or into bricks or concrete in the process? Will you need to cut a notch in sandpaper-grit filled plywood or OSB? Any hidden screws or nails in the way that might require more than stern words?
Jobsite installations and remodeling often demand work everyday tools can’t accomplish without being serious damaged. At that moment, having a tool tougher than the job is the difference between working and whining. This is that tool.
DESCRIPTION
HSS oiirenomi are a modern variation of mentori oiirenomi made using high-alloy steels tougher and more resistant to abrasion and high temperatures than more traditional steels.
Sukemaru High-speed Steel Oiirenomi
These chisels are useful for doing remodeling work and cabinet and equipment installations where plywood, MDF, OSB, LVL, drywall, acoustic board, insulated board, plaster, mortar, underlayment and studs full of hidden nails, and even ALC (autoclaved lightweight concrete) panels need to be cut, trimmed, fitted or demolished. Demolition…Oh joy (not).
What is High-speed Steel?
So just what is high-speed steel (HSS), and why bother with it?
HSS is a tool steel developed for manufacturing commercial cutters, dies, etc. In this case, Usui-san uses a high-speed steel designated SKH51 in Japan, the equivalent to M2 in the USA, BM2 in the UK, HS6-5-2 in Germany, and Z85WDCV06-05-04-02 in France. This is the most popular HSS in the world. If you own router bits without carbide cutters, and not made in China, you own this steel.
This variety of HSS contains buckets-full of tungsten, molybdenum, chrome, with a stout vanadium chaser.
After oven heat-treat, these chemicals make the steel tougher, more abrasion-resistant, and more resistant to softening (aka “temper-loss”) when subjected to high-temperatures than regular high-carbon steel. Its nickname of high-speed steel comes from the tendency of cutters made from this steel to retain their hardness even when worked so hard blade temperatures become hot enough to draw the temper of standard steel cutters, softening and making them useless.
The chemical composition is listed below, just in case you are interested. You can see what I mean about buckets.
C
MN
Si
Cr
W
Mo
V
0.85%
0.28%
0.30%
4.15%
6.15%
5.00%
1.85%
Chemical composition of SKH51/M2 High-speed steel
Why Use HSS?
The next question arising in Gentle Reader’s exquisitely perceptive mind, no doubt, is “what are the properties of high-speed steel and what difficulties can a chisel made from this special steel help me overcome?” Let’s answer these questions below.
Toughness and Shock Resistance
Perhaps the most significant property of high-speed steel is its toughness. SKH51 (M2) steel is the most shock-resistant of the high-speed steels, making it especially suitable for use in a chisel that may impact hard objects in daily use but must survive without chipping or breaking. This toughness provides huge benefits in the situations described further below.
Abrasion Resistance
Abrasion resistance goes hand-in-hand with toughness, but it is a different characteristic many misunderstand. It does not mean a cutting edge will be sharper than a cutter made of high-carbon steel, only that it won’t wear and become dramatically rounded-over as quickly. In the case of chisels, a blade made from highly abrasion-resistant tool steel will reach a certain level of sharpness (or dullness) and remain at that level a relatively long time allowing a cutter to keep on cutting without becoming useless. But the quality of the cut will decrease, the blade’s ability to cleanly cut weaker woods, and the energy necessary to motivate the blade will of course increase as the blade gradually dulls.
Abrasion resistance is not typically considered overly important in blades where great sharpness is given priority, but it is extremely important when the blade is used to cut materials such as exotic hardwoods that contain silica crystals, or Engineered Wood Products that contain hard adhesives and/or highly-abrasive particles such as silicon carbide deposited by sandpaper, or dirty wood contaminated with sand and grit, contaminants that will literally destroy the cutting edge of a plain high-carbon steel blade making it useless.
Just as a strong truck with a trailer hitch would be at a hopeless disadvantage in a Formula One race, a McLaren MP4/6 with all its speed, power and agility couldn’t tow a heavy trailer 100 yards through the mountains. Horses for courses.
Engineered Wood Products
One major challenge the HSS Oiirenomi excels at overcoming is working modern wood products called Engineered Wood Products (EWP)
Commercial carpenters and cabinet makers nowadays have no choice but to use modern EWP such as plywood, MDF, HDF, OSB, LVL, glu-lams, etc.. Unlike new, clean, solid lumber cut with saws and planed with knives to final dimensions, engineered wood products are comprised of wood veneer, chipped wood and/or sawdust glued together by hard adhesives that will harm standard steel tool blades. HSS handles these difficult adhesives easily.
A bigger problem associated with EWP is the extremely hard abrasive particles left embedded in them by the sanding belts used to dimension and smooth them, particles much harder than any heat-treated steel, that will quickly destroy a good high-carbon steel chisel. Being much tougher and more abrasion resistant than high-carbon steel, HSS can handle this abrasive residue without being destroyed. That does not mean abrasive particles do not scratch and dull HSS cutting edges, it just means they won’t chip or break and will keep on cutting longer than HC steel blades.
Restoration & Remodeling Work
Velkoprevorsky PalaceVelkoprevorsky PalaceBeloved Customer Pavel cutting timber joints using his Sukemaru HSS atsunomi for the restoration of the Velkoprevorsky Palace located in Prague. Notice the tight working conditions. More photos can be found at this link.
Another type of work this HSS Oiirenomo excels at is restoration work, remodeling work, and chisel work around concrete and masonry.
In the case of restoration work, the job usually involves cutting wooden structural members and finish materials that are old and dirty and contain hard abrasive dirt, sand, small stones and of course hidden nails and screws that will not only dull a chisel blade but may badly chip it.
For instance, a Beloved Customer who is a timber-frame carpenter in the Czech Republic was tasked with splicing segments of new timber to replace rotted-out sections of a large number of 400 year-old rafters in a restoration project located in Budapest, an ancient city with many beautiful, old structures. The wood was dirty and full of gravel and broken-off nails that chowed down on standard chisels without pausing for a drop o’ Tabasco Sauce. But this Beloved Customer’s set of our HSS Atsunomi chisels (identical to the HSS Oiirenomi chisels which are the subject of this article only much bigger at 300 (12″) overall length) made it possible for him to cut and fit the timber splices while working on the steeply-slanted roof four-stories above a cobble-stone road without chipping the blade and without frequent resharpenings, as professional timber framing work frequently demands.
Being smaller in size and weight, oiirenomi are often handier than atsunomi for remodeling work and installation work, a job that requires one to cut precise holes through existing wood contaminated with abrasive dirt and hiding screws and nails, as well as lathe, plaster and drywall containing abrasive sand, and in close proximity to mortar and concrete which contains sand and gravel aggregates that will dull, chip and even destroy a standard chisel in two shakes of a lamb’s tail.
If you have ever done remodeling work or an installation that took a chisel to perform, you know the despair one feels when gazing upon the damage done to a beloved tool.
Likewise, during installations, cabinetmakers must make precision cuts in abrasive engineered wood products such as plywood, OSB and MDF. Our HSS Oiirenomi are far more durable than standard chisels with high-carbon steel blades for these jobs.
Plasy monastery by Santinii located near Pilsen, CZ, another historically-important project that benefited from Usui-san’s HSS chisels.
Jigane
The jigane Usui-san uses for his HSS Oiirenomi is a harder version of the standard low-carbon steel he uses for his other chisels. The furniture (katsura (hoop) and kuchigane (ferrule) are made from ordinary mild carbon steel, not stainless steel, despite the bright appearance, and will exhibit corrosion over time. As an option, these two parts can be ordered blackened creating a two-toned chisel some people find attractive.
Heat-treat and Hardness
To prevent chipping, the HSS blade is heat-treated in a special oven in accordance with a prescribed formula to a hardness of Rc63, intentionally a little softer than the Rc64 max hardness listed for this steel. Even then, this is harder than nearly all currently-available Western chisels we are aware of.
The blade’s bevel angle is 30°, the standard angle for Japanese woodworking chisels. You may want to increase this angle to 35° if you will be routinely cutting through hard materials to reduce denting.
Resharpening in the Field
Another huge advantage of Sukemaru’s HSS chisels is that they can be quickly resharpened to a useful cutting edge in the field using angle grinders and/or belt sanders without losing temper and softening, so long as one is careful to keep temperatures below 650°C (1200°F), not difficult to do if one pays attention. Don’t underestimate the efficiency this feature will bring to your work some days in the field. For instance, in the case of the project
The compromise with HSS chisels is that, while they can be made extremely sharp using stones and proper technique, they will never become as sharp as our hand-forged high-carbon steel chisels. Moreover, they will take twice as long to sharpen by hand using conventional wetstones and waterstones. Thus, they are not ideal for all jobs.
Sharpening time can be reduced dramatically by using aggressive diamond plates.
Before I tried my first HSS oiirenomi, I kept a couple of old plastic-handled steel-cap Stanley chisels in my toolkit as “beaters” for cutting gritty, abrasive materials. They were soft and instantly dulled, but their edges would dent instead of chipping and were easily repaired. Poor things; some days they ended up looking more like rounded-over wide-blade screwdrivers than wood chisels. HSS chisels, by comparison, are just the ticket for this kind of brutal work.
We have personally tested these chisels to failure and resharpened them, and therefore are confident of their quality and performance.
Standard widths for high-speed steel oiirenomi are 3mm, 6mm, 9mm, 12mm, 15mm, 18mm, 21mm, 24mm, 30mm, 36mm, and 42mm.
YMHOS
If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook or the IT department for the US House of Representatives and so won’t sell, share, or profitably “misplace” your information. May my high-speed steel turn to turtle steel if I lie!
Kakuuchi Oiirenomi by Hidari no Ichihiro (Hyotan mark)
“Do not wait; the time will never be “just right.” Start where you stand, and work with whatever tools you may have at your command, and better tools will be found as you go along.”
George Herbert
The oldest style of oiirenomi currently available nowadays is called the ”kakuuchi oiirenomi” （角打追い入れ鑿）which means ”square-forged oiirenomi,” referring to the squarish shape. In cross section, the blade is rectangular with 4 more-or-less square outside corners. Other than this cross-sectional detail, it is identical in appearance to the mentori oiirenomi we discussed in my earlier post here.
DESCRIPTION
Where the Shinogi Oiirenomi in the previous post is thin and light, the Kakuuchi Oiirenomi is bulkier and heavier. They are also stiffer in the blade and even in the neck, which can be an advantage in narrower widths.
This added stiffness is not due to the extra mass of metal alone, but also to the fact that the steel layer is wrapped further up the blade’s sides than is possible for the thinner beveled sides of the mentori oiirenomi, as you can see in the photos above. Wrapping the high-carbon steel cutting layer up the blade’s softer low-carbon steel sides in this way creates in effect a hardened steel “U” channel with an increased moment of inertia, which makes the blade much stiffer. The thicker the chisel’s sides, and the deeper the U channel, the stiffer the blade will be.
The U-channel construction of Japanese chisels is a clever but subtle structural detail unique in the universe of chisels and one few are aware of.
Carving chisels do not have this U-channel detail and therefore are not as stiff or as tough as chisels that do. When you are considering buying a chisel, this is an important feature to confirm.
This style of chisel is better suited to cutting mortises than mentori oiirenomi (beveled oiirenomi), not simply because they are stronger, but because the squarer side edges tend to keep the blade better aligned in the mortise hole leading to a cleaner cut with a little less effort, especially in contrary wood.
The following are some pictures of two of our Kakuuchi Oirenomi by Nagamitsu, hand-forged, of course, from Hitachi Yasugi Shirogami No.1 Steel (aka “White Steel).
36mm Kakuuchi Oiirenomi by Nagamitsu (face)36mm Kakuuchi Oiirenomi by Nagamitsu (ura)36mm Kakuuchi Oiirenomi by Nagamitsu (Side)12mm Kakuuchi Oiirenomi by Nagamitsu (Face). This was the standard shape of Japanese chisels until about 70 years ago when the mentori variety became popular. Please notice how the angle between the face (surface with brand) and right and left sides is more or less 90˚.12mm Kakuuchi Oiirenomi by Nagamitsu (Ura)12mm Kakuuchi Oiirenomi by Nagamitsu (Side)
Kakuuchi chisels take less time for a blacksmith to shape than the mentori oiirenomi we discussed in Part 2 of this series. The difference in shaping these two styles of chisels is the added step of grinding the extra bevels that make the mentori oiirenomi sleeker.
Indeed, most styles of Japanese chisels can be obtained with a kakuuchi cross section, including the oiirenomi version shown in my previous post, as well as atsunomi and usunomi chisels we will examine in future posts.
Kakuuchi-style chisels take a little more effort to sharpen because the area of the bevel is larger, and more significantly, the area of the hard steel layer is greater, but on the other hand, they feel more stable on the stones.
More than a preference for greater weight, stiffness and stability, I suspect most individuals who prefer this old-fashioned style of chisel are making a fashion statement, something like “brogues not oxfords,” if I can adapt a movie quote.
In my opinion, they are not quite as elegant in appearance nor as handy as either the mentori oiirenomi or shinogi oiirenomi referenced in previous posts, but they do have undeniable dignity and presence.
What do you think?
YMHOS
If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may my dignity perish and my diapers leak.
“The best investment is in the tools of one’s own trade.”
Benjamin Franklin
The next variety of oirenomi we will look at is called the ”shinogi oiirenomi” (鎬追入鑿).
Shinogi Oiirenomi – Nagamitsu 長光
Shinogi (鎬) means ”ridge” as in the angled ridge of a rooftop or mountain. It is pronounced “she/noh/gee.” I believe the word was borrowed from the sword world where it refers to an angled ridge design on the back edge of Japanese swords (shinogizukuri 鎬造り). This detail is used not only in tatakinomi but in tsukinomi as well.
Two Angles of Sword Shinogi
Blade Cross-section
View of Sword’s Shinogi and Hamon
Shinogi oiirenomi are beveled like mentori oiirenomi but are different in that the bevels extend all the way to the center line of the blade’s face creating a definite ridge. The thickness of the blade’s right and left edges is typically thinner than oiirenomi making it easier to get into tight corners.
I am very fond of this handy, lightweight style of oiirenomi and keep a 10pc set mounted to the inside of my toolchest’s lid.
The downside to this design is that the chisel blade loses some stiffness compared to other styles, so they are less than ideal for heavy-duty wood hogging.
Some call these ” umeki” or ” dovetail” chisels. Indeed, some blacksmiths will grind the bevels to a very thin edge for this purpose.
My blacksmiths will not create these thin edges for three reasons: First, shinogi oiirenomi are not all that rigid to being with, and thinning the sides further is inviting breakage. Second, warpage is especially difficult to control in thin cross-sections resulting in more rejects and increased costs. And third, people always cut themselves badly using chisels with sides made thin enough to actually fit dovetails. Neither my blacksmiths nor I want that responsibility.
Most umeki chisels do not have the thin sides most people expect.
If you need very thin, sharp sides, you should grind and polish the side bevels yourself. Don’t forget to keep a first-aid kit close by, one you can use with just one hand. Seriously.
Shinogi oiirenomi are available in the same widths as oiirenomi.
In the next post I will introduce an old-fashioned but still useful oiirenomi called the “kakuuchi oiirenomi.” Stay tuned.
YMHOS
If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
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42mm Mentori Oirenomi by Hidari no Ichihihiro, a beautiful sculptural chisel by a renowned blacksmith, Mr. Yamazaki (RIP)
The Oiirenomi (pronounced oh/ee/reh/noh/mee) is the most common variety of Japanese woodworking chisel, and the style best known both inside and outside Japan. There are several varities of oiirenomi made, but in this post we will examine the most popular one called the ”mentori oiirenomi” ( 面取り追入鑿) meaning ” beveled” oiirenomi.
DESCRIPTION
As your most humble and obedient servant mentioned in the previous post in this series, “nomi” means ” chisel” in the Japanese language, but the term ”oiire” 追入れ” is not so straightforward. I am uncertain of the origin of this word, but some hints of the original meaning may perhaps be deduced from the Chinese characters used to write it: ”Oi” 追い meaning ”to chase” or ” to follow,” and ”ire” 入れ meaning ” insert” or ”place in.”
As the name suggests, this chisel’s face is beveled at both sides making it lighter and better able to get into tight locations than the bulkier kakuuchi oiirenomi, the older forerunner of this chisel, which we will examine in a future post.
I think most people agree that the two bevels moving up the blade, curving around the shoulder, and feathering into the neck give this chisel a sculptural, elegant appearance. While these bevels do indeed make this chisel handier and better able to access tight spots, they also sacrifice some stiffness, and authority compared to the kakuuchi style. But clearly, these compromises are acceptable to most consumers.
APPLICATIONS
A member of the tatakinomi family, it is designed to be struck with a steel hammer and has a hoop (called a “katsura” in Japanese which means “crown”) on the handle’s end to prevent it from cracking.
There are larger types of tatakinomi called atsunomi better suited than the oiirenomi to heavy cutting and wasting wood in applications such as timber frame joints, and most of those share the same mentori bevel detail, but oiirenomi are handier and better suited to lighter tasks such as furniture work and interior installation work the same as Western bench or butt chisels.
Oiirenomi in general and mentori oiirenomi especially are light-weight, relatively inexpensive, and handy to use. All woodworkers in Japan own at least a few of these.
Materials and Manufacturing Techniques
Our oiirenomi are hand-forged by traditional self-employed blacksmiths each with more than 40 years of experience working in their self-owned one-man smithies. They are stubborn gentlemen absolutely dedicated to quality.
These blacksmiths use onlyHitachi’s Metal’s Yasugi Shirogami No.1 Steel (aka “White Label Steel”) for the cutting edge, a plain, exceptionally high-purity, high-quality, high-carbon steel that does not contain significant amounts of chrome, molybdenum, nickel, vanadium, or tungsten, chemicals which are added to nearly all commercial tool steels to make products easier to mass-produce by factory workers (instead of more expensive skilled blacksmiths) with fewer rejects. These alloys add considerably to the cost of the strip steel, while resulting in a finished product that will not become as sharp as Shirogami steel, will not hold a sharp edge as long, and will be more unpleasant and more time-consuming to sharpen. If you have the sharpening skills, then Shirogami No.1 is a steel you should experience.
The blade of this chisel combines a strip of this high-carbon steel forge-laminated to a softer low/no-carbon steel body and neck. During heat treatment the high-carbon steel layer becomes very hard, but the low-carbon steel body and neck remain relatively soft. In use, this construction protects the more brittle steel from breaking, which is what would happen if the entire chisel was made of one piece of steel hardened to the degree Japanese professional woodworkers demand. It also makes it easier to sharpen the hard cutting edge, a task that would be difficult if the blade was all the same hardness. Please see this page, this page, and this page to learn more.
Our blacksmiths perform a minimum of 3 heats to each blade while using hammers and spring hammers to forge this special steel. This “hand-forging” process, combined with special heat-treating techniques they have perfected over many years, such as multiple quenchings, the application of temperature modulating clay coatings, normalization and low-oxygen carbon soaks produces a “fine-grained” steel of the sort that has been coveted by professionals for tools and weapons since ancient times.
The final hardness is between 65~66 on the Rockwell C hardness scale. Most Western Chisels are softer at 55~60 HRc. This extra hardness makes the blade stay relatively sharper longer, and the fine-grain crystalline structure of the steel ensures each blade will become sharper without sacrificing durability.
These are professional-grade tools made by craftsmen in their own smithies, not factories, and are intended to meet the severe performance expectations for Japan’s most uncompromising woodworkers, unlike the mediocre-quality but attractive-looking “hardware-store-grade” chisels peddled inside Japan to the amateur market, and outside Japan to the uninformed. How much bacon do you like with your sizzle?
Availability
Our oiirenomi are available individually, or in discounted 10 piece sets with Japanese Red Oak or White Oak handles. Standard blade widths are 3, 6, 9, 12, 15, 18, 24, 30, 36, 42mm. 48mm and 54mm are available custom-order.
We usually have all varieties in-stock ready to deliver, but as the blacksmiths that can reliably produce these handmade products are few, and are becoming fewer every year, there are occasionally times when our stock is low. We apologize for any inconvenience that may result and humbly beg your kind understanding.
Our Sukezane brand 42mm oiirenomi with Japanese Red oak Handle. Face ViewOur Sukezane brand 42mm oiirenomi with Japanese Red oak Handle. Ura ViewOur Sukezane brand oiirenomi 10pc box set with Japanese Red oak Handle. Also available with White Oak handles
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may I swallow a thousand needles.
“Electrical tools are consumables, but handtools are as part of our bodies. Do not treat tools as just things, or as some recent invention. The shape of every tool was not decided recently, but over a long time.”
Nishioka Tsunekazu, Temple Carpenter in charge of the Horyuji and Yakshushiji Temple Restorations
There are many varieties of Japanese chisels, and most people, including Japanese, are confused by the meanings of their names, and their various applications. Your humble and obedient servant is not an historian or archaeologist, but I have been using them for over 40 years both professionally and for the fun of it and like to flatter myself I know a bit about them. Perhaps this and future posts will help de-muddle a little of the confusion.
In this first article in the series I will explain the components of Japanese woodworking chisels, and the two main categories. In later posts I will explain the various types of chisels included in these categories in some detail. But let’s begin with some language matters.
Terminology and Translation
Where a suitable English word is available, I will use them, but for the most part, I will employ the Japanese terms converted from Kanji (Chinese pictogram characters) and Hiragana (phonetic Japanese characters) to the Roman letters used in most English-speaking nations. I apologize in advance if this causes consternation, but at least it will not add to the general confusion about these tools common among English speakers.
The word for “chisel” in Japanese is “nomi” (noh/mee 鑿). The Chinese character used to write this word is complicated, so it is normally converted to the phonetic hiragana letters as “のみ.” You will notice that nomi is part of every chisel’s name, so I will use it too.
Structure and Components of Japanese Chisels
The design of Japanese chisels is a little more complicated than their Western counterparts, and for good reasons, but the basic components are generally the same. So let us examine the similarities and differences.
Traditional Japanese chisels have laminated blades with a body, neck and tang made of iron or very low-carbon steel that remains relatively soft during heat treatment.
A layer of high-carbon steel is laminated to this iron body beginning where the neck meets the flared shoulders and extending to the cutting edge. During the quenching process, this layer becomes very hard, typically 62~67 Rc versus the typical hardness of 58~60 Rc found in Western chisels. These two layers of metal are most visible at the bevel. The additional hardness of the steel layer has both advantages and disadvantages, depending on the crystalline structure of the steel after heat-treating and the skill with which the tool is used and maintained.
In the case of hand-forged (teuchi 手打) blades, this lamination is made by forge-welding the two types of metal over several heats using hammer, tongs, and anvil.
European chisels were also fabricated using this technique before the advent of mass-produced inexpensive steel. Unfortunately, this once-universal excellent technique has been all but forgotten outside of Japan.
Materials & Process
The best professional-grade chisels are made of high-quality iron and the purest plain high-carbon steel. These ancient metals are difficult to work, being very sensitive to temperature and thermal shock and tending to warp and crack badly in less than experienced hands. Many alloys and processes have been developed over the last 60 years to make tool production more profitable using unskilled labor, but for simple cutting ability and ease of sharpening, nothing rivals this combination.
The blacksmithing process involves forge-welding the two types of metal to form a laminated blade, then shaping and hand-forging over multiple heats, followed by carbon soaking and annealing, a coating of secret mud sauce after which the blade is heated to just the right temperature and subject to multiple quenches followed by multiple temperings, a process that varies from blacksmith to blacksmith with each craftsman using different formulas and procedures. Of course, warpage must be compensated for by shaping a curve in the blade that straightens out during heat treatment. Learning these skills takes years of hands-on training from a young age under the eye of a master, and decades of dedication to quality. It certainly cannot be accomplished in a mass-production situation, much less by Chinese peasants or even CNC robots.
Mass-produced consumer-grade Japanese chisel are made of pre-laminated strip steel manufactured in steel mills by either cold-rolling or hot-rolling a layer of high-carbon steel to a layer of mild-steel. This material, called ” rikizai” (利器材）or ” fukugozai” (複合材）was originally developed for mass-producing inexpensive kitchen knives as a labour-saving material to reduce manufacturing costs.
Blades made from rikizai typically perform adequately for most consumers, but many professionals seek the higher performance of so-called ” fine-grain” steel’s smaller and more uniformly-distributed carbides as found in hand-forged, expertly heat-treated blades. Those who develop the skills necessary to discern the difference between such professional-grade and consumer-grade blades, can never be satisfied with the inferior tool.
Hollow-Ground “Ura”
Kiyotada Atsunomi ura
Japanese chisel blades have a hollow-ground back (the so-called ” flat” on Western chisels) which makes the harder steel easier to sharpen and keep flat. Without this hollow-ground ura feature you would find sharpening a chisel blade of similar hardness time consuming and almost impossible to keep flat over many sharpenings.
Tang and Ferrule
Japanese chisels appears at first glance to be socket chisels, but they are definitely tang chisels with the distinct advantage over socket chisels that the blade and handle stay connected instead of separating at inconvenient times.
The handle incorporates a steel ferrule shaped like a truncated cone and called the “ kuchigane” (口金) which translates to “mouth metal.”
The Four Components of a Tatakinomi: Blade, Handle, Kuchigane, Crown
This component receives the reaction forces of hammer impacts from the blade’s shoulders converting these thrust forces acting in the handle’s long axis to compression forces acting on the handle’s end thereby preventing splitting and locking the tang tightly into the handle. It is a subtle but clever and effective design that combines the best features of both tang chisels and socket chisels without any of the downsides.
The Crown
The “Keima” Chess Piece
Chisels intended to be struck with a steel hammer have a sturdy steel hoop called a ” katsura” installed at the handle’s end to prevent the wood from splitting. The characters used for this word include 冠, pronounced “kan” or “ kanmuri” meaning “crown” or 桂 meaning Judas Tree or “ knight” （桂馬）as in the chess piece. The word Katsura can also mean “ wig” a term that does not quite work in this case because chisel handles are as bald as I am. I have the bad habit of anthropomorphizing my tools. They hate that, so to avoid giving further offense (they sometimes bite, donchano), I prefer to translate katsura as the more elegant word “crown” instead of the more constrictive word “hoop,” or follically-challenged word “wig.”
Just in case you aren’t entirely confused, please note that this same steel hoop is also called a ”sagariwa” (下り輪) which translates to ”drop hoop, ” a term that is accurately descriptive because, over many years of hammer blows, the handle gradually shortens and the hoop “drops,” shifting its position down the handle.
The crown is made of relatively soft but still strong mild steel. In use, it will occasionally be struck by a steel hammer. This choice of material is not based on economics or convenience but on the practical reality that the face of a steel hammer impacting the edge of a hardened steel hoop would get dinged and even deform after enough hits.
But this creates another problem, namely that the crown may eventually become deformed by hammer strikes unless preventative measures are taken. This is not a trivial cosmetic matter because the hoop’s edge may deform to the point it curls back inside itself. Then, if the user continues to beat on the chisel, the hoop will gouge and eventually split the handle.
Damaged Crown and Handle
The best way to avoid this grief is to use a hammer with a flat instead of convex face and to properly setup the chisel when new. For instructions on doing this, please see my earlier post about Setting-up Japanese Chisels.
Another downside to the crown and steel hammer arrangement is that the end of Japanese tatakinoni are far from smooth and can be uncomfortable to use when paring. The solution to this is three-fold. First, setup the crown properly and chamfer and smooth its edges. Second, avoid hitting the crown with hammer so it doesn’t become rough and gnarly. And finally, use a tsukinomi chisel for paring. Life is good.
Handle Materials
Chisel handles can be made of a variety of woods, but strong hardwoods such as oak are commonly fitted to chisels designed to be motivated with hammers.
Chisels not intended to be struck with a hammer can be fitted with more brittle but decorative wooden handles such as ebony or rosewood.
The Two Categories: Tatakinomi and Tsukinomi
Tsukinomi
There are two primary categories of Japanese chisels. I think these same categories apply to other traditions, but in the difference is especially clear-cut in Japan.
The first category is the “tsukinomi “ (突き鑿). Tsuki means “to push,” so tsukinomi refers to push, or paring, chisels. Standard widths range from 1.5mm to 48mm. Handle lengths and materials vary with the type of tsukinomi, the intended purpose, and personal preferences.
A Kiyotada mentori usunomi
Tsukinomi are pushed by hand and sometimes by shoulder in the case of the large ootsukinomi, known in the West as “slicks.” Most tsukinomi have relatively longer, more slender and elegant necks. They incorporate the same kuchigane ferrule at the blade end of the handle, but do not have a steel crown hoop reinforcing the opposite end.
48mm Mitsuura Ootsukinomi Paring Chisel
By definition these chisels are not intended to ever be struck with a hammer. Even if the handle does not split, their more slender necks will not endure impact forces gracefully. More often than not they are used to clean and pare to final tolerances joints cut using other chisels.
The second main category of Japanese chisel is called the “tatakinomi” (叩き鑿）meaning “striking chisel.” This is the style of Japanese chisel best known outside Japan. Stronger and tougher than tsukinomi, they are intended to be struck with a steel hammer. More details can be found at this Article
42mm Atsunomi Ura – Sukemaru (300mm (11.8″) Overall Length)
Wooden mallets are not typically used with Japanese chisels. The logic for this practice is simple: A steel hammer is the smallest, lightest, and most energy-efficient way to motivate a chisel. The physics of this are self-evident. Accordingly, the logic behind the tatakinomi design is that, since it must efficiently remove lots of wood, and a steel hammer is the most efficient way to transmit kinetic energy produced by the user to a chisel, the tatakinomi’s handle must be designed and made strong enough to endure being struck by a steel hammer from sunrise to sunset. A simple calculus.
200 Monme Kosaburo Gennou (938gm, 33oz) Black Persimmon Handle
By contrast, Western chisels with their inherently fragile handles require users to baby them with relatively soft, energy-wasting, un-aerodynamic, big-ass mallets, an illogical and inefficient practice. But to each his own.
Some people stubbornly insist on using mallets to strike their Japanese tatakinomi too. They are perhaps like the country bumpkin that bought a newfangled chainsaw from a hardware store in town to cut firewood only to take it back to the store the next day complaining it was slower and more work than his old axe and handsaw. The puzzled hardware store owner checked the fuel and spark plug, but found no obvious problems. With a perplexed look he yanked the starter rope. The chainsaw’s motor started right up with a roar and a cloud of smoke. The shocked customer almost jumped out of his overalls in wide-eyed surprise, screeching “ what the hell’s that racket!?!”
According to the Takenaka Carpentry Tools Museum located in Kobe, there are 9 varieties of tatakinomi. The most popular by far is the oiirenomi. We carry several varieties of oiirenomi including mentori,shinogi, kakuuchi, and HSS mentori oiirenomi. Another popular style is the larger, stronger heavy-duty atsunomi, preferred by timber framers. And when we can get them, mukomachinomi.
In Part 2 of this series we will describe some of these beginning with the “Mentori Oiirenomi.”
YMHOS
If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or thuggish Twitter and so won’t sell, share, or profitably “misplace” your information. If I lie may I grow an extra arm from my forehead.
f set up and maintained properly, the blades of quality chisels and planes will endure many decades of hard daily use. In this article your most humble and obedient servant will describe a useful tool Beloved Customer can make yourself, one that will not only make maintenance easier and more efficient, but will make your tools perform better and last longer.
Historical Precedence
Versions of the oilpot have been used in all nations since ancient times. Indeed, we know from the archaeological record that tallow, simply rendered animal fat, was commonly placed in open grease pots to use as a tool lubricant in Europe and America from pre-Roman times right up until petroleum products, including petroleum-based waxes, became widely available in the 1920’s. I am told that the black crust found on many antique plane bodies (wood planes not airplanes) and workbenches is a remnant of this tallow, albeit oxidized, hardened, and combined with dirt.
Indeed, I can recall my father, uncles, and grandfather using sticks of paraffin caning wax for the exact same purpose when I was a child, and before that my English ancestors probably used tallow candle stubs.
Vegetable oil was more commonly used in Asia, and probably in Europe as well.
I haven’t tried soft tallow as a lubricant and probably never will since rancid fat has even less appeal to me than rancid vegetable oil, but I’m confident you will find the solution described below a serious improvement over these ancient methods.
Corrosion Protection
It’s a sad truth that the blades of woodworking tools often receive more damage while they impatiently wait to be used than when they are actually being used. Thankfully, microscopic pitting at the cutting edges of steel tools this sort of neglectful corrosion produces can be easily avoided.
When not in use, please store your chisels, planes and handsaws where they will be protected from dings, dust and large temperature swings. And oil your blades after every use to limit their exposure to oxygen, moisture, and chemicals that might persuade your expensive blades to “turn red and go away.”
A speedy and convenient way to apply good oil to your blades is to use an oilpot, or aburatsubo (ah/boo/rah/tsu/boh 油壺) as it is called in Japan, similar to the one in the photo above. This is an effective, inexpensive, and time-proven tool for this purpose, certainly better than bottles and more economical than spray cans.
Friction Reduction
Oil pots are useful not only for keeping corrosion at bay, they also help minimize the friction your chisels, saws, planes, and knives generate when cutting wood, as well as the energy you need to expend in cutting. By using an oilpot to reduce friction as your blade cuts wood, that same wood, and especially the “hairy” fibers that project into the kerfs of sawcuts, will not deflect the blade away from your intended line of cut as easily, noticeably increasing the precision of your work. Do you doubt me? Give it a try and prepared to be pleasantly surprised
Making the Essential Oilpot
In Japan, an oilpot is traditionally made by cutting a joint of well-dried, large-diameter bamboo into a cup 3 to 4 inches deep. If you don’t have access to bamboo where you live, a hollowed-out piece of some close-grained wood suitable for making water-tight barrels, such as white oak, or a plastic mug, or even a segment of capped PVC pipe will work just as well. The important thing is that the container not be made of metal, glass, ceramic or any other material approaching the hardness of a chisel blade. While convenient and sized right, tin-plated steel cans are risky.
Shape the bottom or foot of the cup so it will rest on a more-or-less flat surface with a few irregularities. Some people scallop the bottom and foot so it rests on only three or four spots at the foot’s perimeter thereby making it more stable on irregular surfaces. And a piece of sandpaper glued to the bottom of the container will prevent your planes from dragging it around when you pass their soles over the wick.
If you use bamboo or wood, be sure to prime and paint both the inside of the cup, and underside of the foot, with a high-solids urethane or polyurethane paint. I used a natural urethane extracted from the cashew tree called “Cashew” on the bamboo joint in these photos. The gaudy orange color is not a fashion statement, but makes it easy to differentiate my oilpot from others on a jobsite
If you make your oilpot from bamboo or wood, after painting it be sure to line the inside of the cup with an unbroken sheet of aluminum foil to prevent the oil from soaking through. The paint alone will slow down the oil’s movement through the wood’s fibers, but sure as hogs are made of bacon, without an impermeable liner of some sort, it will eventually seep out making a mess. An aluminum foil liner will fix this.
Next you will need some clean, white, cotton T-shirt fabric. Used clothing is fine. White because you want to be able to tell how dirty the fabric is at any time. T-shirt fabric because it’s knitted, not woven, and sheds the least fibers, unlike flannel. Clean because pixies hate it. If you don’t believe me, just ask them.
Roll the cloth up very tightly into a wick just a hair smaller in diameter than the inside of your container and bind it tightly with string or thread. You should be able to force this dense cloth wick tightly into the cup with approximately ½” projecting above the lip. It must be a tight enough fit to prevent the wick from falling or pulling out accidentally, but not so tight it breaks the container. It will take several tries to judge just the right amount of fabric, so be patient and keep at it until you get it right.
Add Oil
Now that the oilpot is made and wick installed you need to add some oil. Just soak the cloth wick with your favorite lubricant and you’ll be ready to rock-n’-roll like Zeppelin. It will take some time for the oil to saturate the dense wick, so be patient or it may overflow without saturating the wick. I get impatient and spill a little oil sometimes (ツ).
In Japan, I was taught to use vegetable oil and change the wick when it became rancid, which it always did. But I recommend Beloved Customer be smarter than I was back in the days when dinosaurs roamed the earth and use a non-organic oil from the start. Stinky wicks are not only unpleasant, but more importantly, rancid oil encourages corrosion.
Some people prefer to use straight mineral oil or scented furniture oil, which is just perfumed, industrial-grade mineral oil. The lemony smell of furniture oil is nice. But please avoid any furniture polishes or oils that contain insidious silicon because it will weaken glue bonds.
Please also be especially careful to avoid linseed oil. A wick loaded with such oil is inviting spontaneous combustion, a dangerous inconvenience in a woodshop.
Some people prefer to use camellia oil, an organic product with a long history of usage as a lubricant, cosmetic and hair oil in Japan. But beware that the so-called camellia oil sold for rust protection nowadays is actually just mineral oil with a bit of yellow dye and some fragrance added, sold at an inflated price, much like commercial furniture oil. Caveat emptor, baby.
Mineral oil is a petroleum distillate sold as lubricant laxative in pharmacies. It’s not only cheaper than the fake “tsubaki abura,” or “sword tsubaki” sold as tool oil, but is higher quality and performs better than genuine camellia oil because it will not become rancid and gummy.
While it sounds strange, the best lubricant by far in my experience is a lightweight, light-colored 100% synthetic motor oil such as Mobile-1 (5W). I have tried regular motor oil too, but the synthetic variety smells better, lasts longer and seems to perform better. And while I like to flatter myself that I’m a “high-volume guy,” my chisels never get hot enough nor rev high enough to justify the zinc, organic sulfur, or chlorine compounds added to high-performance motor oils. Your mileage my differ. (ツ)
Oilpot Storage
Store your oilpot in a metal or plastic container with a lid when not in use to prevent abrasive dust from contaminating it. Some people make a container from a segment of PVC pipe with a flat end-cap glued on one end to form the bottom of their oil pot and a domed cap slipped on the other end to serve as a lid. I use a tin can with a slip-on lid to store my bamboo oilpot.
Place a pad of newspaper in the bottom of your container to absorb any oil seepage and cushion the pot from rattling around.
Even a plastic bag will do until you find something better.
Using the Essential Oilpot
This is the most important part of this article.
When you are cutting a mortise with your chisel, make it a habit to occasionally jab its cutting edge into your oil pot’s wick, and even wipe the sides and ura (flat) on the wick to lubricate the blade. You will be pleasantly surprised to find that this bit of oil will make your chisel work not only go faster, but more precisely and with cleaner results. Don’t worry, mon ami, the oil will not weaken glue bonds, so long as it doesn’t contain silicon, I promise.
Likewise, when using a handplane, occasionally swipe its sole over your oil pot’s wick, or rub the wick over the plane’s sole. This little bit of oil will greatly reduce friction, reduce wear on your planes’ soles, and give you more control. But, if you value your public dignity, be forewarned that the first few cuts you make after doing this will make you grin like a lunatic! (ツ)
The same benefits of reduced friction and increased precision can be found in the case of handsaws too, although the difference may not be as noticeable.
Before you store your tools away for the day, a dab of oil from your ever-present oil pot will prevent rust and frustrate corrosive iron pixies.
Maintaining the Essential Oilpot
During use, the cloth wick will naturally become frazzled, coated with sawdust and wood chips, and will discolor accordingly. Not a problem!
If, heaven forfend, you drop the oilpot and it hits the ground, Murphy’s Law of Buttered Toast dictates it will land oily-cloth down contaminating it with abrasive grit (unless you work in a cleanroom). If ignored, frikin Murphy will smugly use your oilpot to damage your tools and ruin your work. But never fear: simply brush the wick vigorously with a steel-wire brush and all the sawdust, wood chips, dust, grit and pixie golf balls will be gone. The sound you will hear while doing this will be Murphy gnashing his teeth in frustration.
Of course you always have a steel-wire brush close at hand to remove embedded grit from boards before planing them, right?
When the wick becomes too dirty for the steel wire brush to clean (difficult to imagine though that may be) you can either cut off a few millimeters to expose uncontaminated cloth, or replace the cloth wick to present a clean surface.
As the cloth wears, the wick will shorten and stop projecting from the oilpot’s mouth. When this happens, simply remove the wick and place some clean rags in the bottom to elevate it thereby restoring the necessary projection.
The oilpot is an ancient, dirt-cheap tool you will find to be an invaluable addition to your woodworking tool kit. I promise it will make you grin when using handplanes!
If you have questions or would like to learn more about our tools, please click the see the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.
Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or a Director of the CIA and so won’t sell, share, or profitably “misplace” your information. If I lie may ticks, fleas and biting flies be my only friends.
Covington & Sons Tools 
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