The Japanese Gennou & Handle Part 5 – Kigoroshi

The difference between something good and something great is attention to detail.

Charles R. Swindoll
A Japanese shipwright using a hammer to perform “kigoroshi” on the edges of planks for a traditional boat. The planks are joined using long nails “toenailed” from the upper plank into the lower plank. The pilot holes for these nails are made using a “tsubanomi.” When the boat’s hull is later wetted the fibers crushed during kigoroshi will swell back to near their original size filling gaps and tightly locking the planks together, even when the planks are once again dry.

In previous articles in this series about the Japanese hammer known as the gennou, we examined the background, history and general varieties commonly available nowadays. In this article, we will expand our analysis of the gennou to include a function not well known outside Japan. We hope our Beloved Customers and Gentle Readers find it amusing.

Kigoroshi 木殺し

As mentioned in Part 4 of this series, the standard ryoguchi gennou hammer has a flat striking face on one end and a domed striking face on the opposite end. The flat face is well suited to striking chisels, driving nails and the ceremonial wacking of thumbs, while the domed striking face excels at setting nails below the surface of a wooden board, just as Western hammers are. It can also be used for a task called “kigoroshi.” Indeed, this is a technique that can be employed with any hammer having a domed face, although the domed face on many Western claw hammers may be too drastic in some cases. It is a technique worth knowing.

The term Kigoroshi (木殺し)translates to “wood killing” meaning to use a hammer to temporarily crush wood cells. It is achieved by judiciously striking the wood with the hammer or gennou’s domed face. Easy peezy.

When a piece of wood is subjected to successful kigoroshi, the wood cells are deformed reducing their internal volume, but if the pressure is later relieved and some moisture added, over time the cells of many (but not all) species of wood will swell back to near their original volume.

So how is kigoroshi used? For instance, in the case of a mortise and tenon joint, the tenon is cut oversized, and then struck with the convex face of a gennou to deform the wood cells to the point the tenon will fit into the mortise. With time, the tenon absorbs moisture from its surroundings and naturally tries to swell back close to its original size locking it tightly into the mortise. I’m sure you can see the possibilities.

In this short video, the carpenter is performing kigoroshi with the convex face of his gennou to the shoulders of an Akita Sugi (Cryptomeria japonica) beam to enable it to fit inside a housed dovetail mortise. The shoulders will later swell back to close their original dimension closing any minor gaps and perhaps locking the beam tightly into the mortise hole.

Another application of kigoroshi is seen in traditional Japanese boat building where the edge joints between planks forming the hull are hammered, effectively making the planks narrower. After the planks are attached to the ship’s ribs, their crushed cells gradually swell and attempt to return to their original volume, tightly pressing the planks against each other and closing any gaps to create a waterproof joint. In this way, a joint that might otherwise loosen with time and changes in moisture content can be made to remain tight and waterproof. This boat building technique is not unique to Japan, of course.

A Japanese shipwright performing kigoroshi on the edges of planking prior to joining them together.

One more example. When making a rectangular wooden cask or bathtub from hinoki-wood boards (not staves) in the Japanese style, grooves are cut in the bottom board to receive tongues from the vertical side boards. If these tongues are planed oversize and then their sides are pounded judiciously with a hammer with a slightly rounded face like that of a ryouguchi gennou to reduce their thickness to fit into the groove, when assembled and then wet with water the crushed wood cells in the tongue will rebound and will expand to close its original thickness not only locking the tongue and groove tightly together, but also creating a watertight connection. If done properly, the joint will remain tight even after all the boards are no longer wet, same as the ship’s planking mentioned above.

Many people’s understanding of kigoroshi is too shallow to use the technique effectively and consistently without some practical experience. The opinions of inexperienced people therefore should be scrupulously ignored, but the Beloved Customer of C&S Tools are expected to meet a higher standard of woodworking, so I share this advanced technique with you.

There are a few points you should be aware of before attempting kigoroshi in a professional situation, in other words, a situation where cost, schedule, or reputation are at risk.

First, please remember that if the flat face of the genno is used for kigoroshi, or the domed face is cocked so its corners dig in too far, or is used with too much force, the striking face’s perimeter edges may crush cells and sever fibers permanently so that they cannot return to anywhere near their original volume thereby defeating the purpose of kigoroshi and simply weakening the wood. That’s not good.

Second, be aware that if used in fine cabinetry and joinery work, kigoroshi can create unpredictable tolerance shifts at joints, making, for instance what should be a flush joint offset, so caution and experimentation may be necessary to avoid embarrassing snafus.

And third, kigorishi does not work well with some woods, especially hard, stiff woods, and can cause permanent damage in some cases. We will discuss this further below. But first, let’s examine the mechanics of kigoroshi.

Nuts and Bolts

Most commercial varieties of wood grow in climates with seasonal changes of winter and summer. A tree is essentially a big water pump that pulls (not pushes) water and some nutrients up from the ground through the pressure differential created by water evaporation at its leaves. The highest volume of water pumped, and cellular growth, occurs when the weather is warm, water is moving, and the sun is shining. Without water, sunlight, and functioning leaves, the pump stops. In the case of freezing weather, evergreen trees stop pumping water to prevent freezing and the resulting expansion that would destroy the tree.

During the colder months, beginning when leaves fall and the sun fades in Autumn, the pump as well as the tree’s growth slows and then stops. The pump starts up again during the spring thaw when water moves, the sun again shines, and leaves bud.

The stained cross-section of oak below is an excellent illustration of this point. The photo is bifurcated by a a nearly solid band of tight fibers bordered above and below by larger cells, some are rather large white voids. This nearly solid band of cells forms during late Autumn and early spring and is called “late wood” or “Autumn wood.” The areas of less density and larger voids is formed during warmer months of high-growth and is called “early Wood or “Spring wood.” These voids form branching and merging tubes leading from the tree’s roots to the tiny holes in the leaves where the water they carry evaporates powering the pump.

The difference in appearance between these bands of cells (aka growth rings”) can be seen on the surface of a board as its “grain.”

Every type of wood, indeed every piece of wood, is different and will react differently to kigoroshi attempts. Let’s review the physical properties of wood relevant to kigoroshi by examining a cross-section of a tree. For instance summer wood is carefully designed to transmit large amounts of water and nutrients, and so is comprised of large cells with thin walls. After the tree is felled and as the moisture content of the wood decreases, the cells shrink, the cell walls become thinner, harder, stronger and wrinkled and crinkled.

A cross-sectional slice of White Oak dyed red for clarity.

Winter wood in most commercial varieties is designed less to transmit water and nutrients and more to resist wind and winter storms. It is comprised of much smaller cells with thicker, stronger walls.

Effective kigoroshi temporarily squashes the cells of summer wood in what is called elastic deformation, meaning the deformation is temporary so that the cells rebounds to near their original volume when the moisture content is increased depending on the nature of the wood and the elapsed time.

The cell walls of winter wood, on the other hand, instead of squashing and then rebounding, are often shattered by kigoroshi in many cases and will rebound little. This is called plastic deformation.

Why does this matter? Consider a cube of quartersawn Douglas fir, a wood with very soft summer wood, and very strong winter wood. If we strike this cube perpendicular to the parallel rings, the larger, weaker cells of summer wood will squash down while the harder lines of winter wood will just be pressed closer together as the layer of summer wood squashes. An application of moisture to this block of wood will cause the summer wood to return to near its original volume and the cube of wood may retain any apparent damage.

https://i0.wp.com/www.microlabgallery.com/gallery/images/Pseudotsuga%20MenziesiiCS40X.jpg
Doug Fir

Now what happens when we wack an identical cube in-line with the layer of harder winter wood? Some of the winter wood cells are squashed elastically and will rebound. But the rebound will be less and some of deformation will be permanent.

The oak, on the other hand is more dense and the cell walls are stiffer than a softwood like pine, so crushing the cells in kigoroshi will result in even less rebound, and may greatly weaken the wood permanently.

The point is to be aware of the nature of the wood you plan to do kigoroshi to beforehand.

Kigoroshi for Gennou Tenons, and Chisel Handles

There are those who advocate using a hammer to perform kigoroshi on the tenon of gennou handles, the idea being that an oversized tenon can then be crushed a little allowing it to fit into the eye, and that the wood will rebound later locking it into the eye tightly. This sounds like a great idea, but it has problems that stem from the fact that gennou handles are typically made of dense hardwoods like white oak, and not softwoods like cedar.

We need the extra toughness and density that hardwoods provide when making a gennou handle because tenons cut in softer woods will loosen over time. Hard woods like white oak, for instance, do not submit well to kigoroshi because the more rigid cell walls are broken in plastic deformation instead of elastic deformation and won’t rebound enough. In other words, kigoroshi on hardwoods like oak, hickory or persimmon may decrease the cellular volume, but it will also physically weaken the wood. Why would you want to do that?

Instead of kigoroshi, a better solution is to use a good dense hardwood and to precisely cut the tenon just enough oversize so that a lot of force is required to insert it fully into the eye. In this way, you will have a tight tenon without compromising it’s cellular strength, a better long-term solution and a more craftsman-like technique.

Another option especially effective when making a gennou handle in humid months is to cut the tenon oversized and shrink it by removing water from the cells using gradual heat. Placing the handle in a more-or-less sealed container with a dry heat source such as an incandescent light bulb will do the job. Silica gel desiccant is another method, but slower. I do not recommend putting the handle in an oven of any kind to accomplish this, however. You have been warned.

Still others advocate performing kigoroshi on the ends of chisel handles to make the crown (hoop) fit better. They then say one must soak the end of the handle in water to make it swell back to shape and lock the crown in place. While popular, this is poppycock which wastes your time and weakens the handle. Please do not do this with C&S Tool’s chisels.

If the handle is in fact too big to accept the crown (unlikely if you purchased the chisel with a handle and crown already attached), please shave or file the end of the handle down to a dimension where it takes a number of hard hammer blows from a steel hammer to drive the crown onto the handle. The crown will thereby automatically perform all the kigoroshi necessary. This method is more professional and will provide better service.

Kigoroshi is a useful technique in some applications and with some types of wood. You may not need it but it’s worth understanding, especially if you have a gennou.

In the next post in this series we will examine the ancient ergonomic roots of the gennou handle we advocate and the unusual Japanese carpentry guild that codified them.

YMHOS

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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

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

It’s hubris to think that the way we see things is everything there is.

Lisa Randall

Varieties of Gennou: Ryouguchi Gennou

There are several types of gennou. The most popular is the standard, double-faced symmetrical gennou called the “ryouguchi gennou” 両口玄翁 pronounced ryou-guchi-gen-nouh. “Ryou” 両 translates to “both” and ”kuchi” 口 means mouth, so a ryoguchi gennou is one with a striking face on both ends. This category includes its stumpy brother the daruma gennou, which is a shorter, stubbier version of the ryouguchi gennou. One face of ryouguichi gennou hammer is flat, and the opposite face is domed. The flat face is used for striking chisels and nails, with the domed face is used for the last couple of hits on a nailhead to recess it below the wood’s surface. It can also be used for something called kigoroshi (“wood killing”木殺) which we will touch on in a future post.

This most popular of gennou is symmetrical in all axis, an extremely stable shape making it well-suited for using at many different angles and at different swing velocities to make powerful hits where stability during the swing is important. And stability is often not just important but critical because a hammer that easily wiggles or twists out of alignment during the swing, or jinks upon impact, will make you look like a child.

Varieties of Gennou: Kataguchi Gennou

〔千吉〕片口玄能 小

Besides the ryoguchi, the other common variety of gennou is called a “kataguchi” 片口 or single-face gennou. “Kata” 片 in Japanese means “one” or “half” and “kuchi” 口 means “mouth” but for some reason unknown to me is used to mean “striking face” in the case of hammers. It has a slightly domed face on one end with the opposing end tapering to a small square face for setting nails. Besides setting nails, the tapered end is handy for “tapping-out” (uradashi) the hollow faces of Japanese plane blades. The domed face of the kataguchi gennou is shallow enough to be used for striking chisels, but is not as good for kigoroshi. Kataguchi genno include the yamakichi style common to Kyushu Island, the funate or Iwakuni style common to Western Honshu Island and Hokkaido way up north, and several variations thereof. 

The hammer pictured immediately below is the “Funate gennou” 船手 which translates to “boat hand” gennou. It is especially suited to driving nails, while it’s tapered tail can be used to make a starting hole for nails, a capability especially suited to ship building.

A funate-style gennou hammer with bubinga handle. The eye has a built-in forward cant. This style is popular in much of Western Japan, but not so much in Eastern Japan and Tokyo.
The face of the tapered end of the funate gennou, much smaller than the Yamakichi-style gennou pictured below. If this end is sharpened it can be used to start a hole for the diagonal nails used to join ship planking, perhaps why it’s name references ship building.

The gennou pictured immediately below is called the Yamakichi gennou 山吉, with Yamakichi meaning “lucky mountain.” This was the brandname of the blacksmith on Japan’s Kyushu Island who developed this style of hammer. It is a stubbier, heavier hybrid of the ryouguchi and funate styles, better suited to chisel work while still being well-suited to driving nails. I am told that Kosaburo received permission from Yamakichi and modified the design slightly to better meet the requests of his customers in the Tokyo area. If you can only have one hammer with you in the field or when doing installations at the Client’s home or facilities, the Yamakichi gennou is hard to beat. It’s unusual and sexy-looking.

A Yamakichi gennou by Hiroki with an American Osage Orange handle (thanks for the wood Matt!). This is the Kosaburo version of the Yamakichi style which originated on Kyushu Island. The face is not entirely flat, but is still flat enough for striking chisels without damaging them. The tapered end has a square face great for starting and setting nails. it also works well for “tapping-out” plane blades. Not quite as stable as the more symmetrical ryouguchi style, but it’s undeniably more versatile. If you need a gennou for driving nails, including finish nails, as well as striking chisels the yamakichi style gennou is hard to beat.
The tapered, square end of the Yamakichi gennou, perfect for starting and setting nails as well as tapping-out plane blades.
The butt of the osage orange handle. This shape, which we will explain in detail future posts, is a key factor in the handle design on which this series of articles is focused. Osage orange is a very tough, stringy wood used for fence posts, tool handles, musical instruments and bows for millenia. The color is a scary neon yellow when freshly cut, but when exposed to sunlight changes to this interesting color.

The Varieties of Gennou: Daruma Gennou

The daruma gennou (dah-ru-mah) 達磨玄翁 is a variation of the double-faced ryouguchi genno, but at the same weight, it is shorter and fatter. It is named after Bohdi Dharma, a Buddhist Monk who was the founder of the Zen (Chan) sect of Buddhism in China, as well as an important person in the history of the Shaolin Temple made famous in Hong Kong Kung Fu movies. You will remember seeing Shaolin Priests in Hong Kong movies dressed in saffron robes, and with rows of dots on their bald pates, jumping around thwarting evil warlords with long mustaches. 

There are many legends about the Enlightened Dharma, but one story says that while meditating for nine years in a cave near the Shaolin Temple, his atrophied arms and legs fell off leaving just his trunk and head. Because of this legend, in Japan he is portrayed as an oval-shaped figure without any limbs, and with bushy eyebrows glaring out from inside a red hood. He has come to symbolize wisdom and victory through persistence and endurance. This image has deep roots in Japanese culture.

The daruma genno is named after him because, like the buddhist priest, it is short, stubby, and round. Religious matters aside, at any given weight, the daruma is not as physically stable as the standard genno due to its reduced Moment of Inertia. 

The Moment of Inertia refers to the tendency of a body to resist changes in position. Quoting from Wikipedia (which is no doubt a quote from some physics textbook): “It is the moment of inertia of the pole carried by a tight-rope walker that resists rotation and helps the walker maintain balance. In the same way the long axis of a dragster resists turning forces which helps to keep it moving in a straight line.” 

It is the increased Moment of Inertia that makes a steel I-beam so much stiffer and stronger than a plain steel rod of the same length and weight.

Like these three examples, the standard genno head has its mass spread out from the center, making it more resistant to movement than if the same mass were concentrated in a solid ball. 

The math for a rod about a center, which is a close approximation of a hammer head, is I= (1/12) x ML2, where I equals the Moment of Inertia, M equals the mass of the rod, and L equals the length of the rod. As you can see from the equation, the Moment of Inertia varies with the square of the object’s length, so that a ball has the lowest possible Moment of Inertia for a given mass, and is the easiest shape to get moving, while a hammer head with its mass moved away from the center will have a much higher Moment of Inertia, and will therefore be more resistant to changes in direction. 

For any given mass, the daruma gennou head has less length than the standard genno head, and therefore has a reduced Moment of Inertia, and so is less stable. 

Why is this important? Because you are not a machine, and when you swing a hammer several contradictory forces act on the hammer. Sometimes those forces are large and problematic and sometimes they are small and insignificant, but often some of those forces work to drive the hammer off course so it misses the target, and others tend to cause it to twist during the swing so that a line drawn through center of the hammer’s face and the center of its mass is not aligned with the target causing a glancing blow wasting time and energy. But since a longer hammer head has a higher Moment of Inertia, it will tend to not twist out of alignment as easily as the shorter daruma will during a swing, and is more likely to impart more of its energy into the chisel even if the hit ends up being a bit off-center.

In comparison to the shorter daruma, the longer standard ryouguchi gennou head, or even Yamakichi gennou, will tend to rebound straight back, instead of twisting, helping the user to maintain a steady rhythm thereby saving time. Of course, with practice, the daruma can perform just as well as the standard ryouguchi gennou head, but if you intend to make a lot of fast, hard strokes at various angles, which is common in carpentry and timber framing, a standard ryouguchi gennou with its higher stability is a superior choice. 

The daruma gennou has traditionally been the preferred primary hammer for two trades: Joiners (tategushi), who use the daruma to their advantage in a specific way, and sculptors, who don’t require stability but do appreciate a large face. Cabinetmakers, tategushi and tansu makers often have a heavy daruma on hand for assembly work because the high face area/weight ratio is convenient for knocking joints together.

I learned about daruma genno from a retired joiner in Tokyo who was kind enough to instruct me occasionally over a period of several years in the making of Japanese tategu, especially wooden doors, shoji, ranma, and free-standing screens (tsuitate). Nowadays, commercial joiners (tategushi) cut mortises mostly by machine, but traditionally, all joints were cut by hand, so the old boys were required to do very precise work, very quickly, frequently cutting hundreds of small mortises for a single screen or door. The daruma gennou exceeds at this precise, repetitive, speedy work where the chisel is almost always oriented vertically in the cut, the workpiece is almost always located at an unchanging height from joint to joint, and the hammer is not so much swung at the chisel as dropped on it to ensure a very predictable depth of cut with stability not being a significant problem making the daruma suited for very precise cuts in narrower workpieces such as door and furniture parts.

For example, when cutting joints in shoji, the material remaining at the bottom of a mortise cut in a stile to receive a rail may be only be 1/4 millimeter thick, almost translucent, so if care is not taken, the chisel will cut all the way through ruining the stile. To avoid this, the joiner needs to be able to control the depth of cut very precisely, and rather than swinging the hammer, it is more-or-less allowed to drop imparting uniform impact forces than would be more difficult to achieve by swinging the hammer. The hammer should not rebound from the chisel but transfer all its energy for smooth, consistent cuts. When used properly, a daruma genno feels like it is sucked towards the chisel, and when it strikes, it feels like it sticks to the chisel for a fraction of second with little or no rebound providing excellent control and more precise control of the depth of cut. This technique takes lots of practice to master.

I have seen carpenters in Japan laugh at a fellow that brought a daruma gennou to a jobsite because the stumpy things are thought by many carpenters to appear clumsy. I must agree. Also, they assume that a fellow that uses a hammer with a face as big as a daruma does so because he has a hard time finding the end of his chisel with a standard hammer. They may have a point. 

For reasons unclear to me, Americans and Europeans have an illogical affinity for the daruma gennou. That said, when I need to cut a lot of small, precise mortises, I use a daruma. When I need to cut bigger or deeper mortises, or mortises at angles, however, I bring out a standard gennou of the appropriate weight for the relatively greater stability they provide. If you only have one gennou, the standard ryouguchi style head or even yamakichi style would be a good choice.

In the next chapter in this bodice-ripping yarn of romance and intrigue we will examine a more sinister application of the gennou hammer, namely kigoroshi, or “wood-killing.” Please use the bathroom before reading it to avoid embarrassing accidents.

YMHOS

Previous Posts in The Japanese Gennou & Handle Series

Part 1 – Introduction

Part 2 – Ergonomics

Part 3 – What is a Gennou?

Part 5 – Kigoroshi

The Japanese Gennou & Handle Part 3 – What is a Gennou?

What we have is given by God and to teach it to others is to return it to him.

Gian Lorenzo Bernini
56-1
Kiyomizu Temple, Kyoto, Japan

There are as many varieties of hammers in Japan as there are in western countries. With one notable exception, and in one specific application, Japanese hammers are not especially superior to their western counterparts. That exception is the gennou (pronounced gen-noh), a hammer intended specifically for striking chisels, adjusting plane blades, and crushing wood (i.e. “kigoroshi” or “wood killing”). This article will provide a further introduction to the gennou hammer.

What Is a Gennou?

A box-stock, garden-variety, economy Japanese gennou hammer with a one-size-fits-somebody handle

The Japanese have different terms for different hammers, of course. A hammer used strictly for driving nails, or banging sheet metal, or driving stakes is called a “kanazuchi” meaning “steel mallet.” The gennou (pronounced gen-noh), on the other hand, can be used to drive nails, but it is also suited to striking chisels and adjusting planes. The word genno was borrowed from the name of a buddhist priest who lived, or so the story goes, in the 1300’s and used a steel hammer to destroy a poisonous rock that was troubling the common folk. I’m not sure what one has to do with the other, but there you are.

The Attraction of the Gennou

Many Japanese craftsmen often have an emotional attachment to their gennou. Perhaps this is because, unlike saws, chisels, and planes that are gradually but inevitably sharpened away until almost nothing remains, or squares or making gauges that loose tolerance or wear out, a quality gennou will last for a lifetime relatively unchanged other than the occasional replacement handle. A good gennou is a simple, reliable, hardworking friend that never complains. It doesn’t have a pigtail; It doesn’t need to be sharpened. And most importantly, it will never ask a dangerous question like “do these pants make my butt look big?”

Technical Matters

The gennou is a simple tool consisting of a steel body of some shape or another and a wooden handle. The head has a rectangular hole called the “eye” in English and “hitsu” in Japanese to receive the handle’s tenon. A high-quality gennou with a good eye and a handle made by a skilled craftsman doesn’t have wedges or other silly contrivances to connect the two.

The steel used is typically designated SK, a standard high-carbon tool steel made in Japan used for making hammers, axes, and many other tools. It is very similar chemically speaking to 01 steel in the Americas. Not as pure as Hitachi Metal’s Shirogami or Aogami steel, but still completely adequate for hammers. I wouldn’t pay extra for a gennou head made from Shirogami or Aogami steel, and you shouldn’t either

Mass-produced gennou are drop-forged very inexpensively. The eyes are rough and the handles are secured with wedges. Indeed, the eyes are typically so irregular that the head will not stay on the handle without wedges. A gennou head with rough and/or irregular eyes can create unnecessary problems for the user.

“Irregular” has several connotations when talking about gennou eyes. One obvious problem is an eye that is not truly rectangular. For instance, it may have curved, twisted walls, wonky interior dimensions, or interior corners that are not square. Not only is it a pain in the tuckus to make a handle to fit an eye with these deformities, but you can bet your sweet bippy it will cause the handle tenon to loosen up sooner.

Another irregularity commonly seen in the eyes of poor-quality gennou is rough interior walls. You would think that rough walls would hold onto the tenon better, and perhaps they do compared to highly-polished walls, but rough, uneven walls tend to wear-out the tenon and cause it to loosen over time. Imagine the vibrations the tenon is forced to absorb through those walls and the grinding motion between wall surface and handle that results.

An intentional irregularity frequently seen is end walls (versus the longer side walls) that are sloped from each opening towards the center of the eye, essentially making the eye bulge inwards in the center. The purpose of these bulges is to crush the wood of the tenon when it is forced into the eye, increasing friction, while also providing a dovetail-like area for the steel wedge to expand the eye back into. It is a reasonable solution for rough, irregular eyes in low-cost hammers to be used by amateurs, but one that the craftsman that truly understands gennou and wants a lifetime tool finds undesireable. We will touch on this detail more in future posts.

Still another irregularity the careful craftsman must watch out for is an eye that is not perfectly centered in both axis in the head. You might think that an eye that is a little skewampus couldn’t make a big difference, but it does because, not only is the balance and center of mass of such a head also skewampus so that the head tends to twist during the swing and wiggle on impact, but because making handles for such a head is unnecessarily troublesome. A clean, uniform, straight, properly-centered eye is worth every penny it costs, especially if you are a professional and consider your time and sanity of any value.

A difficult question I am frequently asked is “how much irregularity is acceptable?” The answer is simple: If you think it is too irregular, then it is, because the work to correct the defect or compensate for it will all be on you.

Please understand that properly correcting major defects in hammer eyes is hard work. It takes time, concentration, a good eye, a flashlight, and a deft hand with skinny files and rulers to remove just the right amount of metal in just the right places inside that narrow eye, a task that is much more difficult than removing metal on an exposed surface because the files are thin, it’s hard to see what you’re doing, you don’t have much leverage, and consistently making a straight pass is not easy. Try it yourself and you will quickly see why.

This is the whole point of high-quality heads like those made by Kosaburo and now Hiroki and why they are worth the high cost: Their eyes are true when new, no adjustment necessary, saving the purchaser many hours of tedious work and blisters. Every time you make a handle for a high-quality head, it saves time and leaves you with a good feeling. It’s a friend. On the other hand, a poorly-made head is a curse, a money-pit (if your time is worth anything), and a frequent source of irritation (especially when the head loosens inexplicable) its entire life.

I hate to say it, but our Beloved Customers should watch out for one last defect when purchasing an expensive handmade gennou head. A perfect eye is truly a difficult thing to make, certainly more difficult than making a head cosmetically beautiful. Unfortunately, one or two famous blacksmiths (who shall remain unnamed in this series of articles, so don’t ask) have earned a reputation among knowledgeable professional woodworkers in Japan for occasionally making gennou with skewampus, eyes. Caveat emptor, baby. She may wear high-heels, a short skirt and be beautifully made-up, but if she has a curly tail and oinks she’s probably be a pig, unless she’s a boor.

If you cannot hold and eyeball an expensive gennou head before concluding the transaction, at least make sure you purchase from someone with a solid guarantee, one with no weasel-words and that reimburses you for return shipping, like C&S Tools’s guarantee does. A guarantee that you must argue about and then spend more money to benefit from is less than half a guarantee IMO.

We will delve further into the tempering and differential hardening of gennou, as well as laminated gennou heads in future posts in this series, same bat time same bat channel.

Why Use a Gennou for Chiselwork?

This is a questions we addressed in a previous post, but which we also examine further here.

Almost any striking tool, from steel hammer to leather mallet, can be used to strike a chisel. The problem is that, unless one is either gentle or the handle of the chisel is reinforced, a steel or even brass hammer will eventually destroy the handle. The solution in the West in the last century has been to use a mallet made of wood, leather, rubber, or plastic instead to cushion the blow and preserve the handle. Let’s consider this for a moment. 

The purpose for striking a chisel with a hammer is to drive the chisel into and through the wood by cutting it, right? But a soft-faced wooden mallet deforms when it impacts the chisel cushioning the blow and wasting energy through this deformation as well as generated heat. It may also waste energy through air drag, as we discussed in the Part 2 of this series. Since energy is lost, more mallet strikes are necessary, wasting time. This is demonstrably counter-productive.

Besides being relatively soft, a mallet is bulkier, slower to swing, has a huge face, and is therefore less precise than a smaller steel hammer. While there may be some that are thrilled with cutting slowly and expending extra time and energy in the process of cutting a joint, most people want to cut as much wood as possible, as precisely as possible, in the shortest amount of time as possible, and with the least energy expenditure possible. But if a chisel handle is so fragile that one must sacrifice time and energy to keep it intact, then it is only logical to conclude that there is something wrong with the design of the chisel.

Ise jingu Shrine, Mie Prefecture, Japan

The Japanese are very serious about woodworking, as anyone who has gone to Kyoto or Nara and seen the ancient wooden temples there can attest. When it comes to chisel work, Japanese carpenters don’t tolerate such silly nonsense as a chisel that must be coddled, and quite early developed a wooden-handled chisel that can be struck hard with a steel hammer all day long without breaking. 

When using a Japanese striking chisel (versus a push or paring chisel) with a hard steel hammer, as much of the user’s energy and time as possible goes into actually cutting wood. The same cannot be said of mallets made of wood, rawhide, or plastic.

The excellent design of the Japanese chisel combined with the quality of steel, and the forging and heat treatment techniques used in manufacturing most Japanese chisels provides a tough cutting edge that stays sharper, longer, placing Japanese chisels at the very top of the evolutionary pyramid of chisels. As the Japanese are wont to do, they developed a hammer specifically for striking chisels.

Most hammers intended for driving nails have a domed face which does not work well with Japanese chisels because it tends to dish out the end of the handle causing the hoop to loosen. This can even result in the handle cracking or splitting. A flat-faced hammer is much better. The Japanese double-faced genno has one face that is forged flat, for striking chisels, and an opposing domed face for driving nails or performing “kigoroshi.”

The simplicity of the design combined with these two types of faces are the primary reasons we recommend using the gennou for motivating chisels.

And while one could grind the face of a Western claw hammer flat and use it to strike Japanese chisels without any problems, the gennou is a hammer that is designed specifically for striking chisels. In my opinion, it is a superior tool for the intended purpose.

In the next post in this series we will examine three varieties of gennou to help you decide which is best for you.

YMHOS

Pagoda at Horyuji Temple, registered as one of Japan’s National Treasures.

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.

Previous Posts in The Japanese Gennou & Handle Series

Part 1 – Introduction

Part 2 – Ergonomics

Part 4 – Varieties of Gennou

Part 5 – Kigoroshi

The Japanese Gennou & Handle Part 2 – Ergonomics

“We become what we behold. We shape our tools, and thereafter our tools shape us.” – 

Professor Marshall McLuhan
A Kosaburo hand-forged gennou head on a Black Persimmon handle

Marketing and mass-production have changed many things, but not how the human body works.

In this post we will examine some ergonomic factors of hammers you may find interesting, and ask some questions you may want to consider.

Ergonomic Factors

Making tools that fit the user’s body and way of working is an old idea. Here is an example.

Since the time I was a boy with a Daisy BB gun, I have enjoyed making beautiful rifle stocks using marbled walnut for my bolt-action guns and curly maple for flintlock longrifles. But a custom gunstock is not just a chunk of beautiful wood.

During my research into the art I learned how craftsmen have, for centuries, made custom shotgun and rifle stocks to fit each customer’s body. Indeed, unlike factory stocks, custom gunstocks are not straight, but are bent, twisted and offset in subtle ways to fit their user’s bodies to provide a steadier hold, quicker target acquisition, and reduced recoil. These techniques work.

Indeed, there’s a surprising number of calculations one must crunch, measurements that must be made of the rifle’s components, and details of the user’s body that must be determined in advance of designing a custom rifle stock. I’m talking about a rifle made using thousands of dollars of wood and precision-machined steel, designed to fit a particular person’s body, and intended for a particular type of shooting, not a K-Mart blue-light-special killer of unsuspecting tin cans.

Through trial and error and handwork I learned how employing these ergonomic principles could yield significant improvements in the performance of everything from reproduction flintlock longrifles to 1000 yard target bench guns, and even .45 caliber bolt-action elephant rifles. When I heard that a group of specialist Japanese carpenters had, over centuries of experimentation, developed tool handle designs that applied similar principles, the pieces clicked together in my mind like a Purdy double-gun’s breech.

A hammer is not a complicated piece of precision machinery like a modern benchrest target rifle, so we tend to think of the hammer as a stupid tool lacking finesse, but I disagree. Let us consider some of the challenges the lowly hammer is expected to meet that an ergonomic design can help it overcome.

The first challenge is air drag. The hammer is the most dynamic handtool a woodworker uses, moving relatively long distances at relatively high speeds. And during the swing the hammer pushes a lot of air aside creating drag and expending energy. It adds up. This is just one reason why big-faced mallets are inefficient compared to a steel hammer. There are those who will revel in their ignorance by disputing this fact, but to them I say: There is no medicinal cure for stupidity so learn some basic math. If you remember your freshman physics classes, you will recall that the formula for drag in a fluid (which includes air) is as follows:

F_{D}\,=\,{\tfrac {1}{2}}\,\rho \,v^{2}\,C_{D}\,A

where F D is the drag force, ρ is the density of the fluid, v is the speed of the object relative to the fluid, A is the cross sectional area, and C D is the drag coefficient, a dimensionless number.

The drag coefficient depends on the shape of the object and on the Reynolds number {\displaystyle Re={\frac {vD}{\nu }}},

You don’t need to input actual numbers into this formula to see that the two factors in this equation we can readily control are the area of the hammer (A) and its speed (v). The factor that we can manipulate to our benefit when designing our handle is the area (A), which includes not only the size of our hammer’s face but the width and length of its handle.

Second, when using our hammer we draw its head back beyond the range of our vision, and then, without looking, swing it with great force to precisely hit targets as small as a chisel handle or nail head, while avoiding hitting our own head, ear and hand. If the hammer’s head naughtily wiggles out of proper alignment during the swing, a headache or smashed finger may result, so we need a hammer head and handle combination that will be easy to keep in alignment during the swing without giving it a lot of thought.

The third challenge our hammer must overcome is the tendency of its striking face to impact the target with its center of mass misaligned with the centerline of the nail or chisel, or with the striking face canted forward or backward or to the side instead of square to the target’s centerline. Think about this next time you bend a nail or your chisel cuts in one direction when you wanted it to cut in the opposite direction.

A person proficient in using mass-produced hammers must train their eye and body to match the hammer they are using at the moment. Of course, this can be done, but it is inefficient. What I am proposing instead is to design our hammer handles so they match our individual bodies and the work we need it to perform instead of being forced to adjust our grip and swing to fit standard one-size-fits-nobody design parameters.

A lot of blowhards and marketing departments give lip-service to so-called ergonomics, but not here at C&S Tools, madame. Indeed, in future posts in this series we will discuss in great detail a number of ergonomic factors our Beloved Customers should include in their gennou design specific to their individual bodies and style of work, including the length of the hammer handle, twist and offset, grip location and shape, handle details to help the gennou index automatically in their hand without having to actually look it, and of course, the angle of the head.

We will both explain why and show you how to design, draft, and make a hammer handle suited to overcome these challenges while in your hand.

Questions

I am not fond of gaudy, decorated tools, but that does not mean my tools are plain as mud. As you may be able to tell from the photographs of one of my favorite gennou in this article, I enjoy subtle details that give them a unique attractive appearance, especially if those details improve their performance. My gennou are tools that please both my eyes and hands. I don’t know if they have shaped me, as Professor Mcluhan suggests, but they certainly give me more confidence and joy in my work than a run-of-the-mill rubber-handled hammer ever could.

For years I have encouraged people to ask themselves three questions on the subject of hammers. So I pose them to you now, Gentle Reader.

First, does your hammer and its handle fit your body and style of work, or is it a “one size fits nobody” product made by a conglomerate that knows everything about selling hammers but nothing about using them?

Second, is your hammer aesthetically pleasing to your eye and an extension of your hand, or is it like every other hammer that ever fell off the hardware store’s rack?

And finally, is your hammer likely to become an heirloom appreciated by your descendants, or will it end its days sad and lonely in a landfill?

If you answered nay to any of these questions, I promise you will find something of value in this series of posts.

In the next post in this series on designing and making gennou handles, we will examine some history and the ergonomic factors that resulted in the design that is the subject of this series.

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.

Previous Posts in The Japanese Gennou & Handle Series

Part 1 – Introduction

Part 3 – What is a Gennou?

Part 4 – Varieties of Gennou

Part 5 – Kigoroshi

The Japanese Gennou & Handle Part 1 – Introduction

I do think a carpenter needs a good hammer to bang in the nail.

Oliver Reed

Introduction

This is the first in a series of posts about the Japanese gennou hammer (pronounced “gen-noh) in general and and how to design and make a unique one that perfectly fits your body and style of work.

The objective of these posts is to share with you, Gentle Reader, what I have learned over the years about gennou handles to help you design and make your own handle.

I will gladly share the entire series, including the drawings, as a single document with Beloved Customers upon request.

The True Craftsman Makes His Own Tools

A handful of generations ago quality high-carbon steel was difficult to make and expensive, so woodworkers worldwide, especially Japan, could not afford many tools, and the ones they did own or inherit were very important to them.

At least partly to reduce costs, it was standard practice back then for a woodworker (or his master) to commission the metal parts of his tools, such as the heads of his axe, hatchet, adze and hammer, and the blades of his chisels from the local blacksmith. In the United States or other British colonies a craftsman may have purchased chisel and plane blades imported from Sheffield, but he would not want to pay the high costs of shipping wooden components across oceans and over mountains when he could make them himself. After all, woodworking was his business, so a self-respecting craftsman would make all the wooden components of his tools, such as handles and plane bodies, himself as a matter of course. Needless to say, those old boys knew how to make handles.

But things have changed. You may not realize it, but we live in a time of extreme wealth where even the poorest live better than most humans did 100 years ago, partly due to widespread industrialization of all aspects of our societies making the necessities of life, and even what would have been called luxuries, available to everyone cheaply. This industrialization combined with cheap transportation has resulted in craftsmen purchasing pre-manufactured many things they would have made for themselves as a matter of course, including tool handles. I would wager that most woodworkers younger than 60 years old have never made an axe handle, hammer handle, or a plane body, and don’t even know how to.

Accustomed to the easy availability of standard tools, lacking an eye for performance and focused like a laser on lowest cost, most woodworkers nowadays get by with poor quality tools made by farmers in Chinese factories from poor quality scrap metal designed by kids using computers working in marketing departments that have never used a handtool professionally. Those tools may look great on the internet or wrapped in theft-proof plastic hanging on pegs in the big-box retailers, but how do they perform? And how long will they last? And what do they say about the men using them? Tools are terrible gossips, you know.

You cannot purchase a hammer handle like the one we will discuss in this series, and no one can make it for you. A hand-forged gennou head fitted with a handle made in accordance with the guidelines presented in this series will become a unique lifetime tool and the sure sign of a superior craftsman. More importantly, it will help you work more efficiently and give you greater confidence in your skills.

If you think this all sounds too good to be true, I challenge you to put it to the test. In fact, there will be a series of performance tests listed in the last post in this series that will allow you to generate hard proof of the truth of these claims for yourself. You will be impressed with the results.

While Japanese hammers are the primary focus of this series, you can apply the ergonomic principles and solutions I will describe to all varieties of hammer and axe handles.

Modern Tools: Marketing, Design & Manufacturing

I grew up using hammers designed for maximum sales in a competitive marketplace of amateurs, of the type I call “One Size Fits Nobody.” Back then they were made in the USA, but nowadays they are cheaply mass-produced in China. Prices are rock-bottom, and quality is focused solely on getting an attractive product out the door at the right price-point while fending off the hordes of snaggle-tooth slavering lawyers that specialize in product liability and personal injury lawsuits. To these corporations, you and I are beasts in a herd, of no import beyond the content of our wallets and our willingness to open them.

Like the cover of a manga comic book, mass-produced modern tools are carefully designed to immediately draw the eye and excite the senses of those passing by. Bright colors and futuristic shapes war with each other for attention on the pegboards of big-box retailers. Handles are made of plastic and rubber over steel or fiberglass, secured with globs of glue intended to hide malformed ulcerous eyes.

The designers of these blister-makers and nail-benders intend their products to age poorly so they will be discarded by purchasers after just a few years to ensure unending sales of new-and-improved replacements. Plastic and rubber are the materials of choice because they are cheap to fabricate, easy to make colorful, look exciting when new, and speedily surf the spiral wave into the depths of the toilet of planned obsolescence. 

The international playboy that Billy Crystal introduced the world to in “Nando’s Hideaway” might have been talking to one of these hammers when he said “This is from my heart which is deep inside my body: You look mahvelous, absolutely mahvelous dahling. Remember, it is better to look good than to feel good.” Perhaps these tools do look mahvelous hanging on those pegboards. But how good do they feel?

The tool conglomerate’s product development departments and marketing geniuses have taken the Latin Lover’s philosophy to heart. They know that tools that look good and turn to garbage quickly sell better and are more profitable than tools that merely feel good. I am sure ‘Nando would go “crazy nuts” if he observed modern hammers in their natural environment, but alas my friends (saludos, my darlings, you know who you are), Nando will not make the journey to a big-box home center to inspect their pegboard tools because he does not feel good.

Clever people these marketing strategists, stuffing their pockets with money and landfills with plastic and scrap metal by selling imitation tools to the herd. But as for me, I’ll have none of that churlish fraud, than you very much.

Would you buy a hammer like this? If so, please don’t call yourself a craftsman or operate heavy equipment.
Wow, a comprehensive torture kit. And just the right color too. Please don’t puke on your computer or smartphone.

Hammer Handle Morphology

The hammer is an extremely simple tool, literally as old as rocks. I suspect humans made the first multi-component tools by attaching wooden handles to stones to make hammers, axes and clubs. 

People have all but forgotten how to make a proper tool handle nowadays, but it wasn’t always that way.  Everyone made their own replacement handles only five generations ago, and their expectations were guided by sweat and blisters. They didn’t need product development departments in Shanghai to tell them what handle worked best.

Axes are an obvious example of how marketing has morphed handle design. Take a gander at an old tool catalog and notice how axe handles have become thicker and curvier in the last 120 years. Do these changes mean that for millennia humans didn’t know how to use axes or make proper handles for them? Do modern human joints and tendons endure the higher vibration and impact forces a thicker, heavier, stiffer handle transmits better than those of our forefathers? Has the nature of modern trees changed such that grain runout no longer weakens a handle made from their wood? No, these recent changes in handle design are not intended to make tools more functional, or more durable, but are rather intended to increase sales of cheaply mass-produced tools of apparently innovative design, but of mediocre quality and disposable utility. They simply look mahvelous, absolutely mahvelous dahling, especially as an illustration in a catalogue or hanging on a peg in a hardware store.

But please, don’t get me started on modern mass-market saw handles.

In the next post we will look at the history and types of gennou hammers. In the meantime, here is some music from Fernando.

YMHOS

PS: Here is an excellent article about the “Devolution of Axe Handles” that jives well with my research and experience, and the advice my grandfather gave me about making an axe handle 50+ years ago.

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. I swear it on a stack of bibles.

Subsequent Posts in The Japanese Gennou & Handle Series

Part 2 – Ergonomics

Part 3 – What is a Gennou?

Part 4 – Varieties of Gennou

Part 5 – Kigoroshi

Hammers to Use With Chisels Part 6 – Hammers & Health

I wanted a perfect ending. Now I’ve learned, the hard way, that some poems don’t rhyme, and some stories don’t have a clear beginning, middle, and end. Life is about not knowing, having to change, taking the moment and making the best of it, without knowing what’s going to happen next. Delicious Ambiguity.

Gilda Radner
A box-stock hardware store gennou hammer. Delicious Ambiguity. A good place to start.

In previous posts in this series about hammers to use with C&S Tools’s chisels, we looked at factors such as the type of hammer to use, the sort of face a hammer should have, how much it should weigh, and how to use hammers and chisel as a dance team effectively. In this final post we will look at how the hammers can impact our health.

Health Matters

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Swinging a hammer is a violent movement that places large, repetitive impact and vibration stresses on joints, tendons, nerves and muscles. These stresses can make our bodies stronger, or break them down. Carpel tunnel syndrome in office workers clicking away at computer keyboards gets all the attention, but hammers are much more likely to cause health problems. Before nailguns it was common for carpenters to have nerve damage in their hands and arms. Chopping dovetails with a pneumatic chisel is not an option, however.

When I was a young apprentice carpenter working in Las Vegas I wanted to be like the older more experienced carpenters on the jobsite that used shiny 32oz waffle-face Vaughn hammers to drive 16d nails through stacked 2×4’s in a single swing (this was before the advent of nailguns and LGS studs). I got where I could do that. I still own that hammer, although it is no longer smooth and shiny, and I have replaced the wooden handle 3 or 4 times.

I barely remember him, but he was a young man with lots of energy focused on gaining respect and being productive. Fortunately, I was blessed to work on crews led by older guys with no ego left, whose joints ached (like mine do now), and who just wanted to get as much good work done as efficiently as possible each day until beer-thirty. What I learned from them went beyond wacking nails, and more about actually building things. 

At first I wondered why the bosses would hire old farts when younger guys moved faster and got more work accomplished. What I learned, however, was that while the old guys did not appear to be as active as the younger carpenters, at the end of the day they had always accomplished more actual work, and with less rework. It was difficult for the young man I was back then to accept, but the bosses new their business, including two important points:

  1. “Fast” and “productive” are not the same thing (the tortoise and the hare principle, “Festina lente“);
  2. Rework takes more than twice the time and money to accomplish than doing the work right the first time.

These two principles are key to being a successful professional woodworker, so a forehead tattoo might help to remember. Just a suggestion….

None of those old boys I worked with used extra-long extra-heavy hammers because they knew that productive work required driving nails of different sizes in many different directions (not just straight down or straight forward) more accurately with fewer misses, something a heavy single-purpose framing hammer was not suited to. They knew how to avoid wasted motion and time. They knew about rhythm.

They were not what could be called kindly gentlemen, but looking back I prefer to imagine they were looking out for me when they said things like “bring us more 2×12’s, quick now dammit,” and “stop being a pain in the ass, kid.” Ah yes, good times.

They were prophets too when they warned me that the stresses I placed on my hands, arms, knees and back when I was young and dumb and full of something may not hurt at the time but would hurt every day many years later. It truly pains me to admit it, but those crusty old farts might have been right.

So in memory of those cranky carpenters who are sorting boards in the big lumberyard in the sky nowadays, let me summarize three pieces of profound wisdom they taught me. Do with them as you will. If you still have room, you might want to add them to that forehead tattoo you’ve got going (ツ)

First, strive to use your hammer efficiently with minimum force, minimum wasted motion, and minimum stress on joints and tendons. Or as they put it: “less swingin more hittin.”

Second, use an efficient hammer of the right type and weight that will get the job done without damaging your joints and tendons.

And third, stop being a pain in the ass.

Just be thankful that I am kinder than those crusty critters were and will tell you clearly in words what they communicated to me only with grunts and curses and boots while chewing on stogies and chortling as they watched me struggle with concrete form-work 16 feet in the air like the proverbial amorous monkey with his football. Yes, love was in the air…

Indeed, just to prove what a sweetheart I am, here are two more pieces of detailed advice specifically related to hammers: First, determine the style of hammer and weight that works best for you and the work situation. This will take experimentation.

Second, make handles for your hammers that suit your body and the combined natural frequency and the work you use them for instead of settling for the usual one-size-fits-nobody hammers hanging like noxious neon-colored plastic fruit on the walls of big-box retailers.

This last point will be the subject of another series of future articles.

That forehead tattoo is down past your chin by now, I suppose.

Series Summary

For such a simple subject this series has been rather long. Let me summarize what you should take away:

  1. Use a steel hammer to strike Japanese chisels instead of a mallet made of wood, rawhide, rubber, plastic or brass;
  2. Use a hammer with a flat, polished face to strike your C&S Tool’s chisels for greater efficiency and to increased lifespan;
  3. Through experimentation, determine and use the hammer weight(s) that best compliments the chisel’s weight and width, the hardness of the wood, and the natural frequency of your hand and arm;
  4. Make a handle for your hammer that follows sound ergonomic principles (versus marketing hype), fits your body, and helps you work with greater speed and precision;
  5. Less swingin more cuttin;
  6. Cut the wood with a sharp blade instead of beating it to slivers and prying it out with a sharpened screwdriver;
  7. Control your chisel’s depth of cut to prevent the cutting edge from binding in the wood, slowing the work down, and dulling the chisel;
  8. Do the “chisel cha-cha” but never the “chisel wiggle;” just don’t.
  9. Don’t use the chisel to lever out waste, but instead flick waste out of joints with a quick twist of your wrist without slowing down or setting aside chisel or hammer;
  10. Work to a rhythm to maintain your cutting pace and focus.

YMHOS

Other Posts in this Series “Hammers to Use With Our Chisels”

Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

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. May the fleas of a thousand camels infest my crotch if I lie.

Hammers to Use With Chisels Part 5 – Rhythm & Song

This life’s hard, but it’s harder if you’re stupid.

George V. Higgins, The Friends of Eddie Coyle
A specialized chisel used for cutting precise acoustic hollows into the underside of a thick wooden gameboard called a “goban” used to play the Japanese game of “Igo.” This carefully designed hole is intended to tune the clicking sound the white and black stones used in the game make when they are are placed on the board, a sound considered critically important to the quality of the game. The chisel is designed to produce a cleanly radiused internal corner where the walls meet, precise work that requires a delicate dance by chisel and hammer, especially in a production situation. Don’t ever let anyone tell you that using chisels is not elegant and artistic.

In previous posts in this series about the characteristics of the hammers our Beloved Customers should use with C&S Tools chisels, we looked at factors such as the type of hammer to use, the sort of face a hammer should have and how much it should weigh. We even examined ways to use our chisels and hammers more effectively when cutting mortises, and how to avoid the dreaded chisel wiggle. It was a footloose post.

In this post we will delve a little deeper into how to use hammers and chisels as a dance team.

The photos above and below are of gameboards, and while gameboards are not really the subject of this post, these photos illustrate an aspect of precise work with chisel and hammer intended not to create a shape to please the eye, but an artistic sound to improve concentration. Perhaps you never have thought about using a chisel to make beautiful sounds, but many of our Beloved Customers that make musical instruments professionally are focused like a laser on this very objective. I hope you will find this little article amusing.

A masterpiece goban made in 1910 from a single block of wood. Overall height: 29cm (11.4″); 45.2×42.4cm (17.8″square) x thickness: 16.1cm (6.3″). This is the old style goban and a little smaller than modern models.

Natural Frequency

Much hammer and chisel work is very repetitive with motions repeated thousands of times in a single day, each motion consuming time and energy, hopefully with precision and speed. Are time, energy, precision, and speed important to you? I propose that “Sure and steady wins the race,” sooner and more efficiently than a 2lb steel woodpecker on meth.

If you have studied pendulums and harmonic motion in physics classes you understand that every moving object from watch balances, to buildings, to mountain ranges (yes, mountains wiggle) have a natural “frequency” that defines the vibration of that object when subjected to specific forces. This reliable characteristic is why a mechanical clock can keep accurate time. Like the pendulum in a grandfather clock, within a certain range of energy input, the longer and heavier an object is, the longer it’s natural frequency is likely to be. In the case of hammer work this means that a man with a long, heavy arm and hammer combination will naturally swing a hammer cyclically slower than a man with a shorter lighter arm/hammer combination. That does not mean one is better than the other, it just means that an arm/hammer combination will work most effectively if the assembly’s natural frequency is worked with instead of fought against.

There are several ways to reliably adjust this natural frequency, for instance changing the weight of the hammer/chisel combination, or changing the length of the hammer handle. The closer the hammer weight is to the ideal for a particular arm/chisel/wood combination the easier it becomes for us to consistently adjust the assembly’s frequency and rhythm of the cutting process while controlling the impact force and thereby the depth of cut.

Rhythm

So let’s say we have the hammer/chisel/wood/arm combination (or saw/wood/arm combination) where we need it to be and we start cutting wood in a repetitive motion. If we keep this motion consistent, like a clock pendulum, we will develop what in music is called “rhythm,” a phenomenon deeply rooted in the human beast. Rhythm is critical to cutting speed and precision. Anything that breaks that rhythm other than the job being completed is counterproductive.

Rhythm has psychological benefits too because it helps us to maintain focus and thereby accomplish more work quicker and more consistently without losing focus.

But how does one maintain rhythm when cutting mortises? Perhaps you have an internal metronome. If not, it may help to take advantage of an extremely ancient tool called the “work song,” later called the “sea shanty.” These were songs sung by men and women working in groups to coordinate their physical labor and make it more effective, whether planting rice seedlings in flooded fields, pushing wagons over mountains, dragging logs through forests, or pulling ship anchors up from the depths. If the song is in your head instead of just your ear you can easily adjust the song’s rhythm to match the natural frequency of your body and your tools.

I hum a work song when I do repetitive chisel work. I suppose two of my favorites are “What will we do with drunken sailor,” and “Roll the Old Chariot Along.” There are also lots of old plantation and work gang songs that work well. Two modern tunes I sometimes hum are “Señorita” and “Poker Face,” depending on my mood. Here is another, more unusual version by an entertaining German polka band.

Just so there’s no confusion, unlike Miss Germanotta, I don’t wear a sequin bikini and white Gestapo hat when I hum Poker Face while sawing wood or chopping scarf joints. No doubt I would look fetching in such an outfit, but I have found some of my chisels to be quite sensitive in matters of decorum. Don’t hate me because I’m beautiful.

Summary

The main points I wanted to make in this article can be summarized as follows:

  1. Whether you realize it or not, your chisel, hammer, and body have a natural frequency that you can either work with to your advantage, or fight against;
  2. Using the principles listed in earlier posts in this series you can develop a chisel/hammer combination that balances well with your body, adjusting your natural frequency to improve your productivity and precision;
  3. Develop a rhythm when doing repetitive work that compliments your natural frequency and that helps you maintain both focus and a steady wood-eating pace. Work songs really help. A sequin bikini and Ray Bans are optional.

Well that’s enough German polka music and doggie apparel for now. In the final article in this series we will examine some health matters related to hammers. Y’all come back now, y’hear.

The traditional Japanese roof structure. Notice that no members are subject to tension forces, only compression and bending. Notice also that the bottom of the central beam is finished with just an adze in the classical “naguri” style.

YMHOS

Other Posts in this Series “Hammers to Use With Our Chisels”

Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

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 conveniently and profitably “misplace” your information.

Hammers to Use With Chisels Part 4 – The Chisel Cha-Cha

Stan Laurel

You can lead a horse to water, but a pencil must be led.

Stan Laurel

In previous articles in this series about hammers to use with our chisels, we discussed the varieties of suitable hammers, the appropriate faces on those hammers, and recommended some weight ranges. In this article we will examine some important hammer and chisel techniques you should consider that will make your chisel work more efficient and help your chisels last longer.

Your Most Humble and Obedient Servant hard at work. A dab of skin lotion might be nice.

The Chisel Wiggle

Something to keep in mind about our chisels when beating on them is that their cutting edges are intentionally and carefully hand-forged and heat treated by experienced blacksmiths (none with less than 40 years independent experience) to be especially hard to meet the demands of professional craftsmen who demand the extra sharpness and cutting longevity hard, fine-grained steel makes possible. They are not the sharpened Chinese screwdrivers sold by the big corporations that amateurs are accustomed to using nowadays.

To maximize the advantage such excellent steel affords, our Beloved Customers must avoid driving the chisel so deeply into the wood when cutting mortises, for example, that the extreme cutting edge binds in the wood forcing the user to wiggle the chisel forward and backward to loosen and extract it from the cut. I call this movement the “chisel wiggle.” I know this is contrary to what many woodworking gurus teach, but it is careless in the case of our professional-grade tools because binding the blade in the wood this way creates what we call a “high pressure cut” placing a tremendous amount of clamping force on the thin, extreme cutting edge. Doing the “chisel wiggle” in this high-pressure situation will damage the cutting edge dulling it quickly. If you doubt this, please dig out your hand-dandy loupe and do a before-after comparison.

In addition, the time lost extracting the chisel and the resulting interruption in the workflow caused by repositioning one’s hands, and perhaps even setting aside the hammer (egads!) while doing the chisel wiggle, makes it impossible to maintain an efficient cutting rhythm. If you doubt this, we double-dog dare you to do timed comparative tests. The difference in efficiency will become instantly clear.

People accustomed to using Western chisels with their softer, more plastic blades made from high-alloy high-scrap metal content steel with higgledy piggledy crystalline structure are actively taught to use the chisel like a crowbar to lever waste out of cuts. This is another type of “high-pressure cut” that damages the tool’s cutting edge at the microscopic level.

The sharpened screwdrivers sold as chisels in the West nowadays are relatively soft, can’t be made that sharp to begin with, and they dull significantly during the first few hammer strikes anyway, so most people can’t detect the edge degradation the chisel wiggle and prying create. Those who are satisfied with sharpened screwdrivers don’t buy our chisels so I have no advice for those poor benighted souls, only prayers: Namu Amida Butsu. But it is of little matter: they seldom have the sharpening and tool skills required to tell the difference anyway. Horse, meet water; Ah… not thirsty I see.

The Chisel Cha-Cha

Now that we have explained what not to do, let us examine what we should do instead.

Here is wisdom: A more efficient, more craftsman-like way to remove waste when cutting a joint is to stop striking the chisel with hammer during each cut just before the chisel binds, or just before waste clogs the joint, and then, without changing your grip on its handle or losing a beat in your cutting rhythm, flick your wrist forwards or backwards so the chisel blade flips the waste out of the joint you are cutting. And Voila! No time lost extracting a stuck blade or setting down and picking up your hammer; and no repositioning your grip on the chisel. And the cutting continues uninterrupted.

Its very much a crisp dance step performed by hammer and chisel with a rhythm something like: “chop, chop, flick, (reposition chisel for next cut)… chop, chop, flick, (reposition chisel for next cut) … chop chop flick.” With each “flick” bits of cleanly cut wood fly out of the joint. But please use your hands, not your feet.

Next let’s examine the nexus between hammer weight and avoiding the dreaded chisel wiggle.

The Dance of the Hammer and the Chisel

Cha Cha

As mentioned above, the way to avoid the chisel wiggle and instead dance the more efficient chisel cha-cha is to avoid banging the chisel into the cut too deeply/tightly. You need to stop hammering just before the blade binds in the cut, precisely and unconsciously controlling the depth to which your hammer drives your chisel, stopping just before the blade binds. Easy to say but difficult to accomplish if the hammer is too heavy. On the other hand, too light a hammer is also inefficient. Therefore, there is no one-size-fits-all-situations hammer weight.

A well-balanced, stable hammer with a handle that fits your hand/arm, and of a controllable weight makes it easier to develop and maintain this precise, unconscious control. Lots of factors are involved but the weight of the hammer/chisel combination is the most important one of the bunch.

How to determine the best weight? It changes with the work and tool and material and the nut holding the hammer so trial and error is the only practical solution. But generally, a hammer that feels a bit on the light side is best. And a good handle makes a world of difference. More on that in future posts, so stay tuned.

Summary

The following summarizes the points you should take away from this series of articles so far.

  1. Select a hammer weight that balances well with the width and weight of the chisel, the hardness of the wood you are cutting, your body, and the type of cuts you are making.
  2. The hammer should not be so heavy that you cannot precisely control the chisel’s depth of cut while maintaining an efficient cutting rhythm close to the natural frequency of the hand/arm/hammer assembly;
  3. Don’t drive the chisel so deeply into the wood that it binds forcing you to wiggle the chisel, or heaven forfend, set down your hammer to extract it;
  4. Use your sharp chisel for cutting wood, not prying out waste like a screwdriver. Instead, remove waste from the joint you are cutting by flicking your wrist without stopping, disrupting your cutting rhythm, or setting down your hammer.

There is nothing to stop you from using your hammer and chisel as a graceful but oh so violent dance team, so enjoy!

In the next installment in this tale of bold hammers and graceful chisels we will examine in more detail the rhythmical motions involved in doing chisel-work efficiently and the role of the hammer in that dance. No champagne or pretty girls but there just might be a song or two.

YMHOS

Other Posts in this Series “Hammers to Use With Our Chisels”

Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

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.

Hammers to Use With Chisels Part 3 – Hammer Weight

“All that is gold does not glitter,

Not all those who wander are lost;

The old that is strong does not wither,

Deep roots are not reached by the frost.

From the ashes a fire shall be woken,

A light from the shadows shall spring;

Renewed shall be blade that was broken,

The crownless again shall be king.

J.R.R. Tolkien, The Fellowship of the Ring
Top: 375gm Yamakichi gennou head by Hiroki with new osage orange handle. Bottom: Ryoguchi-style gennou head by Kosaburo with a seasoned handle of the same osage orange. This same hammer was shown in Part 1 of this series when it was fresh and nuclear-flash yellow. With time and exposure to sunlight the color has changed to this pleasant brown. Thanks Matt for the OO!

In previous articles in this series about hammers to use with our chisels, we discussed the varieties of hammers and the types of faces suitable for using with our chisels. In this article we will examine not only hammer weights but other factors to help your chisel work go more efficiently.

Beater & Beatee

You can usually tell when a hammer is too light because the chisel or nail isn’t moved and the beater bounces off. But it’s the other end of the weight scale that causes problems so let us consider the case of too heavy hammers so we can bracket the Goldilocks weight: Not too heavy, not too light, but just right.

Some people like to use heavy hammers for striking chisels. 2~3-lb ox-killers are good for some jobs, but there are a few things you should consider before defaulting too such a heavy lump.

Is the impact force produced by a heavy hammer really necessary to drive a chisel? Not so much. But not everything we do must focus exclusively on efficiency: swinging a hammer is good exercise and it burns calories, something those with excess “ dignity,” such as your most humble and obedient servant, could use more of. However, maintaining one’s girlish figure is not adequate justification for using excessively heavy hammers in light of other factors we must also consider.

Besides the herculean strength of your mighty arm and the chisel’s durability, you should also consider the durability of your body. Swinging a hammer that is too heavy stresses muscles, tendons, and bone, stresses that can make the day long, the nights painful, and your work sloppy, if not now then certainly as you age. But if the weight of the head is a good balance with the work you are doing and you have a good handle on your hammer or gennou, things just go better. A word to the wise. We will look at this more in the final post in this series.

Let’s consider the movement of the hammer and the flow of forces that result starting at the beginning. Accelerating the hammer towards nail or chisel initially takes energy and creates stresses on muscles, tendons, bones and joints. Obviously, it is wise to keep these stresses within acceptable limits, especially if you need to repeat this movement hundreds or even thousands of times in a day. It should likewise be obvious that a hammer that is overly heavy makes limiting these stresses difficult.

Now that we have the hammer moving, let’s examine what happens when it stops as it strikes nail or chisel. Is wacking the nail or chisel as hard as possible the goal, or is the goal to drive the nail into the wood, or to motivate the chisel to cut wood an appropriate distance? If the latter, then there is a practical limit to the impact force required. In other words, driving the nail so deeply the wood is damaged, or the chisel so deeply it cuts all the way through, or even binds in the wood, is not useful, but is a waste of time and energy that damages our work product and our bodies, and that harms precision rather than improves it.

These forces and the positive and negative results are easier to control if the hammer’s weight is balanced with our bodies, the nail or chisel, and the wood. Heavier is seldom better.

Another factor to consider is the nature of the object the beater is to beat. Nails are one such beatee, but they don’t have feelings while chisels do, so I encourage you consider your chisel when selecting a hammer weight.

Our chisels are hand-made professional-grade tools intended to be used by craftsmen who demand the extra sharpness and cutting longevity only hard, fine-grained steel makes possible. Therefore they are not as tough as the soft, sharpened Chinese screwdrivers sold by the big corporations that amateurs are accustomed to using nowadays. Accordingly you should select a hammer weight that won’t damage the blades or splinter the handles of your fine chisels even if you must use them all day for days on end hard enough for the impact forces to make the handles hot. You may be as strong as John Henry, but a 2-lb hammer will destroy most any chisel given time and determination.

Weighty Matters

Of course, the harder the wood, the deeper the cut, the wider and heavier the chisel, the heavier the hammer needed. But what is an efficient hammer weight? Let’s look at some guidelines.

Oiirenomi & Mukomachinomi Chisels

For most commercially-available woods you are likely to cut with your oiirenomi chisels or mukomachinomi (mortise chisel), 180gm (6.5oz) is a good place to start when using narrower width chisels 18mm and less.

300gm (10.5oz) to 375gm (14oz) is probably good for wider chisels. BTW the standard carpenter’s hammer in Japan weighs 375gm (14oz), but this is too heavy for most precision work using oiirenomi in furniture, cabinets, and joinery work.

Atsunomi Chisels

For the heavier atsunomi chisels from 12 to 24mm in width, 375gm (14oz) is usually a good weight.

For wider atsunomi chisels, 675gm (24oz) to 750gm (26oz) is good. Maybe as heavy as 937gm (32oz) for motivating wide 48-54mm chisels when cutting hard woods if you have experience, strong wrists, and speed is not important. Yes, within limits, lighter weight hammers tend to accomplish more work quicker.

As Captain Barbossa explained the Pirate’s Code, these are “more what you’d call “guidelines” than actual rules.”

In future posts in this series we will examine factors such as how to use hammers and chisels efficiently, and how to avoid injuries.

We also have another series of posts in the batter box about making a handle for your hammer that fits your body and will work most efficiently for you. So let’s talk some more soon.

YMHOS

Related image
Harrrr. 180grams it is then matey!

Other Posts in this Series “Hammers to Use With Our Chisels”

Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

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. And that’s not a pie-crust promise.

Hammers to Use With Chisels Part 2 – Hammer Faces

Beware the Jabberwock, my son!
      The jaws that bite, the claws that catch!
Beware the Jubjub bird, and shun
      The frumious Bandersnatch!

Lewis Carroll
375gm gennou by Kosaburo with a black Persimmon handle resting on a Go board. The head is a classical style seldom seen nowadays.

This is the second post in our six-part series about hammers to use with our chisels. As with all the tool-related articles we publish, this one is based on past communications with, and in response to direct questions from, our Beloved Customers. We hope that not only our Beloved Customers (may the hair on their toes never fall out) but our Gentle Readers too may gain something from these articles.

We sell limited quantities of hand-forged professional-grade chisels to professionals who use them to please their customers and feed their families. We are tickled pink when amateurs purchase our products, but our target customer is the experienced professional woodworker. If you do your part our chisels will provide faithful, reliable service until, after many decades, nothing is left of the blade but a nub. But to make that possible, and to avoid smiles turning upside down, we insist our Beloved Customers use flat-faced hammers to motivate our chisels as a condition of our warranty. It’s that important, at least for the professional that uses his chisel even after the blade and handle become hot.

In the previous post in this series we looked at the Japanese gennou hammer with its two faces: one domed and the other flat. In this post we will examine these two styles of hammer faces in more detail. We will leave waffle-faces to the Belgians for now.

The Domed Hammer Face

Few people in industrialized countries outside of Japan have any experience with flat-faced hammers since manufacturers automatically grind a convex or domed striking face on their hammers. It’s simply what consumers are accustomed too. But I daresay few have ever considered the ramifications of the domed face.

1920x1080 Wallpaper hammer, nails, wood
An average-looking hammer. But is the shape of the domed face uniform, or is it skewampus or tilted? Is the centerpoint of the face and the center of mass of the head in-line? Good luck figuring it out.

A domed face on a hammer has some advantages. For instance, when one needs to “set” a nail with it’s head just below the flat surface of the piece of wood into which the nail is driven. But does a domed face help the hammer drive nails faster or straighter? Does it help reduce the ratio of bent nails to straight nails? Does it motivate chisels more efficiently? No, no and no.

Does this domed face look perfectly centered to you? Does it looks smooth? Can it be improved?

Another more questionable feature of the domed face (depending on your viewpoint) is that it makes it difficult to judge the accuracy of the alignment of the dome’s centerpoint in the face and with the centerline of the hammer head. Who, praytell, profits from this ambivalent construction? I’ll give you one guess, and it ain’t me or thee.

Indeed, if your working hammer tends to bend a lot of nails, I recommend you carefully examine its face with a square for center and uniformity. “Doh! (palm to forehead). No frikin wonder,” may well be your genteel reaction.

So why is a domed-face hammer a problem when striking Japanese chisels? Simply because a domed face tends to focus the impact forces on a relatively smaller area on the wooden handle than a flat-faced hammer does accelerating the wear and shortening the life of the handle.

In addition, and especially if you are skilled at hitting the handle dead-center a high percentage of the time, a domed face will actually cause the crown to try to jump off the handle and to become beaten up, sometimes even dangerously deformed, eventually damaging the handle.

The Flat Hammer Face

You can easily modify a decent-quality, properly-hardened hammer to have a flat face by simply abrading it with a grinder or sander.

Be sure you make the new face planar (flat) and truly square to the hammer’s centerline because a tilt to the left or right will make doing precise work inexplicably difficult and may lead to insanity. I once knew a frugal carpenter (read “cheap jackass”) who insisted on using a hammer with a skewampus face. The cumulative corrosion to his confidence caused his wits to wander into the weeds. A sad but common story, I fear.

If you are modifying a standard hammer with a standard handle, you may want to tilt the face’s plane a bit inwards towards the handle, but there is not adequate space in this post to discuss this modification in more detail.

Be especially careful to avoid overheating the hammer’s face while grinding/sanding it: too hot and the temper will be damaged softening the hammer’s face and ruining it. Seriously. Even a wooden chisel handle will eventually mushroom a steel hammer that has lost its temper. Here’s a guideline: If the hammer’s face becomes becomes too hot to touch with your bare finger, the temper is at serious risk.

Finally, once the face is as flat and square and smooth as you can make it with your grinder or sander, be sure to polish the face because a smooth face wears out the chisel handle slower. A final polish with 320 grit W/D sandpaper is adequate. We polish ours even finer on sharpening stones. Overkill? Yup. Why bother? Because we like purty hammers. Don’t worry, the polish won’t make the hammer face slippery.

By the way, once you have your flat-face hammer, try driving nails with it. You will find it works a lot better for everything except setting nailheads below the board’s face. A nailset works better for that job anyway.

We hope our Beloved Customers will take this article to heart for the sake of their chisels.

Summary

In this post we reviewed two types of hammer faces: domed and flat. We also considered the advantages and disadvantages of each, and explained why a flat face is best for beating on Japanese chisels, and gave an example of the brutish damage a domed face can inflict on a poor innocent chisel. Like me, some of you may have shed a tear at the sight, but I bid you take heart because we also instructed you in how to convert a common domed-face hammer of any sort to a more genteel and polished flat-faced hammer at no cost, one that will also drive nails better. O frabjous day! Callooh! Callay!

To motivate chisels efficiently, the hammer must not only have a flat face, but it must be of the appropriate weight. Of course, the harder the wood, the deeper the cut, the wider and heavier the chisel, the heavier the hammer needed. But what is an efficient hammer weight? We will examine some options in the next post in this series. Please stay tuned, my beamish boys.

YMHOS

A hand-forged square gennou head by Hiroki with a handle made from a traditional Japanese handle wood called “Kamatsu” (Pourthiaea villosa) meaning “sickle handle, also called “Ushikoroshi (“cow killer”). Despite the appearance, the head is one-piece of uniform steel, not a jigane body with forge-welded steel faces. BTW, if someone tells you that hammers with forge-welded faces are superior, direct them to the closest legal marijuana dispensary so they can maintain their waking psychotic dreams.

Other Posts in this Series:

Part 1 – Hammer Varieties

Part 2 – Hammer Faces

Part 3 – Hammer Weight

Part 4 – The Chisel Cha-Cha

Part 5 – Rhythm & Song

Part 6 – Hammers & Health

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.