Covington & Sons

A man in love is incomplete until he has married. Then he’s finished.

– Zsa Zsa Gabor

This is the last article in our series about designing and making a handle for a Japanese gennou hammer.

In previous articles in this series Beloved Customer completed designing, shaping and fitting the handle of your gennou hammer and attached the head. Then you tested it and perhaps made adjustments. Assuming Beloved Customer is satisfied with the results of those adjustments, at least for now, the time has come to sand it and apply a finish.

Finishing Options

There are a couple of approaches your humble servant might propose on the subject of finishing tool handles. The first is perhaps the oldest, and easiest, and that’s to do nothing. After all, tools are made for hands not museums, and flashy finishes too often make otherwise workmanlike tools look silly.

In addition, most woods (except for those that might cause allergic reactions) perform just fine unfinished, thankee kindly. In this “au natural” approach, you may choose to leave tool marks on the surface of the handle without sanding them into oblivion, lending your handle undeniable gravitas and dignity, even character.

An unsealed, unfinished handle will, however, unavoidably become stained and discolored, and it’s head may not stay attached as long as a well-sealed, well-finished handle. I say this from experience.

A good light-duty finish material for an au-natural handle is a quality non-slip floor paste wax like Johnson’s well-known product in the yellow metal can. Does it seal the wood? No, but it does help keep the handle looking cleaner. Why floor paste wax? Some waxes, for instance those used to polish furniture and automobile paint, are intended to provide a slick surface that encourages water to run off and to which dirt doesn’t adhere well. History has shown that slippery waxes used on floors will result in slips, falls, and a transfer of wealth to the legal profession. For the same reason, carnuba automotive wax is not ideal for tool handles, while non-slip floor wax is.

And then there are the chemical finishes such as linseed oil (BLO), milk finish, tung oil, shellac, varnish, lacquer, polyurethane, etc. To one degree or another, these chemicals tend to seal the wood reducing the penetration of dirt and oil, and (sometimes) slowing the movement of moisture into and out of the wood.

But what chemical finish is best suited to a gennou handle? It is far beyond the scope of this humble scribble to properly describe, much less evaluate, the many varieties of finish applied to wood, so I will simply provide a few comments.

Linseed oil and BLO, a by-product of the flax plant, are organic materials used for centuries if not millennia as a traditional finish in Europe. It was once used widely for paint and, until it was replaced by rubber and later petroleum products, flooring and waterproofing materials. Have you heard of “linoleum?” Of course, this was back in the day when lead was a common ingredient in paint and makeup. Linseed oil no longer has any value as a finishing material for wood because it never really dries without adding problematic, even toxic, chemicals called “driers,” it seals poorly, collects dirt, and discolors badly over time. But because it’s constantly mentioned in old writings, which many people trust just because they are old, linseed oil products are still in-use today. To advocates of linseed oil products I say “make sure you soak your oily rags in water and dry them outside well away from any fuel (like your house).”

I am a fan of the modern milk paints, but do not like it for tool handles. Nonetheless, it’s a valid option.

Tung oil is an ancient finish, but the price nowadays far exceeds its value, assuming you can even find an unadulterated source.

Shellac creates a beautiful surface coating but it’s far too delicate for tool handles.

Standard synthetic varnish, nitrocellulose lacquer, urethane and polyurethane are readily available, easy to use and can create a beautiful, durable finish, but when used in the traditional manner, the surface film coating they produce eventually chips and cracks with time, exposure to ultraviolet light, and expansion and contraction of the wood to which they have been applied. And every scratch accelerates this degradation.

Why is degradation of film finishes the a problem you say? The obvious downside of a once beautiful finish looking ratty aside, every defect in a surface film finish promotes the movement of moisture into and out of the wood, and of course increases the swelling and shrinkage of the wood it’s intended to protect. What most people don’t realize is that, as time goes by, the solvents and compounds in film finishes intended to provide flexibility in dealing with expansion and contraction of the wood dissipate causing the finish to gradually become more brittle, and break down and crack at a ever-increasing rate, independent of dings and other defects.

In modern times, the use of latex rubber in water-based paints has greatly reduced this problem, but such paints are not especially durable as a tool handle finish.

Sanding

If the au-naturel approach appeals to you, I recommend erasing marks left by files and rasps and replacing them with crisp marks and cleanly cut surfaces left by sharp edged tools like knives, carving tools, and spokeshaves. Unless a chemical sealer/finish material is applied afterward, a plain sanded finish is probably the worst surface treatment possible, whereas a surface cleaned with sharp blades will serve you better. I often use this texture for the endgrain butts of my hammers and saws.

If, on the other hand, you prefer a smoother finish, and are prepared to apply a chemical finish, then by all means sand away. But please do not sand the tenon. If you decide to sand the handle before installing the head, please apply masking tape protection to the tenon.

How fine should you sand your handle? I think 600 grit is fine enough, but I’ve gone as high as 1200 grit on fine-grained, hard woods like black persimmon. Did using such fine sandpaper make a difference? Nah.

After you’ve sanded the surface to where you like it, the next job is to eliminate hidden hairs. No, this does not involve applying hot wax to delicate areas of the body and then violently ripping out body hair so that you look delightfully-sleek in your new sequin string bikini, but rather it’s the job of encouraging the naughty ends of wood fibers still connected to the handle, but currently pressed flat onto and into the handle’s surface, to stand up so we can cut them off using sandpaper.

Dealing with these fiber is always important when finishing wood because, with time and moisture, they may pop up over time creating rough patches in the finish encouraging degradation. Once they are standing and no longer hidden, we can cut them off at the base with sandpaper to create a durable, smooth surface long-term even when exposed to moisture and sweat.

Although it’s not used much nowadays, sanding sealer was originally a shellac product developed specifically for this purpose.

To raise hairs, lightly wet the handle’s surface (but never the tenon) with water and allow it to dry completely. Some hasty people like to dry the wood quickly with a forced-air blower or even propane torch at this point to make any loose fibers stand up immediately in preparation for the next sanding pass. But simply allowing the wood to dry naturally is effective too.

This is an ancient, very effective technique. Please do this at least twice, after which you can apply the finish material.

Kanō Hōgai, Two_Dragons_in_Clouds (1885), ink on paper. Philadelphia Museum of Art. Father and son dragons are depicted playing in the clouds.

The London Finish

There’s a durable wood finishing technique I learned from custom gunstock makers that I wrote about in an earlier article about handplanes called the London Finish. This is the finish I recommend for hammer handles too. It can be as subtle or as flashy as you like.

A pretty handle is nice, but the key objectives for applying a finish to your gennou handle should be (1) to moderate swelling and shrinking of the tenon during seasonal and climactic changes in humidity; and (2) to prevent oil and dirt from penetrating the wood making it look grubby. This matters because such swelling and shrinking can cause the head of your gennou to loosen and do naughty, acrobatic stuff at inconvenient times. And a greasy, dirty handle is no way to treat a friend.

If the head is attached when applying the chemical finish of your choice (I recommend it be so), please tape it well to keep finish off the metal. Apply masking tape to the hammer head on all four sides of the eye, but leave the end of the wooden tenon exposed.

Tape the rest of the head well with masking tape.

Soak the finish material (flat varnish or polyurethane thinned 100% with high-quality thinner) into the eye and the butt as deeply and thoroughly as possible. Plan for three or four applications allowing time for the material to soak in and dry.

Do no use low VOC thinners as they contain politically-correct compounds of water, acetone, emulsifiers and other counterproductive substances the State of California’s poorly-educated but thoroughly-conflicted and richly-corrupt lawyers have determined will save the polar bears, but that will weaken the finish.

If you faceted the butt and want to keep it that way, you must be careful when sanding it or the facets will disappear. This is a matter of personal preference.

Of course, be sure to apply lots of finish to other surfaces of the handle, and wet sand them well as described in the article linked to above. Don’t allow a surface film to dry except for the first time as described in the webpage linked to above.

Hammers are lifelong tools, but too often handles are not. You can help your gennou’s head stay tight longer, stay cleaner, and look better longer by applying a London Finish instead of a thick surface film finish.

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below or email us at Covingtonandsons@gmail.com. Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, incompetent facebook, or gossipy X and so won’t sell, share, or profitably “misplace” your information. Promise.

A list of our gennou heads: C&S Tools – Gennou Hammer Head Pricelists & Photos

Previous Posts in The Japanese Gennou Hammer & Handle Series

• Part 1 – Introduction
• Part 2 – Ergonomics
• Part 3 – What is a Gennou?
• Part 4 – The Varieties of Gennou: Kataguchi, Ryoguchi & Daruma
• Part 5 – Kigoroshi
• Part 6 – The Ergonomic Anaya
• Part 7 – The Unblinking Eye
• Part 8 – Head Style & Weight
• Part 9 – Factory vs. Hand-forged Gennou Heads
• Part 10 – Laminated Gennou Heads
• Part 11 – Decorative Gennou Heads
• Part 12 – The Drawing: Part 1/6
• Part 13 – The Drawing: Part 2/6
• Part 14 – The Drawing: Part 3/6
• Part 15 – The Drawing: Part 4/6
• Part 16 – The Drawing: Part 5/6
• Part 17 – The Drawing: Part 6/6
• Part 18 – Wood Selection
• Part 19 – Laying-out the Handle
• Part 20 – Making Sawdust
• Part 21 – Installing the Head
• Part 23 – Finishing the Job

True perfection is unattainable, but if you chase perfection you will catch excellence!

Vince Lombardi

In previous articles in this series about a craftsman-made gennou hammer handle, we discussed how to design and make a handle to fit Beloved Customer’s body and way of working. This article assumes you’ve mostly completed your handle, attached the head, and are now ready to test it. So let’s get started.

Why Testing Matters

I don’t know about you, but after all the research, design and fabrication work we’ve invested in your gennou handle, I need to see how it performs and determine if its performance is superior to a Minion impaled on a stick. Being a Beloved Customer and therefore highly intelligent, you’ve asked yourself the following three indubitably perspicacious questions about testing.

1. What can I learn from testing?
2. Against what performance standards should I compare my most excellent new hammer handle (besides to a Minion on a stick)?
3. How should I conduct that evaluation?

To perfect your hammer, you will need the answers to these questions and more. You can get them over years of use, or get many of them now by testing it in a methodical manner and paying attention, but one way or another, you must get answers, bro.

Desired Testing Results

We can learn several things from testing our gennou with its new handle, but I encourage you to do your best to ascertain the following two things at minimum.

The first thing, of course, is whether or not the hammer with its new handle is comfortable and stable to use, and if possible, what needs to be improved to make it more stable and comfortable. This may entail many small details depending on your requirements and powers of perception.

Whether it’s comfortable in-use or not is subjective and entirely up to you, but you can probably identify problems easily through this testing process. Pain, soreness and blisters and the lack thereof are solid indicators (ツ).

Whether or not it’s stable in use is another important thing to determine early. Does it tend to track straight on the downstroke, or does it want to twist off your intended path of travel striking chisel handle or nail head erratically? When it hits the chisel or nail, does it convey its energy into the target smoothly, or does it wiggle like an eel on a hook on impact?

An unstable head and handle combination may perform well for one or two consecutive strikes, but because Murphy’s Law of Buttered Toast irrevocably dictates that small errors accumulate to maximize damage, an unstable head will often wiggle off-line enough for the third swing to hit weakly, even miss entirely, ruining your rhythm, damaging your confidence, and eliciting snide looks from resident bench cats. Oh, the shame…

A second thing you need to learn is whether or not the face of the hammer is striking the chisel/nail squarely and if the center of mass of the head is aligned with the vertical axis of the chisel handle or nail. Please make sure you understand the meaning of the previous sentence.

With this experience and the answers to these questions under your belt, you will be in a position to adjust the handle to perform its best for you and the way you work.

Testing Procedures

Out of an abundance of well-deserved humility combined with a strong desire to avoid looking even more the fool, your humble servant will refrain from suggesting any specific objective tests, or urge you to use quantifiable standards, or seek concrete empirical results because that would be too silly to even contemplate. Unless, of course, Beloved Customer will conduct these tests in your super-secret laboratory, possibly located at the heart of a dormant volcano on an uncharted South Pacific island, maybe covered by coconut palms with cold beer taps, probably surrounded by hundreds of horny bikini babes, likely frolicking in crystal surf. BTW, if you do have such a lab, please text me the address!

In this super-secret lab you will probably have access to equipment and software suited to more scientific, empirical, replicable methods of comparison, such as those developed for analyzing and improving the apparent performance, marketability and profitability of mass-produced sports equipment such as baseball bats, golf clubs, and green dildos (シ). Sadly, while your humble servant does not possess such equipment, most (but not all) humans own and operate one of the world’s most refined super-computers and sensor networks: our bodies and brains. I therefore propose you focus these formidable tools on this analysis. (brains and bodies, that is, not dildos).

Below are four absolutely subjective tests only you can perform, the results of which only you can evaluate.

Incorporating Test Results

To thwart the confusion promulgated by Murphy and his multitudinous malevolent minions, I strongly recommend you use the results of your analysis to guide you in making incremental improvements to your handle over time rather than large changes immediately, so to that end, please plan to remake your handle, once, twice or even thrice, improving it a little each time. Such is the true path of the craftsman.

Please update your handle drawing each time to record the improvements you’ve made and ensure no “increments” are misplaced.

In scobe veritas. (“In sawdust, truth”).

The Grip

As you are aware, for any testing other than drinking beer or women choosing wall paint color to be meaningful, some basic techniques must be established and followed to reduce variables to a manageable degree. How you hold the gennou handle to be tested is just such a basic technique.

The handle design presented in this series of scribbles is intended to work best when gripped in a particular way, so when performing the following tests, it’s important that you grip the hammer correctly thereby removing one huge, often-problematic variable.

Of course, I’m describing a particular grip here as being “correct,” but that’s just my well-informed opinion. In any case, I promise your hammer will work more efficiently if you abandon the so-called “hammer grip” (what I call the “Hobbit-killer” grip with the handle grasped in your fist) right away and switch to this more advanced grip.

I didn’t invent this grip, BTW, but observed and consulted with craftsman I respected in the USA and Japan who used it for many decades, all of whom are now working overtime in the big lumberyard in the sky. I later came to call it the “Sam Snead grip,” after the extremely successful pro-golfer of the same name who made it famous, and him rich, in tournaments and in dozens of books he wrote on the subject of using golf clubs skillfully.

We’ve talked about this grip in some detail in Part 13 of this series, but please review the photos below to confirm your understanding.

The first photo labeled “Bridging the Palm” shows how the hammer’s handle is NOT held in a fist, but is angled diagonally across the palm, supported on the first joint in the index finger, as well as the heel of the palm.

You can see how the index finger wraps around the handle while the thumb is pressed against the side so that the handle is strongly clamped between index finger and thumb, but can still pivot the handle if the operator so desires. This grip affords the joints of the forefinger and thumb, digits accustomed to fine motor control (unlike the fist), absolute control over three critical surfaces of the handle.

This grip also provides better control, more power, and greater reach without forcing the wrist to do the strange, unnatural contortions the Hobbit Killer grip does.

Bridging the palm Index finger wrapped around the handle with the tip pressing against the rounded front edge of the handle. Handle pressed between tip of the thumb and first joint of the index finger. The tip of the index finger presses against the rounded front edge of the handle, and applies most of the force required to return the handle to battery. Notice how the handle is pressed between the pad of the thumb and the side of the index finger in the famous “Sam Snead” grip.

The Three Tests

Following are three tests to help you ascertain how well your new gennou and its handle suits your body and your work style.

Before attempting these tests, however, it is important to use your new handle for a time to establish a connection between it, your hand, and your eye (using the proper grip, of course).

Besides moral virtue and a sense of humor, you will need a few things.

1. A wood chisel suitable for cutting a mortise hole, around 24mm.
2. A piece of light-colored scrap wood for cutting a test mortise hole;
3. A stick of light-colored wood approximately the size and shape of the handle of the chisel you would normally use for cutting mortise holes:
4. An ink pad, wide-tip marking pen, or Dykem.
5. A lab assistant. I recommend a buxom, young lass with a cute giggle wearing a sexy lycra lab uniform (Warning: bad stuff may happen if you let She Who Must Be Obeyed meet, or even see, this assistant!)

So, now that we have our supercomputer and its sensor suite warmed up and focused, our tools laid out, and a bubbly lab assistant standing by, sound the trumpets and let the testing begin! We who are about to dye salute you!

Test No. 1: The Blind Retrieval Test

After you have used your gennou with its new handle for a few weeks such that your hand has become accustomed to it, please give your bench dogs a few treats, shoo away any arrogant bench cats, set it on your de-cluttered bench, step back a few steps, close your eyes and turn in-place once or twice like a ballerina with hairy legs. Now, have your lab assistant, perhaps a child, a friend, a neighbor, your girlfriend, or wife, or even a clever bench dog (but never your neighbor’s girlfriend’s wife’s cat!) change the gennou’s orientation on your benchtop by turning it over, switching it end for end a few times, spinning it, or whatever. Random orientation is what’s needed.

Next, with your eyes still closed, grab the gennou with your hammer hand in a proper grip ready to rock-n-roll. Notice how easy or difficult it is to grip the handle correctly, without fumbling and without opening your eyes. If it’s not easy to do, however, you need to know it now. It may be simply that you’re not accustomed to the chisel, more importantly, it might mean the geometry or details are out-of-wack.

By “correctly” in the previous paragraph, I mean (1) the flat striking face of the head is facing away from you and toward the chisel or nail; (2) the head is aligned straight in your hand, and not twisted, (3) the heel of your hand is pressing against the flat spot on the handle adjacent the butt; (4) the distance from the center point of the face to the heel of your hand is located precisely the distance shown in your design drawing.

BTW, whether you picked up the habit from your daddy or some internet guru, choking-up on the grip is an inefficiency you should discard simply because it’s counterproductive and silly, like a powerful cane corso dog wearing flower brocade.

If your grip is shaped as shown in the drawing with a flat back edge and sides perpendicular to it, a radiused front edge, and a flare beginning at the grip area, it should be easy to instantly grip the handle in precisely the proper place, with the intended striking face oriented properly, without opening your eyes and without any fumbling whatsoever. 

If, on the other hand (the one with six fingers (ツ)), your hammer doesn’t leap into your hand in perfect alignment without argument or eyeball action, some adjustments to the handle are called for. For example, a frequent cause of disagreement between handle and hand is the leading edge of the grip being square instead of rounded. Or the sides and butt of the handle being angled wrong. These details can all be adjusted once you know they need to be adjusted

A gennou that naturally orients itself in your hand with the striking face in the right direction, the same distance from the striking face first time every time without your having to look at it, will provide you a tremendous advantage in speed, efficiency and confidence. It will become a good friend and companion.

BTW, just for gits and shiggles, try this test with any name-brand one-size-fits nobody nail bender you have laying around. The virtues of your new handle will become immediately apparent.

Test No. 2: The Blind Swing Test

This test will teach you something about handle length and other details.

Once again, perform this test after you have used the gennou with its new handle for some time and have become accustomed to it. A sexy lab assistant (one who doesn’t talk too much) in slinky woodworking togs is optional (ツ).

Grip the gennou properly in one hand and the stick shaped like your chisel handle in the other just as you would an actual chisel. But instead of placing the end of the stick against something as if you might cut it, please keep the stick in the air without butting it against anything. Now, with your eyes still closed, swing the gennou at the end of the stick of wood.

You should be able to strike the stick with the flat end of the gennou solidly and squarely on the first, or perhaps second try. Success in this test is common.

If your hammer misses the stick consistently, it may be because you are not yet accustomed to the handle, or it may be that you are chocking-up up on the grip, or maybe you need to make it shorter or longer, or the grip shape needs to be adjusted. Or it may be that Murphy keeps distracting you by sending dick pics. It’s absolutely worth figuring out.

Once again, if you consistently miss the target, pay attention to why and where you are missing. Is the handle too long? Is it too short? Are you missing off to the side? Make notes recording the results and your observations on the design drawings to incorporate in your Mark II handle.

If accuracy can be improved by shortening the handle or modifying the grip, go ahead and make the necessary changes a little at a time. It’s easy to shorten the handle, but lengthening one requires an ACME Wood Stretcher Mark 2. I can lend you mine if you don’t have one (ツ)

Test No. 3: The Ink Test

Never fear: this test has nothing to do with gossip screeds or crime scene investigation. It will help you determine if the handle of your gennou is the right length, if it is cocked at the most effective angle, and whether or not it should be canted to the left or right, and all without pulping an innocent tree.

This test works best if preformed after the Blind Retrieval Test and Blind Swing Test.

Begin by coloring the striking face of your gennou with an ink pad or by applying dark marking pen ink or Dykem to the gennou’s striking face (the flat face). Clean or sand the end of your chisel’s handle to produce a clean, white surface. Then cut a mortise using this gennou in the same posture you assume when cutting most of your mortises.

For instance, if you mostly cut mortises in wood located at a constant height on your workbench, such as drawers and furniture parts, you should employ that position. Or, if you tend to cut mortises in timbers while sitting on or straddling them using the venerable butt-clamp, please assume that position.

The impact with the chisel’s handle will wipe ink off the face of hammer and deposit it on the end of the chisel’s handle at the same time. This ink transfer will print the story you need to read. Check the ink on the gennou’s face and the end of the chisel every two strikes.

This is a time-tested technique professional golfers use to select/design golf clubs, BTW.

If the ink at the center of the striking face is scrubbed clean first, and the center of the chisel handle becomes inked first, then you have made your handle the right length with the head angled correctly. If not, you should make notes describing the results in the handle drawing you made earlier, and adjust the design of your next handle accordingly.

Again, you may find it enlightening to perform this same test with conventional hammer with a standard handle.

When your done testing, be sure to record your conclusions. Either erase and adjust the drawing, or trace over it to make and date a new drawing with your revised details. Tracing paper is our friend.

In either case, be sure to add a date and/or revision number to the drawing to ensure you don’t confuse it with older, superseded drawings. Don’t put this off but do it right away before you forget. This applies to all the tests described herein.

Adjustments to Your Handle

You should use the results of these tests to make small, incremental adjustments to your handle, as you deem necessary, rather than big, drastic changes.

For instance, you may need to shorten the handle. This is easily done if your handle is a little long and you’ve made the neck as I recommended. Worst case, make notes, adjust the drawing and remake the handle with as few changes as possible to avoid confusing over-complication.

A common correction you may want to try is, after becoming accustomed to using the hammer, to reshape the grip area to distribute pressure more evenly over the hand, and to reduce stresses induced in skin, muscle, tendons and bones by easing edges and corners while maintaining control and indexing. Most importantly, you should shape the handle so it doesn’t twist in your hand stretching your skin in uncomfortable ways, a common cause of blisters, especially in plastic-handled one-size-fits-nobody hardware store hammers.

If I may share an example from my experience, every new hammer handle I make tends to produce a blister on the first joint of my right hand index finger. Obviously a lot of pressure focus on this location on my hand. So I know to smooth the transition from back edge to the side just where this joint bears to avoid blisters.

This modification creates an obvious dent in the smooth lines of my handles, but your humble servant is resigned to sacrificing beauty for performance when necessary. Just look at the sorry state of my career as a fashion supermodel.

Another less-common problem is the hammer’s face striking the chisel handle or nail head at an angle instead of being centered on, and at a 90˚ angle to, the long axis of the chisel handle. The ink test will reveal this impish behavior.

This tendency usually improves with practice, but you can adjust for it by making a new handle with the head skewed to the left or right as necessary.

As a way to determine how much skew is required, you can plane down the sides of your test handle, glue on slips of wood, shape them as you see fit, and test the results. Once you’ve determined how much total correction is necessary, you can remake your final working handle accordingly.

Once again, work patiently to achieve small, incremental improvements, and be sure to record the results on your drawings.

Don’t hesitate to methodically scrape, shave and experiment with this first handle.

The design of this handle, and the process your humble servant has described for making it, is suited not just for Japanese gennou hammers, to all short-handled hammers and axes. Give it a try and you’ll see what I mean.

In the next article of this series we’ll apply a protective, and maybe even tastefully elegant, finish. Please remind me to call Ramon and beg him cater the unveiling party! I simply love his cheesy shrimps on crackers, don’t you?

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. To see a list of our tools and their pricing, or to contact us, please click the “Pricelist” link here or at the top of this page.

Please share your insights and comments with all Gentle Readers in the form located further below labeled “Leave a Reply.”

We see data miners and their bilious bots as dastardly sneak thieves and so promise to never share, sell or profitably “misplace” your information for any reason. If I lie may the heads of all my hammers fly away to Valinor!

Brother Saint Martin and the Three Trolls by John Bauer. Supernatural creatures are everywhere, if you have eyes to see.

Previous Posts in The Japanese Gennou & Handle Series

• Part 1 – Introduction
• Part 2 – Ergonomics
• Part 3 – What is a Gennou?
• Part 4 – The Varieties of Gennou: Kataguchi, Ryoguchi & Daruma
• Part 5 – Kigoroshi
• Part 6 – The Ergonomic Anaya
• Part 7 – The Unblinking Eye
• Part 8 – Head Style & Weight
• Part 9 – Factory vs. Hand-forged Gennou Heads
• Part 10 – Laminated Gennou Heads
• Part 11 – Decorative Gennou Heads
• Part 12 – The Drawing: Part 1/6
• Part 13 – The Drawing: Part 2/6
• Part 14 – The Drawing: Part 3/6
• Part 15 – The Drawing: Part 4/6
• Part 16 – The Drawing: Part 5/6
• Part 17 – The Drawing: Part 6/6
• Part 18 – Wood Selection
• Part 19 – Laying-out the Handle
• Part 20 – Making Sawdust
• Part 21 – Installing the Head

No one should be ashamed to admit he is wrong, which is but saying, in other words, that he is wiser today than he was yesterday.

Alexander Pope

In the previous article in this series we finished fitting and shaping the handle of our gennou hammer in accordance with our design document. Some refinements may be pending the results of testing, but in any case the time has come to attach the head.

This is an important task, perhaps not as easy as it sounds, because this is a craftsman’s handle, made with love and skill, not a mass-produced cockroach killer ground out by barefoot Bangladeshi farmers and secured with crude wedges. It’s not a typical tool of the sort sold at Home Despot designed to fail quickly and be tossed into a landfill soonest. And because the head is not secured with barbaric wedges but relies entirely on the extremely tight fit between the eye of the steel head and the tenon Beloved Customer cut on the end of the handle, some careful, but nonetheless violent action is required to successful connect head and handle. The purpose of the article, therefore, is to help you install it carefully with all due violence.

Installing the Head

Beloved Customer can install the head either before or after sanding and finishing the handle, but in this example we’ll attach the head before testing and finishing the handle. This approach will be most efficient if you decide to adjust or rework the handle after performing the tests I recommend in the next article.

In this case, I use the word “finish” to mean to apply a chemical “finish material” to the wood, not to “complete” the work or “conclude” the job. This difference in definition matters to me because confusion regarding the dual, even treble meaning of the word “finish” has caused problems for me in the past. So there you are.

Preparing the Tenon

First, remove any tape remaining on the tenon and, if necessary, use a solvent such as lacquer thinner to remove any adhesive residue. DO NOT USE soap, water, or any water-based chemical as this will make the tenon swell! After cleaning there should be no finish material, wax, oil or unicorn wee wee left on the tenon.

Depending on the relative humidity the handle is acclimated to, it may be advisable to make an effort to shrink the tenon a bit by placing the handle in a low-humidity environment for a time. Please do NOT microwave your handle, cook it in your oven, or heat it in your toaster, not even with cheese and Tabasco Sauce.

There are several ways to remove moisture from the tenon in order to shrink its width and thickness a bit without ruining the handle or burning down your workshop. Perhaps the safest way is to store it for a time in a tightly-sealed plastic container with packages of silica desiccant. Other ways include placing it in a warm spot close to an operating gas furnace, or indirectly exposing it to an electric room heater for a day or so.

If you use any method that involves heat, make sure you are nearby to monitor progress and deal with scorching and fires.

Orienting the Tenon

You’ve already shaped the handle, and shaved and lightly chamfered the tenon so it should partially fit into the head’s eye almost as deep as the chamfer, but should go no further using only hand pressure.

Please keep in mind during this process that it’s extremely important to get the tenon started in the eye straight, and to keep it straight, without allowing it to become cocked.

It’s also important to install the head in the correct orientation. This usually means it’s flat striking face is oriented towards chisel or nail, and with the brand oriented towards the handle’s butt.

Some people like to orient the head’s brand so it faces up (away from the butt) when using the hammer. I can understand this compulsion, and while it makes no difference in performance one way or the other, you should be aware that it’s seen as bass-ackwards among professionals in Japan.

Starting the Tenon

Of course, in accordance with your humble servant’s advice in previous articles, you’ve already created an elegant dome on your hammer’s butt to prevent these taps and strikes from damaging the handle.

I like to place the head on a working surface such as a benchtop or a softwood board like pine or cedar resting on the floor/ground cushioned by a piece of leather or rubber to prevent slipping.

Insert the tenon into the eye, and, after sighting the handle and head from multiple directions to check alignment, when you are absolutely certain the tenon is poised to go into the eye straight, tap the handle’s butt with a flat-faced hammer, genno (not a domed-face hammer) or mallet. After a few taps, stop tapping, check your progress, and make sure the tenon is going in straight and not cocked.

Although the tenon should not have entered the eye more than a millimeter or two, it should be an extremely tight fit, with each tap making barely any progress.

I can’t describe the sensation in writing, but if the fit is too tight at this point in the process, you may need to scrape or sand the tenon a little.

Driving the Tenon Home

This is where the “violent” part of the job I mentioned above begins.

With the tenon properly aligned and started in the eye, stand up, hold the hammer in a fist with the head hanging straight down, and strike the butt of the handle with your hammer or mallet paying attention to its progress into the eye with each strike and the friction created. Gradually adjust the impact force of your strikes accordingly. Don’t be surprised if it takes literally dozens of extremely hard strikes to install the handle completely. If the tenon just slips in, however, we have a problem, Houston.

If you find that the fit is too loose, however, don’t despair, simply shim it with quality paper as described in the last section of the previous article. Remember, most people find it difficult to get the tenon/eye fit right the first time. Such adjustments to a new handle are nothing to brag about, but neither are they something to be ashamed of. It’s more the rule than the exception until experience is gained.

Some people like to make their tenon extra-long so it projects out of the eye 6-12mm or so. Nothing wrong with this approach, but it looks silly to me in the case of a new handle. Once again, beauty is in the eye of the bean holder.

I was taught that the ideal is for the tenon of a new handle to remain recessed inside the eye a few millimeters. The purpose for this goes back to one of the reasons for the gennou handle design described in this series of articles, namely, that the handle does not have a tumorous swelling below the head but the neck is approximately the same dimensions as the eye for a portion of its length to permit the user to tap the handle further into the eye should it loosen. By leaving the end of the tenon short of the end of the eye in the case of a new handle, one provides visual evidence that (1) the handle is tightly fitted and; (2) that plenty of tenon length is available for making such adjustments.

Accordingly, a tenon projecting a long way out of the eye indicates to the knowledgeable observer that either the handle is either old and has been adjusted many times, or the tenon fit was sloppy from the beginning. In my humble opinion, a tenon of a new handle projecting from the eye a significant distance looks odd, but in practice, it doesn’t make much difference. The choice is yours.

In the next article in this series of articles about danger and violence, we’ll test you’re new handle. How exciting!

YMHOS

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. To see a list of our tools and their pricing, or to contact us, please click the “Pricelist” link here or at the top of this page.

Please share your insights and comments with all Gentle Readers in the form located further below labeled “Leave a Reply.”

We see data miners and their bilious bots as dastardly sneak thieves and so promise to never share, sell or profitably “misplace” your information for any reason. If I lie may all my hammers swim away from me!

Previous Posts in The Japanese Gennou Hammer & Handle Series

• Part 1 – Introduction
• Part 2 – Ergonomics
• Part 3 – What is a Gennou?
• Part 4 – The Varieties of Gennou: Kataguchi, Ryoguchi & Daruma
• Part 5 – Kigoroshi
• Part 6 – The Ergonomic Anaya
• Part 7 – The Unblinking Eye
• Part 8 – Head Style & Weight
• Part 9 – Factory vs. Hand-forged Gennou Heads
• Part 10 – Laminated Gennou Heads
• Part 11 – Decorative Gennou Heads
• Part 12 – The Drawing: Part 1/6
• Part 13 – The Drawing: Part 2/6
• Part 14 – The Drawing: Part 3/6
• Part 15 – The Drawing: Part 4/6
• Part 16 – The Drawing: Part 5/6
• Part 17 – The Drawing: Part 6/6
• Part 18 – Wood Selection
• Part 19 – Laying-out the Handle
• Part 20 – Making Sawdust
• Part 21 – Installing the Head

 

Woodworking minus patience equals firewood. 

– Author Unknown

In the previous article in this series, we selected and prepared the wood for our gennou handle and layed-it out in accordance with our design drawings.

The next step in the process is to gather our tools and begin the fun work of making sawdust.  Yeeehaaaa!

Tools

I prefer to use the following tools when making a gennou handle. You will need to have similar tools on hand for layout and fabrication, but the specific choice is entirely yours. 

1. Divider with sharp points (transferring dimensions and tenon layout); 
2. Sharp pencil (making pencil marks (ツ); 
3. Small try square (laying out and checking tenon); 
4. Marking gauges (Titemark and kama kebiki. Marking tenon and centerlines) ; 
5. Marking knife (layout); 
6. Rip handsaw for roughing out; 
7. Hozohiki rip saw and/or dozuki crosscut saw and/or rip saw for cutting the tenon (in hardwood, a sharp hozohiki rip saw frequently makes both rip cuts and crosscuts cleaner and more precisely than a crosscut dozuki saw);
8. A fine saw such as a fret saw or coping saw with a fine blade for making curved cuts;
9. Auriou cabinet rasp (Lie-Nielson) (optional); 
10. Bogg-pattern flat-sole spokeshave (Lie-Nielson) (optional but really handy);
11. Sandpaper; 
12. Satin Polyurethane finish (optional); 
13. Mineral spirits (optional.
14. A board to support the handle-in-progess. I suggest dimensions of 300-400mm long x 50-60mm wide x 40-50mm thick, with a “V” groove cut full-length and a cross-stop inlet about 2/3 its length. The handle will rest, more-or-less securely in this groove, and be restrained at one end by the stop when using spokeshaves and rasps. This support board can be clamped in a vise, or clamped to a workbench with a C clamp. I also find it most efficient to place this board on my benchtop with the gennou handle resting in the v-groove with one end touching my chest, perhaps cushioned by a rag, and use rasps and spokeshaves pulled towards me to shape the wood.

The Tenon and the Unblinking Eye 

Let’s start by cutting the tenon and fitting it to the gennou head’s eye. 

You’ve already layed-out the tenon, so use a fine precision rip saw like or 210mm hozohiki to cut the four cheeks being extremely careful, like a big-eyed kitten stalking a grasshopper, to stop short of the layout line. Be careful to work very precisely with your saw to not cut too deeply as any excess meat removed from the tenon, or sawcuts left in the tenon, will fatally weaken it. I’m not kidding!

I’ve made this mistake more than once, ruining all my work to that point and wasting some nice wood. Indeed, it may be best to cut the shoulders shallow and trim with a chisel, once again being careful to not cut too deeply. Ruthless, merciless, unrelenting control of your naughty inner-badger is critical!

At this point, the handle is a chunky, graceless block with square edges and flat surfaces. That’s alright. There’s no need to contour the handle yet.

Cut itsy-bitsy teeny-weeny chamfers on the end of the tenon to help guide it into the eye without cocking and binding. A big chamfer will benefit nothing and look ghastly.

Mark the reference face annotation on the corresponding tenon cheek because you don’t want to mistakenly force the tenon in bassackwards.

Test fit the tenon into the eye a few millimeters but without driving it all the way on. It should not start by hand pressure. 

Although you shouldn’t have to try tried a full-power test fit, when you are satisfied that the tenon will fit into the eye of your gennou head without the driving forces shaving off much wood, and marked the reference faces, then tape the tenon with masking tape so you don’t accidentally knick or shave it. Don’t ask me why I know this risk exists.

With the tenon close to completion, let’s next shape the curved front, back and side surfaces to fit.

The Back and Front Edges 

Cut the back and front edges (surfaces parallel with the long axis of your gennou head) to your design profile using saws, rasps and/or spokeshaves. The two guiding details in this process are the butt and the tenon, with the tenon being most important. These two surfaces should be shaped to smoothly connect the butt with the tenon, not the other way around.

However, leave the corners square for now to help guide you in shaping the critical back and side surfaces because, if you start rounding and smoothing edges and corners now, it often happens that the geometry which aligns the hammer’s face with chisel and nail will be compromised.

The tools you use don’t matter so long as when this step is complete the back edge is perpendicular to the reference face, the opposing side face, and is consistent with the layout lines. 

I recommend you cut outside the layout lines plus a millimeter or two because accidentally cutting deeper than your layout lines will not only disrupt the even flow of the design but may damage the structural integrity of this elegant, minimalist tool. 

Do not cut or shave the handle’s sides flush with the tenon yet, but leave them just a hair proud. 

When done with the this, lightly remark the centerline and extended the eye’s lines. 

The Sides 

At this point in the process the right and left sides should still be flat and parallel, perpendicular at any point with the back surface, and have neat, square corners.

Use the paper/cardboard profile pattern from your design drawing to mark the handle’s layout on the back and front edges. 

Just as with the back and front edges, cut the side surfaces using saws, a drawknife, rasps and/or spokeshaves.

The transition from tenon to butt should be uniform and smooth. As you approach the final dimensions, be careful to avoid tearout or gouging in the neck area since removing these irregularities may require you to reduce thickness too much. 

Do not cut or shave the sides flush with the tenon’s cheeks yet, but leave them just a hair proud. 

Smoothing and Rounding 

I find it most effective to leave the back edge (opposite the flat striking surface of the head) flat with slighty relieved corners. Some people like to make the back edge of the handle oval or egg-shaped, but I recommend you leave it flat at first and then adjust it to fit your hand as you use the gennou. 

Common sense will scream at you in a voice like a nazgul to round the the back surface or to make it oval-shaped, but while such surfaces might look better hanging on a peg in a hardware store, or feel better when using your hammer to kill coackroaches, it is counterproductive when doing serious work, I promise you.

Why? Because, despite what you may think, a flatter back surface does not bite into the hand in-use, but because of the greater surface area in contact with the hand it provides, actually reduces the pressure of impact reaction forces on the hand reducing fatigue and bruising. More importantly, it helps with quickly and unconsciously indexing the striking face of the head correctly.

With the back edge where it needs to be, next round the front edge into the design profile. I prefer this surface to be more-or-less a perfect radius at any point in the handle area, but some guys feel an egg-shaped cross-section fits their fingers better. Six of one half-dozen of the other.

In any case, this surface must smoothly morph into a flat surface with slightly radiused corners in the neck area, and finally with no radius as it approaches the tenon. Yes, you read correctly: no radius.

I usually round-over the flat on the back edge right where my index finger wraps around to the side just a little to avoid developing a blister. But keep in mind that the only way to tell what small details works best for you is trial and error. 

Doming the Butt 

The butt should be flat with sharp edges at this point in the process. 

You may find a domed butt strange, but it has both a practical purpose and an aesthetical one.

Let’s consider the structural, practical purpose first. If the wood is adequately hard, and the tenon is not too skinny, you will need to hammer the butt like a son-of-a-gun dozens of times to get the tenon into the eye. Don’t start yet, but when the time comes you must be careful with the direction of your hammer strikes to avoid breaking the tenon.

If the butt is flat with crisp edges, unless you have perfect aim with every swing, your hammer might chip or even split the butt. A domed surface directs impact forces away from the edges of the butt and into the neck, helping to prevent chipping. Likewise, a curved butt will also reduce damage to the handle over many years of hard service.

With regards to aesthetics, a domed surface is more organic and, to my sensibilities, more elegant than a flat one because straight lines seldom exist in nature, are boring to the eye, and seldom please it.

A warning. Everyone has different opinions about what pleases the eye, as you know. Beauty is in the eye of the bean holder, or something like that, so I entirely understand if you dismiss the aesthetic reasons I’ve suggested. But please don’t ignore the practical, structural reasons if you want to avoid wasting your time and wood.

Assuming the butt is flat and its surface is more or less perpendicular to handle’s centerline, use a marking gauge set at ¼” to scribe a shallow line along the handle’s edges and sides. Lightly scratch another shallow line the same distance around the perimeter of the butt. These lines will be the limit of the chamfer between the grip and the butt. 

Next, mark a cross on the butt using the front and back edge’s centerline, and a perpendicular line parallel to the back edge. This cross will be useful in profiling the butt. 

Use a knife, chamfer plane, block plane, files or other tools to chamfer to the lines just scratched.

Next facet the butt using planes or a sharp kiridashi kogatana knife and remove all tearout and filemarks. The time for using sandpaper will come later in this adventure when we apply finish. 

Fixing a Loose Head

So here’s the “I toljaso” in advance.

If you were not a clever little big-eyed kitten when fitting the tenon, you may find the tenon becomes loose and the head begins to wiggle with the passing of a few seasons. A Sergent Elias moment!

I won’t say it out loud, but just between you and me and CCP you can remedy a loose head by removing it and shimming the eye with quality high-rag-content typing paper. Don’t have any such paper in your bat cave? Don’t tell the Secret Service I said so, but a strip cut from a dollar bill works best. Crane Stationary makes the best paper in the world.

In the next post in this series we will attach the gennou head to the handle.

Until then, I have the honor to remain,

YMHOS

Lena Dances With the Knight by John Bauer 1915

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. To see a list of our tools and their pricing, or to contact us, please click the “Pricelist” link here or at the top of this page.

Please share your insights and comments with all Gentle Readers in the form located further below labeled “Leave a Reply.”

We see data miners and their bots as dastardly sneak thieves and so promise to never share, sell or profitably “misplace” your information for any reason. If I lie may the heads of all my eyes become egg-shaped!

Previous Articles in The Japanese Gennou & Handle Series

• Part 1 – Introduction
• Part 2 – Ergonomics
• Part 3 – What is a Gennou?
• Part 4 – The Varieties of Gennou: Kataguchi, Ryoguchi & Daruma
• Part 5 – Kigoroshi
• Part 6 – The Ergonomic Anaya
• Part 7 – The Unblinking Eye
• Part 8 – Head Style & Weight
• Part 9 – Factory vs. Hand-forged Gennou Heads
• Part 10 – Laminated Gennou Heads
• Part 11 – Decorative Gennou Heads
• Part 12 – The Drawing: Part 1/6
• Part 13 – The Drawing: Part 2/6
• Part 14 – The Drawing: Part 3/6
• Part 15 – The Drawing: Part 4/6
• Part 16 – The Drawing: Part 5/6
• Part 17 – The Drawing: Part 6/6
• Part 18 – Wood Selection
• Part 19 – Laying-out the Handle

Not all those who wander are lost.” 

J.R.R. Tolkien, The Fellowship of the Ring

 

Introduction 

In previous articles in this frightfully sexually-charged series, Beloved Customer produced a design drawing for your gennou handle based on the parameters of your actual gennou head and your body. You should have also selected, or at least rolled out of bed onto the floor, opened on eye, and seriously considered, an appropriate stick of wood. Assuming you’ve procured said stick, let’s get to the layout. 

Tools 

There are as many ways to layout the shape of a hammer handle as Carter has pills. I won’t tell you how to do it or what tools to use, but after making dozens of gennou, hammer, and axe handles for myself and customers, I prefer to use the following tools. You will need to have a similar set of tools on hand for layout and fabrication. 

1. Divider with sharp points; 
2. Sharp pencil; 
3. Small try square; 
4. Marking gauges (Titemark and kama kebiki); 
5. Marking knife; 
6. Rip and crosscut handsaws for roughing out; 
7. Handplanes for creating the flat sides and edges in preparation for layout;
8. Dozuki crosscut and/or rip saw for cutting the tenon;
9. Auriou cabinet rasp (Lie-Nielson); 
10. Bogg-pattern flat-sole spokeshave (Lie-Nielson); 
11. Bogg-pattern curved-sole spokeshave (Lie-Nielson); 
12. Sandpaper; 
13. Satin Polyurethane finish; 
14. Mineral spirits. 

Can you get by with fewer tools? Of course. A pencil, handsaw, hammer, marking gauge, dividers, and pocket knife are a minimum set. Will this minimalist set take more time, produce more blisters, prove frustrating, and produce an inferior handle? Absolutely yes. But it can get the job done.

Layout 

Select a board or stick with dimensions a little greater than the length, height, width, and thickness of your handle design, with 6 flat, parallel, square sides. 

You can prep this board or stick using electrical tools, but if you can’t do it with handtools alone, I strongly encourage you to work on your basic skills. In this age, surprisingly few have these skills.

Looking back on the old texts, one of the first tasks assigned trainees in cabinetmaking technical schools and apprenticeships was making a number of sticks or boards like this because this job combines many of the essential tools skill while developing an understanding of the material. I can attest to the bullet-proof validity of this concept.

1. Begin your layout by selecting and marking a flat and wind-free side of the selected board corresponding to a profile view on the drawing to be the “reference face.” Don’t forget to label this critical surface somehow so there will be no confusion moving forward.
2. Plane the surface of the board that will form the handle’s back edge (seen from above in plan view) flat and perpendicular to this reference face. All further layout will be indexed from these two faces. 
3. Mark the maximum thickness of the handle on the surface opposite the reference face, as determined by the widest dimension of the butt, using a marking gauge against the reference face.
4. Plane all the surfaces flat, free of wind, and where appropriate, planar. This needs to be done pretty precisely.
5. Use a marking gauge to draw the appropriate centerlines on both sides, edges, ends of the board/stick.
6. Use dividers to measure and layout the width of the eye, centered on the centerline you just marked, and spin this around the eye, butt, back edge and front edge. 
7. Make paper, cardboard, or wood patterns based on your design drawing of the handle’s elevation and profile views. Paying close attention to minimize grain runout, especially in the tenon and neck area, position the patterns and mark the board. 
8. Using these cardboard patterns, carefully layout all the tenon’s dimensions on the board, measured from the reference face and back edge. Be sure to make the tenon a half-sheet of copy paper too large in width and thickness. This can be trimmed down later if the fit is too tight. 
9. Adjust the lines of the handle design to meet your requirements for beauty.

In the next post in this series we will begin making sawdust. Oh joy!

YMHOS

Two Trolls by John Bauer, 1909. Not wanting to pay for the bread oven your humble servant has just installed, Granny Troll is trying to convince me to climb inside and do a closeup inspection. Will I fit? Do you like my fetching new shoes?

If you have questions or would like to learn more about our tools, please use the questions form located immediately below. To see a list of our tools and their pricing, or to contact us, please click the “Pricelist” link here or at the top of this page.

Please share your insights and comments with all Gentle Readers in the form located further below labeled “Leave a Reply.”

We see data miners and their bots as dastardly sneak thieves and so promise to never share, sell or profitably “misplace” your information for any reason. If I lie may the heads of all my hammers fly away to Valinor!

Previous Posts in The Japanese Gennou & Handle Series

• Part 1 – Introduction
• Part 2 – Ergonomics
• Part 3 – What is a Gennou?
• Part 4 – The Varieties of Gennou: Kataguchi, Ryoguchi & Daruma
• Part 5 – Kigoroshi
• Part 6 – The Ergonomic Anaya
• Part 7 – The Unblinking Eye
• Part 8 – Head Style & Weight
• Part 9 – Factory vs. Hand-forged Gennou Heads
• Part 10 – Laminated Gennou Heads
• Part 11 – Decorative Gennou Heads
• Part 12 – The Drawing: Part 1/6
• Part 13 – The Drawing: Part 2/6
• Part 14 – The Drawing: Part 3/6
• Part 15 – The Drawing: Part 4/6
• Part 16 – The Drawing: Part 5/6
• Part 17 – The Drawing: Part 6/6
• Part 18 – Wood Selection

Torre Civica in Assisi, Italy

I’m not only a philosopher, sir, I’m a fatalist. Somewhere, sometime, there may be the right bullet or the wrong bottle waiting for Josiah Boone. Why worry about when or where?

Doctor Josiah Boone, Stagecoach, 1939

This series of articles is about tools that have been around a long time, used by nearly every craftsman and builder throughout the span of human existence. Tools without batteries, with no plastic parts, with no need to update or replace glitchy decepticon software that intentionally breaks or evaporates after a few months. These are tools that don’t lend themselves to mass-production and corporate profits. You could even make them yourself with little effort.

I call them “Ancient Tools” because their origins are older than writing.

In this post, your humble servant would like to consider two of the most ancient such tools: the noble stringline and its stiffer brother: the straight edge. We will also touch on the divider.

But before we go into details, let’s consider some background about these tools and why they are so important.

Some History

It’s not even a featherweight of exaggeration to say that each of these tools was essential to the design, fabrication and installation of the wood, brick, stone and steel that make up the foundation of both ancient and modern human civilization.

Indeed, beyond simply making stuff, these small tools were critical to the elevation of human civilization above subsistence hunting, gathering, and the herding of goats. How did these simple tools build civilization, Gentle Reader may ask?

Well the reasons are simply that the stringline and straightedge were essential to the development of mathematics, geometry, trigonometry, navigation, astronomy, architecture, engineering, external ballistics, and many other practical sciences, all of which are essential to not only craftsmen, but modern civilization in total. An exaggeration? Not in the least degree.

Does Gentle Reader use round objects? How do you think the number Pi was first approximated? 

Does Gentle Reader ever ride ships on oceans, or airplanes in the sky? Or use objects transported by trains, cars or trucks over long railways and highways? Have you given thought to how ancient builders were able to plan and layout those railways, roads and highways? Or layout and cut the earth, stones and wood to make them?

Have you considered how ancient sailing vessels were able to navigate oceans and chart constantly changing courses?

You may think that these tasks are all handled by theodolites, lasers, computers and GPS widgets nowadays, and that may be so, but it was the string line and straightedge that started it all.

It’s my humble contention that these simple tools remain of significant utility even to modern woodworkers.

Relevant History

Pardon me while I momentarily wax academic.

Did you know that the oldest and most respected treatise on geometry was a 13 book collection titled Elements of Geometry, written around 300 BC by the Greek mathematician, Euclid? That was along time ago.

A fragment of Euclid’s Elements on part of the Oxyrhynchus papyri.

The fact is that Elements is the world’s oldest, extant, large-scale deductive treatment of mathematics, and for nearly two thousand years was the definitive document studied in the West and Middle East by those seeking an education about the physical world. This includes, of course, Leonardo of Pisa (Fibonacci) (c. 1170–1250 CE), René Descartes (1596–1650), Sir Isaac Newton (1642–1727), and every other mathematical giant. It’s an impressive set of books by any standard.

Of course, Maestro Euclid did not invent all the principles presented in his books but summarized the works of Eudoxus of Cnidus, Hippocrates of Chios, Thales and Theaetetus.

The exact same principles of mathematics and geometry written about in the Elements are taught in schools and universities nowadays, although the textbooks employed are abbreviated, fancier, plagiarized versions of the Elements shamefully giving no credit to Maestro Euclid or his teachers. Interestingly, the word plagiarize comes from the Latin word plagium, meaning to kidnap.

And here’s why The Elements is relevant to this humble scribble, because, you see, Euclid limited the constructions he presented in his books to those that could be produced using just a simple straight edge (not a ruler) and a basic divider, the two most important tools to civilization, and worthy of mastery.

Let’s first examine the father of the straightedge and ruler: the string line.

The Stringline

Before the straightedge there was the string line, a simple tool older than the straightedge, the ruler and the divider. Anyone can make one.

Think about it. If you must draw a straight line, or check that something is straight, and you lack a precision straightedge or carpenter’s square, or the tools you have are too short, how would you do it? The quickest, cheapest, most reliable tool for the job is the simple string line, be it made from palm fiber, camel hair, hemp, nettles or dried fish guts. Anyone can make it, and anyone can use it. They sell it at Home Despot, but batteries are not required!

The same string line can also be used as a divider or compass.

For example, if you need to divide a distance into 4 segments, simply stretch the line over the total distance and fold it back on itself 3 times. Each fold is a perfect 1/4 division of the total distance. This may be the origin of the 1/2″, 1/4″, 1/8″, 1/16″ progressions of divisions used in imperial measurements.

If we tie a knot, or make an ink mark at each of these divisions, we’ve now made a very accurate, graduated string line which can be used like a tape measure. And all it took was just some cordage made from a nettle plant or horse tail. Batteries not included.

A commercially-available string line I recently purchased for quality control of a robotic customer fulfillment center construction project in Chiba, Japan. In Japan this tool is called a “mizuito” (水糸), which translates to “water string.” In Japan the “water line” has nothing to do with boats but is a datum line critical to layout in construction, BTW. Made by Takumi in 4 colors, this string line is made of 0.8mm x 120m low-stretch nylon. Stretchy nylon would be a big failure. The black plastic reel that came with it measures 80×52×31mm and comes in both 120m and 240m sizes and is designed to fit into a breast pocket. To use this reel, one places one’s thumb and forefinger on the opposing free-wheeling red circular centers on each edge of the reel. This allows one to completely control the reel with just two fingers while spooling line in or out and all without striking the web of the hand. A very handy tool indeed and one I use all the time.

The Straightedge

The straightedge is a stiffer, shorter, handier version of the string line. It takes some skill to make.

The ruler is a straightedge with marks (graduations) instead of knots. This takes more skill to make.

The folding rule and metal ruler are more durable, convenient versions of the wooden ruler, but take a lot of skill and expensive materials to make. They were too costly for ordinary craftsman to own until recent times.

Public Standards of Measurement

In ancient times, each upstanding, well-organized community, be it town, city, abbey, temple, or castle, had a person responsible for establishing local legal standards of weights and distances, for maintaining official references materials (e.g. actual weights, graduated rulers or containers), and for checking on behalf of the local authorities, such as the Pharaoh, king, baron, castle owner, abbot or mayor, that the subordinate members of the community were in compliance with those standards.

In past millennia this system of public standards was considered proof of civilization, one of the primary justifications for government and taxes, while the lack thereof was considered a sure sign of barbarism and crooked government.

Indeed, failure to establish, maintain and enforce these standards frequently resulted in bitter disputes and even bloody wars in the not too distant past.

With every Tom, Dick and Pharaoh striving madly to become emperor of the world and establish themself in history forever as the person who governs “standards” (aka the “ruler”), until relatively recently, these weights and measures varied from kingdom to kingdom, castle to castle, and town to town. What a confusing mess!

Matters of health, welfare and uniform commerce aside, from the days of Melchizedek, standards were, and still remain, absolutely essential to taxation, of course.

To ensure that buyers and vendors were familiar with the standard measures current in a certain place, in ancient times these standards were carved onto or embedded into the walls of public buildings and church facades in such a way that all could see and copy them, and so they could not be removed or defaced.

Defacing/modifying standards, sometimes by the taxed and often by those imposing taxes, has always been a convenient but ruinous way to make money. The recent bout of intentional high inflation and currency devaluation the world is experiencing is a symptom of currency adulteration, another ancient criminal activity related to defacement of standards.

Indeed failure to comply with officially-established standards was deemed a serious offense in many communities punishable by fines, imprisonment, dunking, public exposure, dismemberment, hanging and even crucifixion. Worldwide more than a few shopkeepers, bakers, brewers, weavers and even tile makers were maimed or executed for “shorting” their customers.

Historically, master builders and tool makers were often required to provide a letter from the local standards officer attesting that their measuring tools were in full accord with the latest standards.

While we no longer embed standards of measure made of iron or stone in the walls of churches and city halls, in one form or another, this practice continues even today.

Standard measures on the façade of the Torre Civica in Assisi (photograph Elizabeth den Hartog). Shown are public standards for various units of length at the time (yard, foot and palm), as well as the respective official standards for the thickness and size of roof tiles, bricks and floor tiles. These standards often included the minimum size of a loaf of bread and size of a tankard of ale.

How To Use a Straightedge

I learned how to use straightedges, scales, dividers and compasses for carpentry and woodworking as a boy from my father, and from carpenters and other craftsman on jobsites over the years. But I learned the most from drafting classes in college. This was before drafting heads, digital protractors, dot-matrix printers, and CAD. Back then even lettering was done by hand or using plastic/metal templates. The professors back then were justifiably proud of their hard-earned skills and the beautiful and precise documents they could deftly produce entirely by hand.

The first lesson the Masters taught was this: Never lay one’s tape measure, rule or scale on the drawing/workpiece and mark from it directly using pencil, pen, scribe or marking knife, but instead use dividers to first measure the required distance on the scale/ruler, indexing the divider’s points in the engraved lines, and then use those same dividers to transfer and mark the distance onto the workpiece or paper. High precision indeed.

The intuitive, but inefficient way most careful people do the job is lay the ruler, yardstick or tape measure on the workpiece, index one end (a careful man will always “burn” 1″ or 12″ or 10mm and not index directly on the tool’s end), locate the target distance on the measuring tool, and make a mark. But if he is trying to layout an irregular distance like 2-3/64″ (= 52 (51.99) mm), for instance, a pencil’s lead or pen’s tip is too wide for precision, so he will use a scribe or marking knife instead. But in many cases, this requires extremely good eyesight, and sometimes even a magnifying glass. When I as a young man, many senior carpenters kept a magnifying glass in their toolbox. It works.

The wiser craftsman will tip the scale or ruler on its edge, kneel or bend down so he can see the scale’s/ruler’s marks clearly, fit the point of his marking knife or scribe into the engraved line on scale/ruler, and then transfer that to the workpiece, paper, or story stick with a quick “tick.”

There is a risk that the far end of the ruler/scale at the point he is measuring from may wiggle out of alignment messing up his precision. Or that the scribe/knife point may shift while making the “tick.” With practice, these tendencies can be overcome, but clearly this method is time consuming and the results may be questionable.

The improvements I recommend to make one’s marking knife more effective at this task can be seen here.

But using dividers, the wise craftsman can fit/index their points quickly and precisely into the engraved lines in scale/ruler at each end of the measurement, first time everytime, and without kneeling, squinting, pressing down, or worrying about wiggling and shifting mark the desired distance on the workpiece. Once he has set the dividers to the required distance, he can fit one of the sharp points precisely into the index hole, or onto the line he is measuring from, and then use the other point to make a precise scratch or hole in the workpiece, which can be used again for future layout reference. This technique greatly improves precision without using a magnifying glass.

This technique works with both dividers and trammel heads.

Standard dividers are quickest, but a locking divider with screw adjustment is easier to adjust precisely and is more likely to retain the measured distance with repeated usage.

You will find when drafting or doing layout that you repeat some distances frequently. Having 2 or 3 locking dividers set to these distances close at hand will allow you to layout those distances quickly and accurately without the need to refer to scale/ruler. Your humble servant keeps three in my toolchest.

The quality of your scale/ruler becomes important when attempting precision layout. A high-quality, professional-grade scale or ruler must of course be of proper length and uniform width and thickness, be free of twist, and have accurate lines. But to qualify as a high-quality scale/ruler, it must pass 2 simple quality tests, not an easy task nowadays. 

1. Accurately spaced graduations. Performing this quality check requires the skillful use of precision tools and time, so it is seldom economical to purchase discount scales/rulers.
2. Consistently engraved graduations. Besides being spaced at the right distances, the graduations engraved into the metal must be the right length, width, depth and have smooth, straight walls. This too is also uncommon. Don’t settle for cheapo tools with shallow, uneven laser-etched or acid etched graduations. Photo-engraved graduations are best. Seldom found in Chinese or Indian tools.

We’ll consider more uses for these tools in the next installment of this crazy adventure.

YMHOS

A fusuma screen by Kano Nagatoku, a designated National Treasure of Japan, commissioned by the Tokugawa clan, Japan’s last and most famous shogunate. Imagine presiding over a meeting with this as your background!

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