Category Archives: At Mark Grable’s Place

Practicing Hizumi: Hammering saws flat

Most woodworkers that are interested in hand tools manage to collect a fair number of saws that have seen better days…That’s a polite way to say they were beaten the hell out of, bound in a cut and bent, kinked, or otherwise mangled. A bent saw will give no end of trouble when sawing, basically relegating it to a wall ornament. That is, unless a little love and care can straighten them out.

Rather counter intuitively the best way to remove distortion from a saw is beating on it with a hammer, the process that is known in Japanese as Hizumi. Apparently hizumi also refers to working the kinks out of peoples backs and body, should give you some idea that this is analogous to massage. Hizumi is used in almost all of the blacksmithing trades dealing with tools, from knives to chisels and kanna, all require a bit of straightening after rough forging and tempering before the final work can be done profitably at the grinding stone. With saws metate take the art of hizumi to a whole different level, as a saw often comes out of hardening shaped like a potato chip.

One of the biggest reasons I endeavored to make my way to Vermont and Mark Grable has been to study hizumi, as I have no shortage of saws that need straightening, and metate is close to becoming a forgotten skill in this age of power everything and disposable blade culture.  Of course, you know better, otherwise you wouldn’t be reading this blog. So where to start?

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How about cleaning up that rusticle you just found in grandpa’s old barn or on ebay? Mark’s approach is to use 40 grit sand paper and a tool made by Yataiki that lets you apply a lot of pressure and control as you work off the rust.

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It consists of a sen like handle with a piece of bicycle tire nailed on to grip the sand paper. Simple and effective. The point here is not to sand out all of the pitting and restore the tool to a bare metal fine finish, merely to render it free of rust and to a point where the saw plate can be viewed well in the correct light condition.

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So, take one potato chip…I mean saw blade and sit back in some indirect diffuse light and get the shape of the saw in your head. The whole shape of the saw, its not enough to merely notice a bump here or there. The thing about distortions in a saw is that they have a habit of relating to each other, a certain balance of forces and tension that is effected in the saw as a whole. Attempt to remove one problem and you might just make another worse.

Its better to start on thicker western style saws, and better yet to practice on stuff like the above photo of an old circular saw blade that’s been annealed (a bit over annealed, I’d say).

Flex the saw lengthwise between your hands and listen for the dreaded nuki, poka-poka, or oil-canning. That consists of a section of over tensioned metal that wants to pop back and forth in its unrequited state of inbalance with the rest of saw plate. If that’s apparent you need to put the saw away and not work on it until you have quite a bit more experience, but at least its a problem that can be dealt with. Just today somebody sent Mark a ryoba saw with the worst twist and nuki I’ve ever seen in a saw, and Mark got right to work hammering that shit out, not that I could tell exactly how he went about it.

The first tool you’ll employ looking at the saw’s condition is a straight edge, with the saw held up to the light in such a way that you can see the line of light between the saw and the straight edge. First look along the width of the saw on both sides, then both directions diagonally, and finally along the length of the saw. Remember, you’re trying to get in your minds eye the total shape of the saw, not merely a localized spot or two.

Next you look at the saw along its width and length at a low angle to the incoming light. Its hard to describe what the right angle is like, but you’ll know it when you start picking up the surface topography of the saw. A cold beer is appropriate at this stage as you contemplate the saw and your local universe, the birds and the mountains, and the wind rippling the pond. If its late in the evening you put the saw down and go enjoy the sunset, maybe practice some calligraphy, hew a beam, or get stoned and enjoy the company of your friends.

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Back in the shop the saw awaits and the anvils and hammers are positioned. In the Japanese tradition you work seated, maybe with the anvil tilted to return the light to your eye at the right angle to allow you to see your hammer strikes on the lightly oiled surface of the plate.

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Hammers for major distortion are any heavy round faced hammer at hand. More refined and focused work involves a cross-peen hammer.

The hammer strikes the high spots, with the cross peen edge perpendicular to the length of the bow. Try to connect areas of distortion, and notice how working on one spot effects the others. Work both sides of the saw, an absolute necessity with removing twist that consists of concave bows that oppose each other diagonally. Strike blows hard enough to remove half of the distortion, and then half again, and so forth.

Flex the saw constantly to check for the pop of oil-canning, which can happen from working one spot too intensively. If you catch it early its much easier to remove.

A word on nuki. I don’t know enough at this point to give any advice should you find yourself with a saw that has this problem, but from what I’ve seen it involves working the periphery of the nuki on both sides of the saw, evening the tension and pulling it into the rest of the saw with a large round faced hammer.

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At first, to put it bluntly, I was beating the hell out of this saw blade, and left a pretty crappy surface as a result.

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But it is a lot straighter, no? If you just read this whole blog post and realized I didn’t really tell you how to straighten your saw, good point. Its not so simple as a prescription for hit here and the problem will be solved. If I can say one thing it is this, something Mark told me when I first arrived in Vermont, know when to stop.

 

Making a Seiro Rice Steaming Box

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If you’re steaming large quantities of rice for making koji, mochi, or miso there are a number of routes you can take, including making a traditional Japanese rice steaming box known as a seiro.

I used plain sawn white cedar from northern Vermont, and the satisfaction of not having to buy one of these is immense. But lets step back a moment for a little explanation.

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There are tons of good ways to cook rice, but sweet glutinous rice is at its best when steamed above a pot of boiling water. In Thailand you might see a woven bamboo basket, in China perhaps a round stacking bamboo basket on top of a wok. I’ve been using a colander inside of another pot, but it doesn’t cook the quantities of rice that I need for making other fun foods, specifically for mochi tsuki. A good explanation of what the deal is with pounding mochi can be found here.

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This is a book that Mark pulled off the shelf for me, and I fell in love with the mysteries of miso.

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It had a good drawing of seiro, though being a woodcrafter I upgraded the joinery a bit based on other pictures I’ve seen of seiro online.

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The critical dimension that you might plan making one of these around is the size of the bamboo mat that sits inside. Cedar is wonderful, lovable, excellent working wood, but you shouldn’t feel bad about making one out of pine if that’s what you have available.

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I’ve been getting better with ripping the tenons bent over a low saw horse. White cedar is so soft that I use the cross-cut side of my saw for everything. Give this sawing position a try! Its not easy on the back but you gain freedom from a bench vise which you might not have access to in a lot of places you’d find yourself working. Free yourself from the “I must build a massive European joiners bench” mentality that we all start out with!

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I also like holding material with my foot vertically against the end of my planing bench. This works for sawing the waste with a fret saw on dovetails too. And of course you’re feet are much faster acting clamps than a screw vice so you waste less time screwing shit. Just another little bit picked up watching shokunin on YouTube.

I borrowed some of Mark’s chisels for this work. Cedar being so soft requires exceptionally sharp chisel to pare end grain, and the steel in some of my chisels is kind of a joke. I still work with a few Harbor Freight chisels…

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These are the chisels I’m talking about, Kiku Hiromaru. You can get them from Japan Tool for a mere 85,000 yen (about $750 USD at todays exchange rate). I’m not joking when I say ‘mere’, these nomi are dreamy. Literally, I dreamed about them last night.  The modern one’s are made by the son of the smith who made these, but I’d wager that the quality is still exceptional and you may even be able to find old stock to buy.

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I made the hole on my steam board a bit large and added a shallow frame to help distribute the steam before the box that holds the rice.

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I also let in the tenon sides of the box an eight of an inch to help restrain the wood from warping and help keep the sides steam tight. You’ll see in the line drawing from the book of miso that they can be made with a single wedge pinned through tenon, but a double tenon, though harder to cut the mortises for the wedges, resists the movement of the wood much better. Two battens mortised into the the sides hold the bamboo mat which the rice, inside of a cotton cloth, will sit upon while cooking.

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And of course, with a soft wood like cedar there’s no better way to finish it off than a sharp hand plane. I’m getting some rice soaking tonight, by tomorrow I’ll be ready to pound some mochi. Maybe I’ll make some koji trays and try cultivating my own strain of mold for making sake and miso! Mark is working on a round bottomed plane for hollowing the inside of barrel staves, cedar barrels being preferred for fermenting miso.

Turning Bombs into Anvils

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I’ve been gaining immense enjoyment out of working white cedar and a dovetail kanna, in this case classing up my washing water bucket with a Japanese style lid with sliding dovetail battens, made from some scraps that came off the deck I put down for Mark’s wife.

I suppose this being a woodworking blog I should show a few more shots of how this goes together…

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Take one dovetail kanna for the male side of the joint. What an excellent tool! All of my joinery planes are western push style and really need two hands to operate well, which is fine, especially working hardwoods that require more force and control. Japanese joinery planes on softwood are fast though, one handed, and no dogging the work to the bench as its enough for the other hand to hold things steady. It takes strong hands though.

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I love this shot because it sums up all of what I love about the Japanese approach to woodworking. Such a tight, controlled, and productive little space. I used the dovetail kanna to make a guide for my dozuiki noko so that I could saw the dovetail slots in the top of the lid.

Sitting in seiza can take some getting used to but I really feel the dozuki performs at its best like this.

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I don’t have crane neck paring chisels for cleaning out long sliding dovetails, but even better is a router plane with cross grain blade for cleaning the waste. I switched to a straight edge blade when close to the bottom of the groove because the spear tip doesn’t leave a flat bottom. It doesn’t hurt that the router plane is easy to use with a pull stroke.

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And how about a bunch more use of the dovetail kanna!

I’m making a traditional Japanese rice steaming box out of more of this excellent cedar. The one with the hole in it sits on top of the pot of boiling water and permits the steam to rise into the rice. Mmm…tasty steamed rice which will faintly have the aroma of cedar.

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It was oddly warm for March yesterday, Mark and I took the opportunity to move a canoe he’s restoring over to his shop on a piece of land he bought when first moving to Vermont. The amado Mark is pulling off have two inches of poly-iso insulation inside the frame, good idea!

Now, this structure isn’t much to look at, but there’s some treasure inside.

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How about an anvil made from an old naval artillery shell? Its not hardened, but the bounce is good.

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And as if that wasn’t enough, how about some Japanese forging anvils? You rarely see them not planted in the ground. The one on the right is about 250lb, to be place next to the smith at the forge. The smaller one is used to beat on rough forgings, something for between forging and hizumi. Yataiki really had a lot of faith in Mark to send him all of this steel half way around the world.

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One of the more important elements to hizumi of saws is the correct light condition. Here with the light coming through the south facing shoji you can see what  Mark might see while seated working on saws. The anvils are tilted so that the light is returned to the eye at the right angle.

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Also something I’ve not seen discussed is the fired clay tuyere for a fuigo. This is the bit that sticks into the forge proper, another carved piece of kiri would be used to connect the fuigo to the tuyere. The opening at the forge end is about one inch.

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The opening at the back is about three inches. The taper inside is not straight the whole way, it necks down to the exit diameter about three inches from the end and I suspect produces a bit of venturi effect.

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Spring is almost in the air, plenty warm for dipping my feet in the creek and getting grounded to mother earth.

The Pain and Pleasure of Sawing While Seated

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Continuing from my last post, the rotten heart of this pretty little piece of Black Locust. There was a knot that healed over and decayed into the heartwood, something I didn’t think could happen with Black Locust given its reputation as exceptionally rot resistant.

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So now I have slabs that are exceptionally…artistic. What would Nakashima have done?

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And when you don’t sharpen your saw the cut can cup in the middle and binding, chaos, and pain in your arms ensue as you curse the very existence of the tree you’re sawing.

Mark Grable is fond of saying, “Know when to stop”.

And, “Sharpen your saw, its so easy, its a rip saw”.

Okay, okay, I’ll sharpen the damn saw when it needs it.

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You may find yourself in a pickle needing to snap a line off the end of the cosmic void…I mean off the end of the butt of the log. Get creative with a level batten and some marks and you’ll be fine.

And finally, some video of sawing horizontally, sorry it took so long to the guy who asked.

Black Locust Crotch and the Sumitsubo

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No, Black Locust Crotch is not some terrible venereal disease.

You may have dreams of lumber like the picture above.

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But not have access to a $25,000 Woodmizer bandsaw mill. Pretty sweet machine though. Mark and I recently traveled several hours north to a place outside the town of Derby Line, VT, right on the border with Canada, to buy some white cedar. This is the guy’s saw mill.

All shed dried lumber, White Ash, lots of different Pine, and the fragrant aroma of air dried White Cedar drifting in the air. Dreamy, no?

It was the kind of place with such heavy tree cover that the road in was a skating ring of ice that not even studded snow tires could cope up the last hill. We walked in and had the proprietor give a helpful tow.

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Back at Mark’s place I’ve had the time to lash together a new kobiki sawing frame from Black Locust poles I felled and bucked by hand with my madonoko. It was the first time I’ve had a tree barber chair on me from a poorly cut hinge notch and too slow of cutting through from the other side. If you’ve ever seen video of guys felling a tree with a two man cross cut saw and wondered why they’re sawing like the devils in them, its to avoid just such an occurrence. The hinge needs to be a certain width to break cleanly before the tree starts falling. Best to start learning this stuff on small trees.

This Locust wood is mostly in the open, which means a lower branching habit and not a lot of clear boules for typical board lumber. What is there is crotch wood, the kind of stuff Nakashima spoke so eloquently of and used to good effect in writing “The Soul of a Tree”.

And its the kind of stuff that I imagine lots of woodworkers happen upon and wonder how the hell to get it sawn into usable boards.

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Here’s a small piece with the bark off, and I’m trimming the ends flush so that a level can be laid across. The blocks I’m working on are oak offcuts from the ‘free’ bin of Vermont Timberworks.

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Starting with a plumb line on one face I measured out the thickness for the slabs to be taken off, in this case a 4/4 board in the middle to box in a heart check from the pith on the other end and two healthy thick slabs on either side.

You’ll notice that my boards are off center from the pith on the crotch side. While this means I’ll have a crossing pith on the inside face of my slabs it will also produce some interesting figure to the run of the grain.

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With my layout done on either end and small notches cut on the edge of the ends with a pocket knife to register the string the ink line is used to snap straight marks on the convoluted surface of the log. One problem that arises is snapping a line into a deep hollow, the bounce of the string only gives you so much, and the farther back you pull the string to pluck it the more likely you are to pull to one side and produce a curve.

By stretching the string between the two ends you can use a level to drop a mark into the hollow and then snap from either end to that point. Presto, a straight line! I’ve seen this technique used to locate the mortises on koyabari for the posts that support the purlins on a Japanese roof.

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Hang in there sumitsubo!

 

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Very satisfying and rich, the dark marks from sumi ink.

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Its helpful to understand the limits of what the ink line can do. A beautiful little protrusion like this is tempting to shave off, because I know I can get a good line. In this case I could extend vertical batens from my marks on the end grain and again drop a level into the hollows either side, but there’s enough of a mark that I simply sight down along the line and trace in with the sumisashi.

Ready for happy sawing!