Kezurou-kai #39

Last weekend I went to the 39th annual Kezurou-kai event in Itoigawa, Niigata. It was my first time going to the event here in Japan, and it was such a blast. For those who are unfamiliar with kezurou-kai, it’s an event where people compete to take the thinnest shavings of wood using Japanese planes. But more than that it’s really a gathering of people who are passionate about woodworking and carpentry, sharpening and hand tools, who are pushing their skills to the absolute limits of what is possible.

The event takes place over two days, with preliminary planing running all through the first day, and ending around mid-day on day 2. Throughout that time competitors have three chances each day to bring a plane shaving up for official measurement. 5 individuals with the thinnest shavings then go on to the final planing contest toward the end of the day on day 2.

The main contest required using 70 mm kanna, and the material was limited to hinoki at 55 mm wide by 1800 mm long. Hinoki has become the standard wood for thin planing, since it cuts beautifully and can be planed down to an extreme level without breaking up. For preliminary planing each competitor or group was required to bring their own material for planing. The final contest however involved planing material selected by the event organizers, with the final 5 competitors all planing the same board.

The event took place in a gymnasium which was filled with planing benches shared by teams and individuals. When I arrived on day 1 I met up with my friends from Somakosha and we pretty much started taking shavings right away. Here’s Yamamoto-san getting things started.

We all came with a few different planes, and myself I brought 2 kanna, an old Ishido blue steel blade and another from an unknown maker which I’m pretty confident is some type of white steel. We also had a Mitutoyo digital micrometer for measuring our shavings.

Given than none of us had been doing any kind of practice our shavings on day one were pretty decent. We were all able to take really clean and consistent shavings in the 10-12 micron range without too much trouble. It was getting under 10 microns that was the real challenge.

This is something that I’ve faced before when having “kezurou-kai nights” with friends. With careful sharpening and tuning of the dai, it’s fairly straightforward to get really clean consistent shavings in the 10-15 micron range. But pushing past 10 microns requires a whole other level a fastidiousness when it comes to every aspect of planing. In any case, on that first day at Kezuroukai we struggled a bit, but we kept sharpening and adjusting out planes trying to break the sub-10 micron barrier.

Once you had a good shaving you could take it up for official measurement. The shaving needed to be full length and free of tears, splits, etc. Simple jigs were provided which allowed you to clamp a 1 meter section of the shaving for the purpose of bringing it up for official measurement. Here’s a line of people waiting to get their shavings measured on day 1. You can see everyone holding a the jig with their shavings clamped.

And here is the official measuring device; three digital calipers which were pneumatically controlled to measure each shaving with a consistent pressure. When you brought your shaving up, you had to carefully set it below the calipers, and when everything was set the operator would push a button and all three calipers simultaneously plunged down. The calipers were offset along the length of the shaving, but also across the width, giving measurements which revealed the overall consistency.

If the measurement was satisfactory you could then take it over and paste it on the boards seen below. Shavings on the far right were all 5 microns and less. The other two boards were for the remainder of the shavings, most of which were between 6-12 microns.

Outside the venue was a space setup for sharpening. There was a good mix of people using synthetic and natural stones. I personally stuck with a variation on my usual routine, 1000 grit Hibiki, an 8000 King or 8000 Hibiki, and a 12000 grit Kagayaki stone, doing a micro-bevel on the 8000 and 12000 stones.

Day 1 went fast. I planed a lot but I also spent a fair amount of time catching up with old friends. In terms of shaving I wasn’t able to break through the 10 micron barrier with a consistent shaving. It’s easy enough to have parts of a shaving break below that barrier, but getting a consistent shaving for the full length and width of the board is really difficult. On one hand it’s frustrating but it’s also becomes an interesting puzzle figuring out how to improve things. At the Izakaya that night pretty much all we talked about was sharpening and how to improve our results.

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Day 2 was a fair amount busier, with more people showing up to plane. All of us from team Somakosha experimented with some different sharpening techniques to see if we could get thinner shavings. Some things seemed to work better than others, but more than our sharpening technique or dai adjustments, it became clear that our material was a big limiting factor. As you approach ultra thin sub-10 micron shavings the quality of the material becomes a huge factor in how thin you can go. The evenness and density of the grain, and especially the moisture content of the wood are really important factors.

Overall we had really nice material, with nice even straight grain, but it was definitely on the drier side. It was really interesting to see how much other competitors cared for and maintained their material. Most people had their planing blanks wrapped in plastic to prevent moisture loss, and many went to great lengths to protect the wood when not planing by protecting it with blankets or foam packing.

The two guys who we shared a bench with were Kezurou-kai veterans, having started some 20 years ago, and they had 2 planing beams that they were rotating in and out as they planed. Whenever they set aside a board they would cover it will moist towels to maintain a high moisture content in the wood. In another case Yamamoto-san went over to a friend’s bench and was able to take some shavings from their hinoki which was definitely higher quality and well maintained. He had been pulling shavings in the 10-12 micron range on our board, but taking the same plane, without resharpening to the his friend’s higher quality board, he was able to plane down to 6 microns. Pretty amazing how much of a difference the quality of material and moisture content makes.

As day 2 went on you could sense the energy level rising as everyone worked to take ultra-thin shaving before time was up. About an hour before the deadline for preliminary planing and the leaderboards really started to fill up.

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Back at our bench we started to try every possible trick we could think of to improve our results. What seemed to work best was simply wiping the board with a lightly damp rag prior to planing. It would definitley be better to have the wood “pre-soaked” rather than wiping the wood before hand, since exceess moisture on the surface of the wood can cause the dai to move, but given the situation and with time running out we did what we needed to do. And it did help, a lot. The quality of shaving between really dry wood and moist wood is completely different.

In the end one of my last shavings turned out to be my best. With a freshly sharpened blade, and a touch of moisture on the wood, I was able to pull a really clean shaving. I took it up to the judges for measurement and the results were 10, 6, and 9 microns. I’m pretty happy with that result. It’d be great if the whole thing came out around 6, but I’m glad to have gotten a really clean full length/width shaving at that level.

Here are the top 5 winners from the preliminary contest and their numbers. Insanity! Crazy thin and consistent.

With the preliminary contest over, the top 5 went on to the final challenge which was planing a 3 meter quartersawn piece of sugi (Japanese cedar). Compared to hinoki, sugi is not an easy wood to plane, especially thin. This time the rules for the final round also changed, and each person had just a few minutes (I think it was 3-4) for both setting their planes and planing. In otherwords, before the timer started your blade had to be loose in the dai. Then once the clock started ticking you could begin setting the blade in dai and start planing. Kind of intense given the time allotted and overall pressure of the situation.

Here’s the first person up, taking a fairly thick shaving.

With sugi theres a fine line between planing too thick and too thin. Too thin and the shaving just falls apart.

Each person only had one chance to have a complete shaving measured, which means you have to really gauge the material and your capabilities. It’s all about taking the thinnest shaving you can manage and knowing when to stop. Spend too much time trying to get a thin shaving and you risk running out of time. But it’s also tricky to gauge the thickness of the shaving until you ask the judges to measure it. In reality it may look thinner than it actually is.

The winning shaving from the final round of 5 competitors was somewhere around 50 microns (it may have been 48), which just goes to show you how different sugi is from hinoki. It also reveals how different it is to plane material that is of unknown quality versus planing your own moisture controlled material.

I love the challenge of ultra-thin planing, and it’s fascinating to see the skill and dedication it takes to plane at a this level. But planing in the sub-10 micron range really requires a high level of control over the material (not to mention the kanna), which as a woodworker/carpenter is pretty far from the reality of day-to-day work. So I like the idea of a contest which requires people to plane an unknown piece of wood, which is more or less how the final competition here goes. I’d also love to see some sort of tear-out challenge, where the goal is to plane a really gnarly piece of wood with knots or difficult grain, and try to perfect the surface. A challenge like that would be really beneficial for folks looking to use kanna for real work.

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Throughout the event I was pretty focused on visiting with friends and planing, but I did take a quick lap towards the end of day 2 to snap some photos of other some of the other things taking place.

In one corner of the venue a craftsman was demonstrating carving a sumitsubo. (I didn’t realize until later when I edited these photos that he also had carved wooden shoes in the foreground!)

Next to him was a guy demonstrating how to cut a new kanna dai. If you search for Kezuroukai videos you can find a good video of this same person chopping a dai at a previous event.

Outside near the sharpening area were several people demonstrating hewing, and brave spectators could also give it a go with a bit of supervision.

Back inside the venue were also plenty of vendors selling anything and everything related to planes and handtools. Here was one of the natural sharpening stone vendors.

The NSK company who are making a new variety of diamond sharpening stones were also present. They made their stones available to try for anyone who was interested.

And of course there were plenty of kanna for sale…

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There’s a lot I wasn’t able to cover but that’s the quick story behind Kezuroukai #39. It really was a busy couple of days, and hard to take everything in. I’d love to go back and try my hand at planing again, but I’d also love to just go as a spectator and spend more time watching. There’s so much you can learn at Kezuroukai, and also so many really passionate and inspired people to meet. I highly recommend a visit to anyone who can make the trip to Japan, but if not then definitely seek out a more local event or start one up! In the US now we have Kezuroua-kai USA along with a few other kez events like Jason Fox’s Maine event. So go, plane wood, and help spread the joy of hand tools and craft!