竹を伐りに行ってきた My First Bamboo Cutting Experience

１月の中旬のころ、直入町に住んでいる御沓さんのところに竹を伐りに行った話しをポストにアップして、映像も載せたのを皆さんは見ていると思うけど、今回はそれについてもっと詳しいことを書きたいと思う。（映像はこのポストの一番下の方に残した。）

In mid-January I put up a quick post and video about my experiences of cutting bamboo in the town of Naoiri to be used in my baskets. I'll go into a little more detail about that project in this post. (Scroll to the bottom to see the video.)

御沓さんという方は私の友達、飯田さんを経て知り合った方で、ずっと前から私が参加してきた稲刈りとか芋掘りの農業体験事業を企画・運営している方だ。行くたびに仲が親しくなっている感じがするが、今回は御沓さんの実家の裏山にある竹を伐りに行った。御沓さんの実家では野菜とか牛などいろいろな農産物を作っている。その中のひとつである椎茸の栽培面積を御沓さんは来年から伸ばしたいと考えているんだけど、杉の木の間に盛んに生えていて、邪魔になっているのが竹なのだ。御沓さんが「使ってくれんか」と言ってくれたのか、私の方から「使いたいんですけど」とお願いしたのか、よく覚えていないけど、邪魔になっているものが無駄なく使われることになるという出発点から、すごく気持ちのいい協力関係ができた。

Caitlyn and I went with our friends, the Iida family, to visit Mr. Mikutsu on his farm in Naoiri, located in southern Oita prefecture. We've visited Naoiri before to harvest rice or dig up sweet potatoes as part of the local agricultural events planned by Mr. Mikutsu, but this time we went to cut down the bamboo growing in Mr. Mikutsu's own backyard. On the Mikutsu farm they raise beef cattle and grow vegetables and the like. Immediately behind their house is a mountain slope covered by tall cedar trees, under which they maintain their shiitake mushroom stands. Mr. Mikutsu hopes to expand the area of these stands next year, but growing tall and green in the large spaces between the cedar is bamboo. Mikutsu-san said I could use the bamboo if I like, since he would cut it down and pile it up to rot anyway, so we all decided to get together to cut it down and prepare it for temporary storage. It's a mutual cooperation like this that I imagine was so much more common in the olden days of Japan when farming was a major way of life. (Bamboo being seen by farmers or foresters as a nuisance in Japan, by the way, seems to be the general trend as bamboo is used less and less for the production of daily goods or other commercial products. As far as I know, in Oita prefecture at least there are several town revitalization projects that focus on trying to find ways to make use of the bamboo groves that are either not maintained or cut down and thrown away.)

ところが、ただ単にそこら辺に生えている竹を使おうと思っても、実際ある竹の用途はその種類や成長状況、材料にするための下ごしらえなど、いろいろな要素の影響で決まってくるから、必ずしも御沓さんの竹を私が作っている籠に使えるとは限らないというのが最初は心配だっだ。まず、第一に知らないといけないことは、これは何の竹？結論から言えば、マダケかハチク、両方とも籠の材料となるヒゴに出来る種類だった。それをどうして確認できたかというと、節のところを見ればすぐ判る。伐採して籠に使う対象になっているのが左側の竹で、右にあるのはそのまた近くに生えていたモウソウチク。節の断面をよく観察すると、モウソウチクは竹皮部（ちくひぶ）という部分が一番出っ張っていて、そこからまた低くなって真っ直ぐになる。それに対してマダケとハチクは下側の竹皮部とその上にある節峰（せっぽう）が両方出っ張っていて、二重になっている。これはマダケなのか、ハチクなのか、そう簡単に見分けが付かないらしいんだけど、一応私達が伐った竹がモウソウチクではないことがわかって、一安心した。

I've used the word "bamboo" here so far without specifying type. There are over 600 varieties of bamboo in Japan, only a handful of which can be used to make baskets. At school we use only one variety, madake, otherwise known as giant timber bamboo, or, scientifically, Phyllostachys bambusoides, but hachiku (Phyllostachys nigra var. henonis) another timber bamboo almost exactly identical in appearance to madake is also usable. On the Mikutsu mountain I also found mosochiku, or Phyllostachys edulis, which is full of fiber and useful for some crafts, but is much coarser and less pliant than madake or hachiku. In Japan they're called the "big useful three (三大有用竹)," not only because they're the largest varieties, but also because they are naturally common and used so often in so many things. Luckily, the "nusiance" in this case was either hachiku or madake. You can tell the difference between these and moso by looking at the node. Moso (on the right) has one ring that sticks out, while madake or hachiku (on the left) has two rings. Supposedly it's practically impossible to pick out madake from hachiku just by looking at the two, so for now I'm satisfied with the observation that it's either one of them, both of which I can use.

さて、朝１０時ぐらいの時に本番の作業に入った。御沓さんと飯田さんのご家族、皆の力を借りながら、竹を倒したり、倒された竹の枝を鋸で落としたりしていった。鋸のない人は枝のない竹を適当な場所に積んでくれた。飯田さんの２歳の息子さん、けいすけにまで竹の片っ端を持って手伝ってもらった。この作業で１時間半ぐらい経ってしまった。次は、ひどく年取った硬そうな竹とか、キズの多い竹を除いて、長さを切り揃えて、５，６本ずつ結束した。さあ、ここまで来たんだけど、次はどうしよう。本来だったら油抜きなどの処理をして天日干しするけど、油抜きをするための釜もないし、青いまま天日干ししたら竹の表面が変色してしまう。センターの課長からいただいたアドバイスは、直射日光の当らない、湿気のなるべく少ないところに保管するように言われた。そうすれば、カビや虫による害が発生しにくい。ちょうど牛小屋の軒下がこれにぴったりの環境だったので、一束にまとめられた竹を御沓さんが一人で、僕と飯田さんが二人で山から下ろしていった。その一日の中でこれこそが一番疲れた作業だった。とにかく重い。伐りたての青い竹は水分をたくさん含んでいるので、白い竹よりもずっと重い。何とか山から下ろせた竹は幅や年齢がばらばらの状態で軒下に収めてようやくその日の仕事が完了した。皆はほっとした気持ちで集合写真を撮ってから、おいしい料理と温泉のために近くの旅館へと向かった。


So we all got together, and got to work. Mikutsu-san cut down the canes with a chainsaw (not my choice of tools, but farmers sure do know efficiency!) as the rest of us (even grandma and grandpa!) busily cut off the branches with hand saws and piled the culms together. After about an hour and a half of doing this we were finished clearing the area. I then chose the best looking bamboo, mostly by clearing out those that looked too old, worn, or damaged, and then we cut them all to about the same length, bound them in bundles of 4 or 5, and carried them off the mountain.


Knowing basically what kind of bamboo it is, the next question on my mind was how to prepare it for my baskets. The madake bamboo we use at school is never fresh--it's always cured through boiling and then dried in the sun for around a week. Uncured bamboo supposedly gets a little stiffer than cured bamboo even after it's dried, according to one of the veteran instructors at school. As long as I don't use Mikutsu's bamboo for extremely thin strips it shouldn't have any affect on my baskets. He also recommended storing the bamboo in a dry location where it wouldn't see direct sunlight. We found a perfect place in the rafters of the cow barn, where they'll be stored at least until school ends and I have time to work on my own baskets.

After a long, tiring morning of cutting and carrying, we all took a group photo and then made our way to the local ryokan, where we had a delicious meal of kiln-cooked rice (kama-meshi; 釜飯) and fried chicken, and then a soothing dip in a hot spring bath.

年齢と直径がばらばらの竹。２０本はあったんだろう。一人で使いきれるか、ちょっと不安。My friend Akira and I piling up the bamboo before storing it. Only later when I split the bamboo will I find out how old, and therefore workable, each one is.

（左上から時計周りに）飯田亮、僕、御沓さん、ケイトリン、御沓さんのご両親、飯田友美、飯田佳祐。
(Clockwise from top-left) Akira Iida, me, Mr. Mikutsu, Caitlyn, Mr. Mikutsu's parents, Tomomi Iida, and little Keisuke.

mikutsu farm, naoiri, oita from Stephen Jensen on Vimeo.

Yomiuri Shimbun Article 読売新聞の記事

２００９年１２月７日の読売新聞（朝刊）、２９面（大分のコーナー）。画像をクリックすると、拡大し読めるようになる。

Here's an article of me that appeared in the December 7th, 2009 morning edition of the Yomiuri Shimbun (Oita section, page 29), a national newspaper here in Japan. Click on the picture to get a larger image. English translation pending. Stay tuned!

Using a Bending Mold

I had a request recently to show bamboo being bent on a bending mold (what they call a himage-jigu, meaning "fire bending jig", here in Japan; 火曲げ治具）so here I'll go into a little more detail about how the bending mold is used to bend bamboo, and keep it that way. Once again, a picture of the mold we use at our school above. Shaped like a wedding cake, there are numerous tiers with different circumferences to bend the bamboo at tighter and tighter curves. Underneath this hollow wedding cake is a propane burner, which heats the jig from within. You can control the level of heat with the burner, but the jig is also made to release extraneous heat through an adjustable vent at the top.

Bending bamboo on the mold is both conceptually and technically a fairly simple procedure. At school there are specially made wooden wedges that fit in between the round central part and the arms that stick up. Wedges of varying thickness are on stock, but because most of the bamboo we bend at school is between 2-3 mm thick we almost always use the same wedges. You start by placing the end of the strip you are bending in between the central tier and the arm, and hammer in a wooden wedge between the strip and the arm, pressing the strip against the central tier and locking it in place. You bend the strip around the tier as far as the next arm, and hammer in another wedge (after the first wedge it's best to point the remaining wedges in the direction you are bending the strip, to keep the strip from floating away from the central tier, but my picture shows the opposite). You continue this at each arm until you get to the end of your strip. When bending strips to make rims, the strip will always double up on itself, in which case you have to bend the strip around in a slight spiral; this doesn't have much affect on the final product. Also, its best to bend a strip that's longer than the final strip's length, because bending the very ends of the strip is most difficult (in the picture I used the handle of the hammer to press the end of the strip against the mold). You measure the length of the strip you need before bending, and then cut off the extra ends after bending.

A couple other pointers about bending molds, or bending bamboo with heat in general:

• Always use bamboo that's dry. Moisture keeps bamboo from setting after it's heated. Semi-dry bamboo will release moisture from the ends when bending it, which is usually a sign that it's being heated enough. Even days with high humidity can have an effect on how well bamboo retains its shape after molding.


• It's easy to burn bamboo on a bending mold. Once the jig is warmed up or has been in use long enough, it only takes a minute or two to heat the bamboo enough to shape it.


• As a basic rule, bend bamboo with the vascular bundles on the outside. When bending strips with the skin/vascular bundles on the inside, bend the strip more slowly, allowing the heat to soften the strip as you bend it, otherwise it could break (especially for thicker strips).


• After the strip is molded, take it off the mold by hammering out the wedges. Bamboo that is still hot won't retain it's shape, so it's important either to hold the bamboo with gloved hands, or use another non-heated mold to keep it bent until it's cooled. At school we place the strips in tin containers roughly the same circumference as the final rim (see picture).


• It's best to bend a strip more tightly (at a smaller diameter) than the curve it will be used for later. It's easier to unbend a strip without breaking than bend it more tightly after it was heated.

The bending mold we use at school is a rather complex piece of equipment that had cost the equivalent of several hundred dollars to have specially made. It's useful on an industrial scale, but remember that you don't need as fancy a device when making your own crafts at home. I've been successful bending 2.5 mm thick strips at home buy using a metal cake tin I bought at a 100-yen (1 dollar) store, screw-on clamps, and my kitchen stove. It takes a little longer but works just as well. Also, keep in mind that Japanese craftsmen long ago and some even today didn't/don't even use a round bending mold like this to make rims; they just rubbed the bamboo across their knees to soften and bend the bamboo enough to make a circle. Cutting the strip extra long before bending makes this method much easier.

I think that's about it. The process has become so natural to me by now that I can't think of anything else that might be worth mentioning. If you have any questions please leave a comment.