Mujitsu and Tairaku's Shakuhachi BBQ

Hmm been thinking, maybe an aluminum foil wrap around the root ends would prevent the open flame from charring the tips while still dehydrating the stalk...

The rest of it went great, the Bamboo had five or so stages as far as I could tell: 1. Initial bubbling which I wiped down the stalk, 2. Loss of bright green color with fade to a mossy green (less moisture released), 3. A very quick jump from mossy green to straw brown (almost like a mirage in the way it appears), 4.  Browning without charring (which allowed for design), and 5. Charring, where the surface becomes rough and carbon starts forming at a high rate.

The roots had one stage, 1. Ohh crap... I burned them ;-)... so I charred the rest for unifomity.

There is a chance that the carbon could be taken off with sanding and still look OK, but I'd rather do it right (if there is such a thing) the first time.

Has anyone ever tried using a heat gun?  The temp is about 40% that of propane (1500 deg F opposed to around 3800 deg F).
This is what I used:



Here is a heat gun:

I suggest you do a bit of practice on some fresh culms not intended for flutes. I'm sure you will get good results in no time. The colour is in the skin and you have most likely destroyed it in your burning. Shouldn't have any effect on the sound though, so why not progress that culm into a flute anyway, and being at the root end you won't be handling it while playing.

Kel

I like your tinfoil idea, John.  The abura-nuki process (hope I spelled that right -- the oiling & drying process) as it was shown to me involves lots of wiping and watching (in, out, in, out) since the color can change very very quickly, as Ed and others have mentioned.  Maybe leave a little extra length on the root outgrowths before burning so when you trim and refine them later, the worst of the burned parts will likely be snipped and filed off.

Here are the same culms of bamboo, changing over a short period of time (click for bigger versions)...

In-the-ground: Freshly-cut: Abura-nuki:
Post-abura-nuki: Post-sun-tanning:

The sun tanning step above was approximately two weeks hanging outside in the December (Tokyo) sun.  There must be a good Japanese word for tanning one's bamboo... 

The shot with Okuda-san shows the transition from dark- to pale-green in mid-culm.  I'm fascinated by the color changes and what must be going on inside the bamboo as that happens.  Beyond the cosmetic appearance, there are bound to be molecular and structural changes in those long fibres.  Bamboo is cool stuff.

-Darren.

Some Bamboo links:

http://www.inbar.int/publication/txt/IN … r_No49.htm

http://www-users.rwth-aachen.de/Christo … asics.html

http://www.americanbamboo.org/FAQ.html

Q. How do I work with bamboo in crafts?

Nancy Bess, Arts & Crafts Coordinator, provided this answer. “I am a basket maker and use a little bamboo in my work; however, I have watched lots of Japanese craftspeople at work, so I’ll share what I have learned. Also, there is a new book that is out now from Carol Stangler. Called The Craft and Art of Bamboo (Lark Books, ISBN: 1579901913), it covers lots of the questions having to do with tools and procedures. I know she interviewed the Lingens who are fence builders.

I use a paint stripping gun to bend bamboo. The pieces I use in the garden are about 3/4” wide and quite stiff. I pass the gun back and forth (it will scorch if you hold it in one place) over a four to five inch area -- you can actually feel the cell structure break down -- practice so you can control how much and how sharp the angle is. Where it cools down is where it stays. If you try bending after a long period of soaking, then where it dries is where it stays. Lots of craftspeople who make a product, make a jig (headless nails into plywood works) into which they can drop the hot (or wet) bamboo. This way they can produce identical pieces...if they want.

Many Japanese craftspeople use a heat source (boiling bath for some, gas oven for others, hibachi for many) to help remove the oil that is in bamboo. They roll the bamboo over (or in) the heat source and continually wipe the surface with a clean rag, much like stripping furniture. The bamboo must move continually or splotching occurs. Oil is removed to make the bamboo less inviting to insects, to harden it and stabilize the color. Air dry after - bamboo is a plant after all and loves to get mildew, etc.

Most craftspeople harvest bamboo when it is between two and five years old. The tissue is too soft before two years and it starts to deteriorate after five (some books say seven). Some craftspeople (especially for fences, work baskets, etc.) use bamboo green. For high quality products, the bamboo is aged. Dried in the sun, stored, oil removed, air dried.”

http://www.greenyarn.com/charcoal.htm

Hey Eddie.  Thanks for the complement.  Re/ sizes...  We took what the grove offered us.  Can't speak for the others but I came back with a handful of diameters & lengths, maybe toward the medium-large end of the spectrum.  But probably nothing longer than 3.2 in finished state.

We did actually hang around for a couple of weeks while the bamboo got its tan.  After burning, we went up and down Japan soaking up as much experience as our kind hosts, sore feet, and sore knees (from zazen) could tolerate.

-Darren.

Thanx Perry, I dont have the patience to wait a few years to begin tinkering so I'm kinda flying by the seat of my pants and making it happen right now...  the flutes I'm making at this point are all for me and really they are all just practice so that one day in the future when I find the perfect piece I will be able to approach it with more confidence.

So do you use the wet rag to spread the natural bamboo oil as well as to moisten the skin, or is it two separate rags...  I would have thought the water on the rag would interfere with spreading the oil, since the two don't mix well.  I decided on wearing a work glove covered in an old sock turned inside out for mine.  Anyways a pic is worth a 1000, will do...

I like your stove set up, necessity is the mother... for sure ;-).  I don't have a gas range, but the tinfoil diffuser is interesting.  I'm pretty sure that there are different tips for my propane torch that will spread the flame out so it doesn't produce such a concentrated hotspot... hmm I guess I'll look right now...

Well here we go:



The combination of the flame spreader and my tinfoil idea just might work...  I'll take pics tonight as a reference to future flute fiddlers (ahh an accidental alliteration) ;-) and as a clarification to my disjointed writing.

Yungflutes wrote:

I also bend bamboo this way since it can isolate and heat one spot easily.

Hi Folks,
Is it possible to bend or straighten bamboo once it is cured and dried?
Thanks

Last edited by Thomas (2006-04-21 21:04:37)

johnstrr wrote:

So do you use the wet rag to spread the natural bamboo oil as well as to moisten the skin, or is it two separate rags...  I would have thought the water on the rag would interfere with spreading the oil, since the two don't mix well.  I decided on wearing a work glove covered in an old sock turned inside out for mine.

As John asked, I too was wondering Perry, if you wipe down with a dry cloth first, followed by the wet cloth?

Thanks!

edosan wrote:

In images I've seen of the process done in Japan by Perry Yung, a very wet rag was used to repeatedly dampen the culm at the heating point during the process.

eB

This is what I was referring to about the wet rag Perry uses in curing the bamboo, and what John was asking about also, I believe.

waryr wrote:

I think that the wet cloth, as Perry stated, is just to keep the boo skin from scorching. Bear in mind that the bamboo is already cured. That indicates that heating the bamboo to raise the oil has already taken place quite some time ago. That is if proper procedures have been followed. This procedure is for bending the bamboo. Right Perry?????

Hi all, Sorry for the slow reply. Sasa's being potty trained and Jet's teething these days so my hands are quite full:)

For aburanuki, the wet rag is used first mostly as a preventative measure against unintentional browning. The wet surface dries rather quickly and is followed by the oils seconds later, which is wiped off by a second dry cloth. This is how it was shown to me. I don't know if the wet rag is actually neccessary for aburanuki. Maybe the Madake bamboo skin likes the wet rag first. maybe Kinya just wants to spread clean oils when it's sweated. Oils mixed with dirt on the bamboo skin can end up gummier and harder to wipe off. I'll try it without the wet step next time to see if there's any difference in the skin texture.

However, for bending, the wet rag is very important since the heat is left on one spot for a much longer duration.

Derek ask about a bending jig a while back but I didn't have a chance to post a photo. Here is my jig. It's a simple one that will do the trick for most bends. It would not work for a curvey piece with multiple bends.





All the best,
Perry

dstone wrote:

Re: wet/dry rags...  another data point, from a beginner but keen observer and participant in some burning and bending sessions with experienced makers...

1. Abura-nuki...  We used strictly dry rags for wiping when burning.  (Unless I missed the wet one being passed around somewhere, but I don't think so.)  This was immediately after harvest in late November, so the cut culms would have had significant water still present, so maybe that's why additional water wasn't introduced.  Not sure.  Also, this was over a bonfire, so maybe the heat is less intense than Perry's method.-Darren.

Good point Darren, about the fresh cut bamboo having lots of moisture still in it-maybe the wet rag wouldn't be much use there.  But I can see if you are curing older cut bamboo, it might be a logical step to introduce some moisture first with the wet rag.  I'll try that on some older culms I have when I cure them and see how it works.  Probably couldn't hurt, anyway.

Also a good point about the charcoal fire maybe being a cooler fire than the propane flame-might very well make a difference too.

Thanks for your reply too, Perry.  It does seem that you indeed have your work cut out for you with Sasa and Jet at the moment!  Good luck with them, and enjoy parenthood while you can, and you're young and strong!

Last edited by bluespiderweb (2006-04-26 00:27:35)