Mujitsu and Tairaku's Shakuhachi BBQ

No similarity between the two. Urushi is a liquid, like paint, that cures and hardens.

The inside surfaces of bores on jiari shakuhachi are built up using a plaster-like material mixed with urushi, then shaped during the tuning process, then the bore is coated with plain urushi to give it a glassy finish.

There is a type of modeling claylike material (one brand is called 'Sculpy'--it is synthetic) that can be hardened after forming, but heat must be used to do harden it--200 degree oven--can't do that to a bamboo shakuhachi without risking a crack. Plus, anything like that will tend to shrink a bit and pull away from the bore, PLUS, there's no good way to make the soft modeling material stick to the bore in the first place, before it's cured.

Look elsewhere for ideas.

eB

Last edited by edosan (2008-02-24 22:07:55)

I have just used a product called 'Knead-It'. This is a putty like substance, soft, but contains the two ingredients to make a hard epoxy like filler. You take a portion of this material and fold it into itself repeatedly for about a minute, this mixes the two elements together. You then apply it to the area you wish to fill. Initially, for five to ten minutes it is sticky and soft, then begins to harden. After 24 hours it is cured chemically and can be filed, sanded etc.
I used it to fill in the upper side of a Shakuhachi finger hole to lower the pitch of that note. I improvised a mold to contain the putty while I pressed it in. After half an hour I was able to remove the containing mold, leaving the putty in place. The next day I filed and sanded the putty into shape. That was a week ago and the filler is still in place and I have been blowing this flute every day. I am so far pleased with the results.
I think the chemicals in this mix are similar to a product called 'Araldite', a two part liquid epoxy glue.

Kel.

Ed, do you know what Monty is using ?
When I got my flute from him it had an aroma inside the bore, I emailed him asking about it. He did not know or realize any aroma came from the flute. I can still notice it 18 months later, though not as strong.

Kel.

Thanks for the advice guys,i had know idea what consistancy urushi had, but know that i know its a liquid it makes a whole lot more sence!  Where can you get urushi! or is there like a formula for making it!

A number of makers in Japan use an epoxy putty called "Bond Wood". It is not as dense as the Plumber's stuff found in the US, but sets up very hard after a number of hours and takes well to sanding. After it has been kneaded together it is quite soft and can easily be applied to the inside of the bore, in layers thicker than traditional urushi-based ji. It also seems quite dimensionally stable over time and is not as friable as the usual stuff. I find it much more friendly to work with and quicker than normal ji, and it cures much faster. I'm told by some of the other makers in Tokyo that another good substitue is body putty for cars, but I have never tried it.

Toby

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The Forum has an excellent search function, here: http://shakuhachiforum.com/search.php 

     

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eB