Curing Urushi
Curing Urushi
How long does it take to cure the urushi on a new shakuhachi? I tested it on myself when I received it and got a serious skin rash. I have been keeping it at room temperature enclosed in a styrofoam box with bowls of water for a month. I can still smell the lacquer. How can I tell when it has completely hardened?
I'm sure allergic reaction varies from person to person but for me a flute with that had a coat of fresh urushi applied up to a year prior can still cause a reaction.
Re: Curing Urushi
"Earl Saxon""Earl Saxon"How long does it take to cure the urushi on a new shakuhachi? I tested it on myself when I received it and got a serious skin rash. I have been keeping it at room temperature enclosed in a styrofoam box with bowls of water for a month. I can still smell the lacquer. How can I tell when it has completely hardened?
Hi Earl, As Erin mentioned, some people can be sensitive long after the urushi has hardened. Visit this page on the Shakuhachi BBQ for much more info:
http://www.shakuhachiforum.com/viewtopic.php?id=4213
If you feel confident to experiment, try washing the bore with dish washing liquid. You'll need to make a soft scrub, something like a chopstick with a cotton cloth wrapped around the tip with a rubber band. After drying, wipe the area of contact with anti- Poison Ivy or Lansinoh Baby wipes before playing. They will clean the oil residue from the urushi that was emitted during the slow curing process.
Let us know what happens!
- Perry
I'm wondering about the statement in the original post about keeping it in a Styrofoam box with bowls of water. Does that help it dry? Intuitively, I'd think open air might do better, but I remember reading that some chemicals cure better in the presence of humidity, which goes against intuition.
If you are interested you might want to read more about urushi sensitivity and the properties of urushi as related to curing in a post I wrote on my blog here: http://ashakuhachijourney.blogspot.com/2010/06/urushi-adventures.html
Put urusi inside shakuhachi is like put senf inside wurst. Possibling but not Best Way.
Not possibling eat raw wurst. But is possibling play raw bambus. Jinshi ohne urushi.
Urushi mak from poisioningss. Poisioningss bad like e.coli in bad schnitzel.
Jinshi gut.
Ji ohne urushi beter.
Plastick more beter. When being plastik be the plastick.
Cast form Best Way.
This is evilution of shakuhachi in modernen welt.
Amerikanische wurst dificulties:
[Flash unavailable]
Not possibling eat raw wurst. But is possibling play raw bambus. Jinshi ohne urushi.
Urushi mak from poisioningss. Poisioningss bad like e.coli in bad schnitzel.
Jinshi gut.
Ji ohne urushi beter.
Plastick more beter. When being plastik be the plastick.
Cast form Best Way.
This is evilution of shakuhachi in modernen welt.
Amerikanische wurst dificulties:
[Flash unavailable]
The blog post is very informative. However, again intuitively, there seems to be contradictions. If the skin irritation problem is due to gasses being carried in the air, it seems that vaporization is an essential part of the curing process, and keeping the object with the uncured urushi on it in an airtight container would impede the curing process by not allowing vaporization. On this wikipedia page: http://en.wikipedia.org/wiki/Lacquer I see that "Urushiol-based lacquers differ from most others, being slow-drying, water-based, and set by oxidation and polymerization, rather than by evaporation alone. In order for it to set properly it requires humidity and warm temperature. The phenols oxidize and polymerize under the action of an enzyme laccase, yielding a substrate that, upon proper evaporation of its water content, is hard." So it appears that high humidity should help the curing process for urushi, but evaporation is still an important part of the process. Again intuitively (which I only add because I know intuition can't be fully trusted), one would conclude that it would help to allow the vapors in the surrounding air to escape so that the vapor saturated air may be replaced to allow the curing process to continue. This seems to go against some of the advice given in the blog to keep the uncured instrument in an airtight environment with high humidity, advice which could be prevalent considering that the original poster of this thread decided to keep his uncured shakuhachi in a styrofoam box with bowls of water.
I hate to be an upstart, but this issue seems to have too many health related concerns to follow counter-intuitive advice without question.
I hate to be an upstart, but this issue seems to have too many health related concerns to follow counter-intuitive advice without question.
"Earl Saxon""Earl Saxon"I have been keeping it at room temperature enclosed in a styrofoam box with bowls of water for a month.
I have good results curing urushi on warm, humid summer nights leaving the flute out on the balcony, just during the night not in the sun, of course. I've had no cracking issues doing this, also. Doesn't work as well on cool, humid nights. Haven't seen any nude sausage/shakuhachi thieves, either

"CharlesKoeppen""CharlesKoeppen"...So it appears that high humidity should help the curing process for urushi, but evaporation is still an important part of the process. Again intuitively (which I only add because I know intuition can't be fully trusted), one would conclude that it would help to allow the vapors in the surrounding air to escape so that the vapor saturated air may be replaced to allow the curing process to continue. This seems to go against some of the advice given in the blog to keep the uncured instrument in an airtight environment with high humidity, advice which could be prevalent considering that the original poster of this thread decided to keep his uncured shakuhachi in a styrofoam box with bowls of water.
I hate to be an upstart, but this issue seems to have too many health related concerns to follow counter-intuitive advice without question.
Hi Charles, Yes, it is a serious issue. The advice is in accordance with the curing procedure so it makes sense. Urushi does not "air out". There is a slightly oily film on the surface after the initial polymerization. It's like an oil spot on your driveway. It may eventually go away with a lot of rain, but it will take some time. On a flute, the breath moisture and draw cloth will eventually remove the toxins (those who wash their tsuyutoshi will be better off).
There are some stories from the BBQ thread from those who are very sensitive. Even multiple washings didn't help for a while.
"Perry Yung""Perry Yung"
Hi Charles, Yes, it is a serious issue. The advice is in accordance with the curing procedure so it makes sense. Urushi does not "air out". There is a slightly oily film on the surface after the initial polymerization. It's like an oil spot on your driveway. It may eventually go away with a lot of rain, but it will take some time. On a flute, the breath moisture and draw cloth will eventually remove the toxins (those who wash their tsuyutoshi will be better off).
There are some stories from the BBQ thread from those who are very sensitive. Even multiple washings didn't help for a while.
Just for clarification, do you mean the advice of keeping it in an airtight bag (that the original poster on this thread seems to have modified by using a styrofoam box ) with high humidity is correct?
The advice you gave previously in this thread about washing the bore with dish-washing liquid and wiping with something like Cortaid was not the focus of my question. It was the advice found in Erin's blog (that Erin provided a link to in this thread) that I was questioning. The particular passage in the blog is
"Erin's blog""Erin's blog"Supported by what I had learned about urushi and guided by a message from Ken LaCosse, I placed the new flute back in its plastic bag with a damp clothe and allowed it a little more curing time. Once I took the flute back out, a week later for Wednesday longtones, I again experienced eye irritation so back into the bag for another week. Two weeks later, still the same problem.
In both Erin's blog and for the original poster of this thread who says he has been keeping the shakuhachi in an airtight humid box, keeping the shakuhachi in a high humidity airtight environment did not help. So, it is the particular piece of advice about keeping the shakuhachi in an airtight humid environment (and it isn't clear where that advice originated from) that did not work for at least two individuals that I was questioning the validity of.
Charles, in my case, I would say it wasn't that the method of allowing the urushi to cure that didn't work but rather that it took longer to cure than I would've liked. A few weeks in a humid environment was not sufficient time for the flute I had which was coated in urushi on the inside and had rubbed urushi on the outside, to cure. That flute had a more urushi than most. I was the one who requested the urushi rubbed exterior because it gives the flute a very handsome dark finish. But that was before I realized that I had a sensitivity to fresh urushi. Up to that point an older flute with urushi in the bore did not cause me any problems whatsoever.
Urushi does draw moisture from the air as it cures. Placing the urushi flute in a moisture laden environment, like a humid shower room, will help speed the curing process. In my case I did not want to have much exposure to the urushi while it cured so I choose to put it in a plastic bag with an available source of moisture in the form of the damp cloth.
Hope this helps clarify the method and process of urushi curing on a shakuhachi.
Urushi does draw moisture from the air as it cures. Placing the urushi flute in a moisture laden environment, like a humid shower room, will help speed the curing process. In my case I did not want to have much exposure to the urushi while it cured so I choose to put it in a plastic bag with an available source of moisture in the form of the damp cloth.
Hope this helps clarify the method and process of urushi curing on a shakuhachi.
"CharlesKoeppen""CharlesKoeppen"
In both Erin's blog and for the original poster of this thread who says he has been keeping the shakuhachi in an airtight humid box, keeping the shakuhachi in a high humidity airtight environment did not help. So, it is the particular piece of advice about keeping the shakuhachi in an airtight humid environment (and it isn't clear where that advice originated from) that did not work for at least two individuals that I was questioning the validity of.
The advice makes sense to me as that is how urushi is cured. But the reason why some people still get the rash is probably because they are very sensitive to the urushiol.
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