David Wong
06-29-2012, 5:52 PM
I have not seen this documented anywhere, so I thought I would throw some pictures up for for reference...
My japanese natural waterstone had developed some pretty serious layering cracks. This was probably my fault for not mounting the stone to a permanent base. I read mentioned that a method of repair and support for cracked stones is to use japanese lacquer (urashi), and layers of a persimmon soaked paper (yoshino-gami shibu-tsuki). So when my wife was traveling in Japan, I asked her to order some cashew lacquer and paper from a sword supply store Namikawa Heibei Co., Ltd. (http://www.namikawa-ltd.co.jp/english/index.html) Cashew lacquer is reportedly far less toxic and faster drying than regular urashi lacquer, though there is a caution that some people report having serious allergic reactions. The paper description says that the persimmon tannins make the paper stronger.
I waited until the first 100+ degree day, since urashi is normally cured in hot humid environments. Cashew lacquer has the consistency of molasses. I used an acid brush to paint it onto the outer surface of the stone. I then pressed on a strip of paper. The paper strip was not long enough to cover the entire stone, so I brushed on another coat of lacquer and pressed on another strip of paper to fully cover the stone. The stone then received another coat of lacquer. Finally, I coated the bottom of the stone and folded the paper down.
After a few days to let the lacquer dry, I made a base of hardwood and hot-glued the stone to the base. I have been using the stone for a couple of weeks now and the repair seems to be holding up well.
David
235578235579235580235581235582235585235584
My japanese natural waterstone had developed some pretty serious layering cracks. This was probably my fault for not mounting the stone to a permanent base. I read mentioned that a method of repair and support for cracked stones is to use japanese lacquer (urashi), and layers of a persimmon soaked paper (yoshino-gami shibu-tsuki). So when my wife was traveling in Japan, I asked her to order some cashew lacquer and paper from a sword supply store Namikawa Heibei Co., Ltd. (http://www.namikawa-ltd.co.jp/english/index.html) Cashew lacquer is reportedly far less toxic and faster drying than regular urashi lacquer, though there is a caution that some people report having serious allergic reactions. The paper description says that the persimmon tannins make the paper stronger.
I waited until the first 100+ degree day, since urashi is normally cured in hot humid environments. Cashew lacquer has the consistency of molasses. I used an acid brush to paint it onto the outer surface of the stone. I then pressed on a strip of paper. The paper strip was not long enough to cover the entire stone, so I brushed on another coat of lacquer and pressed on another strip of paper to fully cover the stone. The stone then received another coat of lacquer. Finally, I coated the bottom of the stone and folded the paper down.
After a few days to let the lacquer dry, I made a base of hardwood and hot-glued the stone to the base. I have been using the stone for a couple of weeks now and the repair seems to be holding up well.
David
235578235579235580235581235582235585235584