Shibuichi is an ancient Japanese alloy of copper and silver, with the percentage of silver ranging between 5% – 25%. There is a very informative article about this alloy in March 2010 issue of Art Jewelry Magazine by Lee Rumsey Haga, which I highly recommend.I have been often asked about combining different metal clays together, so I decided to try. I made “Shibuichi clay” of 5% silver and 95% copper, using mixed Quick-fire copper and PMC Plus.One way to measure is to use a scale. To make 10 grams of this type of Shibuichi clay, mix 0.5 grams silver clay with 9.5 grams copper clay.
I fired it with a torch for 6 minutes from the moment the binder had burnt off, and immediately dipped in water. I found that torch-fired Shibuichi clay is stronger than torched-fired copper clay.
I also tried it in a kiln. I fired it for 1:00 hour at 1470°F (800°C) in my top loader kiln. In a front loader, fire at 1550°/843°C.
Another source is www.sculptnouveaux.com. They also have different sealers and their products come with full instructions.
Art Clay Copper How To: