When Pat Accorinti floated the idea of creating an alloy with metal clay as a supplement to our demonstration with Mitsubishi’s quick fire copper clay, Kathleen Gordon and I were on board immediately. Pat had read Hadar Jacobson’s blog post about creating an alloy of copper and silver by combining PMC+ with her formulation of Quick Fire Copper Clay. Pat had also read the Art Jewelry Magazine article on shibu-ichi alloys which Hadar mentioned in her blog post, because we’d all just recently received our copies in the mail.
I had Mitsubishi’s clay products on hand, and I have a wonderful book on Japanese patinas which lists shibu-ichi alloy ratios and shows patina on some pieces made with shibu-ichi. Once we decided on a ratio, I calculated the amounts of silver metal clay and copper metal clay needed to mix the nami-shibu-ichi alloy of 25% silver and 75% copper.
After Kathleen and Pat mixed up the clay alloy, Pat created samples to match the copper clay samples she’d made almost a month earlier. The domed circles of nami-shibu-ichi clay were then split up for various treatments and finishes by the three of us. Kathleen fired her set of samples immersed in carbon in a kiln. Pat fired her samples by torch and in a kiln without carbon. And, I kept some of the torch fired samples to patina. Pat also took some of the samples to enamel on and to paint with purchased patina solutions.
Results Summary: the quick fire clays seem to sinter reliably in the kiln. The nami-shibu-ichi does take patina differently than pure copper. Care needs to be taken to avoid the introduction of air bubbles in the clay alloy mixture. Torch patina and kiln patina on the nami-shibu-ichi were very popular with the demonstration audience.