Tuesday, July 31, 2012

Combining Sterling and Fine Silver Clays

I still get blank looks sometimes from people who think that different silver clays cannot be mixed. From a chemistry point of view, all the silver clays are totally compatible, with the caveat of potential shrinkage mismatch. I routinely mix Art Clay syringe with PMC clay. The very first piece I made in sterling clay had a bit of fine silver syringe work added. Yesterday I loaded up the kiln with sterling and threw in a couple of pieces that have been on my bench for months. They were in an area of my bench that I've come to reserve for sterling clay, so I slapped sterling hallmarks on the back and fired away.

Fine silver clay with sterling clay applied
After the first stage open shelf firing, it was obvious that they were actually fine silver. The color of the two green clays is pretty different, with the fine silver being whiter, but these had sat out long enough to darken due to sulphur from the air. After the first stage firing, the two pieces were bright white, while all the others were even darker gray. No fear! The sterling hallmark still needed to be fired in carbon, so I packaged them all up and fired again.

Sterling clay components (and a couple of fine silver)
fresh from the kiln

The sterling comes out of the carbon with a light golden color, which cleans right off.  The fine silver components come out bright white. Once it's all polished and patinated, the difference is less obvious.