Tuesday, November 19, 2013

Shrinkage: Friend or Foe?

I just love it when my students have an, “Ah ha!” moment -- especially when it’s something that I’ve been harping about for ages. Then one day the light goes on and they magically GET IT!

That happened in my class last week when someone applied fresh clay to a previously fired silver piece. The result, of course, came out with an interesting arc as the pre-fired silver yielded to the fresh, new silver. It was a serendipitous and beautiful result. 

The fact that metal clay can be fired over and over really amazes beginning students. The one caveat that messes with their heads, however, is what happens when they apply fired to unfired silver. Yes, size matters. ( :) ) The larger the amount of fresh clay that is used, the more shrinkage will result. And the higher and longer the piece is fired, the greater the shrinkage. The results can be unpredictable and surprisingly interesting.

Sometimes it’s the unintentional results that give us the happiest rewards. This is a great way to salvage accidents or previously fired pieces that you have not yet found a use for. Take a brave, bold step and paste some pre-fired pieces to unfired silver and fire them at a high temp (1580) for about an hour. Try using stones for added interest. If you don’t like the result, texturize them with a hammer, add granulation (pre-fired balls of fine silver) and fire again. There are no mistakes!

Some unique and original holiday gifts may get you voted Santa of the Year!
Creative blessings!

by Linda Kline
Director of Education

Image above: Steel wire and PMC Sterling tested for shrinkage. To read all of Janet Alexander's PMC Sterling tests, including extensive explorations on shrinkage, search this blog for Sterling.