Wednesday, January 30, 2013

Glaze Testing

Ken mixes all his pottery glazes.  Some potters buy glazes, and like cake mixes they are consistent.  But mixing glazes leads to some pretty exciting results.  

For the last few years Ken has been using more and more local materials - local rock powders and ashes from burning plant parts like corn stalks or bean husks.

Doing this means gathering the materials and running glaze tests.  As he lists out ingredients and what they do - melt, stick to the pot, add color, add matte shiny or opalescent qualities, my head spins.  And then as he moves to molecular weights and chemical bonds, I am left behind!

Today he is trying six versions of one local rock.  First he ground it in the ball mill for about a week.
This magical jar is filled with rock powder and porcelain balls.  The turning moves the balls, and they crush the rock.

Then he measures out the same substances, but in somewhat different ratios.  He weighs them combines them with water and mixes them.

After he labels each test to keep them all straight,  he has to let them sit for hours so the ingredients become consistently wet.  

Soon the glaze tests will go on small fired pieces of clay into the test kiln.

No comments:

Post a Comment