Sandra Talarico (home) on mon 23 feb 04
I've recently done some glaze color experimentation involving
rutile and copper carbonate. Found a nice set of combinations
of the rutile/copper carb that I liked. Tested them several times in
different firings. Satisfied myself that they colors/glaze was what I
wanted. Mixed up a big batch to create 4 variations of rutile/copper
carb combination. Test fired
the new/big batch of glazes, and everything is a different color.
My tests glazes were in the khaki greenish family with the familiar
breaks caused by the rutile. That was the test batch. The big batch -
everything is in the BLUE family. Bluish greenish to gunmetal blue/gray
in one of the combinations.
I did run out of copper carb from one source and finished
the large batch with copper carb from a different source. I'm convinced
this is the problem. I plan to order more copper carb from the
original source and test again.
Has anyone else experienced this green to blue color change
with copper carb from various sources? Can anyone name a high
quality reliable source for copper carb?