Lili Krakowski on tue 28 jun 05
White clay! Ah!
Sometime in the last century (I love the way that sounds!) I was invited to
do a show. At the time I was working with the Delft look--blue on white.
But as a special treat I decided to use white instead of buff clay. I
called my supplier and said: I want a magnesium free white clay. None of
our white clays contain magnesium the person said.
So--trusting little country mouse that I am--I set to work--white clay,
white glaze, cobalt brush work.
When I opened the glaze kiln--purple brush work.
Seeing red, my face red, I called the supplier.
"I asked....I was told..." Well it turned out (you guessed) that
the )*()(&(*^ I had talked to had not known that talc contains magnesium....
Lesson learned. Both dolomite and talc are used, can be used, in clay
bodies. Both contain magnesium with its purpling effect on cobalt.
Somewhere,--is it Cardew?--- I read that phosphates in kaolin can have same
purpling effect.
So. When Gay confirms that three white clay bodies turned out quite
different glaze results---that is why.
NO one expects clay body manufacturers to reveal their recipes. And I still
am incensed at the person who recently said --in defense of homemade clay
bodies--that the manufactured ones are "crap"! BUT one cannot trust that
every gofer who answers the phone KNOWS. And there are other variables.
SO TEST ALREADY!
Lili Krakowski
Be of good courage
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