Cummings Pottery on thu 26 sep 96
Beth,
Read this in FireMagic:
Low fire red clays often contain significant soluble salts that can deposit
on the surface during drying, leaving an unsightly whitish scum and
affecting the overlying glaze. Make sure your supplier is putting enough
barium carbonate in the mix to precipitate these salts. Don't worry about
barium leaching, it is under the glaze, it transforms to nontoxic barium
sulphate during precipitation, and it participates in glass-building during
the firing.
Maybe this is the answerer?
Pat
Vashon Is., Wa.
patpots@wolfenet.com
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