iandol on sat 29 mar 03
Dear Paulette Carr,
I like your style. Good way to ask a question.=20
I think this confusion arrises because the oxide conforms to the R2O/RO =
system of the Segar or Unity formula. ZnO is analogous to CaO.
Certainly, Zinc Oxide would not be a substitute for Boric Oxide under =
any circumstances. Their physical attributes are poles apart. Boron =
Oxide melts at 460=B0 Celsius, Zinc Oxide at 1975=B0 Celsius.
It is my opinion that the continuing use of Molecular oxide names when =
explaining glaze behaviour is intellectually confusing. It ignores the =
nature of the materials we put in our glazes. It would be of greater use =
if we could add Zinc to our glazes as its Silicate, Willemite in the =
same way we can add Magnesium through Talc and Calcium through =
Wollastonite or Anorthite rather than as Carbonates which decompose to =
become pure oxides. Pure oxides are not melting fluxes. They do nothing =
until they dissolve in a molten compound
Best regards,
Ivor Lewis
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