•The secret to cool bodies and glazes is a lot of testing.
•The secret to know what to test is material and chemistry knowledge.
•The secret to learning from testing is documentation.
•The place to test, do the chemistry and document is an account at https://insight-live.com
•The place to get the knowledge is https://digitalfire.com
Between the melting and boiling points (and, of course, especially while boiling is proceeding) all glaze compounds vaporize to some extent. The amount of vaporization is related to the time and temperature and atmosphere of the firing. Obvious examples of cases where vaporization must be considered are chrome, zinc, fluorine sourcing materials.
The firing of fluorine containing materials (e.g. frits) must proceed quickly to minimize the loss and get the benefit of their presence. Zinc vaporizes in reduction atmospheres. Another example is bismuth compounds, they source the very low melting oxide, that, if fired too high could vaporize. The reason this is a concern is because bismuth is very very expensive.
Volatilization is not the same as vaporization. The former refers to oxides within materials that burn off, and are expected to burn off during firing (e.g. carbon, H2O). The term "flashing" can refer to vaporization (e.g. chrome flashing).
Out Bound Links
Zinc Oxide - ZnO - Pure Source Of Zinc
ZnO, Zincite, Zinc 99
Bismuth Oxide - Bi2O3
Bismuth(III) oxide, bismite, Bismuth trioxide
Chrome Oxide - Cr2O3
Chromium (III) Oxide, Cr2O3, Chromium Oxide
F - Fluorine
In Bound Links
Compounds with clays or glazes that burn away during firing. For example, calcium carbonate decomposes during firing to produce CO2 gas and loses almost half its weight. Other common volatiles are sulphur, carbon, water, fluorine, nitrogen. The term "volatilization" refers to the burning off of vola...
By Tony Hansen