John Sankey on thu 16 aug 07
Is there any practical model that can predict approximately what
temperature a glaze has to reach in order to be fully molten,
given its mineral composition?
I'm interested in modifying recipes that have expansion
coefficients outside the optimal range to move them closer to
optimum, but would need know how the cone rating would change.
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Ivor and Olive Lewis on fri 17 aug 07
Dear John Sankey,=20
You ask <<...:Is there any practical model that can predict =
approximately what temperature a glaze has to reach in order to be fully =
molten, given its mineral composition? ...>>
There is a rule of thumb that you might try.
Using the formulations for Seger Cones as guidance, their compositions =
will melt at a temperature approximately five cones higher than the cone =
setting temperature . For example, Seger Cone 1a with a setting =
temperature of 1100 deg C and a Seger composition of 0.3 K2O, 0.7 CaO, =
Al2O3 0.3, Fe2O3 0.2, SiO2 4.0 should be fully molten a 1200 deg C, =
Seger Cone 6a.
Chose you own ingredients to give this composition. I would omit the =
Iron oxide.
Ivor Lewis.
Redhill,
South Australia.
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