iandol on fri 2 may 03
Dear Jorge Nabel,
Although it is possible to concoct a formulation which will give the =
same elemental oxide analysis as Nepheline Syenite it may not have the =
same low melting point qualities Substitutes will not have the potential =
to create one of those rare and elusive natural Eutectic entities which =
enhance the early melting of a glaze recipe.
Best regards,
Ivor Lewis
Tony Hansen on sun 4 may 03
I agree, however efforts to match the chemistry
of substitutes has always given me better results
than not doing so. The three main differences between
materials are chemical, mineralogical and physical
and accounting for these using the best information
you have is guaranteed to give the best success rate.
> Dear Jorge Nabel,
> Although it is possible to concoct a formulation which will give the =
> same elemental oxide analysis as Nepheline Syenite it may not have the =
> same low melting point qualities Substitutes will not have the potential =
> to create one of those rare and elusive natural Eutectic entities which =
> enhance the early melting of a glaze recipe.
> Best regards,
> Ivor Lewis
========
clayart@digitalfire.com
iandol on mon 5 may 03
Dear Tony Hansen,
You say <<<substitutes has always given me better results than not doing so. The =
three main differences between materials are chemical, mineralogical and =
physical and accounting for these using the best information you have is =
guaranteed to give the best success rate.>>>
Very true. Furthermore, when we run the much needed but currently absent =
material to ground, we can reconsider the options and make fair =
comparisons.
But people are wise to remember, Chemistry is about the inter-reactions =
between the compounds we use. Our substations are about matching =
contents in terms of Elemental Oxides. So chemical behaviour will =
differ.
Best regards,
Ivor Lewis. Redhill, South Australia
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