iandol on thu 11 sep 03
Dear James Bowen,
I think the remark about Calcium Based fluxes was with regard to the =
substitution of Wollastonite for Whiting or any of the Calcium Carbonate =
based equivalents since a reaction with Hydrochloric Acid would lead to =
the formation of a water soluble salt.
The question to ask first is "which of the material used can be =
flocculated or deflocculated?". So ask ; can you flocculate GB, Whiting, =
Frits, Silica, Felspar, carbonates? Then ; What are the principles of =
the flocculation-deflocculation reaction?
In considering glazes which are sprayed, my own preference would be to =
use a glaze slurry which is deflocculated and brought to a viscosity =
which will allow good flow and atomisation with the minimum of medium, =
which will be water. Evaporation of a small volume of water would =
rapidly set up the coating, allowing for the build up of very thick =
layers which would not shrink during drying.=20
If Tom Coleman visits Clayart, perhaps he would like to discuss this =
topic with us.
Best regards,
Ivor Lewis. Redhill, South Australia
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