Causes of Devitrification
is part three of a multi-part tip on the causes of devitrification.
Click here to go to part one.
9. Some mold ingredients and
separators can also contribute to devitrification. Whiting,
for example, will cause devit in some glasses, as will the plaster
in a plaster/silica mold. Glass in prolonged contact with
fiber products can also be more prone to devitrify.
10. The kiln atmosphere can also
contribute to devitrification. Venting from room temperature
to 1000F/540C can help reduce the likelihood of devitrification by
giving binders, glues, and impurities in mold mixtures the
opportunity to escape from the kiln.
11. Repeatedly firing the same glass
can lead to an increased chance for devitrification. This can
happen even at relatively low temperatures that wouldn't cause devit
in a normal first firing.
Copyright 2006 Brad Walker.
All rights reserved.
Thanks to Graham Stone for some
of the items in this tip.