How much silica can some glazes accept?


Thursday 21st May 2015

G2922B is a cone 6 clear glaze that started as a well-known recipe "Perkins Studio Clear". We substituted Gerstley Borate with a frit (while maintaining the chemistry) and then noted that the glaze was highly fluid. Since I wanted to keep its thermal expansion as low as possible, I added 10% silica. 2926B shows that it is very well tolerated. Then I added 5% more (2926D) and 10% more (2926E which is still very glossy). That means that E represents a full 20% silica addition! SiO2 has no real downsides in any well melted glossy glaze, it hardens, stabilizes and lowers expansion.

Pages that reference this post in the Digitalfire Reference Database:

SiO2, Co-efficient of Thermal Expansion


This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.