Two transparent glazes on the same dark burning clay. Why different?

Friday 11th September 2015

These two glazes are both brilliant glass-like super-transparents. But on this high-iron stoneware only one is working. Why? G3806C (on the outside of the piece on the left) melts more, it is fluid and much more runny. This melt fluidity gives it the capacity to pass the micro-bubbles generated by the body during firing. G2926B (right) works great on porcelain but it cannot clear the clouds of micro-bubbles coming out of this body. Even the glassy smooth surface has been affected. The moral: You need two base transparents in which to put your colors, opacifiers and variegators. Reactive glazes need melt fluidity to develop those interesting surfaces. But they are more tricky to use and do not fire as durable.

Pages that reference this post in the Digitalfire Reference Database:

G3806C - Cone 6 Clear Fluid-Melt Clear Base Glaze, G2926B - Cone 6 Whiteware/Porcelain Transparent Base Glaze, A super glassy ultra-clear brilliantly glossy cone 6 clear base glaze? Yes!, One example where a highly melt fluid clear glaze is better, Transparent Glazes, Melt Fluidity, Clouding in Transparent Glazes

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