Iron oxide vacuums up glaze bubble clouds at cone 6

Friday 23rd June 2017

These two mugs are the same dark burning insight-live.com/glossary/85">stoneware (Plainsman M390). They have the same clear glaze, G2926B. They are fired to the same temperature in the same C6DHSC firing schedule. But the glaze on the left has 4% added iron oxide. On a light-burning body the iron changes the otherwise transparent glass to honey colored (with light speckle because of agglomerates). But on this dark burning clay it appears transparent. And, amazingly, the bubble clouds are gone! We have not tested further to find the minimum amount of iron needed for this effect but with other glazes 2% is working.

Pages that reference this post in the Digitalfire Reference Library:

Iron Oxide Red, A cone 6 clear glaze plus iron vs. Alberta Slip amber base, Clouding in Ceramic 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 digitalfire.com.