Iron oxide vacuums up glaze bubble clouds at cone 6

Friday 23rd June 2017

These two mugs are the same dark burning stoneware (Plainsman M390). They have the same clear glaze, G2926B. They are fired to the same temperature in the same 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 amber colored (with speckle). But on this dark burning clay it appears transparent. But amazingly, the bubble clouds are gone. We have not tested further to find the minimum amount of iron needed for this effect.

Pages that reference this post in the Digitalfire Reference Database:

Iron Oxide Red, A cone 6 clear glaze plus iron vs. Alberta Slip amber base, Clouding in Transparent Glazes

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