The foot ring on the left is plucking, the right one is not. Why?

Sunday 14th June 2015

These are translucent porcelains, they are vitreous. The firing is to cone 10. The one on the left is a cone 6 body, and, while it survives to cone 10 it does warp. But more important, it is much more vitreous (more melted). The plucking problem makes it quite difficult to get a good foot ring. The other, which has only slight plucking, is also quite vitreous (high in feldspar). The plucking problem on both can be solved by simply using a better kiln wash. What is better? More refractory, and therefore having a powdery, non-stick surface. Spend more money on your kiln wash, base it on calcined alumina or zircon.

Pages that reference this post in the Digitalfire Reference Database:

Plucking on a vitreous porcelain at cone 6, Kiln Wash, Porcelain, Vitrification, Plucking

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