The best way to opacify a low-temperature terra cotta glaze

Thursday 3rd October 2019

insight-live.com/material/1642">Tin oxide is a powerful opacifier, but the 5% in this Frit 3124 based Arbuckle Majolica cone 04 recipe on the left is not sufficient. Adding 10% zircon (e.g. Zircopax, Superpax) produces the one on the right. Would just using 15% zircon be better? No. More zircon means a stiffer melt and more issues with crawling (notice the small bare spots on the right edge). This could be managed by the addition of CMC gum or a higher clay content to get better adhesion and dry hardness). But another improvement would be worth trying first: Use 4% tin and 8% zircon. That should opacify enough and present fewer problems with crawling.

Pages that reference this post in the Digitalfire Reference Library:

Arbuckle Majolica glaze using Fusion Frit F-19, G1916Q on L215, L212, L210, L213, Buffstone at cone 03, G1916Q transparent on terra cotta body at cone 06, 05, 03, Opacifier, Terra Cotta, Majolica

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