How to reverse-engineer a commercial transparent glaze

Monday 2nd September 2019

The commercial insight-live.com/glossary/119">cone 04 clear brushing glaze (on the left) works really well on our clay bodies so I sent it away to be analyzed (about $130). That revealed high Al2O3/SiO2 levels, this explains its resistance to crazing on our clay bodies and, even better, indicates high durability. In my account at insight-live.com I was able source the same chemistry from two Fusion frits (plus a little kaolin and silica). The melt fluidities are almost identical (my G3879 has a little more surface tension). I needed to make a dipping glaze version and chose a method that would produce a thixotropic slurry. One caution: An assay lab cannot analyze the complexities of a colored glaze, instead focus on the base clear and add stains to that. The first two-gallon bucket made saved the development cost plus more! And knowing the recipe made it possible to adjust for even lower thermal expansion. Another plus: I can now make my own low SG or high SG brushing version.

Pages that reference this post in the Digitalfire Reference Library:

G3879 - Cone 04 Transparent Low-Expansion transparent glaze, A Low Cost Tester of Glaze Melt Fluidity, Getting a chemical analysis of your ceramic powder, How and where to have a glaze tested to learn its chemical analysis, Five low fire glazes: Which is the best?, Glaze Chemistry, Kovar Metal

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.