A cone 8 comparative flow tests of Custer, G-200 and i-minerals high soda and high potassium feldspars. Notice how little the pure materials are moving (bottom), even though they are fired to cone 11. In addition, the sodium feldspars move better than the potassium ones. But feldspars do their real fluxing work when they can interact with other materials. Notice how well they flow with only 10% frit added (top), even though they are being fired three cones lower.
Pages that reference this post in the Digitalfire Reference Database:
Feldspar, Custer Feldspar, MC 200K Feldspar, Soda Feldspar, MC Na-200 Feldspar, A Low Cost Tester of Glaze Melt Fluidity, Low Budget Testing of the Raw and Fired Properties of a Glaze, Feldspar 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.