From my first and second round of testing, I realized that my granite needed more flux. It was too stiff and this was making the glazes uninteresting. So I set out to test every flux I could think of in the Utah State University materials store room. I added 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45% and 50% of each of these fluxing materials to my Devil’s Playground granite (which accordingly went from 95% down to 50%).

This was a broad test and I was hoping to hit on some interesting things, but I also just wanted to see the effect of different materials. When I leave USU, I am not going to have access to such a range of potential ceramic ingredients. The granite offers a blank slate with which to experiment, in a way; it is a stiff grey translucent glaze on its own at cone 10.

I was particularly interested to see the differences that the fluxes had on the granite. For example, the difference between minspar and custer feldspar (very minimal difference) or between lime and wollastonite (a marked difference, lime being much more green and faster at matting out the surface, the wollastonite being much bluer).

I also decided to add 4% iron to every test, in order to see how the added iron content played with these various fluxes, too.

This video is about 25 minutes long and takes you through the results of each set.

Check out my next post for all the notes and photos of this batch of tests.