Hi All,
I just did my first crystalline glaze firing (glaze formula and firing schedule below) and for the most part I am very happy with the results I got. The one problem is that the glaze that settled into the bottoms of the bowels is not smooth or glossy like the sides. In fact it almost looks charred with an abundance of very black, small needle like crystalline forms. No glassy appearance at all in the bottoms.
Formula Ferro Frit 3110 50 Zinc Oxide 28 Flint 22 Bentonite 3 Manganese Dioxide 2 Cobalt Carb. 0.5
Firing Schedule Rate Temp F Hold Time
200Hr 800 150Hr 1250 300Hr 2100 100Hr 2282 12 Min Quick Cool 2012 1 Hr 22 Min. 150Hr 2066 2 Hours Shutdown and cool normallyAny input is welcome. Thanks Larry