test 6

Red Iron Oxide 9% with the addition of Gerstley Borate
Cone 6 Oxidation

Recipe:
Kona F-4 49
Whiting 18
Zinc Oxide 9
EPK 1
Flint 6
Gerstly Bor. 17
+
Red Iron Oxide 9.0

Evaluation:
Extremly unstable. The positive qualities...transitions nicely from matt to gloss, and the interior pools to a rich and deep black/brown. However this glaze runns! Only use on top half (if not higher, top third).

This glaze is one of 18 tests. Students of the fall 2009 semester tested in 100 g. batches, recalculated to assure glaze stability, then further tested 500 g. batches, and finally compiled a list of 18 glazes to go through a uniformed batch test. All batches of this 18 recipe set were mixed through a process of precise measurements, 60 and 80 mesh screening, were dipped on cone 04 bisque for 3 seconds, and were finally fired to a witnessed cone 6 oxidation in an electric kiln. (Firing schedules are to follow shortly).