Bobbruch1@AOL.COM on fri 7 nov 03
<<<<< wrote:>>>>>>>>>I have 100 liters of white
feldspar glaze that I don't want to trash. This glaze will not take Cobalt
Oxide painting without "spritzing" all over the piece. After firing there is a
dusting of blue around the area I've painted. Recently I added 2% Colmanite to
the white glaze (before doing this the white worked with the cobalt). I am
guessing the Colemanite is
interacting with the cobalt. If you have experienced this I'd love to know a
way to neutralize the problem. Thanks---Guy
Guy: I had the same issue, with cobalt carb. My glaze base was a somewhat
matte white, and the cobalt is very volatile, which is why I think the blue
behaved as it did. I am not sure about this, but you could try using less of the
cobalt. But if your base glaze is matte, you may have to add small amounts of
additional neph sy until it gets to the point where the "dusting" stops.
Bob Bruch
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