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replacement for gerstly borate?

updated sun 30 jun 96

 

Jack Phillips on wed 12 jun 96

To the collective brilliance of the group,

I have just met a friend in South Africa, and my question is for her. What
would be a near replacement for gerstley borate for raku glazes? I have
plenty of raku glaze recipes, most containing GB. Now I know colmanite is
available to her, but she says it is tricky to use for her. She may mean
that it is not as desireable in results, I'm not to sure. Near replacement
anyone?

Also, If any one has raku glazes formulated for materials available in
S.A., (inc. frited) please post them and I will pass them on to her. TIA



Jack Phillips
STONART Ceramic art
Portland, Oregon

LINHARES on thu 13 jun 96

Hi Jack,

As I was reading your post I brought up my Hyperglaze 2 materials list to
compare gertsly borate. Colemanite looks very simliar but it has a
little less silica. Hommel frit 14, Ferro frit 3134, and Pemco frit P-54
are almost identical to each other (enough to be interchangable) and are
all high in CaO and B203, but they have a good deal more silica than
Gertsly Borate. Many of the raku glazes that I know of call for 80
Gertsly and 20 Neph. Sye. I don't think I would want to try to keep a
fritted glaze of that proportion in suspension (NO FUN). Maybe a glaze
that used Cloemanite and one of these frits in combination could come
closer to a match for G.B. Tell your friend good luck, and I hope some
of this was helpful.

>From Paul in Ohio where it's wet wet wet.