Re: Gerstley Borate - has anyone come up with a GOOD replacement

If the amount of gerstley isn't too high you should be able to reformulate them
with a frit like Ferro 3134 or 3124. You can't make a direct substitution
though and will have to run the original recipe through a program like Insight
or Matrix to get the molecular formula and then match it using a frit. Boraq is
supposed to be a pretty good substitute. Some of the substitutes work on some
glazes but not others.
I have some cone 6 glazes with pictures and recipes on my web site if you'd
like to take a peek.

Regards,
June
http://www.angelfire.com/art2/shambhalapottery/