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gerstey or colemanite?

updated fri 17 dec 99

 

ababy sharon on sun 12 dec 99

Hi!
I would like to hear (through-E-Mail) your opinion which of the two is
better.
the problem with Gerstley Borate is that I don't know it, exact annalists,
whenever I try to use it instead of the expensive frit 3134( here in Israel)
...Is I know it is not the same material, I do it through Insight!

David Hewitt on tue 14 dec 99

I would stick to using a frit. Both gerstley borate and colemanite give
rise to problems and, as Tom Buck illustrated in a recent posting, the
analysis of GB has changed quite significantly over the years and hence
if you are copying a recipe with GB you need to know the date it
originated or an analysis of the glaze at that time.
Not being in North America, GB is not that cheap anyway and I have never
used it. I would think that the consistency of using a frit to introduce
boron into a glaze is well worth any additional cost.
David
In message , ababy sharon writes
>----------------------------Original message----------------------------
>Hi!
>I would like to hear (through-E-Mail) your opinion which of the two is
>better.
>the problem with Gerstley Borate is that I don't know it, exact annalists,
>whenever I try to use it instead of the expensive frit 3134( here in Israel)
>...Is I know it is not the same material, I do it through Insight!
>

--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP18 3DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Own Web site http://www.dhpot.demon.co.uk
IMC Web site http://digitalfire.com/education/people/hewitt.htm

Lee Marshall on wed 15 dec 99

ok i hate gerstley borate. how do i change yo a frit
lee marshall
lmarsh1220@aol.com

Vince Pitelka on thu 16 dec 99

>ok i hate gerstley borate. how do i change yo a frit
>lee marshall
>lmarsh1220@aol.com

Lee -
We use the Jaquie Rice lithium glazes at ^04 on terracotta, and we had the
regular problems with Gerstley borate going into solution over time. Had to
throw away lots of glaze. So we just substituted directly for 3134 frit,
and they work perfectly, with no deterioration over time. The finished glaze
is slightly less matt, but in my opinion they were a little too dry-matt
with the Gerstley. I am happy with their performance using the 3134.
- Vince

Vince Pitelka
Home - vpitelka@DeKalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166