Craig Martell on mon 8 jan 01
Hi:
Poise finger near delete key before reading this. Thank you!
There aren't any materials presently available that will sub directly for
Gerstley Borate. As John Hesselberth has pointed out, it also depends on
which analysis you use for GB. Tricky stuff. The closest that I've gotten
is by using cadycal 100 with high sodium frits. I don't use much gerstley
borate so it's not a big deal as far as I'm concerned. Others feel
differently and rightly so.
The whole GB thing is a good example of how glaze calculation can be of
great service to those who will use it. It's much easier to take each
glaze using boron with GB as the source and recalculate it with materials
that will bring the oxides back to the same values sans GB. This means
making adjustments with clay and silica and perhaps feldspars, as well as
the boron bearing material.
Some of the substitutes currently available are fine and you can really get
close and sometimes right on the original glaze by calculating the whole
glaze.
regards, Craig Martell in Oregon
Ababi Sharon on tue 9 jan 01
Hello Craig!
I Don't know if you can find this frit in America, this company has agents
there, try this E mail gloriagg@ix.netcom.com of Hobby Colorobia I just
got this frit, I do not know if the huge amount of B2O3 is stable. If I will
buy again I will ask for more information.
Frit F5(Colorobia).. 100.00 100.00%
========
100.00
CaO 0.40* 10.99%w 12.97%m
K2O 0.21* 10.00%w 7.03%m
Na2O 0.39* 11.99%w 12.80%m
Al2O3 0.04 2.02%w 1.31%m
B2O3 1.10 38.00%w 36.15%m
SiO2 0.91 27.00%w 29.74%m
Cost/kg 18 Israeli Shekel about 4.5 $
Si:Al 22.65
SiB:Al 50.17
Expan 11.83
About software to those of you that hastiest, aseptically 'novice' : The
ceramic software allows you to play with the glaze, the way, when you do,not
have it, the glaze "plays" with you! You develop, change materials rule it!
Few tests instead of tens!
Ababi
----- Original Message -----
From: "Craig Martell"
To:
Sent: Tuesday, January 09, 2001 1:23 AM
Subject: Gerstley Borate subs
> Hi:
>
> Poise finger near delete key before reading this. Thank you!
>
> There aren't any materials presently available that will sub directly for
> Gerstley Borate. As John Hesselberth has pointed out, it also depends on
> which analysis you use for GB. Tricky stuff. The closest that I've
gotten
> is by using cadycal 100 with high sodium frits. I don't use much gerstley
> borate so it's not a big deal as far as I'm concerned. Others feel
> differently and rightly so.
>
> The whole GB thing is a good example of how glaze calculation can be of
> great service to those who will use it. It's much easier to take each
> glaze using boron with GB as the source and recalculate it with materials
> that will bring the oxides back to the same values sans GB. This means
> making adjustments with clay and silica and perhaps feldspars, as well as
> the boron bearing material.
>
> Some of the substitutes currently available are fine and you can really
get
> close and sometimes right on the original glaze by calculating the whole
> glaze.
>
> regards, Craig Martell in Oregon
>
>
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Craig Martell on tue 9 jan 01
Ababi said:
>I Don't know if you can find this frit in America, this company has agents
>there, try this E mail gloriagg@ix.netcom.com of Hobby Colorobia I just
>got this frit, I do not know if the huge amount of B2O3 is stable. If I will
>buy again I will ask for more information.
Hello Ababi:
I've never seen this frit in the US. I could have missed it though. Thank
you for the information.
Craig Martell in Oregon
Joanna Jorgensen on thu 14 nov 02
Martin,
These are all websites that discuss the substitutions for gerstley
borate.
http://www.alchemist.nl/gerstleyengels.htm
http://www.kickwheel.com/Murrays.Borate.html
http://www.digitalfire.com/gerstleyborate/dupgerstley.shtml
http://www.ceramicsmonthly.org/mustreads/substitutions.asp
Joanna Jorgensen
Coconut Creek, FL
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