Dupre Mr Marcy M on fri 25 oct 02
All,
"Gerstley borate." The words can send shivers of ecstasy or horror up the
spines of most potters. There was much public weeping, wailing, and
gnashing of teeth at the announcement that the GB mines were stopping
production. Much cheering and high-fives when Laguna announced that they
still had a few thousand tons of the Ghastly Dust in their carefully guarded
warehouses. As I write this, there is still debate over availability of the
one-and-only Gerstley, how much longer it will be available, and what will
substitute for it when the last gram is fired.
I have read about fritted substitutes, mixed substitutes, and
naturally-occurring mined substitutes. It seems that nearly everyone has a
favorite glaze recipe that absolutely, positively, has GOTTA HAVE the TRUE
Gerstley Borate, or it just won't function. Some potters have complained
that extensive tests with recommended substitutes have been fraught with
failure.
It may be that I missed something. Isn't our lot as potters to adjust to
and be somewhat content with the leavings of ceramic industry? We get the
left overs. We work with them. When a particular material falls out of
favor with the industries that use millions of tons per year, we who use
maybe 150 pounds a year have to go along with the program. Find something
else.
Jordan clay. Albany slip. Colemanite. And probably a bunch of other
materials I missed learning how to use and abuse. So what to do?
I have made and tested several substitutes for other materials. David
Hendley's Albany substitute works wonderfully. With a little testing and
adjustment, many glazes designed with Albany Slip can be re-formulated with
Alberta Slip. I've done some straight substituting of Redart clay for
Albany. Different colors, different surfaces, still good lookin'!
So now we come to the Gerstley Borate Lament. (The poem by Paul Lewing is
available on-line at
http://www.oregonpotters.org/Newsletter/gerstley_borate_lament.htm)
Without going into a litany of lament for the lost material, let me tell
what I have done. Adjust your responses accordingly. First a disclaimer:
I have no financial interest in, or ownership of any of the products I am
suggesting. I do not yet depend completely on the manufacture of pottery
for my livelihood. I do not yet have a standard string of glazes that are
linked to my name or the name of my studio, compiled with Gerstley Borate as
a significant portion of the formulation. Having said that, here's what I
have tried.
I tried Ferro Frit 3124 and Gillespie Borate as one-for-one substitutes.
Tony Hansen's Digital Fire website www.gerstleyborate.com has a
comprehensive article on borate substitutes. For my experience, Gillespie
Borate is a reliable addition to my glaze chemistry set. I don't get quite
the same reaction from Frit 3124, but it can be used in most iron-based
glazes, instead of GB.
I looked over some of the other recommendations and discarded them as too
complex for me. "Substitute 30 parts of Product X for 20 parts of GB, and
subtract 10 parts..." Nah. "If the recipe calls for 23 parts GB, use x
parts of Product 1, plus y parts of Product 2..." Nope.
KISS. Keep It Short and Simple. "Substitute one part of Product B for each
part of GB." Yup. I can do that.
Bottom line is: it works for me. As always, TEST, TEST, TEST. Your mileage
may vary...
Best to all,
Tig
in a marvelously relieved Springfield, VA, where the shooters are in jail,
and the evidence against them continues to pile on...
Ron Roy on tue 29 oct 02
Hi Tig,
Some wise words here and what you say should be an inspiration to all potters.
My approach is different of course - I think we are on the way to being a
lot more independant materials wise.
I can add Calvert clay , Buck spar and Kingman spar to the list. When
Calvert and Bucksape when down many of the clays bodies I worked on
contained them - G200 was a quick and compatible sub for Buck Spar. Calvert
was a different story.
I had to reformulate many of the body which contained it - quickly - I had
just started using a calculation program - did it first try.
What the point? The sooner we start learning to use calculation software
the better - sooner is not soon enough. If you want to be free from fear -
not feel helpless or reliante - in fact become truely independant - get
started.
Trial and error is all very well and good - and you can never get
completely away from that - but learning how to use calculation - with
reliable analysis of materials is like turning on a light in a dark room -
the difference between night and day.
Thanks for triggering my thoughts on this - evidentally I have been wanting
to say this for a long time.
RR
>"Gerstley borate." The words can send shivers of ecstasy or horror up the
>spines of most potters. There was much public weeping, wailing, and
>gnashing of teeth at the announcement that the GB mines were stopping
>production. Much cheering and high-fives when Laguna announced that they
>still had a few thousand tons of the Ghastly Dust in their carefully guarded
>warehouses. As I write this, there is still debate over availability of the
>one-and-only Gerstley, how much longer it will be available, and what will
>substitute for it when the last gram is fired.
>
>I have read about fritted substitutes, mixed substitutes, and
>naturally-occurring mined substitutes. It seems that nearly everyone has a
>favorite glaze recipe that absolutely, positively, has GOTTA HAVE the TRUE
>Gerstley Borate, or it just won't function. Some potters have complained
>that extensive tests with recommended substitutes have been fraught with
>failure.
>
>It may be that I missed something. Isn't our lot as potters to adjust to
>and be somewhat content with the leavings of ceramic industry? We get the
>left overs. We work with them. When a particular material falls out of
>favor with the industries that use millions of tons per year, we who use
>maybe 150 pounds a year have to go along with the program. Find something
>else.
>
>Jordan clay. Albany slip. Colemanite. And probably a bunch of other
>materials I missed learning how to use and abuse. So what to do?
>
>I have made and tested several substitutes for other materials. David
>Hendley's Albany substitute works wonderfully. With a little testing and
>adjustment, many glazes designed with Albany Slip can be re-formulated with
>Alberta Slip. I've done some straight substituting of Redart clay for
>Albany. Different colors, different surfaces, still good lookin'!
>
>So now we come to the Gerstley Borate Lament. (The poem by Paul Lewing is
>available on-line at
>http://www.oregonpotters.org/Newsletter/gerstley_borate_lament.htm)
>
>Without going into a litany of lament for the lost material, let me tell
>what I have done. Adjust your responses accordingly. First a disclaimer:
>I have no financial interest in, or ownership of any of the products I am
>suggesting. I do not yet depend completely on the manufacture of pottery
>for my livelihood. I do not yet have a standard string of glazes that are
>linked to my name or the name of my studio, compiled with Gerstley Borate as
>a significant portion of the formulation. Having said that, here's what I
>have tried.
>
>I tried Ferro Frit 3124 and Gillespie Borate as one-for-one substitutes.
>Tony Hansen's Digital Fire website www.gerstleyborate.com has a
>comprehensive article on borate substitutes. For my experience, Gillespie
>Borate is a reliable addition to my glaze chemistry set. I don't get quite
>the same reaction from Frit 3124, but it can be used in most iron-based
>glazes, instead of GB.
>
>I looked over some of the other recommendations and discarded them as too
>complex for me. "Substitute 30 parts of Product X for 20 parts of GB, and
>subtract 10 parts..." Nah. "If the recipe calls for 23 parts GB, use x
>parts of Product 1, plus y parts of Product 2..." Nope.
>
>KISS. Keep It Short and Simple. "Substitute one part of Product B for each
>part of GB." Yup. I can do that.
>
>Bottom line is: it works for me. As always, TEST, TEST, TEST. Your mileage
>may vary...
>
>Best to all,
>
>Tig
>in a marvelously relieved Springfield, VA, where the shooters are in jail,
>and the evidence against them continues to pile on...
>
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Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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