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colemanite question

updated fri 29 sep 06

 

mel jacobson on wed 27 sep 06


others may help on this topic.
years back colemanite had some drastic
changes....i had all kinds of problems and realized
that the base formula had changed. had missed while
in japan, some new information.

it was a basic in the paint industry and they
seemed to not care, it was a disaster for potters.

so, i would like to know if those issues still exist?

i know i do not use, or have any colemanite in my studio.
mel

from: mel/minnetonka.mn.usa
website: http://www.visi.com/~melpots/

Clayart page link: http://www.visi.com/~melpots/clayart.html

Lee Love on wed 27 sep 06


On 9/27/06, mel jacobson wrote:

> so, i would like to know if those issues still exist?
>
> i know i do not use, or have any colemanite in my studio.

I think it is still available here in Japan. Will check it
out (maybe mix up Craig Edwards' cone 6 reduction shino.)

--

Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi

steve blankenbeker on thu 28 sep 06


Colemanite is still used extensively in the fibreglass
industry as a melter. It is imported from Turkey and
milled in Blacksburg, SC for either American Borax or
US Borax. I think they are out of Richmond, VA maybe.
The same mine also produces ulexite. They can both
be used at times to replace Gerstley Borate. They
have different melting points, but both melt extremely
low. Both products are simply mined and ground,
without further beneficiation. Therefore, the overall
nature of the deposits (purity, natural contaminants)
could and probably would be very mine specific. So if
you were comparing colemanite from a US source vs. the
Turkey deposit, there very well might be diferences.
Years ago I gave a potter friend some "synthetic"
colemanite I picked up at a "fire sale", and it was a
disaster.

steve

--- mel jacobson wrote:

> others may help on this topic.
> years back colemanite had some drastic
> changes....i had all kinds of problems and realized
> that the base formula had changed. had missed while
> in japan, some new information.
>
> it was a basic in the paint industry and they
> seemed to not care, it was a disaster for potters.
>
> so, i would like to know if those issues still
> exist?
>
> i know i do not use, or have any colemanite in my
> studio.
> mel
>
> from: mel/minnetonka.mn.usa
> website: http://www.visi.com/~melpots/
>
> Clayart page link:
> http://www.visi.com/~melpots/clayart.html
>
>
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