vince pitelka on wed 6 feb 02
> I'm working on a series of clay tests for woodfire, and remember that
> one suggestion from Clayart was to add epsom salts to the body to
> increase plasticity.
> Do any of you clay makers out there use epsom salts? What percentage?
> How do you incorporate it into the body?
> My water is alkaline, ph 9.
Paul - 1/2 of 1% of the dry clay weight. Dissolve epsom salts in hot water,
and then use that as part of your water content in the claybody.
Good luck -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Paul Herman on wed 6 feb 02
Greetings to all,
I'm working on a series of clay tests for woodfire, and remember that
one suggestion from Clayart was to add epsom salts to the body to
increase plasticity.
Do any of you clay makers out there use epsom salts? What percentage?
How do you incorporate it into the body?
My water is alkaline, ph 9.
Thanks in advance,
Paul in Doyle, where it's cold, crisp and in brilliant sunlight, and the
shop is heating up from the sun.
vince pitelka on thu 7 feb 02
> Would this be a good example to demo flocculation as a way to improve
plasticity?
> I'll try it and see. This is a concept I'm trying to get across to some
students.
> And the .5% is negligible as a change in body fluxes for firing
maturation.
Roger -
Well yes, because that is precisely the point, especially in any claybody
tending towards alkalinity. And in communications and recipes I always
write "1/2 of 1%" rather than ".5%" because in the latter the decimal is too
often overlooked.
For an effective demo of flocculation in claybodies, just mix ten pounds or
so of porcelain body deflocculated with 1/4 of 1% each of soda ash and
sodium silicate. Wedge it very well, and then have the students do some
simple plasticity tests involving bending and stretching. The clay should
be VERY short, and pretty much unworkable. Then mix up a small amount of
saturated Epsom salt solution. Take a good chunk of the short porcelain,
poke a few finger holes in it, and give it a few squirts of the Epsom salt
solution, wedge thoroughly, and repeat the plasticity tests. Wonder of
wonders.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Roger Korn on thu 7 feb 02
Hi Vince,
Would this be a good example to demo flocculation as a way to improve plasticity?
I'll try it and see. This is a concept I'm trying to get across to some students.
And the .5% is negligible as a change in body fluxes for firing maturation.
Roger, who's mailing those marbled clay photos today, honest!
vince pitelka wrote:
> > I'm working on a series of clay tests for woodfire, and remember that
> > one suggestion from Clayart was to add epsom salts to the body to
> > increase plasticity.
> > Do any of you clay makers out there use epsom salts? What percentage?
> > How do you incorporate it into the body?
> > My water is alkaline, ph 9.
>
> Paul - 1/2 of 1% of the dry clay weight. Dissolve epsom salts in hot water,
> and then use that as part of your water content in the claybody.
> Good luck -
> - Vince
>
> Vince Pitelka
> Appalachian Center for Crafts
> Tennessee Technological University
> 1560 Craft Center Drive, Smithville TN 37166
> Home - vpitelka@dtccom.net
> 615/597-5376
> Work - wpitelka@tntech.edu
> 615/597-6801 ext. 111, fax 615/597-6803
> http://www.craftcenter.tntech.edu/
>
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--
Roger Korn
McKay Creek Ceramics
In AZ: PO Box 463
4215 Culpepper Ranch Rd
Rimrock, AZ 86335
928-567-5699 <-
In OR: PO Box 436
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North Plains, OR 97133
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