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testing terra sig finishes

updated sun 11 feb 01

 

potter on thu 8 feb 01


Hi

Does anyone have a way of testing the terra sig finishes for durabilty and
longevity.

Bryan

vince pitelka on fri 9 feb 01


> Does anyone have a way of testing the terra sig finishes for durabilty and
> longevity.

Bryan -
How 'bout this. Use them for a long time and see how they hold up.

Seriously, this is not an issue with terra sig finishes. You cannot get the
durability that you would get from a glaze, and therefore you cannot use
terra sig on primary wear surfaces on utilitarian pieces, and on
non-utilitarian pieces it is not an issue, as long as the terra sig is not
flaking off. As for durability and longevity, check out Greek and Roman
terra sig wares. Seems to me that they provide pretty good evidence.
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 sat 10 feb 01


Bryan wrote:
Does anyone have a way of testing the terra sig finishes for
durabilty and
longevity.

I've never tested terra sig finishes as such: bonfiring to about ^016
which seems optimum for shine. But I've slipped pots with Redart terra
sig, burnished, and "overfired" to ^04 and these are semiglossy and
quite durable. In either case, the finish has great longevity, but the
"real terra sig" (fired to ^016) is not mature in the sense of
significant melting, thus I expect it's not durable in terms of
handling, scraping, and the other aspects of utililitarian use. The ^04
slip-and-burnish stuff holds up just fine, but doesn't have the shine
and carbon trapping that characterize the real thing. Now if there was a
way to get both... lotsa luck.

Anybody else?

Roger Korn
McKay Creek Ceramics