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bald spots on brushed terra sig

updated mon 9 oct 06

 

Teri Lee on fri 6 oct 06


Anyone got ideas why I get naked or bald spots on my pots when I brush red terra sig onto greenware?

At first I thought maybe the terra sig was too thin so I removed some water. No difference at all. The bald spots don't seem to be so noticeable after the pit firing, but I still see 'em.

The bald spots appear on both burnished and unburnished pots. It doesn't seem to matter what kind of clay bodies I use.

Any and all comments and suggestions would be greatly appreciated!





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Vince Pitelka on sat 7 oct 06


Teri Lee wrote:
> Anyone got ideas why I get naked or bald spots on my pots when I brush red
> terra sig onto reenware?
> At first I thought maybe the terra sig was too thin so I removed some
> water. No difference at all. The
> bald spots don't seem to be so noticeable after the pit firing, but I
> still see 'em. The bald spots
> appear on both burnished and unburnished pots. It doesn't seem to matter
> what kind of clay bodies
> I use.

Teri -
It is hard to know what you mean by "bald spots." It sounds to me like the
kind of variation of surface that we always seek in pitfiring and bonfiring,
so I am not sure what the problem is. That said, thickening the terra sig
is NEVER the solution. Terra sig doesn't work well unless it is applied
very thin in multiple coats. Are you applying multiple coats? That might
be the problem. Check out my terra sig article at
http://iweb.tntech.edu/wpitelka/professional/terra_sig.htm - if you follow
those instructions, you will get excellent terra sig with no "bald spots."
There are no shortcuts to get the best terra sig.
Good luck -
- Vince

Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/

Bacia Edelman on sun 8 oct 06


Teri, think about switching to spraying. Use an airbrush or some kind of
sprayer from
which you can control a fine spray. Possibly the brushing goes over a wet
spot
and without your seeing it, removes some of the terra sig. When I did a lot of
sawdust firing and used terra sig, I could paint small areas as part of a
design
but for general coverage, spraying worked wonders.

All the best.

Bacia, very very jet-lagged from a 17 day trip to central Europe

sorry, I can't get my reply to appear ahead of the question



Bacia Edelman
Madison, Wisconsin
http://users.skynet.be/russel.fouts/bacia.htm
http://www.silverhawk.com/artisan/clay/edelman/index.html