Dawnisaacs@AOL.COM on sat 25 may 02
Can someone please advise how to avoid the small lines which appear in coils
of clay and make them more susceptible to breaking, when rolling and perhaps
what causes them. Thank you. D. Isaacs
Dave Gayman on sat 25 may 02
If you mean more or less circumferential cracks appearing as you roll, 3
things come to mind:
1. Clay too dry
2. Clay too short (not plastic enough)
3. Clay not wedged enough (wetter areas next to dryer areas)
The solutions for the first and last are pretty obvious, but if your clay
is too short, such as might happen when you dig your own earthenware clay
with sand in it, you can try adding a bit of plastic ball clay or a small
amount of bentonite. Amounts would have to be experimental.
It's also possible to increase plasticity by adding things that add or
enhance the organic content... all the way from the ancient Chinese (urine)
to real vinegar -- wine that's gone bad -- to baker's yeast. The latter
will give you really bad-smelling clay...
You can also mix up the clay with too much water, cover it, and let it age
for a length of time that varies by culture (Chinese - one or two
generations; American - 2 weeks.)
Dave
At 08:42 AM 5/25/2002 -0400, D. Isaacs wrote:
>Can someone please advise how to avoid the small lines which appear in
coils
>of clay and make them more susceptible to breaking, when rolling and
perhaps
>what causes them.
Sharon Pemberton on sat 25 may 02
I have made several smallish boards from 1" plywood and covered them with
various types/ textures of fabric. The board covered with smooth cotton,
from
a sheet, I use for small coils. I dampen with a fine mist of water and then
roll my coils. Don't let the cloth get soggy. Not only will any porous
surface dry your clay, your hands also suck it dry.
Good Luck!
Sharon
| |
|
