Garret D. Bonnema on mon 6 may 02
I am hoping for some advice on how to improve the casting body that we have
been using for years. It works well, but I am sure that it could be better.
When we formulated it we tried for a "porcelain" body that would not warp
when used for plates and also work well on larger pieces like lamps.
Whiteness was not our prime concern. We fire in reduction to cone 9/10,
We also wanted to work with materials that we could get up here in Maine
from our local supplier. That is not as much of an issue now since our local
suppliers are all connected to major suppliers. We use about 4000 pounds of
this dry mix a year.
The recipe is:
77 lbs. water
50 lbs. Tenn.#5 ball clay
16 lbs. C&C ball clay
34 lbs. Pioneer kaolin
36 lbs. G-200 feldspar
24 lbs. Pyrotrol
40 lbs. Silica (200 mesh)
This recipe is a variation of one I got from Val Cushing in 1987, reworked
with the help of the late Herman Kleiner.
When I was testing years ago, I came up with this strange method for
deflocculating it. I use 15g. BaCo3, 18g. Soda ash, and 20-30ml of Darvan
811.
I would like a body that would cast even better, warp even less, and be less
likely to craze with a variety of glazes. Not asking much.
Anyone have any advice?
Thanks,
Garret Bonnema
Bethel, Maine
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