claybuds@ATT.NET on tue 1 dec 09
Here's my porcelain body:
P3C-1 - cone 10
31 Grolleg
21 EPK
30 200 mesh silica
13 G-200
5 OH #1 ball clay
I've had alot of success with this porcelain body, which I mix as a slurry =
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and dry to moist consistency. It has excellent throwing characteristics, 14=
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.5% shrinkage @cone 10,
0% absorption @cone 10, exhibits no warping or cracking or slumping, has a=
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very fine smooth feel and excellent glaze fit. It does use expensive Groll=
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eg, and is formulated to allow for larger thrown pieces by the addition of =
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EPK. It turns out that EPK, a domestic secondary kaolin, is a natural compl=
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iment to provide excellent particle distribution with the grain size of Gro=
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lleg. The body uses G-200 spar, and I may need to sub Custer at some point,=
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as Ron says G-200 is now unfit to be used in porcelains. The key to the wo=
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rkability of this body is the addition of 5% of a very white-burning high k=
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aolin ball clay from Old Hickory, again to provide crucial particle distri=
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bution. My contact at Old Hickory is Tracy McAlister, tracy@oldhickoryclay.=
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com, 800-242-6885. The body can be slightly translucent if trimmed thin, bu=
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t translucency was not my intention. I wanted to come up with a porcelain t=
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hat could be used to produce larger and taller pieces on the wheel, yet ret=
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ain a white fired color to show off glazes at their best.
My blue celadon glaze is:
J-91 - cone 10 reduction
33 Neph Sy
14 Whiting
49 Imsil A-25 silica
1 99% R.I.O.
1.5 Bone Ash
2 Bentone MA
add: 1% Tin oxide
I owe the lowered expasion of this glaze to Paul Lewing, who worked on it f=
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or me back in 2000. Best if applied rather thick. A slip made from the abov=
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e porcelain body looks great as hakeme under the J-91. Also excellent under=
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a kaki, with wax decoration in between.
David Beumee
Porcelain by David Beumee
Lafayette, CO=3D20=3D20=3D20=3D20
John Britt on tue 1 dec 09
Fantastic post David!
Now that was eductional and generous!
John Britt
www.johnbrittpottery.com
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