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slip cast pottery rakued and porcelain ^10

updated sat 31 may 97


Peter and Sam Tomich on sun 18 may 97

Hi all you slipcasters! Does anmyone have experience rakuing slipcast
ware? Do you have any tried and true body formulas. One I am going to
try (someday) is found in Hands In Clay, by Speight and Toki. It is from
Jim Gremel, California who has been doing slip cast raku for 4 years and
says, "The cast pieces survive the raku process much better than their
predecessors, and their color developement seems to be better."

Cone 07 Raku Slip Casting Body

27.02% Imco #400 fire clay
27.02% Tennessee ball clay
13.52% Custer feldspar
16.22% Ione grain #65 F grog (very fine powder)
16.22% Mullite 100 mesh

45.95 pounds of water (20.86 kilos) and 351.36 grams of Darvan #7
deflocculant per 100 pound (45.40 kilo) batch.
Additional water, Darvan #7, and sodium silicate N are added as needed
to achieve a specific gravity reading of about 1.75. It is important to
bisque fire the clay to cone 06 before raku firing.

HOW do you add the extra stuff to get it to that specific gravity? A
little more water... A little more Darvan etc, till you get it right?
This is vague, and I don't understand. Like a miracle happens in there
somewhere and it just gets right?

Also I am looking for a ^10 porcelain slip casting body. Could I just
get a bag of dry clay and deflocculate it?

Thanks, Sam in Hawaii