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slip casting earthenware

updated tue 4 may 10

 

Centa Uhalde on fri 30 apr 10


For those knowledgeable about the method and who are not opposed to slip
casting as a means of production, I direct this question.

I am trying to push a commercial terracotta slip (04-05) to 02, which the
manufacturer said should work, glaze firing to 03. I'm wanting to fire
higher to get less of the typical chipping and breakage of earthenware (is
my logical is off?). I don't understand why, with earthenware only (slip as
well?), it is advisable to bisque fire higher than your glaze fire.

Anyway, I'm getting cracks in the glaze fire. Serious cracking. I'm not sur=
e
it is the rectangular forms causing the breakage, or pushing the slip
casting body, or an ill fit between the glaze (majolica) and the terracotta=
.

So, my thinking is that I need to 1) further test, 2) consult w/ the
manufacturer and have them adjust their secret (half talc) recipe, or 3)
find a recipe and make a more plastic (guessing?) body, in which case can
anyone recommend a good slip casting body for the higher end range of
earthenware? OR, 4) I could mix a slip of cone 6 "porcelain" and
earthenware, however that would probably further complicate the issue rathe=
r
than simplifying.
THANKS,
Centa Theresa
www.centatheresa.com