Stephani Stephenson on thu 11 sep 03
Janet
have enjoyed reading your posts
One thing that I have discovered from experience
which counters what I learned from books and in school
clay slip for slipcasting need not be finebodied and may in
fact contain a fair amount of grog.
the grog does not seem to interfere with the smoothness of
the outer surface or obscure detail.
The grog is, in fact, quite well suspended in the clay slip
and does not collect in odd places or unevenly.
I use the same claybody for slipcasting as I do for
handbuilding and tile pressing by hand and also the same
body that is used in the presses and is also extruded. The
grog in the clay and also the aging of the slip alleviate
many problems with cracking , also reduce shrinkage....also
allow for a thicker wall to be cast.
the slip is preferably aged at least 6 months, and I do add
the suggested amounts of sodium silicate and soda ash.
a very small part of my work is slipcast, only a few pieces,
and I have done less than 50 of each.
one wonderful use for the sculptor is to slipcast some
sculptural forms for glaze tests. it has always been tough
to develop glaze palettes for sculpture... simple test tiles
don't indicate how glazes will really look, but similar
slipcast forms will give you an idea of the running, , how
the glaze breaks on similarly shaped surfaces etc.....
The guy who makes large pots by hand pressing and building
up section molds, slipcasts small pots to use for glaze
tests for new glazes. these small pots have similar shapes,
and are 14" rather than 40". They aren't sold, and have
prevented some expensive mistakes,
Stephani Stephenson
steph@alchemiestudio.com
| |
|
