Lili Krakowski on thu 3 jan 08
Gina, I am not quite sure what you are doing.
You are using a clay body that I assume you have tested at the firing temp,
and method you want.
You now want to coat it with white slip. And the porcelain body clay you
have pounded and slaked into slip is cracking and peeling.
Why are you not using a regular slip?
White slips are made up of ball clay (40-60 parts) kaolin (60-40 parts) --in
inverse ratio to the other clay.
Other ingredients can include feldspar (up to 20 parts), flint (up to 20
parts, Zirconium opacifier 5 parts, borax 5 parts, bentonite of gum if
desired.
Loree slip (named after the potter who made it up) is 5% borax, 14% Ferro
frit 3124, 14% Neph Sy, 24% ball clay, 24 % kaolin and 19% flint.
More slip recipes in PMI Vo.I, Number 1, Winter 1998.
There are some recipes out there meant to be applied very thick, for
texture. I must have a recipe someplace but where?
Your slip must be coordinated with your clay body--i.e. shrink at it does,
same amount--and it must be applied when the pot is the right dryness.
Proportions of materials for application on leather hard, greenware, and
bisque differ. Rhodes has a good chart on that.
But you have to test. I have used all the slips I mention above on
leatherhard clay.
Lili Krakowski
Be of good courage
Ron Roy on sun 6 jan 08
Most slips that are applied to green or bisque will need to be
deflocculated - especially if they are applied thickly.
Lots of advice about defloccing in the archives - or let me know and I'll
send directions - the way I do it.
RR
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Lee Love on mon 7 jan 08
On 1/7/08, Ron Roy wrote:
> Most slips that are applied to green or bisque will need to be
> deflocculated - especially if they are applied thickly.
>
I have recalculated Rhodes crackle slip for bisque here in
Mashiko, but it doesn't crackle. If I add some bentonite, would that
help it shrink and crackle?
I have always thought using this slip under a clear glaze is
a good way to get the crackle look of a crazing glaze, but with a
smooth surface.
--
Lee in Mashiko, Japan
http://groups.google.com/group/ClayCraft
"Men are born ignorant, not stupid. They are made stupid by
education." -- Bertrand Russell
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