Judith Enright on thu 27 mar 97
Toni, Laura, Martha, Deni and others who may be interested: Mea culpa
-- I committed the faux pas of giving test results without the recipes
or further information. That's what I get for being in a rush, and
I'm sorry. Herewith:
The following were tested on ^6 porcelain bisqued at ^04, as well as a
^04-^6 terra cotta, also bisqued at ^04. Without exception, the terra
cotta results were abysmal.
Recipes are in percentages, fired in oxidation. I recommend judicious
sieving of these glazes.
TOM BUCK'S FOODSAFE CONVERSION OF CREAM BREAKING RED:
Custer feldspar 41
Gerstley Borate 22
Whiting 9
Strontium carb 3
Flint 25
ADD: Tin oxide 13
Red iron ox. 2 (or up it to 4)
Very nice, smooth yellowish-cream with VERY thin flashes of orangy red
with 2% RIO. Brownish speckling on inside of test cup.
LANA'S AQUA BRONZE
Neph Sye 50
Strontium Carb 50
ADD: Gerstley Bor. 3.5
Bentonite 3
Copper Carb 4
This is a rich deep aqua with large splotches of bronze that appear as
they want -- i.e., this doesn't break bronze over edges or modelling.
This needs to be applied somewhat thickly, as thin spots are totally
uninteresting, but give bottoms a wide swathe, or fettle the glaze
near bottoms as this likes to run.
The following is the base glaze from which the Weathered Bronze Green
is derived -- there are additives for other colors listed after the
base. I've only tested the WBG. What I got on a bowl was blistering
that rivaled the ravaged face of Baron Harkonnen in DUNE. The test
cup came through much better -- this looks exactly like it sounds and
has a sort of sugary/crystally effect (I held this in the sunlight and
nearly went blind). Definitely not for food surfaces.
PETE PINNELL'S STRONTIUM MATT GLAZE (BASE)
Neph Sye 60
Strontium Carb 20
Ball Clay 10
Flint 9
Lithium Carb 1
Bonnie Hellman suggests adding 2% bentonite since this glaze wants to
settle rock-hard quickly. (Thanks, Bonnie!)
for Weathered Bronze, ADD:
Titanium Dioxide 5
Copper Carb 5
for Weathered/Periwinkle Blue, ADD:
Cobalt Carb .15
Copper Carb 4
for Dark Mottled Green, ADD:
Copper Carb 8
for White, ADD:
Titantium Dioxide 5
for Cream/Tan, ADD:
Rutile 6
for Charcoal, ADD:
Manganese Dioxide 2
Copper Carb 5
for Dark Gold/White, ADD
Mason stain 6485
or Titanium yellow 6
Happy testing!
-- Judith Enright @ Black Leopard Clayware & Pottery
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