Alisa og Claus Clausen on wed 10 oct 01
Glaze test for: Orange Glaze, cone 6 ox.
Source: Mike Bailey's book
All tests fired on white, mid-range stoneware.
Fired in to cone 6 (1220c) in oxidation.
Firing ramp:
100c (212f) per hour to 600c (1112f)
150c (302f) per hour to 1100c (2012f)
100c per hour to 1220c (2228f)
15 - 30 minute soak depending on matts and glosses used.
Recipe:
46.7 Potash
4 Kaolin
2 Bentonite
15 Bone ash
4 LIthium Carb.
16.9 Talc
11.4 Silica
ADD
10 RIO
Note:
All raw materials measured up or down to nearest whole decimal.
Oxides used on percent basis to a 100 gram batch of glaze.
Substitutions:
Feldshammer feldspar for potash.
Resulted in:
Gloss surface glaze that covered well. No discernable
difference where dipped twice. It is a rich, medium brown with very
vivid orange streaking throughout. Surface is fluid but not
runny. The oranges are very bright.
Variation: added 10 Ochre
Same base color, but no orange streaking. Instead the glaze has a
creamy yellow cast where thickest.
Best regards, Alisa
in Denmark
Cindy Strnad on wed 10 oct 01
Hi again, Alisa.
This one sounds cool. A little low on silica, but I'm going to try it. =
I'm curious. If you know, where does the orange color come from? I =
forget--are you using white or brown clay? It seems all the orange =
glazes I've tried contain some amount of lithium and MgO and at least a =
pinch of Phosphorus. Is that the reason they turn orange? It's sure not =
the iron, is it? I, too, have tried adding iron with disappointing =
results.
I don't know if you have this one, but I like Golden Fake Ash. It's more =
of a burnt yellow than orange and has wonderful drips though they never =
seem to reach the kiln shelf. It was posted by a Clayart person long =
time ago and I can't remember who, exactly. A gorgeous glaze, IMO.
I've only ever used it with a slow cool, so I'm not sure what it would =
do with a normal (unregulated) cooling. It's way low on silica. (I've =
been using it on the outside of vases and haven't tested it for =
durability.) From the look of it, it's low on fluxes, too, though it's =
hard for me to say--too many fluxes for my brain, and it does seem to =
melt just fine. They say a combination of fluxes melts better than one =
alone. Hope I'm using all the right words. As you know, I tend to get =
them tangled up.
Golden Fake Ash, ^6 Oxidation. Gloss to Semi-gloss
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
REDART.............. 29.00 28.71%
OM #4 BALL CLAY..... 21.00 20.79%
BONE ASH............ 5.00 4.95%
STRONTIUM CARBONATE. 9.00 8.91%
DOLOMITE............ 25.00 24.75%
GERSTLEY BORATE..... 10.00 9.90%
LITHIUM CARBONATE... 2.00 1.98%
=3D=3D=3D=3D=3D=3D=3D=3D
101.00
CaO 0.45* 16.11%
Li2O 0.05* 1.04%
MgO 0.32* 8.16%
K2O 0.03* 1.81%
Na2O 0.02* 0.92%
SrO 0.12* 8.07%
TiO2 0.01 0.73%
Al2O3 0.21 13.37%
B2O3 0.08 3.72%
P2O5 0.03 3.01%
SiO2 1.05 40.13%
Fe2O3 0.03 2.94%
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
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