Copper Red
My previous copper red work:
Here I show a glazes with mixed copper red and blue. There are small bits of green
where the glaze flowed into the bottom of the bowl,
and a small amount of
opalescent white streaking. The color of this glaze is dense on both the
inside and outside of the pot.
there are some small colorless spots where the
glaze is thin, and it would seem this is the result of burst bubbles.
The near black appearance of the glaze is the result of an overgenerous
application of glaze. This is the first copper red glaze which can be applied
sufficiently thickly
to display such a dense color.
This glaze has high silica, low alumina, and high alkali metals.
The firing has a two hour hold at 1600 deg F.
The local reduction is produced by the inclusion of 1% of 1000 mesh silicon
carbide in the glaze recipe.
These glazes, as all my glazes, are mixed with CMC gum which aids in
maintaining the silicon carbide in suspension.
cone 10 oxidation
Firing profile
Up Fire profile
150 deg F an hour to 250 deg F
400 deg F an hour to 1800 deg F
300 deg F an hour to 2050 deg F
120 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F
Down Fire Profile
300 deg F an hour to 1750 deg F then a half hour hold at 1750 deg F
300 deg F an hour to 1700 deg F then a Three hour hold at 1700 deg F
300 deg F an hour to 1600 deg F then a two hour hold at 1600 deg F
The cones show this as a cone 10 firing.
K2O .18
Al2O3 .36
SiO2 4.1
molecular percent Silica 74%
I added 1% silicon Carbide and .5% Copper Carbonate to the above glaze.
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula glaze cu-red-Z1K-0 :
Na2O .37
CaO .38
MgO .02
ZnO .05
SnO2 .05
bowl is ~ 4 inches in diameter
outside
inside
