Silicon Carbide
The effect of a local reducing agent, silicon carbide, in a viscous glaze.
I was asked about methods for producing textured sculptural glazed surfaces,
and remembered the effect
I added 0.3% silicon carbide to the
glaze shino_Z2I_1. In a reduction firing, a shino gets its characteristic
orange
The viscosity of a shino glaze is such that the bubbles generated by the
decomposition of the silicon carbide
This glaze was applied thick. Perhaps if the glaze was applied thinner, an
interesting less fragile texture might result.
bowl is ~ 3 inches in diameter.
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
300 deg F an hour to 1750 deg F then a 50 min hold at 1750 deg F
50 deg F an hour to 1700 deg F then a three hour hold at 1700 deg F
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
K2O 0.11
Al2O3 1.17
SiO2 3.18
molecular percent Silica 58.4%
Added:
0.3% of 1000 mesh Silicon Carbide
shown below.
color as a result of the iron in a clay body rising to the surface of
the glaze. I wondered if adding a local reducing
agent to a shino glaze might
have a similar effect in an oxidation firing in an electric kiln.
can't escape the glaze - producing the
frothy pattern seen below.
Image of the glaze shino_Z2I_1 with 0.3% silicon carbide
inside
outside
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile
Down Fire Profile
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula shino_Z2I_1 :
Na2O 0.62
Li2O 0.23
CaO 0.03
MgO 0.01
P2O5 0.09