Saturated Iron
Here are two near neighbor saturated iron glazes, satIron_ZG_7_MliAlk and
satIron_ZG_7_MLi.
The second glaze has lower silica, higher alkali metals, higher phosphorus
and lower magnesium. The second
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 1850 deg F then a 2 hr hold at 1850 deg F
300 deg F an hour to 1750 deg F then a 1 hr hold at 1750 deg F
300 deg F an hour to 1700 deg F then a 3 hr hold at 1700 deg F
25 deg F an hour to 1650 deg F then a 1 hour hold at 1650 deg F
K2O 0.07
Al2O3 0.51
SiO2 3.51
molecular percent Silica 66.5%
K2O 0.06
Al2O3 0.51
SiO2 3.05
molecular percent Silica 62.47%
The first glaze is variegated, with a black matrix and several distinct
micro-crystalline inclusions.
The second glaze contains trace amounts of titanium, which interacts with iron
to produce a characteristic
glaze is an iron red, the coppery colored
micro-crystalline clusters so prominent in the first glaze
are entirely
gone.
Image of the glaze satIron_ZG_7_MLiAlk
inside
outside
bowl is ~3.5 inches in diameter
Image of the glaze satIron_ZG_7_MLi
inside
outside
bowl is ~3.5 inches in diameter
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile cone 10
Down Fire Profile cone 10
Clay body is a grolleg porcelain from Clay Art Center in Tacoma, WA.
glaze compositions
Empirical Formula satIron_ZG_7_MLiAlk:
Na2O 0.56
CaO 0.23
MgO 0.14
Fe2O3 0.21
P2O5 0.04
Empirical Formula satIron_ZG_7_MLi :
Na2O 0.62
CaO 0.21
MgO 0.10
Fe2O3 0.21
P2O5 0.11
TiO2 0.01
Remarks
It also is significantly glossier that the
second glaze. The increased silica in this glaze decreased
the viscosity of
the glaze thus allowing a greater variety of second phase crystals to grow.
iron titanate color, more this glaze is
significantly higher in phosphorus than the first glaze.
The color is a
mixture of several shades of orange and iron red, with a bit of that monkey
vomit green.
The inside of the bowl has a substantially heavier coat of
glaze, and the oranges and browns dominate.
The red dominates only where the
glaze is thin.