Removing the talc from the glaze iron_8_R_Plus_satIron_ZG produces a glaze
with more
Images are shown of the precursor glaze, iron_8_R_Plus_satIron_ZG containing
talc, and its derived
This is the glaze which contains talc.
The derived glaze, the glaze with talc omited.
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 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
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
K2O 0.18
Al2O3 0.52
SiO2   3.25
molecular percent Silica 65%
K2O 0.19
Al2O3 0.56
SiO2   3.43
molecular percent Silica 66%
The derived glaze, iron_8_R_satIron_ZG_MMg, without the talc, is more fluid,
as seen when comparing its
Omitting the talc removed a small amount of both flux and silica. Reducing the
base (flux) content of the glaze
Alternatively, perhaps the higher proportion of alkali metals in the
transformed glaze
The change in both the composition and in the appearance is minimal, the
direction of the
intense colors and a more prominent dusting of micro-crystals.
glaze iron_8_R_Plus_satIron_ZG_PMMg.
Image of the precursor glaze, iron_8_R_Plus_satIron_ZG
inside
outside
bowl is is 5 inches in diameter
Image of the glaze iron_8_R_Plus_satIron_ZG_MMg
inside
outside
bowl is is 3 inches in diameter
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 iron_8_R_Plus_satIron_ZG :
Na2O 0.34
Li2O 0.24
CaO 0.17
MgO 0.07
Fe2O3 0.18
P2O5   0.04
Empirical Formula iron_8_R_Plus_satIron_ZG_MMg :
Na2O 0.37
Li2O 0.25
CaO 0.18
MgO 0.01
Fe2O3 0.19
P2O5   0.04
Remarks
transparent rim, with the opaque rim of
iron_8_R_satIron_ZG.
gives a glaze with higher alumina and would
be expected to produce a less fluid glaze. In this case,
the increased flow
would indicate that lower silica is more important than the missing flux.
caused the greater fluidity.
change was a surprise.