Reactions at the interface between two glazes
The interaction at the interface of adjacent glazes.
Several closeups of the interaction region of the two glazes are shown and,
for context, a picture of the pot.
The background glaze is satIron_ZG_1S_1Munge_3MMg_0, the foreground design is
glazed with alexanderBowl_0_Z1Y
The design is created by adhering a mask and then applying the main
glaze. After drying, the entire pot is coated in wax,
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 2300 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 .20
Al2O3 .51
SiO2 2.97
molecular percent Silica 61%
K2O .09
Al2O3 .43
SiO2 2.67
molecular percent Silica 65%
The interaction region replaced approximately a third of the original design.
The background glaze ate into
The background glaze has narrowed the design glaze, in a few places cut
through it.
The design glaze, alexanderBowl_0_Z1y is a stiff low alkali metal waxy matte
glaze. The background glaze is high
These are dissimilar in character which results in an interaction region which
is unlike either glaze.
then the mask is removed
and the open area filled in with a second glaze.
Close up Images of the interaction region
Image of the piece
bowl with glaze satIron_ZG_1S_3MMg_0 and inlay alexanderBowl_0_Z1Y
bowl is ~6 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
Background glaze
Empirical Formula satIron_ZG_1S_1Munge_3MMg_0 :
Na2O .43
Li2O .2
CaO .16
MgO .01
Fe2O3 .19
P2O5 .17
Inlay Glaze
alexanderBowl_0_Z1Y :
Na2O .05
CaO .7
MgO .16
Remarks
the design glaze
replacing a sharp edge with a ragged edge reminiscent of torn paper.
in both alkali metals and phosphorus.