Interacting glazes at a vertical interface
The matrix (i.e. background) glaze and inlay glaze do not overlap before
firing.
The matrix glaze is a high alkali glaze containing zinc, strongtium and
cobalt. The inlay glaze
Here, we see a similar pairing with the same inlay glaze, and a closely
related matrix glaze.
The wild growth of meso-crystals in many colors is seen here as in the
previous mug. Most particularly,
These two mugs were on the same shelf, next to each other in an electric
kiln. the differences
Several closeups of the interaction region of the two glazes are shown. For
context, a picture of the
The background glaze is zincSr_Z3T_PZn_PSi_2, the inlay design is glazed with
hiAlk_Z3P_Z3V_0.
The design is created by adhering a mask and then applying the main
glaze. After drying,
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 1650 deg F then a 3 hr hold at 1650 deg F
400 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 hour hold at 1700 deg F
K2O 0.15
Al2O3 0.52
SiO2 3.24
molecular percent Silica 67.9%
Added:
2.5% Cobalt Carbonate
K2O 0.18
Al2O3 0.64
SiO2 3.54
molecular percent Silica 64.9%
is a mixed gloss with microcrystals containing
titanium.
an interaction region covering most of what
had been the masked area for the inlay. Here, however, we see a
variety of
translucent acicular crystals not seen in the prior example. Other
differences
in morphology and coloring also are visible.
cannot be attributed to differences in firing.
pot is shown.
the mask is removed and the open area filled in with a
second glaze, using a bulb syringe
with a needle applicator.
Close up Images of the interaction region
Image of the piece
mug with glaze zincSr_Z3T_PZn_PSi_2 and inlay glaze
hiAlk_Z3P_Z3V_0
mug is ~4 inches high
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 composition
Empirical Formula zincSr_Z3T_PZn_PSi_2:
Na2O 0.32
CaO 0.01
MgO 0.18
SrO 0.15
ZnO 0.19
Inlay Glaze:
Empirical Formula inlay hiAlk_Z3P_Z3V_0:
Na2O 0.41
CaO 0.31
MgO 0.10
P2O5 0.07
TiO2 0.21