Micro-crystalline Glazes interacting at a vertical interface.
The matrix (i.e. background) glaze and inlay glaze do not overlap before
firing.
Several closeups of the interaction region of the two glazes are shown and,
for context,
The background glaze is brightMatte_MSn, the inlay design is
glazed with iron_Alex_1_1.
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 1850 deg F then a two hour hold at 1850 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 0.16
Al2O3 0.46
SiO2 2.1
molecular percent Silica 56.6%
K2O 0.09
Al2O3 0.51
SiO2 2.9
molecular percent Silica 63.4%
The original inlay, as placed in the kiln, was a simple ovoid about 3/8th of
an inch thick. The large streaked
The matrix glaze here, brightMatte_MSn, has significantly lower silica and
higher calcium than iron_Alex_1_1.
As is seen above in the image of the inlay glaze iron_Alex_1_1, there is almost
nothing left of it, neither its micro-crystals
The firing is sufficiently rapid, that the matrix glaze wasn't able to
completely absorb the inlay glaze.
a picture of the pot. An image of the inlay glaze is shown
separately.
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 inlay glaze iron_Alex_1_1
bowl is ~3 inches in diameter
Image of the piece
bowl with glaze brightMatte_MSn and inlay glaze
iron_Alex_1_1.
bowl is ~7 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 brightMatte_MSn :
Na2O 0.05
CaO 0.78
MgO 0.01
TiO2 0.15
Inlay Glaze
Empirical Formula iron_Alex_1_1:
Na2O 0.26
Li2O 0.09
CaO 0.45
MgO 0.11
Fe2O3 0.15
P2O5 0.02
Remarks
and textured, nearly filled-in balls are
entirely the result of the interaction between the matrix glaze and inlay
glaze.
Both glazes have low viscosity, are very
fluid, and the large difference in composition leads to high cross diffusion
between the two glazes.
nor its color.