glazes interacting at vertical interface
The matrix (i.e. background) glaze and inlay glaze do not overlap before
firing.
The matrix glaze is a high alkali metal glaze containing titanium. The inlay
glaze is a stiff high calcium
The clash in the interaction region between the distinct micro-crystals which
grow in the matrix glaze and
Several closeups of the interaction region of the two glazes are shown. For
context, a picture of the
The background glaze is hiAlk_Z3P_Z3U_0, the inlay design is glazed with
vermillionBrick_0MFe.
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 1900 deg F then a 3 hr hold at 1900 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 0.12
Al2O3 0.61
SiO2 3.06
molecular percent Silica 61.9%
K2O 0.07
Al2O3 0.58
SiO2 2.78
molecular percent Silica 63.6%
Added:
0.5% Cobalt Carbonate
Both high calcium and titanium glazes will show micro-crystals, especially
with long holds.
micro-crystalline glaze containing copper
and cobalt.
inlay glaze lead to a shingly volcanic
appearance in the interaction region.
pot is shown. These closeups are heavily
edited to make the artifacts in the interaction region visible.
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
bowl with glaze hiAlk_Z3P_Z3U_0 and inlay glaze
vermillionBrick_0MFe
bowl is ~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 composition
Empirical Formula hiAlk_Z3P_Z3U_0 :
Na2O 0.49
CaO 0.37
MgO 0.02
P2O5 0.06
TiO2 0.22
Inlay Glaze:
Empirical Formula vermillionBrick_0MFe:
Na2O 0.11
CaO 0.81
MgO 0.01
3.0% Copper Carbonate
Remarks
Here, with titanium in the matrix glaze there is
diffusion of titanium into the inlay, resulting
in both titanium and
calcium crystals in the interfacial region.