Interacting glazes at a vertical interface

Glazes interacting 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 saturated-iron with metallic micro-crystals. The inlay glaze
is a microcrystalline matte containing both barium and strontium.

Several closeups of the interaction region of the two glazes are shown, and additionally a closeup
of the matrix glaze. For context, a picture of the pot is shown.

The background glaze is iron_satIron_Z2V_0, the inlay design is glazed with hankPaper_Z1R_2C_1Var.

The design is created by adhering a mask and then applying the main glaze. After drying,
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

full view

Close up Image of the matrix glaze

full view

Image of the piece

full view

mug with glaze iron_satIron_Z2V_0 and inlay glaze hankPaper_Z1R_2C_1Var.

mug is ~4 inches high

oxidation firing to cone 10 in an electric kiln

Firing profiles

Up Fire profile

150 deg F an hour to 250 deg F
400 deg F an hour to 1800 deg F
200 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

Down Fire Profile

300 deg F an hour to 1750 deg F then a 50 minute 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

Clay body is a grolleg porcelain from Tacoma Clay Art Center.

glaze compositions

Background glaze

Empirical Formula iron_satIron_Z2V_0 :

K2O        0.19
Na2O       0.30
Li2O       0.27
CaO        0.18
MgO        0.06

Al2O3      0.55
Fe2O3      0.20

SiO2       3.17
P2O5       0.04

molecular percent Silica 63.8%

Inlay Glaze

Empirical Formula hankPaper_Z1R_2C_1Var:

K2O        0.13
Na2O       0.12
Li2O       0.05
CaO        0.14
MgO        0.01
BaO        0.31
SrO        0.24

Al2O3      0.43

SiO2       2.7
TiO2       0.14

molecular percent Silica 63.4%

Added:

Cobalt Carbonate 1%
Copper Carbonate 0.5%

Remarks

Note the rather large acicular crystals growing in the interaction region which are foreign to both the
matrix and inlay glaze.

Note also the needle crystals seen in the inlay glaze at the edge of the interaction region. These needle
crystals are not otherwise seen in that glaze.

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