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 saturated iron aventurine glaze.
Several closeups of the interaction region of the two glazes are shown, and
additionally for context,
The background glaze is iron_8_R_C10_13PSi, the inlay design is
glazed with
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
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
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
K2O 0.11
Al2O3 0.56
SiO2 3.12
molecular percent Silica 63%
K2O 0.13
Al2O3 0.43
SiO2 2.7
molecular percent Silica 63.4%
Added:
Cobalt Carbonate 1%
When observing the close-up pictures, there are sections in which the
interaction region has almost
Iron has diffused from the matrix glaze into the inlay glaze.
The various colors are likely the result of different diffusivities for the
various phases in the inlay glaze.
Thus, there are different concentrations of iron in each phase, and the color
range is the result of the
Note that simply adding iron to either of the glazes is unlikely to cause the
colors seen here.
a picture of the pot is shown.
hankPaper_Z1R_2C_1Var.
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
plate with glaze iron_8_R_C10_13PSi and inlay glaze
hankPaper_Z1R_2C_1Var
plate is 10 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 iron_8_R_C10_13PSi :
Na2O 0.45
Li2O 0.25
CaO 0.17
MgO 0.02
Fe2O3 0.28
Inlay Glaze
Empirical Formula hankPaper_Z1R_2C_1Var:
Na2O 0.12
Li2O 0.05
CaO 0.14
MgO 0.01
BaO 0.31
SrO 0.24
TiO2 0.14
Copper Carbonate 0.5%
Remarks
taken over the inlay, yet neither glaze has
moved much at all.
That is, the iron migrates at different
rates, depending on the phase.
dynamics of the situation.