Reactions at the interface between two glazes
The interaction at the interface of adjacent glazes.
Several closeups of the interaction region of the two glazes are shown and,
for context, a picture of the pot.
The background glaze is satIron_ZG_1S_1Munge_1, the foreground design is
glazed with satIron_ZG_1O_1Q_1MFe
The design is created by adhering a mask and then applying the main
glaze. After drying, the entire pot is coated in wax,
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 1750 deg F then a half hour 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 .06
Al2O3 .54
SiO2 3
molecular percent Silica 61%
K2O .24
Al2O3 .47
SiO2 3.17
molecular percent Silica 66%
The interaction region replaced nearly half of the original design.
The inlay glaze ate into
The inlay melts, diffuses into the matrix of background glaze, it seeps into
the background, eating as it goes.
The design glaze, satIron_ZG_1O_1Q_1MFe is substantially more fluid than the
background glaze which is higher
The contrasting viscosity of the two glazes creates a dynamic interaction region.
then the mask is removed
and the open area filled in with a second glaze.
Close up Images of the interaction region
Image of the piece
bowl with glaze satIron_ZG_1S_1Munge_1 and inlay satIron_ZG_1O_1Q_1MFe
bowl 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 satIron_ZG_1S_1Munge_1 :
Na2O .53
Li2O .2
CaO .2
MgO .01
Fe2O3 .21
P2O5 .17
Inlay Glaze
satIron_ZG_1O_1Q_1MFe :
Na2O .22
Li2O .24
CaO .16
MgO .14
Fe2O3 .09
P2O5 .04
Remarks
the background glaze
replacing a sharp edge with a ragged edge reminiscent of melting snow.
The decoration glaze diffuses into the
background leaving behind
partially melted crystals of the background
floating on/in a contaminated version of the matrix glaze.
in both silica and phosphorus, and lower
in Alumina.
Both glazes are high in alkali metals.