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 microcrystalline matte, as seen in both the close
up images, and in the image of the mug.
As the background and inlay glaze differ substantially in composition, the
micro-crystals which develop
Several closeups of the interaction region of the two glazes are shown and,
for context, a picture of the pot.
The background glaze is longquan-iron-shino-Z38-0, the inlay design is
glazed with iron_Alex_1MFe
The design is created by adhering a mask and then applying the main
glaze. After drying, the mask is removed
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 0.14
Al2O3 0.97
SiO2 3.6
molecular percent Silica 62.6%
K2O 0.07
Al2O3 0.53
SiO2 2.97
molecular percent Silica 64.6%
The original inlay, as placed in the kiln was a simple curve, about 3/8th of
an inch thick. All else is the
The variously colored crystals near the edge of the interaction region show
diffusion of iron and alkali metals
The troughs cut in the inlay by rivulets of the background glaze are evidence
of the background glaze preferentially
While melted, both background and inlay glazes are comprised of both
liquid and crystals; four components,
The inlay glaze
also is a microcrystalline matte. It is seen
here , with higher iron.
in the two glazes are distinct. In the
interface between these two micro-crystalline matte glazes, are seen
crystals not otherwise seen in either glaze. In particular, note the
thread-like microcrystals seen
in several of the closeups.
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
mug with glaze longquan-iron-shino-Z38-0 and inlay glaze
iron_Alex_1MFe.
mug is ~3.5 inches in high
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 longquan-iron-shino-Z38-0 :
Na2O 0.44
Li2O 0.20
CaO 0.17
MgO 0.05
Fe2O3 0.17
Inlay Glaze
Empirical Formula iron_Alex_1MFe:
Na2O 0.34
Li2O 0.11
CaO 0.37
MgO 0.11
Fe2O3 0.08
P2O5 0.02
Remarks
result of the erosion of the inlay glaze by
flowing/diffusing of the background glaze.
from the background glaze into the inlay
crystals.
eating through the fault lines
in the micro-crystalline inlay glaze. In turn, the glossy black regions are
the
remains of the background and inlay reacting so completely that a new
glaze has emerged.
all with distinct compositions and
mobilities. The interactions between these four different components created
the
various effects described above.