transformation
At cone
10,
this glaze has a surface with a variety of distinct artifacts resulting
from the formation and
As seen here at cone 11.5, its surface is nearly covered in coppery colored
metallic micro-crystals. Near the rim,
The rim of this plate flattened completely, it had started as an almost pasta
bowl shaped plate. I believe
The plate has a leaf print. Several closeups of the surface of the glaze,
including images of the interaction
A leaf is softened by soaking in water laced with trisodium phosphate. After
the pot is glazed, the leaf is pressed
plate is ~ 7 inches in diameter
The cone 11 is down past the bottom of the cone pat, both cone 12 and cone 13
are tipped.
150 deg F an hour to 250 deg F
400 deg F an hour to 1800 deg F
300 deg F an hour to 1965 deg F
120 deg F an hour to 2250 deg F
30 deg F an hour to 2325 deg F with a 20 minute hold at 2325 deg F
300 deg F an hour to 1800 deg F then a 2 hr hold at 1800 deg F
300 deg F an hour to 1700 deg F then a 3 hr hold at 1700 deg F
25 deg F an hour to 1650 deg F then a one hour hold at 1650 deg F
K2O 0.12
Al2O3 0.64
SiO2 3.23
molecular percent Silica 62.2%
K2O 0.43
Al2O3 0.54
SiO2 3.33
molecular percent Silica 48%
dissolution of bubbles. It also has leopard spots, and
a variety of copper colored metallic micro-crystals.
there are some silvery colored metallic
micro-crystals, which were not present in this glaze at cone 10. Most of the
micro-structural elements of this glaze at cone 11.5 are found in it at cone
10; however their
distribution has changed considerably.
that is partially responsible for the huge
dunting crack that is seen.
between the glaze and the wash over
the leaf embedded in the glaze are shown. A picture of the plate, and
also
a close up of the rim to show the silvery colored metallic
micro-crystals are also shown.
into the glaze. When the glaze
dries, a swatch of plate including the leaf is coated with wax. When the wax
is dry, the leaf is removed and the indentations in the glaze are coated
with a very thin layer of an
underfired glaze.
Images of the surface and its interaction with the leaf wash
Images of the rim of the plate
Image of the glaze satIron_ZG_0_PK_Z3L with leaf wash leaf_Z3K
oxidation firing to cone 11.5 in an electric kiln
Firing profile
Up Fire profile cone 11.5
Down Fire Profile cone 11.5
Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Background Glaze:
Empirical Formula satIron_ZG_0_PK_MLi :
Na2O 0.69
CaO 0.18
MgO 0.01
Fe2O3 0.22
P2O5 0.1
Empirical Formulae of leaf wash glaze leaf_Z3K:
Na2O 0.53
CaO 0.04
P2O5 0.15