Crystals in high Lithium Iron Glaze
Glazes are fired at cone 6 in an electric kiln
Firing profile
A half hour hold at 1850 deg F
downfire at 50 deg F an hour in the interval 1850 deg F to 1700 deg F
downfire at 25 deg F an hour in the interval 1700 deg F to 1650 deg F
A one hour hold at 1650 deg F
Clay body is a B-mix variant from Tacoma Clay Art Center.
glaze composition
satIron_4Z_1
In the empirical formula:
alkali metals .75 with Li2O .36
alkali earths more CaO than MgO
alumina .42
Silica 3.3
P2O5 .05
The pot is a cylinder ~3.5 inches in diameter,
glaze satIron_4Z_1
the pot
a close up of a small section of the glaze
In the closeup one sees a complex growth of several different overlaping crystals.
This glaze was inspired by the observation that Li2O is more active than
either K2O or Na2O, I'm pushing the edge -
asking how much Li2O can a
glaze absorb.
As is seen from the close up, the glaze is highly textured.
The folds are in the surface of the glaze.
It would appear
that the surface of the glaze freezes while the bulk glaze beneath remains
molten.
At the foot of this pot, a roll of glaze over a quarter inch
thick had formed, and bits of that have flaked off.
This glaze is weak,
owing to its high alkali metal content. The next step will be to scale back
the alkali content,
hopefully improve the mechanical properties while
maintaining the surface crystals.