Glaze Application Thickness

cone 10 oxidation

Firing profile

Up Fire profile

150 deg F an hour to 250 deg F

400 deg F an hour to 2050 deg F

120 deg F an hour to 2250 deg F

60 deg F an hour to 2310 deg F with a hold of 20 minutes at 2310 deg F

Down Fire Profile

A half hour hold at 1750 deg F

A three hour hold at 1700 deg F

slow 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 grolleg porcelain from Tacoma Clay Art Center.

I show a high Phosphorus glaze on two surfaces. The first, a spiral deformed small test bowl, the second a flat plate.

This glaze is sensitive to small variations in glaze thickness, the spiral deformation in the test bowl nicely emphasizes that. By contrast, the result on the flat plate is nearly uniform.
The luster created by pooling is gone.

The plate has a second glaze inlay design, produced by afixing a mask to the bisque before pouring the glaze, then filling the masked region with a second glaze.

glaze composition

Emperical Formula satIron_ZJ_1PPPK:

K2O        0.02
Na2O        0.31
Li2O        0.27
CaO        0.39
MgO        0.01

Al2O3        .59
Fe2O3        .21

SiO2        3.35
P2O5        .13

molecular percent Silica 63 %

The bowl is ~ 3 inches in diameter, the plate ~9 inches in diameter.

bowl

plate