lizard skin
This glaze is a high in alumina, with a silica:alumina ratio approaching
that of a clay. It achieves this level of alumina with
A layer of redart clay slip was brushed onto the inside of the bowl, prior to
pouring the glaze.
This glaze gets its phosphorus from trisodium phosphate (TSP).
The high surface tension of this glaze is responsible for the lizard skin
pattern.
inside of bowl:
Outside of bowl:
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
Alumina Hydroxide 16
K2O 0.11
Al2O3 1.17
SiO2 2.77
molecular percent Silica 55%
This glaze is part of an exploration of high alumina, high alkali metal glazes
containing phosphorus.
The iron in the redart clay applied beneath the glaze on the inside of the
bowl didn't noticeably migrate into the glaze,
The glaze was applied thickly, the crazing is the result of the high alumina
in the glaze.
Where the glaze is thin near the upper rim of the inside of the bowl, it is
translucent and and opalescent.
The trisodium phosphate was disolved in hot water then added to the
glaze to get uniform dispersion within the glaze.
high clay and
alumina hydroxide.
shino_Z2H_0
bowl is ~3 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
Recipe glaze shino_Z2H_0 :
Bentonite 2
EPK Kaolin 17
Lithium Carbonate 4
Nepheline Syenite 53
Trisodium Phosphate 8
Empirical Formula glaze shino_Z2H_0 :
Na2O 0.63
Li2O 0.22
CaO 0.03
MgO 0.01
P2O5 0.10
Remarks
yet a color comparison
of the inside and outside of the pot shows a slight difference in
tint.
It however provides contrast for the texture.