Chrome Yellow
This is a waxy, matte glaze containing barium oxide and tin oxide. It's a pale
yellow as a result of the addition of chrome oxide.
The balance of the alkaline earth basic components of the glaze was
modified;
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
This glaze has .2% Chrome Oxide added
K2O 0.06
Al2O3 0.4
SiO2 2.26
molecular percent Silica 59%
The glaze tsabar-chrome-Z2D-2F, from which this glaze was derived, is a mixture
of several colors and textures.
Replacing nearly all the CaO with BaO removed all but the yellow-green, and reduced
the occurrence of micro-crystals,
The crazing is likely the result of low silica, though increasing the silica
probably pushes the color from its current yellow/chartreuse
on application thickness. The variation
appeared to be partially the result of modification of the alkaline earth
components
from its parent glaze, tsabar-chrome-Z2D. This aroused my curiosity
regarding the effect of the bases in a glaze on its
color with chrome added.
The CaO has been replaced by BaO.
tsabar-chrome-Z2D-2F-2I-0
bowl is ~3 inches in diameter
oxidation firing to cone 10 in an electric kiln
Firing profiles
Up Fire profile
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Clay body is a grolleg porcelain from Tacoma Clay Art Center.
glaze compositions
Empirical Formula glaze tsabar-chrome-Z2D-2F-2I-0 :
Na2O 0.21
CaO 0.02
MgO 0.01
BaO 0.70
SnO2 0.14
Remarks
A surface layer of micro-crystals,
whose prominence depended on glaze thickness, added to the mix of colors to
produce
a markedly varied stone-like glaze.
which now are seen only in the folds of the
clay body where the glaze pools.
toward a classic
chrome green.