Calcia vs Magnesia
firing to cone 10 in oxidation
The Downfire 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.
We show two glazes which differ only in the CaO/MgO balance. In the second glaze Talc replaces Wollastonite.
glaze composition
The glaze recipe for oil_tsabar_L
Bentonite 4
Custer_Feldspar 80
Dolomite 5
Red_Iron_Oxide 8
Wollastonite 10
The glaze recipe for oil_tsabar_R
Bentonite 4
Custer_Feldspar 80
Dolomite 5
Red_Iron_Oxide 8
Talc 10
We show a patch of each glaze. As the appearance of the second glaze differs
greatly with glaze application thickness,
we show a thin, vs a thick
application for that glaze.
glaze oil_tsabar_L
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glaze oil_tsabar_R
The left shows thick glaze application, the right thinner glaze application