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glaze test for val cushing cone 5/6 bairum stone mat, oxidation,

updated fri 23 apr 04


Alisa Clausen on thu 22 apr 04

and colorarants

Glaze test for Cal Cushing cone 5/6 Barium Stone Mat, oxidation.

Glaze tested on white midrange stoneware fired in electric oxidation to =

Source: Ababi
Credited to: Val Cushing

Firing ramp:
100c p/h to 600c (212f - 1112f)
150c p/h to 1100c (330f - 2012f)=20
100c p/h to 1220c (212f - 2228f)
5 min. soak
cool down max. to 800c
Hold 1 hour
Shut off kiln

60 Neph. Syenite
24 Barium Carb.
5 Lithium Carb.
6 EPK Kaolin
5 Silica

Note: All raw materials are measured up or down to the nearest whole =
decimal. =20
Colorants or additives to a 100 gram test batch are measured in percent =
to the 100 gram test batch.

Results: =20
All of the tests appear under fired. The test with Manganese has a =
slightly better melt and the test with Chrome has a bubbled and dry =

Mat, milky glaze. Oxides are visible but slightly muted.

3 Copper Carb.
Mat, strong turquoise in color. Smooth. Thick to thin application shows =
a visible difference.
1 Chrome Ox.
Under fired. Bright yellow color with a slight light green cast.

0.5 Manganese Diox.
Mat, purplish with specs. Smooth and appears melted.

Regards from Alisa in Denmark