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glaze test for white bird mat, cone 5 - 7, ox. plus colorants

updated mon 23 aug 04


Alisa Clausen on sun 22 aug 04

Glaze test for White Bird Mat, cone 5-7, ox.

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

Source:ClayTimes Jul/Aug 2004
Credited to:

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

47 Neph. Syenite
10 Dolomite
10 Ball Clay
23 Gerstely Borate

Any combination of=20
Tin oxide and Zircopax to add up to 10-12%

Used 7 Tin oxide and 3 Zircopax

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.

Base was an opaque white gloss glaze

4 Rutile
White gloss with slight yellow cast.

6 Rutile=20
White yellowish gloss

3.0 Copper carb.=20
Light green gloss

1.5 Cobalt Carb.
Runny opacified blue

1.2 Cobalt Carb. and 0.4 Chrome =20
Teal green gloss

1.0 RIO
Yellowish gloss, darker tan where it stayed in grooves of test tile.

This is only one test of the Tin Oxide and Zircopax in the proportions I =
chose, 70/30.
I am sure the test with these opacifiers in different proportions will =
alter the overall surface and color=20
response of this glaze.

Regards from Alisa in Denmark