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glaze test for revised simple blue, cone 6, ox.

updated thu 11 oct 01


Alisa og Claus Clausen on wed 10 oct 01


Glaze test for:  Revised Simple Blue, cone 6, ox.

Chris Clarke

All tests fired on white, mid-range stoneware.

Fired in to cone 6 (1220c) in oxidation.

Firing ramp:

100c (212f) per hour to 600c (1112f)

150c (302f) per hour to 1100c (2012f)

100c per hour to 1220c (2228f)

15 - 30 minute soak depending on matts and glosses used.

Revised Recipe:

38 Forshammer Feldspar

29 Silica

23 Wollastonite

10 Kaolin


2 Cobalt Ox.

1 Tin Ox.

Original Recipe:

40 Custer spar

30 Silica

20 Whiting

10 Kaolin

2 Cobalt Ox.

1 Tin Ox.


All raw materials measured up or down to nearest whole decimal.

Oxides used on percent basis to a 100 gram batch of glaze.


Resulted in:

A shiny but not glassy, cobalt blue glaze.  Medium blue in color
and even covering.  Stayed where glazed.

Slightly darker and slightly less glossy than original recipe.

Best regards, Alisa

in Denmark