search  current discussion  categories  glazes - cone 4-7 

glaze test for james chappel's smooth alkaline matte bse, cone 6 ox.

updated wed 10 apr 02


Alisa og Claus Clausen on tue 9 apr 02

Glaze test for: James Chappel's Smooth Alkaline Matte base, cone 6 ox.

Source: Marianne Lombardo
Credited to: James Chappel

All tests fired on white, iron flecked, mid-range stoneware.
Fired to cone 6 (1220c) in oxidation.

Firing ramp: Skutt 1227
100c (212f) per hour to 600c (1112f)
150c (302f) per hour to 1100c (2012f)
80c (176f) per hour to 1220c (2228f)
15 minute soak.
cool down to 1020c (1868f)
80c per hour down to 800c. (1472f)
Shut off kiln. (approximately 14 hours)

47.6 Frit F75 (alkaline)
30 EPK
13.6 Flint
7.7 Wollastonite
2.0 Bentonite

All raw materials measured up or down to nearest whole decimal.
Oxides used on percent basis to a 100 gram batch of glaze.

Frit 623 for F75

Resulted in:
Clear gloss glaze that crazed where thickest at base of tile.

Dynast Blue
0.85 Copper Carb.
0.5 Cobalt Oxide
0.5 Red Iron Oxide

Resulted in a dark cobalt gloss glaze that pinholed considerably.

Regards from Alisa in Denmark