search  current discussion  categories  glazes - misc 

glaze test for blue overglaze, fired to cone 6, oxidation

updated mon 3 nov 03

 

Alisa Clausen on sun 2 nov 03


Glaze test for Blue Overglaze, fired to cone 6 oxidation.
Glaze tested on white midrange stoneware fired in electric oxidation to =
1220c.

Source: Clayart =20
Credited to: Cardew, Pioneer Pottery

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

Recipe:
20 Cobalt carb.
20 Tin Oxide
10 Manganese Diox. (HARZARD)
10 Talc
15 Redart (Red Clay)
20 Kaolin
5 Red Iron Oxide

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 precent =
to the 100 gram test batch.

Substitutions:
Oldenwalder red clay for Redart

Results:
On Tony Hansen's 20 x 5 clear base, showed a gloss, dark cobalt blue =
overglaze. The paint strokes on top of the glaze did not move or =
feather.=20

On WoDo White matte glaze, showed a brown matte overglaze. The paint =
strokes did not move or feather.

Regards from Alisa in Denmark