search  current discussion  categories  glazes - cone 4-7 

glaze test for ac metallic black and variations, cone 6 ox.

updated tue 22 feb 05


Alisa Clausen on mon 21 feb 05

Glaze test for AC Metallic Black variations.

Glaze tested on white midrange stoneware fired in electric oxidation to =
1240c. (2264f)

Credited to: Alisa Clausen

Firing ramp:
100c p/h to 600c (212f - 1112f)
150c p/h to 1140c (302f - 2084f)=20
80c p/h to 1240c (176f - 2264f)
10 min. soak
cool down max. to 1100c (2012f)
Hold 1 hour
Shut off kiln

65 Oldenwalder (Red Clay)
20 Borax
5 Silica

2% Cobalt Carb.

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

Well covering, semi gloss, metallic, even black glaze Needs to be =

Recipe plus 5 Rutile
Very similar to above, but overall surface has a slight sparkle. Color =
is not as even and on very close examination,
can see dark blue speckles.

Original recipe minus Cobalt Carb.
A gloss, covering dark black brown. Breaks transparent over high areas =
on test tile. =20

Original recipe minus Cobalt Carb., plus 5 Rutile
A gloss, covering dark brown mustard color glaze. Breaks transparent =
over high areas on test tile.

Regards from Alisa in Denmark