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glaze test for altered conrad engobe, cone 6, ox.

updated thu 3 may 07


Alisa Clausen on wed 2 may 07

Glaze test for Altered Conrad Engobe, Cone 6, Ox.

Source: Ceramic Arts Buyers Guide, 2007, Lana Wilson

Credited to:

Fired on mid fire white stoneware

Firing ramp with an electric controller is:
100c p/h to 600c (212f - 1112f)
150c p/h to 1140c (302f - 2084f)
80c p/h to 1220c (176f - 2228f)
15 min. soak
cool down max. to 900c (1652f)
Hold 30 minutes

Shut off kiln

Colorants or additives to a 100 gram batch are measured in percent to the
100 gram batch.

Substitutions in this test: Frit 3134 subbed with local Boron Frit,
Feldspar used is Forshammer, Boron Frit is subbed for Gerstley Borate. All
substitutions are done not by Mol. Wts., but gram for gram.
Lana comments:
Drop Neph. Sye. for very dry.
Add 10% Black Stain, sponge off.

Amount Ingredient
4 Borax
4 Whiting
26 Nepheline Syenite
12 Feldspar--Custer
17 Kaolin--EPK
17 Ball Clay--Old Mine #4
20 Silica

100 Total

Unity Oxide
.436 Na2O
.209 K2O
.023 MgO
.332 CaO
1.000 Total

1.409 Al2O3
.156 B2O3
.017 Fe2O3

7.61 SiO2
.024 TiO2
.001 P2O5

5.4 Ratio
6.7 Exp

Dry, white engobe. Did not see significant difference in surface with
absence of Nepheline Syenite.

Best regards from Alisa in Denmark