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glaze test for oil spot john and amy's ^6 ox.

updated thu 5 jun 08


Alisa Clausen on wed 4 jun 08

Recipe Name: Oil Spot John and Amy's

Cone: 6 Color:
Firing: Oxidation Surface: Oil Spot

Amount Ingredient
20 Feldspar--Custer
18.5 Silica
20 Kaolin--EPK
20 Frit--Ferro 3110
11.5 Talc
10 Wollastonite

100 Total

9 Iron Oxide--Red
2 Titanium Dioxide

Unity Oxide
.205 Na2O
.092 K2O
.306 MgO
.396 CaO
1.000 Total

.398 Al2O3
.025 B2O3
.005 Fe2O3

3.798 SiO2
.003 TiO2
.001 P2O5

9.6 Ratio
6.8 Exp

Comments: Custer subbed with Forshammer
Frit 3110 subbed with Frit 169

add 2% Cobalt for blue instead of black

Black with brown gloss with a slight tea dust effect overall. Tenmoku like
with a tea dust giving a slightly green nuance.

With added Cobalt, glaze is brown with black edges, and a greenish blue
where thickest. More patches than tea dust effect.

Glaze test for Glaze test for Oil Spot John and Amy's ^6 ox.
Source: John Britt

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.
Standard Substitutions in all tests IF called for in recipe:
Local Boron Frit is used for Frit 3134
Forshammer (a half and half Potash and Soda spar) is the only Feldspar used
Local Boron Frit is used for Gerstley Borate
All substitutions are done not by Mol. Wts., but gram for gram.