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glaze test for rr fat white ^6 ox., colorants

updated fri 29 feb 08


Alisa Clausen on wed 27 feb 08

Glaze test for RR Fat White ^6 ox., colorants


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.
Standard Substitutions in all tests:
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.

Recipe Name: Fat White Ron Roy rev.
Cone: 6 Color:
Firing: Surface: Waxy silk mat

Amount Ingredient
13.5 Kaolin--EPK
5 Frit--Ferro 3134
35 Feldspar--C6
19.5 Dolomite
1 Talc
26 Silica
100 Total

Unity Oxide
.154 Na2O
.065 K2O
.35 MgO
.431 CaO
1.000 Total
.37 Al2O3
.054 B2O3
.004 Fe2O3
3.187 SiO2
.002 TiO2
0 P2O5
8.6 Ratio
6.6 Exp

Base glaze is waxy, covering, white glaze

3 Rutile
Smooth surface, slight crystals and opalescence where thickest.

8 Titanium
Overall golden yellow

3 Manganese
3 Rutile
Overall yellow tan ground with pinkish white fur where thickest.

3 Manganese
3 Titanium
Overall tan ground with whitish fur where thickest

3 Manganese
Light tan ground and pinkish where thickest

May Luk on thu 28 feb 08

Hello Alisa;

So much work! Thanks for the effort.

This glaze makes RR look fat?

I am interested in a FAT white glaze. Have you done much test on white glazes? I have now a glossy tin white and a satin white. I would love to have a fat white like a leaded maiolica lardy glaze. I know it's hard to get above cone 6 (and without lead). If you come across one, please let me know.