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glaze test for oxblood, cone 6, ox.

updated thu 11 oct 01


Alisa og Claus Clausen on wed 10 oct 01

Glaze test for:  Oxblood, cone 6,

This  was tested by Marianne Lombardo.  I made some tests with

All tests fired on white, mid-range stoneware.

Fired in to cone 6 (1220c) in oxidation.

Firing ramp:

100c (212f) per hour to 600c (1112f)

150c (302f) per hour to 1100c (2012f)

100c per hour to 1220c (2228f)

15 - 30 minute soak depending on matts and glosses used.


55 Gerstely Borate

15 Talc

30 Flint

Add 22 RIO


All raw materials measured up or down to nearest whole decimal.

Oxides used on percent basis to a 100 gram batch of glaze.

Substitutions:  see below.

Resulted in:

Iron brown semi gloss glaze.  I am sure more exciting used as
overglaze as it is intended.

Subbed local frit for G.B.

Resulted in a very glittery brown glaze that looks like fool's gold
in natural light.  I have not often seen such a sparkle in a glaze's
surface. It has a dark background surface with a copper sparkle. 
Looks like a Disney version of Tenmoku. 

Will try it with frit 3134. (thanks to Will Edward's gift). This will be
exciting to try over other glazes.

Subbed 15 Ochre for 22 RIO

Streaky brown gloss, with pale yellow streaking.  Ran and
streaked, but stayed above glaze border.

Best regards, Alisa

in Denmark

Cindy Strnad on wed 10 oct 01

Dear Alisa,

Nice to hear from you. I didn't realize I could use HTML rich format in =
Clayart letters. Boy am I going to have fun. It makes your glaze =
recipe so much easier to read.

I really like Andrew's Ox Blood, though I should say from the start that =
it's barely a glaze at all. It's way low on silica, and contains even =
less alumina. Of course, it doesn't contain any nasties to leach out, =
but still . . . . The results I got using Gerstley Borate consisted of a =
textured and mottled glaze with puddles of iron red and low spots of =
black. And then other times I got an over-all iron red (not hardly worth =
it, considering I have well formulated glazes that will do that. But the =
red mountains and black valleys--that is good. I haven't figured the =
trick out to get that effect all the time.

So, if you can, try to get some of Tony Hansen's Boraq. I've heard =
that's pretty much the best GB sub so far.

Your friend,

Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730