David Gordon on sat 9 dec 00
Actually this is a very predictable result for this glaze if the application
is too thin (resulting in brown) and it is overfired (resulting in green).
This glaze is a very consistent substitute for the GB-laden original
floating blue when it is fired no higher than cone 5 with up to a 15 minute
soak and the glaze is applied to at least the thickness of a dime. It has
all the same characteristics as the original, except the crawling.
But of course, just as with the original, there are more ways to screw it up
than to get it right. Still requires a good deal of individual
experimentation.
Just another example of how going strictly by someone else's numbers doesn't
always produce the desired result.
David Gordon
----- Original Message -----
From: "Alisa and Claus Clausen"
To:
Sent: Saturday, December 09, 2000 2:39 PM
Subject: Glaze test for Cobbeldi Floating Blue, cone 6, oxidation
Cobbeldi Floating Blue, cone 6, oxidation.
Source: D. Gordon
Tested on white, mid range stoneware, fired to 1220c, oxidation.
Receipe
43.26 Neph. Sye
13.67 EPK
32.81 Frit 3134
10.26 Flint
ADD
2 RIO
1 Cobalt oxide
4 Rutile
2 Bentonite
Subs:
Local frit for 3134
All measurements were rounded off to the next highest whole decimal.
Resulted in a medium brown glaze, high gloss, with green tinge throughout,
and a green pool in the middle of the test bowl.
Personal: These exacting measurements give me hives. The glaze exhibited
all the worst characterists that Floating Blue can
exhibit when not fired in optimal (tricky? randomly lucky?) conditions for
the glaze. Overall dull brown with THAT green
where it would be nice if it was blue. Extremely similar to the original
Floating Blue receipe with colemanite subbed for Gerstely Borate.
Best regards,
Alisa in Denmark
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Alisa and Claus Clausen on sat 9 dec 00
Cobbeldi Floating Blue, cone 6, oxidation.
Source: D. Gordon
Tested on white, mid range stoneware, fired to 1220c, oxidation.
Receipe
43.26 Neph. Sye
13.67 EPK
32.81 Frit 3134
10.26 Flint
ADD
2 RIO
1 Cobalt oxide
4 Rutile
2 Bentonite
Subs: =20
Local frit for 3134
All measurements were rounded off to the next highest whole decimal.
Resulted in a medium brown glaze, high gloss, with green tinge =
throughout, and a green pool in the middle of the test bowl.
Personal: These exacting measurements give me hives. The glaze =
exhibited all the worst characterists that Floating Blue can
exhibit when not fired in optimal (tricky? randomly lucky?) conditions =
for the glaze. Overall dull brown with THAT green=20
where it would be nice if it was blue. Extremely similar to the =
original Floating Blue receipe with colemanite subbed for Gerstely =
Borate.
Best regards,
Alisa in Denmark =20
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