NELSON@GEORGE.BAKERU.EDU on thu 14 nov 96
Hi,
I have another glaze problem. This transparent glaze
used over a cobalt and white slip causes the slips to
move and give some very interesting blues. I have used
it several times over the last year and a half.
However, the last time I used it, the glaze ran off the
pots and I ruined five pots because they stuck to the
shelves.
I fire at cone 6 oxidation in an electric kiln. I
have been using witness cones the last 9 months or so
and therefore am firing about an hour longer than I
used to and also to a slightly higher temperature.
Cone 5 is definitely down and cone 6 is about 9 oclock.
My question is....Did the glaze run this time because
the temperature is higher or because the glaze was
perhaps a little thicker than I have used it before?
Does this glaze move the slips because of the rather
high amount of Gerstley Borate? Or does the Copper
Carbonate at 4% have a bearing on the amount of running
going on.
Is specific gravity the same from gloss glaze to
gloss glaze or does each glaze have its own opportune
specific gravity?
I want to keep the effect of the slips being moved by
this glaze, but I don't want the glaze to run off the
pot. Any ideas or input would be appreciated. Glaze
follows:
Gerstley Borate 60
EPK Kaolin 21
Flint 39
____
120
Copper Carbonate 4.8
I know the Gerstley Borate is pretty high and this
doesn't add up to 100, but it the way I got the recipe.
Phyllis
Baldwin City, KS
e-mail: NELSON@george.bakeru.edu
Tony Hansen on fri 15 nov 96
If your glaze has 60% gerstley borate it is not surprising that it runs at cone
Gerstley borate is used to make cone 06 glazes. It seems the simplest solution w
be to reduce its amount.
--
Tony Hansen, IMC - Pulishers of INSIGHT, FORESIGHT, Magic of Fire
web: http://digitalfire.com/imc.html
Pelly123@aol.com on tue 19 nov 96
Try
GB = 50%
EPK = 17.5%
Silica = 32.5%
Copper carb = 5%
I go to a high 6 with this and have no running, although it will drip if
applied way too thick.
Pelly in Rochester, NY where winter is rearing it's ugly head and I am
working feverishly in my studio on anything I want to..life is really, really
good.
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