Ron Roy on wed 7 mar 07
Hi Darlene,
I'm about to leave for NCECA so I probably can't do much till I get back -
but tell her to send me the recipe and I'll try.
Usually Neph Cy defloccs a glaze - makes it settle out hard - a glaze with
that much is going to be difficult to deal with but there are some tricks
worth trying.
RR
>I realize the best solution will be to reformulate, and Ron, I will
>be glad to pass her your email if you are willing! ;)
>Thanks to everyone!
>
>Darlene Yarnetsky
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Darlene Yarnetsky-Mudcat Pottery on wed 7 mar 07
Hello to everyone!
I have been out of the clayworld for over a year due to health issues
(LONG story) but am recovering and getting ready to renovate the
studio and jump back in. In the meanwhile, I ran into a friend of
mine recently who is having a glaze problem and I thought I would run
it past you all.
She is firing to cone 6 and the glaze is acting like those old
gerstly borate glazes did - have to add lots of water after it has
sat awhile, and of course this changes the look of the glaze -
especially her blue. If I remember correctly that means the glaze is
floccuated - have I got the term correct? From what she could
remember of the formula without her notes, it was very high in
Nepheline Syenite - which I suspect is the culprit.
Besides recommending Ron and Joe's book, does anyone have any
suggestions for a quick adjustment for this glaze in the meanwhile?
A way to defloccuate the glaze, or perhaps a substitution for 10% or
so of the Neph Sye (the glaze contains 70%) that might be worth a
quick glaze test until she reformulates? She is piled in orders, and
I don't have the recipe, so just hoping for some ideas in the meanwhile.
I realize the best solution will be to reformulate, and Ron, I will
be glad to pass her your email if you are willing! ;)
Thanks to everyone!
Darlene Yarnetsky
Mudcat Pottery
Madison, Indiana
Paul Lewing on wed 7 mar 07
One thing that does help with glazes that do this is to mix about
0.5% soda ash in with the water before you mix the glaze. It helps
to heat the water to get it to dissolve. It doesn't work nearly as
well to add the soda ash after you've mixed the glaze with the
water. This doesn't completely fix the problem, but it helps.
You're right that the best solution would be reformulating the
recipe. Remember that you don't have to get rid of all the Neph Sy
to make the problem at least manageable. But you should be able to
replace at least half of it with frits and such.
Happy testing.
Paul Lewing
www.paullewingtile.com
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