Pam Merkel on tue 18 feb 03
I have had terrible trouble with laguna low fire formulas. They are not
reaching maturity at the recomened temperature with horrible blistering
and glazes not coming out shiny. After applying a coat of a low fire
clear everything is fine but I hate the extra step. Any input?
Snail Scott on tue 18 feb 03
At 11:46 AM 2/18/03 -0600, you wrote:
>...laguna low fire formulas. They are not
>reaching maturity at the recomened temperature with horrible blistering
>and glazes not coming out shiny. After applying a coat of a low fire
>clear everything is fine...
Are you sure your kiln is reaching temperature?
Those sure sound like symptoms of underfiring
to me. Do you use witness cones?
-Snail
Les Haworth on tue 18 feb 03
Pam, Could you give me a little more information. Which glazes are you
having trouble with? Do you buy them dry or moist? If dry, how do you
prepare the glaze? How are you applying (dip, brush, or spray) the glazes?
Also which clay body are you using? Please let me know, and I will get back
to you ASAP.
Thanks,
Lester R. Haworth III
Sales and Technical Support
Laguna Clay Co.
14400 Lomitas ave
City of Industry, CA 91746
(626)330-0631 ext. 229
les@lagunaclay.com
www.lagunaclay.com
"If you can dream it, you can do it!" ~~ Walter E. Disney
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of Pam Merkel
Sent: Tuesday, February 18, 2003 9:47 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Bad laguna glazes
I have had terrible trouble with laguna low fire formulas. They are not
reaching maturity at the recomened temperature with horrible blistering
and glazes not coming out shiny. After applying a coat of a low fire
clear everything is fine but I hate the extra step. Any input?
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Lily Krakowski on wed 19 feb 03
As I have reached the age when I sometimes rage at a nonfunctioning toaster
when its only sin is that I have forgotten to plug it back in after cleaning
it--I dare ask: have you dumped the whole entire contents of the jar into a
sieve, and sieved it before use? And have you done that every time you have
used the glaze?
Because I have seen people use jars of glaze they have stirred
lackadaisically and they have used up some of it, while other stuff stayed a
the bottom, and actually changed the contents of the glaze.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage....
Bob Nicholson on wed 19 feb 03
>I have had terrible trouble with laguna low fire formulas. They are not
>reaching maturity at the recomened temperature with horrible blistering
>and glazes not coming out shiny. After applying a coat of a low fire
>clear everything is fine but I hate the extra step. Any input?
Haven't tried Laguna low fire glazes, but I've had occasional problems
with Western.
First, are you sure you're reaching the right temperature? Don't depend
on a kiln sitter... put in some cones to verify.
If that's not the problem, try adding some soak time at temperature.
I'd start with half an hour. If you don't have an electronic controller,
you'll need to control the kiln manually to prevent your kiln sitter
from shutting the kiln down as soon as you reach temperature.
Hope this isn't too "basic," but these are the first things I'd try.
- Bob Nicholson
Tommy Humphries on wed 19 feb 03
Are these pre mixed glazes?
If so make sure that they are well mixed, or if used in a community studio
that the others have been mixing them well.
It almost sounds like you are using the leftovers from somebody's jar of
glaze, where most of the glaze has been used, leaving only the pigments
behind...the gloss overglaze solution fits in with this as well. If you are
able try again with a fresh jar of glaze.
Tommy
----- Original Message -----
From: "Bob Nicholson"
To:
Sent: Wednesday, February 19, 2003 1:03 PM
Subject: Re: Bad laguna glazes
> >I have had terrible trouble with laguna low fire formulas. They are not
> >reaching maturity at the recomened temperature with horrible blistering
> >and glazes not coming out shiny. After applying a coat of a low fire
> >clear everything is fine but I hate the extra step. Any input?
who may be reached at melpots@pclink.com.
Jon Pacini on thu 20 feb 03
Greetings all ---- I'm glad Snail broached this subject before I did. I hate
being accused of always laying the blame at potters feet. :o)
It does sound like a firing fault rather than a glaze problem. And if
the bisque is under fired, that will compound the blistering part of the
problem. Low fire talc bodies gas an extensive amount and need to be bisqued
at least a cone hotter than the glaze firing. Since after the second firing
the glaze settles down, that leads me to the conclusion that it is an under
fired/gassing type of problem. Try witness cones in your glaze and bisque,
and you may also want to soak a bit at the end of your firings just to even
everything out.
However should you continue to have problems with a higher bisque and
soak combo, every container of Laguna glaze has a QA # on it which
corresponds to a test we ran on that particular glaze batch. Usually glazes
are made in 10-40gal batches, depending on how popular they are. Yes, we
test our glazes too. But if you have a problem with it, Juan Aguilar our
crack glaze man, should be able to help you out. Try contacting him @
626-330-0631 x 213
Best regards
Jon Pacini
Clay Manager
Laguna Clay Co
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