william schran on thu 28 mar 02
Last year, in preparing for my summer raku class offering, I began
testing all the gerstley borate substitutes. One of the materials
advertised as a sub is Dal Tile frit #439. After some preliminary
tests it looked like this might be "the one". A glaze consisting of
frit #439 - 85% & EPK - 15% gave a good smooth melt at raku temps
with the "necessary" crazing. Adding a bit of zirconium silicate
resulted in a good white crackle glaze.
I ordered a 50 lb bag and we made up 10,000 gram batches. Was working
fine, stayed in suspension, then BAM!, in about 2-3 weeks the glazes
lumped up, materials separated and would not re-combine. I got the US
distributor on the line and asked what's up with this frit? They
discovered the frit was soluble and were working on correcting the
problem.
Called them back this week, they think they got the problem solved
and hope to have the new formulated frit out to market in another
month or so.
I really do like this frit. It's a high lime borosilicate frit. It
melts at about 1700=B0F, so I can add needed clay for suspension and
drying hardness and stiil work well at raku temps. The cost was $0.45
per pound, I think a good price for the material.
I'll post again when I have more information.
Bill
Craig Clark on thu 28 mar 02
William, due to a lack of knowledge, I don't understand how the frit's
solubility prevents the reconstition of the glaze. Could you explain? I
haven't yet reformulated my glazes, I've got a nice stash of Gestley, but
will need to do so in the next year or so.
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
----- Original Message -----
From: "william schran"
To:
Sent: Thursday, March 28, 2002 7:47 AM
Subject: raku glaze materials
Last year, in preparing for my summer raku class offering, I began
testing all the gerstley borate substitutes. One of the materials
advertised as a sub is Dal Tile frit #439. After some preliminary
tests it looked like this might be "the one". A glaze consisting of
frit #439 - 85% & EPK - 15% gave a good smooth melt at raku temps
with the "necessary" crazing. Adding a bit of zirconium silicate
resulted in a good white crackle glaze.
I ordered a 50 lb bag and we made up 10,000 gram batches. Was working
fine, stayed in suspension, then BAM!, in about 2-3 weeks the glazes
lumped up, materials separated and would not re-combine. I got the US
distributor on the line and asked what's up with this frit? They
discovered the frit was soluble and were working on correcting the
problem.
Called them back this week, they think they got the problem solved
and hope to have the new formulated frit out to market in another
month or so.
I really do like this frit. It's a high lime borosilicate frit. It
melts at about 1700°F, so I can add needed clay for suspension and
drying hardness and stiil work well at raku temps. The cost was $0.45
per pound, I think a good price for the material.
I'll post again when I have more information.
Bill
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Earl Brunner on thu 28 mar 02
If soluble salts have crystallized, you might need to remove some of the =
water,
heat it and reintroduce it, heat can help disolve the crystals, but don'=
t just
throw the water away, it probably contains some of the disolved minerals.
Craig Clark wrote:
> William, due to a lack of knowledge, I don't understand how the fri=
t's
> solubility prevents the reconstition of the glaze. Could you explain? I
> haven't yet reformulated my glazes, I've got a nice stash of Gestley, b=
ut
> will need to do so in the next year or so.
> Craig Dunn Clark
> 619 East 11 1/2 st
> Houston, Texas 77008
> (713)861-2083
> mudman@hal-pc.org
>
> ----- Original Message -----
> From: "william schran"
> To:
> Sent: Thursday, March 28, 2002 7:47 AM
> Subject: raku glaze materials
>
> Last year, in preparing for my summer raku class offering, I began
> testing all the gerstley borate substitutes. One of the materials
> advertised as a sub is Dal Tile frit #439. After some preliminary
> tests it looked like this might be "the one". A glaze consisting of
> frit #439 - 85% & EPK - 15% gave a good smooth melt at raku temps
> with the "necessary" crazing. Adding a bit of zirconium silicate
> resulted in a good white crackle glaze.
> I ordered a 50 lb bag and we made up 10,000 gram batches. Was working
> fine, stayed in suspension, then BAM!, in about 2-3 weeks the glazes
> lumped up, materials separated and would not re-combine. I got the US
> distributor on the line and asked what's up with this frit? They
> discovered the frit was soluble and were working on correcting the
> problem.
> Called them back this week, they think they got the problem solved
> and hope to have the new formulated frit out to market in another
> month or so.
> I really do like this frit. It's a high lime borosilicate frit. It
> melts at about 1700=B0F, so I can add needed clay for suspension and
> drying hardness and stiil work well at raku temps. The cost was $0.45
> per pound, I think a good price for the material.
> I'll post again when I have more information.
> Bill
>
> _______________________________________________________________________=
_____
> __
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
> _______________________________________________________________________=
_______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pcl=
ink.com.
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
william schran on thu 28 mar 02
Craig - you asked: "I don't understand how the frit's
solubility prevents the reconstition of the glaze. Could you explain?"
The frit, or some constituent parts for the frit, formed small lumps
or crystals that would not break down and go back into the mix no
matter how much the glaze was stirred up.
Bill
william schran on thu 28 mar 02
Earl - Sounds like a solution, but man, what a pain. Hopefully the
solubility problem will be solved, otherwise I'll mix the glazes dry
and add water to small amounts that will be used within a week or so.
Bill
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