Sue Beach on mon 24 may 99
I am using a simple base glaze and am having problems with it thickening on
its own over time as I work with it. When I first mix the glaze, it is the
right consistency and thickness - about like milk. Then over the course of
a glazing session, it gradually gets thicker and thicker until it is almost
impossible to work with. It gets like pudding almost. And I can't tell
whether I have enough glaze on the pot or too much. Can anyone suggest a
way to adjust the base glaze to keep it from thickening? An additive? I'd
like to stick with the base for awhile, if I can get it to work.
I'm firing at ^6 oxidation electric kiln. The base glaze recipe is:
Gerstly Borate 50%
#6 Tile Kaolin 20%
Flint 325 30%
Thanks.
Sue Beach
in Muncie, Indiana where it is gray, cool, and raining hard
Sue (Duncan) Beach & Ron Beach
Muncie, IN
sbeach@iquest.net
PLEASE HELP US FIND OUR MISSING DAUGHTER
Details at http://bsuvc.bsu.edu/~00sdbeach/erin.html
County Coordinator: Loudoun Co., VA USGenWeb page:
http://www.rootsweb.com/~valoudou/index.html
List Manager: VALOUDOU-L: Mailing List for Loudoun Co., VA Genealogy & History
Chris Schafale on wed 26 may 99
Sue,
It sounds like you're experiencing a classic case of flocculation of
your glaze, most likely because of all that Gerstley Borate. If you
are committed to staying with this glaze, you might try adding a
little Darvan 7 (your ceramic supplier should carry this -- it
comes in a liquid form and may be listed with sodium silicate and
other additives in the catalog) to see if you can deflocculate it to
a usable consistency. When I say a little, I really mean a little.
Add just a drop or two at a time, stir well, and wait for it to feel
thinner. You'll know when it works. Go slow, because it may feel
like it's not doing any good and then the next drop will do the
trick. Good luck.
Chris
> ----------------------------Original message----------------------------
> I am using a simple base glaze and am having problems with it thickening on
> its own over time as I work with it. When I first mix the glaze, it is the
> right consistency and thickness - about like milk. Then over the course of
> a glazing session, it gradually gets thicker and thicker until it is almost
> impossible to work with. It gets like pudding almost. And I can't tell
> whether I have enough glaze on the pot or too much. Can anyone suggest a
> way to adjust the base glaze to keep it from thickening? An additive? I'd
> like to stick with the base for awhile, if I can get it to work.
>
> I'm firing at ^6 oxidation electric kiln. The base glaze recipe is:
>
> Gerstly Borate 50%
> #6 Tile Kaolin 20%
> Flint 325 30%
>
> Thanks.
>
> Sue Beach
> in Muncie, Indiana where it is gray, cool, and raining hard
>
> Sue (Duncan) Beach & Ron Beach
> Muncie, IN
> sbeach@iquest.net
>
> PLEASE HELP US FIND OUR MISSING DAUGHTER
> Details at http://bsuvc.bsu.edu/~00sdbeach/erin.html
>
> County Coordinator: Loudoun Co., VA USGenWeb page:
> http://www.rootsweb.com/~valoudou/index.html
>
> List Manager: VALOUDOU-L: Mailing List for Loudoun Co., VA Genealogy & Histor
>
>
Light One Candle Pottery
Fuquay-Varina, NC
candle@intrex.net
Evan Dresel on wed 26 may 99
I believe it's the gerstly borate. Keep stirring it between pots.
-- Evan in W. Richland WA who is trying to decide if he has developed
the dreaded Columbia Basin allergies or if this has just been one heck
of a cold.
Sue Beach wrote:
>
> ----------------------------Original message----------------------------
> I am using a simple base glaze and am having problems with it thickening on
> its own over time as I work with it. When I first mix the glaze, it is the
> right consistency and thickness - about like milk. Then over the course of
> a glazing session, it gradually gets thicker and thicker until it is almost
> impossible to work with. It gets like pudding almost. And I can't tell
> whether I have enough glaze on the pot or too much. Can anyone suggest a
> way to adjust the base glaze to keep it from thickening? An additive? I'd
> like to stick with the base for awhile, if I can get it to work.
>
> I'm firing at ^6 oxidation electric kiln. The base glaze recipe is:
>
> Gerstly Borate 50%
> #6 Tile Kaolin 20%
> Flint 325 30%
>
> Thanks.
>
> Sue Beach
> in Muncie, Indiana where it is gray, cool, and raining hard
>
> Sue (Duncan) Beach & Ron Beach
> Muncie, IN
> sbeach@iquest.net
>
> PLEASE HELP US FIND OUR MISSING DAUGHTER
> Details at http://bsuvc.bsu.edu/~00sdbeach/erin.html
>
> County Coordinator: Loudoun Co., VA USGenWeb page:
> http://www.rootsweb.com/~valoudou/index.html
>
> List Manager: VALOUDOU-L: Mailing List for Loudoun Co., VA Genealogy & Histor
NakedClay@aol.com on wed 26 may 99
Hi Sue, and other glaze mavens!
The next time you mix this glaze (dry materials), add no more than 2%
bentonite to it. This will help keep the minerals in suspension, once you add
water.
Milton NakedClay@AOL.COM
Yucca Valley, CA
Cloudy, wet and warm, from an unexpected (but most welcome) late spring
downpour, here in the Mojave.
Paul Lewing on wed 26 may 99
Sue Beach wrote:
>
> ----------------------------Original message----------------------------
> I am using a simple base glaze and am having problems with it thickening on
> its own over time as I work with it. When I first mix the glaze, it is the
> right consistency and thickness - about like milk. Then over the course of
> a glazing session, it gradually gets thicker and thicker until it is almost
> impossible to work with. It gets like pudding almost. And I can't tell
> whether I have enough glaze on the pot or too much. Can anyone suggest a
> way to adjust the base glaze to keep it from thickening? An additive? I'd
> like to stick with the base for awhile, if I can get it to work.
>
> I'm firing at ^6 oxidation electric kiln. The base glaze recipe is:
>
> Gerstly Borate 50%
> #6 Tile Kaolin 20%
> Flint 325 30%
>
> Thanks.
>
> Sue Beach
Sue,
Your problem is the Gerstley Borate. It's notorious for thickening up
like that. The solution is to recalculate this glaze with no more than
15% or so of GB and the rest of the necessary stuff from a
calcium/borate frit. The danger in replacing all the GB with frit is
that it's hard to keep that in suspension, but with 20% kaolin, you
might be OK using all frit.
Good luck,
Paul Lewing, Seattle
Bill Williams on wed 26 may 99
This happens to me quite often. I don't know if it is right or wrong, but I
just add more water and keep mixing it well, and try to keep it as the
consistancy that I want. Anyway, my glazes work for me when I do that, so it
must not be too wrong. I think someone said that it is the Gerstly Borate
that causes the glaze to do that "pudding" thing. Connie
-----Original Message-----
From: Sue Beach
To: CLAYART@LSV.UKY.EDU
Date: Monday, May 24, 1999 8:50 AM
Subject: Self-thickening glazes
----------------------------Original message----------------------------
I am using a simple base glaze and am having problems with it thickening on
its own over time as I work with it. When I first mix the glaze, it is the
right consistency and thickness - about like milk. Then over the course of
a glazing session, it gradually gets thicker and thicker until it is almost
impossible to work with. It gets like pudding almost. And I can't tell
whether I have enough glaze on the pot or too much. Can anyone suggest a
way to adjust the base glaze to keep it from thickening? An additive? I'd
like to stick with the base for awhile, if I can get it to work.
I'm firing at ^6 oxidation electric kiln. The base glaze recipe is:
Gerstly Borate 50%
#6 Tile Kaolin 20%
Flint 325 30%
Thanks.
Sue Beach
in Muncie, Indiana where it is gray, cool, and raining hard
Sue (Duncan) Beach & Ron Beach
Muncie, IN
sbeach@iquest.net
PLEASE HELP US FIND OUR MISSING DAUGHTER
Details at http://bsuvc.bsu.edu/~00sdbeach/erin.html
County Coordinator: Loudoun Co., VA USGenWeb page:
http://www.rootsweb.com/~valoudou/index.html
List Manager: VALOUDOU-L: Mailing List for Loudoun Co., VA Genealogy &
History
Bob Wicks on wed 26 may 99
You might want to try frit 3124 which is fritted Gerstley Borate. I think
that will solve your problem.
Bob
John Post on fri 28 may 99
Hi Sue,
The problem that you are having with your glaze is that it has way too much
gerstley borate in it. This is what is making it gel. Gerstley borate has
some good qualities and some bad. It yields nice, mottled interesting
surfaces at cone 6. It's a great melter too. But...... if you use too
much you end up with the self-thickening problems you ran into. It is also
not always the same material from bag to bag because of the way it is
processed, or should I say not processed. You can find out more about this
in the archives.
I have found that frit 3134 is good choice to replace some of the boron
(B2O3) in glazes. Notice that I said some... If you replace all of the
gerstley with frit 3134 you will end with a glaze that isn't as nice and
mottled and visually interesting as your original glaze. This is because
the gerstley borate has trace elements in it as well as unique firing
properties that are not in frit 3134. So you have to have some gerstley in
the glaze. Around 10% gerstley should keep the glaze visually interesting
without causing too much trouble with the glaze slurry. With this in mind
I reformulated your glaze. (see below)
Your original glaze has very low expansion. I increased it to the point
where I think it will fit your clay body better at cone 6. The new glaze
also has less MgO than your original, but I don't think the MgO is
contributing much in the way of visual characteristics to this glaze.
Therefore the fluxes are a little different than your original. I used epk
instead of #6 tile as the clay in the glaze, because I don't have #6 tile
in my database of materials. I don't think it will change the calculations
in a big way so feel free to use the #6 tile if you test the new glaze.
I think the key to this glaze is the gerstley borate and since it is still
in the new glaze I'm hoping that this reformulation suites your needs. If
you decide to test it let us know how it works.
++++++++++++++++++++++++++++++++++++++++++
+++ Original Self-thickening glaze +++
++++++++++++++++++++++++++++++++++++++++++
Date: 05/09/99
EPK 20 20 %
Gerstley borate 50 50 %
Flint 30 30 %
-------- ------
100 100 %
===========================
Chemical Analysis
===========================
Na2O 0.14 Al2O3 0.39 SiO2 3.36
MgO 0.20 B2O3 0.77
CaO 0.66
Alumina:Silica ratio is 1.00 : 8.63
Neutral:Acid ratio is 1.00 : 2.90
Alkali:Neutral:Acid ratio is 1.00 : 1.16 : 3.36
Expansion coefficient: 58.4 x 10e-7 per degree C
Oxides causing abnormal expansion effects: B2O3
+++++++++++++++++++++++++++++++++++++++
+++ John's Gerstley Lite Cone 6 +++
+++++++++++++++++++++++++++++++++++++++
Date: 05/09/99
Frit 3134 46 46 %
Gerstley borate 11 11 %
EPK 25 25 %
Flint 18 18 %
-------- ------
100 100 %
===========================
Chemical Analysis
===========================
Na2O 0.29 Al2O3 0.34 SiO2 3.00
MgO 0.03 B2O3 0.66
CaO 0.68
Alumina:Silica ratio is 1.00 : 8.80
Neutral:Acid ratio is 1.00 : 3.01
Alkali:Neutral:Acid ratio is 1.00 : 1.00 : 3.00
>----------------------------Original message----------------------------
>I am using a simple base glaze and am having problems with it thickening on
>its own over time....
>Gerstly Borate 50%
>#6 Tile Kaolin 20%
>Flint 325 30%
>Sue Beach
John Post
Sterling Heights, Michigan
temmoku@actionwebs.net
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