Chris Stanley on fri 9 aug 02
I honestly thought someone else would undertake this and I could vicariously
enjoy the information without ever balancing a scale. Well, I waited until
I dusted the last little bit of my old Gerstley Borate supply out of the bag
then I got real nervous about what the heck I was going to do next. I went
into my old notes, my old books, and finally found the formula listed below.
Far from being a cheap glaze, it does melt early and has a wonderful glossy
fired surface. The big problem was that its application was horrible. The
glaze would dust off too easily, it caked up on the bisque piece, and even
though there is some Bentonite, it sunk to the bottom of the cup so fast
that it was a pain to use.
With the help of several students we attempted to solve the problems with
the glaze.
The following is what we did:
Into a two-cup drinking cup we mixed 200 grams of the glaze below.
A. 200 grams Glaze/Hot water/ 1 tablespoon of Epsom salts:
B. 200 grams Glaze/Hot water/ 1 tablespoon of Calgon
C. 200 grams Glaze/Hot water/ 1 tablespoon of Gum Arabic (old rotten brown
stuff from the lithography studio)
Then in another two cup drinking glass, we mixed two teaspoons of CMC in one
cup of hot water and stirred until dissolved. Literally the dissolving took
about a half an hour with stirring. The solution was even better the next
day!
D. 200 grams Glaze /Hot water/ one index finger of CMC/water solution
Mix A applied better but still dusted off the pot when touched
Mix B same as A
Mix C Same as A with a wee bit better adhesion to the bisque
Mix D perfection
Test Glaze:
GLOSSY WHITE CRACKLE
Frit 3110 47%
Frit 3124 29
Lithium. carbonate 12
Flint 10
Bentonite *2
Now, I am not sure if the GB supplies are gone forever, or if the
substitutes will work. I am hoping to start a discussion about alternatives
and some solutions to material supply issues.
Chris
Gary Ferguson on sat 10 aug 02
You might want to check out:
http://www.gerstleyborate.com
There is a list and analysis of many of the substitutes available for GB.
As far as I know Laguna is still selling GB for the next couple of years.
http://www.lagunaclay.com/gb.htm
Gary Ferguson
Clay Artist
www.garyrferguson.com
----- Original Message -----
From: "Chris Stanley"
To:
Sent: Friday, August 09, 2002 10:30 PM
Subject: Thoughts on Raku without Gerstly Borate
> I honestly thought someone else would undertake this and I could
vicariously
> enjoy the information without ever balancing a scale. Well, I waited
until
> I dusted the last little bit of my old Gerstley Borate supply out of the
bag
> then I got real nervous about what the heck I was going to do next
Cynthia Baker on sun 11 aug 02
Chris --
What cone does this fire to? I'm trying to find a white Raku crackle that
matures around cone 06 -- I like to mix copper glazes and white crackle on
the same pot but I find that most white crackles (like 80/20) mature at
05-04, which makes for ugly coppers.
thanks!
Cynthia
In a message dated 8/10/2002 2:16:17 AM Pacific Daylight Time,
stanley_c@UTPB.EDU writes:
> I honestly thought someone else would undertake this and I could vicariously
> enjoy the information without ever balancing a scale. Well, I waited until
> I dusted the last little bit of my old Gerstley Borate supply out of the bag
> then I got real nervous about what the heck I was going to do next. I went
> into my old notes, my old books, and finally found the formula listed below.
> Far from being a cheap glaze, it does melt early and has a wonderful glossy
> fired surface. The big problem was that its application was horrible. The
> glaze would dust off too easily, it caked up on the bisque piece, and even
> though there is some Bentonite, it sunk to the bottom of the cup so fast
> that it was a pain to use.
> With the help of several students we attempted to solve the problems with
> the glaze.
> The following is what we did:
> Into a two-cup drinking cup we mixed 200 grams of the glaze below.
> A. 200 grams Glaze/Hot water/ 1 tablespoon of Epsom salts:
> B. 200 grams Glaze/Hot water/ 1 tablespoon of Calgon
> C. 200 grams Glaze/Hot water/ 1 tablespoon of Gum Arabic (old rotten brown
> stuff from the lithography studio)
> Then in another two cup drinking glass, we mixed two teaspoons of CMC in one
> cup of hot water and stirred until dissolved. Literally the dissolving took
> about a half an hour with stirring. The solution was even better the next
> day!
>
> D. 200 grams Glaze /Hot water/ one index finger of CMC/water solution
> Mix A applied better but still dusted off the pot when touched
> Mix B same as A
> Mix C Same as A with a wee bit better adhesion to the bisque
> Mix D perfection
> Test Glaze:
>
> GLOSSY WHITE CRACKLE
> Frit 3110 47%
> Frit 3124 29
> Lithium. carbonate 12
> Flint 10
> Bentonite *2
>
> Now, I am not sure if the GB supplies are gone forever, or if the
> substitutes will work. I am hoping to start a discussion about alternatives
> and some solutions to material supply issues.
> Chris
>
Chris Stanley on sun 11 aug 02
The formula I listed originally in my note starts to melt at a low dull red.
By the time the old 80/20 is melting the heavily fritted one is very glossy.
We have begun to cut oxides into the glaze and have seen some pretty blood
reds, and even some metallic lusters. We took the oxide colorants from:
Diane’s Rainbow, Glass Red and Lucy’s Lemon Luster and coil water blue.
They are all working in an acceptable manner, but we have not hit them all
of the post firing reduction possibilities yet!
I will post more as the week progresses!
Chris
-----Original Message-----
From: Blackcatpottery2@aol.com [mailto:Blackcatpottery2@aol.com]
Sent: Sunday, August 11, 2002 11:06 AM
To: stanley_c@utpb.edu; CLAYART@LSV.CERAMICS.ORG
Subject: Re: Thoughts on Raku without Gerstly Borate
Chris --
What cone does this fire to? I'm trying to find a white Raku crackle that
matures around cone 06 -- I like to mix copper glazes and white crackle on
the same pot but I find that most white crackles (like 80/20) mature at
05-04, which makes for u gly coppers.
thanks!
Cynthia
In a message dated 8/10/2002 2:16:17 AM Pacific Daylight Time,
stanley_c@UTPB.EDU writes:
I honestly thought someone else would undertake this and I could vicariously
enjoy the information without ever balancing a scale. Well, I waited until
I dusted the last little bit of my old Gerstley Borate supply out of the bag
then I got real nervous about what the heck I was going to do next. I went
into my old notes, my old books, and finally found the formula listed below.
Far from being a cheap glaze, it does melt early and has a wonderful glossy
fired surface. The big problem was that its application was horrible. The
glaze would dust off too easily, it caked up on the bisque piece, and even
though there is some Bentonite, it sunk to the bottom of the cup so fast
that it was a pain to use.
With the help of several students we attempted to solve the problems with
the glaze.
The following is what we did:
Into a two-cup drinking cup we mixed 200 grams of the glaze below.
A. 200 grams Glaze/Hot water/ 1 tablespoon of Epsom salts:
B. 200 grams Glaze/Hot water/ 1 tablespoon of Calgon
C. 200 grams Glaze/Hot water/ 1 tablespoon of Gum Arabic (old rotten brown
stuff from the lithography studio)
Then in another two cup drinking glass, we mixed two teaspoons of CMC in one
cup of hot water and stirred until dissolved. Literally the dissolving took
about a half an hour with stirring. The solution was even better the next
day!
D. 200 grams Glaze /Hot water/ one index finger of CMC/water solution
Mix A applied better but still dusted off the pot when touched
Mix B same as A
Mix C Same as A with a wee bit better adhesion to the bisque
Mix D perfection
Test Glaze:
GLOSSY WHITE CRACKLE
Frit 3110 47%
Frit 3124 29
Lithium. carbonate 12
Flint 10
Bentonite *2
Now, I am not sure if the GB supplies are gone forever, or if the
substitutes will work. I am hoping to start a discussion about alternatives
and some solutions to material supply issues.
Chris
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