Susan Fox-Hirschmann on sun 11 may 03
Dpes anyone have a recipe for a ^6 oxidation matt turquoise glaze that they
would like to share?
Thanks.
Susan
Wanda Holmes on mon 12 may 03
The following is based on Rhodes Velvet Barium. It leaches slightly in
72-hr vinegar tests, SO 1) use it with care - the barium carbonate may
be dangerous to you, and 2) don't use it on any surface that will come
in contact with food. Having said that, it gives me a brilliant
turquoise matt with tiny sparkles at cone 6 oxidation on a white clay
body. The slower it cools, the more sparkles you get.
Nepheline syenite 44
Barium carbonate 19
Lithium carbonate 8
Silica 19
EPK 10
Copper Carbonate 4
This version uses strontium carbonate in place of the barium. It is
also a nice glaze, but the color is not quite as intense.
Nepheline syenite 46
Strontium carbonate 15
Lithium carbonate 8
Silica 20
EPK 11
Copper carbonate 4.
A final note - I make tile, not pots, so all my tests, so I can't speak
to how this works on a more 3 dimensional surface.
Wanda
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Susan
Fox-Hirschmann
Sent: Sunday, May 11, 2003 9:08 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: turquoise matt
Dpes anyone have a recipe for a ^6 oxidation matt turquoise glaze that
they
would like to share?
Thanks.
Susan
________________________________________________________________________
______
Send postings to clayart@lsv.ceramics.org
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Moderator of the list is Mel Jacobson who may be reached at
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Gina Dewar on mon 12 may 03
Appearance-wise, this is still my favorite glaze but after doing my own
set of dishes I discovered it is not food safe/durable. Acid will pull
it's colour and after a couple years of dishwashing, it fades quite a bit.
I still use it for nonfunctional pieces, and I've saved the color on my
dishes by glazing over with a clear glossy. (so much for the great matt
though)
Source: Kristen from the Community Center in Savannah, GA:
custerfeld 47
EPK Kaolin 17.5
whiting 14
dolomite 10
Gerstly Borate 10
tin oxide 4.9
copper carbonate 4.14
cobalt carbonate 1.04
Ababi on mon 12 may 03
Please see my letter from yesterday about Pinnell's glaze.
and this one
ABABI'S S4B TURQUOISE
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Quartz 25.20
kaolin CC31 30.50
strontium carbonate 15.70
Wollastonite 18.10
Cryolite 10.50
Tin Oxide 5.00
copper oxide 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.236 4.60%
CaO 0.417 7.36%
MgO 0.021 0.26%
SrO 0.327 10.64%
Al2O3 0.422 13.53%
SiO2 3.367 63.62%
Na2O 0.236 4.60%
Al:Si 7.98
Expan. 7.55
ST 374.80
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Clay Body
For porcelain
You can use 5 titanium instead of the tin for green - turquoise. You can use this
version on buff clay too.
In the next recipe I adjusted the recipe for using with EPK however I never tested it
ABABI'S S4B TURQUOISE WITH EPK
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Quartz 25.50
EPK Kaolin 28.80
strontium carbonate 15.90
Wollastonite 18.30
Cryolite 11.60
Tin Oxide 5.00
copper oxide 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.254 5.16%
CaO 0.407 7.45%
MgO 0.022 0.29%
SrO 0.317 10.72%
Al2O3 0.407 13.54%
P2O5 0.001 0.07%
SiO2 3.197 62.67%
TiO2 0.004 0.10%
K2O 0.003 0.09%
Na2O 0.251 5.07%
Al:Si 7.85
Expan. 7.78
ST 373.18
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
If you use a software I suggest to remove some of the EPK and add some calcined
clay or alumina hydrate and silica. If you keep it the way it is in the given recipe use by
spraying.
STONY GREEN-BEHRENS
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1220 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Bone Ash 6.40
Nepheline Syenite 27.60
Magnesium Carb Light 2.50
Wollastonite 14.00
ENGLISH KAOLIN CC31 16.00
STRONTIUM CARBONATE 33.50
Tin Oxide 5.00
COPPER OXIDE 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.125 5.14%
CaO 0.344 11.11%
MgO 0.072 1.66%
SrO 0.459 27.32%
Al2O3 0.247 14.50%
P2O5 0.042 3.40%
SiO2 1.067 36.86%
K2O 0.037 2.00%
Na2O 0.088 3.14%
Al:Si 4.31
Expan. 9.42
ST 399.76
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
A lovely but unstable glaze apply thin and thick. Please see my earlier letters in the
archives ( look for STONY GREEN-BEHRENS) for the ways to use it.
Yours forever
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
---------- Original Message ----------
>Dpes anyone have a recipe for a ^6 oxidation matt turquoise glaze that they
>would like to share?
>Thanks.
>Susan
>______________________________________________________________________________
>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.
Gina Dewar on mon 12 may 03
I forgot to add that this is fired to cone 6 in oxidation....
> custerfeld 47
> EPK Kaolin 17.5
> whiting 14
> dolomite 10
> Gerstly Borate 10
> tin oxide 4.9
>
> copper carbonate 4.14
> cobalt carbonate 1.04
>
Appearance-wise, this is still my favorite glaze but after doing my own
> set of dishes I discovered it is not food safe/durable. Acid will pull
> it's colour and after a couple years of dishwashing, it fades quite a
bit.
> I still use it for nonfunctional pieces, and I've saved the color on my
> dishes by glazing over with a clear glossy. (so much for the great matt
> though)
>
> Source: Kristen from the Community Center in Savannah, GA:
Alisa Clausen on tue 13 may 03
Dear Susan,
In the archives is a recipe for Matte Turquoise. There are a few examples of
it in use on the website I just made at www.alisa-potshop.dk. It is very
smooth, reliable and matte. If you cannot find it, write to me again. I am
going off Clayart until next week, so write to my private email. regards
from Alisa in Denmark
PS. There are two recipes tested by that name. However one is from Marcia
Selsor and indented for cone 6 redux. The other one I like better because
it is has been more reliable in my kiln and does not settle.
Ron Roy on thu 15 may 03
This glaze makes an interesting case study.
It has enough silica and alumina to perhaps be a stable glaze but almost no
CaO. John found CaO to be very adventagous when trying to make durable
glazes.
The fact that it does leach is probably because it has so much alumina for
a cone 6 glaze so it probably does not melt enough ensure stabilty and that
much copper is hard to keep in unless it is a good durable glaze.
The alkalies add up to .66 mols in the seger formula and that is over the
limits.
The expansion is high so I would expect it to craze on the kind of bodies
potters use.
8% Lithium is a lot - there might be some rather serious shivering problems
on some clays so test it well.
RR
>The following is based on Rhodes Velvet Barium. It leaches slightly in
>72-hr vinegar tests, SO 1) use it with care - the barium carbonate may
>be dangerous to you, and 2) don't use it on any surface that will come
>in contact with food. Having said that, it gives me a brilliant
>turquoise matt with tiny sparkles at cone 6 oxidation on a white clay
>body. The slower it cools, the more sparkles you get.
>
>Nepheline syenite 44
>Barium carbonate 19
>Lithium carbonate 8
>Silica 19
>EPK 10
>Copper Carbonate 4
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ron Roy on thu 15 may 03
Thank you both for posting these glazes with the report that they are not
stable - for those of us who are trying to understand what makes certain
glazes durable it is a wonderful chance to learn more about this.
Again this glaze is low in silica and high in alumina - as John notes in
our book - it is difficult to make alumina matte glazes that are stable
under food.
I assume this is a cone 6 glaze (I just looked at the next post - yes cone
6.) makes me wonder - if it's fired higher does the leaching diminish.
In this case the CaO is there in abundance - the questions are - is it
unstable because the silica is so low or - is it because it's not melted
enough - or both.
Makes me wonder - if it's fired higher does the leaching diminish.
RR
>Appearance-wise, this is still my favorite glaze but after doing my own
>set of dishes I discovered it is not food safe/durable. Acid will pull
>it's colour and after a couple years of dishwashing, it fades quite a bit.
>I still use it for nonfunctional pieces, and I've saved the color on my
>dishes by glazing over with a clear glossy. (so much for the great matt
>though)
>
>Source: Kristen from the Community Center in Savannah, GA:
>
>custerfeld 47
>EPK Kaolin 17.5
>whiting 14
>dolomite 10
>Gerstly Borate 10
>tin oxide 4.9
>
>copper carbonate 4.14
>cobalt carbonate 1.04
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
iandol on fri 16 may 03
Dear Friends,
Ron's comments about this glaze are interesting.
I continue to wonder why glazes which contain Copper lend themselves to =
instability. The only clue I can find is that in Nature, Copper does not =
seem to form a single silicate compound. Hydrated Copper Silicates may =
form to give us beautiful minerals and semi precious gemstones but there =
seems to be no Copper Silicate.
Best regards,
Ivor Lewis
Ron Roy on wed 21 may 03
Hi Ivor,
There are many warnings about this in the literature on lead glazes - when
John was doing the research for our book he was interested to find out if
the same was true for other glazes.
It is true but I for one don't know why - it seems to make sense - if it
won't make silicates and silica (amount of) is a key in making stable
glazes - then they would open any glaze to acid attack.
It is the reason John used copper to test for in evaluating durable glazes.
RR
>Ron's comments about this glaze are interesting.
>
>I continue to wonder why glazes which contain Copper lend themselves to
>instability. The only clue I can find is that in Nature, Copper does not
>seem to form a single silicate compound. Hydrated Copper Silicates may
>form to give us beautiful minerals and semi precious gemstones but there
>seems to be no Copper Silicate.
>
>Best regards,
>
>Ivor Lewis
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Marianne Lombardo on sun 1 jun 03
Susan,
Behrens Stony Green (Turquoise matte) ^6
6.0 Bone Ash
26.0 Neph Sy
13.4 Wollastonite
31.5 Strontium carb
15.0 EPK
5.6 Tin oxide
3.0 Copper oxide
2.4 Magnesium carbonate
I have not had this glaze tested. When I fired, I slow cooled it a lot.
It's a lovely, but dry greenish matte on white or red stoneware. I did give
it a 3 day vinegar test and it passed. I also kept it in the dishwasher for
a month and it looks fine.
Marianne Lombardo
Omemee, Ontario
Ababi on sun 1 jun 03
They must doing the vinegar here more concentrated! For me one day in vinegar was
enough to change it from green to white.
Some glazes passing the dishwasher but still not stable.
I did it with English kaolin I will add here the analysis+ like if I would use EPK.
In my last test using the Matrix grid I got it better, still not as good as my S4b - I must
prepare myself to the days after the cryolite will be finished!
This is how I did it:
STONY GREEN-BEHRENS
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1201 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Bone Ash 6.40
Nepheline Syenite 27.60
Magnesium Carb Light 2.50
Wollastonite 14.00
kaolin CC31 16.00
strontium carbonate 33.50
Tin Oxide 5.00
COPPER OXIDE 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.126 5.17%
CaO 0.344 11.10%
MgO 0.072 1.66%
SrO 0.458 27.29%
Al2O3 0.246 14.42%
P2O5 0.042 3.40%
SiO2 1.070 36.96%
K2O 0.037 1.99%
Na2O 0.089 3.18%
Al:Si 4.35
Expan. 9.42
ST 399.36
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Here the only different is the use of EPK:
STONY GREEN-BEHRENS
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1201 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Bone Ash 6.00
Nepheline Syenite 26.00
Magnesium Carb Light 2.40
Wollastonite 13.40
EPK Kaolin 15.00
strontium carbonate 31.50
Tin Oxide 5.60
COPPER OXIDE 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.117 4.70%
CaO 0.349 11.26%
MgO 0.074 1.72%
SrO 0.459 27.33%
Al2O3 0.253 14.80%
P2O5 0.042 3.44%
SiO2 1.063 36.69%
TiO2 0.002 0.07%
K2O 0.028 1.54%
Na2O 0.089 3.16%
Al:Si 4.20
Expan. 9.33
ST 401.80
I think they cheat you with the vinegar!
In this page you can see the tests I made one different claybodies. I chose glaze 11 for
a matte base and 18 for a silky base.
http://members4.clubphoto.com/ababi306910/981929/
Both higher alumina than the original but just a compromise.
I am recalculating it to your materials, I hope it will work for you because I am not
totally sure about the analysis of my Soda feldspar.
BEHRENS GREEN(#18 ABABI'S VERSION)
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1222 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Bone Ash 5.90
Nepheline Syenite 25.60
Wollastonite 8.40
EPK 15.80
strontium carbonate 24.10
Quartz 20.20
Tin Oxide 5.00
COPPER OXIDE 3.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.154 4.10%
CaO 0.359 7.70%
MgO 0.011 0.17%
SrO 0.476 18.82%
Al2O3 0.346 13.45%
P2O5 0.055 3.01%
SiO2 2.298 52.76%
K2O 0.036 1.31%
Na2O 0.118 2.79%
Al:Si 6.65
Expan. 7.90
ST 379.53
Comment: looks best on porcelain or similar claybody!
About the original recipe: looks good on all the claybodies
See here
http://members4.clubphoto.com/ababi306910/186015/
Keep matte - ing
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.israel-ceramics.org/membersGallery/personalpage.asp?MID=507
---------- Original Message ----------
>Susan,
>Behrens Stony Green (Turquoise matte) ^6
>6.0 Bone Ash
>26.0 Neph Sy
>13.4 Wollastonite
>31.5 Strontium carb
>15.0 EPK
>5.6 Tin oxide
>3.0 Copper oxide
>2.4 Magnesium carbonate
>I have not had this glaze tested. When I fired, I slow cooled it a lot.
>It's a lovely, but dry greenish matte on white or red stoneware. I did give
>it a 3 day vinegar test and it passed. I also kept it in the dishwasher for
>a month and it looks fine.
>Marianne Lombardo
>Omemee, Ontario
>______________________________________________________________________________
>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.
Ron Roy on tue 3 jun 03
I would be very surprised if this was found to be a stable glaze - it is
way short of silica and has a fair amount of copper.
As we pointed out in our book - we have not found a cone 6 alumina matte
glaze that was stable - not yet.
I also see that it probably crazes on probably every body a potter would use.
Best to limit this type of glaze to the outside of functional ware.
RR
>Susan,
>Behrens Stony Green (Turquoise matte) ^6
>6.0 Bone Ash
>26.0 Neph Sy
>13.4 Wollastonite
>31.5 Strontium carb
>15.0 EPK
>5.6 Tin oxide
>3.0 Copper oxide
>2.4 Magnesium carbonate
>
>I have not had this glaze tested. When I fired, I slow cooled it a lot.
>It's a lovely, but dry greenish matte on white or red stoneware. I did give
>it a 3 day vinegar test and it passed. I also kept it in the dishwasher for
>a month and it looks fine.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
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