Mert & Holly Kilpatrick on thu 31 jul 03
Al Strauss was looking for a black matt glaze. Browsing old Ceramic Monthly
magazines, I saw a black matt glaze from John Chalke, from the March 1975
issue:
Cone 6,
Whiting 17.9
Zinc Oxide 8.0
Potash Fedlspar 49.2
Kaolin 19.9
Flint 5.0
Add: RIO 6.7
Cobalt Oxide 1.3
He said "I apply a black matt glaze as background, then more expressive
glazes on top. This glaze works well by itself, with a suggestion of hare's
fur when thick and slowly cooled. The oxides bleed through, improving some
of the overglazes and helping others to adhere."
Holly
E. Bangor, PA, US
>22 July 2003 From: Al Strauss
>Subject: Very Very Matte Black Glaze Needed
>
>Hi,
>I need a formula for a very stone matte black glaze for oxidation Cone 6.
>Any advice would be appreciated. I also need a white glaze with the same
Ababi on fri 1 aug 03
When the question was asked the test was in the kiln so here is my
recipe: I must add that the base glaze is an improvement of Stony matte
of Behrens
Ababi's MATTE #11 BLACK
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 6 1222 deg.C. - Oxidation
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Bone Ash 63.00
Feldspar Soda F7 270.0
Wollastonite 87.00
kaolin CC31 247.0
strontium carbonate 257.0
Quartz 77.00
Black Iron Oxide 80.00
Cobalt Oxide 20.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.145 3.95%
CaO 0.360 8.15%
MgO 0.009 0.15%
SrO 0.486 20.30%
Al2O3 0.373 15.36%
P2O5 0.057 3.25%
SiO2 2.015 48.86%
K2O 0.024 0.92%
Na2O 0.121 3.03%
Al:Si 5.39
Expan. 8.12
ST 386.63
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Clay Body all
Colour coal black
Glaze Type Alumina Matt
Opacity Opaque
Texture Stone Matte
Stability No Movement
Fit No Crazing
Last changed: 24/07/03
Status Tested
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Comment:
I will try to change it to your materials:
Ababi's MATTE 11 BLACK
Cone 6 1222 deg.C. - Oxidation
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Bone Ash 6.30
Custer feldspar 32.60
EPK Kaolin 20.60
Wollastonite 8.70
strontium carbonate 25.50
Flint 6.40
Black Iron Oxide 8.00
Cobalt Oxide 2.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.145 4.89%
CaO 0.360 8.09%
MgO 0.010 0.17%
SrO 0.484 20.06%
Al2O3 0.372 15.17%
P2O5 0.058 3.29%
SiO2 2.007 48.25%
TiO2 0.003 0.09%
K2O 0.100 3.77%
Na2O 0.045 1.12%
Al:Si 5.39
Expan. 8.12
ST 386.40
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Clay Body all
Colour coal black
Glaze Type Alumina Matt
Opacity Opaque
Texture Stone Matte
Stability No Movement
Fit No Crazing
Last changed: 24/07/03
Status Tested
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Comment: Was not tested in this version. The glaze looks good with
different oxides.
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
Ron Roy on sat 2 aug 03
This will not be a stable glaze - way short of silica - and the expansion
is high - hard to tell cause it's a matte glaze but I would expect crazing.
Best not to use it as a liner as it will change in use and leach iron and
cobalt into food.
RR
>Al Strauss was looking for a black matt glaze. Browsing old Ceramic Monthly
>magazines, I saw a black matt glaze from John Chalke, from the March 1975
>issue:
>
>Cone 6,
>Whiting 17.9
>Zinc Oxide 8.0
>Potash Fedlspar 49.2
>Kaolin 19.9
>Flint 5.0
>
>Add: RIO 6.7
>Cobalt Oxide 1.3
>He said "I apply a black matt glaze as background, then more expressive
>glazes on top. This glaze works well by itself, with a suggestion of hare's
>fur when thick and slowly cooled. The oxides bleed through, improving some
>of the overglazes and helping others to adhere."
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ababi on sun 3 aug 03
I want to look at this glaze from another point of view.
Holly read that Al wanted a black matte.
Holly found in an old CM a glaze of John Chack.
John Chak a well known potter ( to you) used that glaze.=20
=20
I do not like the way The CM is giving recipes.
The CM, more than any magazine is a World Wide Magazine.
As an example was there an article about an Israeli potter.
I don't remember exactly the article but if you were going to try the
recipe, 55% that you would fail because of the difference between my
ball clay and yours my kaolin and yours.
=20
I don't except the CM to write analysis ( It would be of course the
best) but at least the full names of the material.=20
What is potash?=20
Custer G-200=20
Om-4 or Gleason?
=20
Now I want to go to a different point of view.
Mastering Cone Six glaze is an excellent book.
I disagree with these of you that see it is "THE BOOK OF THE ULTIMATE
RECIPES".=20
I am not sure that you Jon and you Ron meant the book to be another
recipes book. At least I did not interpret it this way.
=20
You cannot believe the astonishment of the people whom I tell about the
glaze - clay tests I make. They thought it was like shellac painting! =20
=20
I did not read Jon Chack's article.=20
If he offered to use the glaze as a food surface: He should be fired! (
Both meaning)
If he meant to use the glaze for his indoor sculpture or even for a
decoration plate than it is fine.
Here is this recipe with analysis
With some materials I had guessed.
MATTE BLACK JOHN CHACK
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
=20
Cone 6 1222 deg.C. - Oxidation =20
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
=20
Calcium Carbonate 17.90
zinc oxide 8.00
Custer feldspar 49.20
EPK Kaolin 19.90
Flint 5.00
Red Iron Oxide 6.70
Cobalt Oxide 1.30
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
=20
Seger Weight%
KNO 0.218 7.34%
CaO 0.504 11.29%
MgO 0.001 0.02%
ZnO 0.276 8.99%
Al2O3 0.441 17.94%
P2O5 0.001 0.05%
SiO2 2.261 54.28%
TiO2 0.003 0.08%
K2O 0.150 5.66%
Na2O 0.068 1.69%
Al:Si 5.13 =20
Expan. 8.05 =20
ST 386.70 =20
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
=20
This is a matte glaze.
Let me disagree with you Ron.
It is not possible and not correct to be in the "golden palace" you and
John had built for us!
The glazes you developed are great. The attitude is more important. As I
wrote before =96 the right glaze for the right use.
I compared this glaze to the one I made last week.=20
MATTE #11
Seger Weight%
KNO 0.145 3.95%
CaO 0.360 8.15%
MgO 0.009 0.15%
SrO 0.486 20.30%
Al2O3 0.373 15.36%
P2O5 0.057 3.25%
SiO2 2.015 48.86%
K2O 0.024 0.92%
Na2O 0.121 3.03%
Al:Si 5.39 =20
Expan. 8.12 =20
ST 386.63 =20
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
=20
Very similar.
=20
We are nor relatives neither he was my student.=20
=20
I also don't think I have to write on every glaze if it is foodsafe or
not.
I think I have to add analysis. This is my responsibility. Perhaps the
CM's too.
The reader can ask a friend or clayart what it means.
Or learn himself.
=20
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
=20
http://members4.clubphoto.com/ababi306910
=20
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
=20
=20
=20
=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Ron Roy
Sent: Saturday, August 02, 2003 7:20 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Black Matt Glaze
=20
This will not be a stable glaze - way short of silica - and the
expansion
is high - hard to tell cause it's a matte glaze but I would expect
crazing.
=20
Best not to use it as a liner as it will change in use and leach iron
and
cobalt into food.
=20
RR
=20
>Al Strauss was looking for a black matt glaze. Browsing old Ceramic
Monthly
>magazines, I saw a black matt glaze from John Chalke, from the March
1975
>issue:
>
>Cone 6,
>Whiting 17.9
>Zinc Oxide 8.0
>Potash Fedlspar 49.2
>Kaolin 19.9
>Flint 5.0
>
>Add: RIO 6.7
>Cobalt Oxide 1.3
>He said "I apply a black matt glaze as background, then more expressive
>glazes on top. This glaze works well by itself, with a suggestion of
hare's
>fur when thick and slowly cooled. The oxides bleed through, improving
some
>of the overglazes and helping others to adhere."
=20
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
=20
________________________________________________________________________
______
Send postings to clayart@lsv.ceramics.org
=20
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
=20
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Mert & Holly Kilpatrick on sun 3 aug 03
Ron helpfully commented that the 1975 John Chalke recipe I posted for Black
Matt is very low in silica. I knew that, and maybe I should have posted the
unity formula with it. To clarify, I did not go searching in old CM's for a
black matt glaze for Al, I just happened to be reading old ones because due
to the generosity of a Clayart member I was able to buy alot of old CM's and
I have been reading them.
I probably should have been a little more descriptive in saying that John
Chalke did alot of experimentation with unusual glaze effects not oriented
towards food surfaces. It is possible that many "very flat very very matt
black" surfaces may not be food safe. Or durable.
All that said, for some purposes, it might be a useful starting point for
the person who asked for a very flat matt black. With all the possible
caveats about safety, leaching, crazing, durability, etc. etc.
By the way, the 1970's were really a heyday of pottery - wow, all the names,
the vibrant activity -- I only started learning about the pottery world in
the mid-90's or so. So many of the well-known US potters I have read about
in books were in their young vital years then.
And I ran across David Hendley's famous carjack extruder article. And so
many other things. If new potters have the chance to immerse themselves in
a couple past decades of CM, you get a great perspective.
Holly
East Bangor, PA
Ron Roy on tue 5 aug 03
John and I wanted to fill in a gap in our collective knowledge -
specifically about stable/durable glazes. We could have done it without
recipes but that would have meant - only a few potters would have applied
the lessons.
The glazes - because of how they look - are the main reason our book is so
popular.
We can safely say - it is - so far - the intimate recipe book on stable
glazes - in fact the only book in which all the glazes are tested for
durability - in fact the only book in which any glazes have been tested for
durability.
There are even some potters - professionals - who now use only our glazes -
I suppose - for them it is the ultimate glaze book - it solves the problem
of stability in glazes and they help sales - a double advantage.
In the end it depends on your point of view - in what you believe in - some
of us must make our own glazes - to others that is a small part of it all -
in the end it is the form - not the clay and not the glaze - everything is
second to the form - so to some that is where the intensity should be.
RR
>Now I want to go to a different point of view.
>Mastering Cone Six glaze is an excellent book.
>I disagree with these of you that see it is "THE BOOK OF THE ULTIMATE
>RECIPES".
>I am not sure that you Jon and you Ron meant the book to be another
>recipes book. At least I did not interpret it this way.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ababi on tue 5 aug 03
Hello Ron
John and you have done a very important work. I am more than grateful to
you (Both). Recently I had a mail exchange with John.=20
I asked him to use your article about glaze stability from his site +
some pictures of your glazes in a CD I made for my adult student. I
wanted to show them how easy they can adjust their glazes not leaning on
glazes that running a long the country that no one ever checked their
analysis.
Before learning from your book I knew which materials to avoid (more or
less). I did not know how much or the way you say durability and
stability. (Still, confused about these too terms. More English Hebrew
translation)
I read you book twice.
I do not remember every word.=20
They say that education is what you remember after you forget what you
have learnt in school.
For me your book is the education.
My glazes:=20
Even when I make the unfunctional glazes, I try to have them as balanced
as possible.
When I make crystal bottles inside, where no one can see I apply (yours)
gloss liner- who knows someone will use it for wine?
Back to your book.
About the fact the people are using your glazes.=20
If they use them as they are, this is a big problem.
If they are changing them this is fine.
If they use them as they are =96 after a while =96 all the foodsafe =
glazes
will be the same everywhere!
Do you understand me Ron? Their uniqueness will not appreciated - they
will be the "common" glazes!
These are beautiful glazes!
Durable too. The fact that you had tested them is very important-
especially you with your big knowledge.
By the way I made recently the first time since I work in Ceramics
plates for home. Inside I applied gloss liner (yours) on top around (it
was tray like) my combination of high alumina blue on low alumina clear.
When the wares came out of the kiln I took one of them to three days
bath in vinegar. Only after I realized the color did not change I took
them home.=20
Yesterday my wife wanted to put one in the Microwave.
(2.5% absorption)
To be sure I told her to separate the food from the plat by using baking
paper and remove it with a towel.
Latter she touched and said it was warm- not hot.
So why do I tell you all this.
I think my way is the right way to understand the book. Not just a
recipes book.
I see these recipes as guidelines =96 try glaze A than try A/1 and
compare.
I have two other questions to you regarding my education (from your
book) I shall send them latter to the list.
Thank you
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910
http://www.matrix2000.co.nz/Matrix%20Demo/Ababi.htm
-----Original Message-----
From: Ron Roy [mailto:ronroy@total.net]=20
Sent: Tuesday, August 05, 2003 7:45 AM
To: Clayart
Cc: Ababi
Subject: Re: Black Matt Glaze
John and I wanted to fill in a gap in our collective knowledge -
specifically about stable/durable glazes. We could have done it without
recipes but that would have meant - only a few potters would have
applied
the lessons.
The glazes - because of how they look - are the main reason our book is
so
popular.
We can safely say - it is - so far - the intimate recipe book on stable
glazes - in fact the only book in which all the glazes are tested for
durability - in fact the only book in which any glazes have been tested
for
durability.
There are even some potters - professionals - who now use only our
glazes -
I suppose - for them it is the ultimate glaze book - it solves the
problem
of stability in glazes and they help sales - a double advantage.
In the end it depends on your point of view - in what you believe in -
some
of us must make our own glazes - to others that is a small part of it
all -
in the end it is the form - not the clay and not the glaze - everything
is
second to the form - so to some that is where the intensity should be.
RR
>Now I want to go to a different point of view.
>Mastering Cone Six glaze is an excellent book.
>I disagree with these of you that see it is "THE BOOK OF THE ULTIMATE
>RECIPES".
>I am not sure that you Jon and you Ron meant the book to be another
>recipes book. At least I did not interpret it this way.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513=20
John Hesselberth on tue 5 aug 03
Hi Ababi,
You are right. We don't consider it just a recipe book. That is why you
have to get to Chapter 6 before you find the recipes. We hope people
read the first 5 chapters first. Even the recipes we consider as just
starting points. We encourage people to develop their own or modify
ours; however we hope they do it with knowledge and care.
Regards,
John
On Tuesday, August 5, 2003, at 09:46 AM, Ababi wrote:
> I think my way is the right way to understand the book. Not just a
> recipes book.
http://www.frogpondpottery.com
http://www.masteringglazes.com
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