Monica Wright on sat 20 mar 10
Looking for a good black that I can use as a liner on some large pots.=3DA0=
I=3D
have several books/resources but none of them have any black glazes in the=
=3D
m.=3DA0 I suppose I could just add some RIO and some cobalt to a base glaze=
a=3D
nd get a black but I always have hated the "blueish"=3DA0tint that the coba=
lt=3D
gives.=3DA0 This is going to be in reduction/salt atmosphere, cone 6.=3DA0=
Tha=3D
nks.
Mary Starosta on sat 20 mar 10
Mc6G ( Mastering cone 6 glazes the book) Good resource for an UNSTOPPABLE
Licorice. Best black I have ever worked with on white and brown stoneware
clay. It is shinny/glossy but works well with Beginners, it's so very
kind! Not picky about how you apply it or getting the thickness just
right. I really LIKE this glaze :) IMO
MaryStarosta
Colorado Potter
http://marystarosta.wordpress.com/
On Sat, Mar 20, 2010 at 7:12 AM, Monica Wright wro=
te:
> Looking for a good black that I can use as a liner on some large pots. I
> have several books/resources but none of them have any black glazes in
> them. I suppose I could just add some RIO and some cobalt to a base glaz=
e
> and get a black but I always have hated the "blueish" tint that the cobal=
t
> gives. This is going to be in reduction/salt atmosphere, cone 6. Thanks=
.
>
Mary Starosta on sat 20 mar 10
OOPS Just read reduction. The MC6G is for electric cone 6 firing.
SORRY.....
Mary
On Sat, Mar 20, 2010 at 7:12 AM, Monica Wright wro=
te:
> Looking for a good black that I can use as a liner on some large pots. I
> have several books/resources but none of them have any black glazes in
> them. I suppose I could just add some RIO and some cobalt to a base glaz=
e
> and get a black but I always have hated the "blueish" tint that the cobal=
t
> gives. This is going to be in reduction/salt atmosphere, cone 6. Thanks=
.
>
James Freeman on sat 20 mar 10
On Sat, Mar 20, 2010 at 8:12 AM, Monica Wright wr=
=3D
ote:
> Looking for a good black that I can use as a liner on some large pots. I=
=3D
have several books/resources but none of them have any black glazes in the=
=3D
m. I suppose I could just add some RIO and some cobalt to a base glaze and=
=3D
get a black but I always have hated the "blueish" tint that the cobalt giv=
=3D
es. This is going to be in reduction/salt atmosphere, cone 6. Thanks.
>
Monica...
The salt atmosphere will "take apart" most black glazes. There is a
salt-glazed pot on page three of my flickr site (address in my
signature line below, or go directly to the picture here:
http://www.flickr.com/photos/jamesfreemanstudio/3811437709/). The top
of the vase is a glaze that is solid jet black in oxidation or
reduction, but you can see what the salt does to it. Likewise with
the yellow glaze on the body of the vase. It is, or at least was,
actually an iron saturate/kaki/persimmon/tomato red glaze.
As you are aware, most black glazes get their color from various
combinations of cobalt, chrome, copper, manganese, and above all, lots
of iron. Salt acts as a bleach where iron is concerned. The sodium
combines with the iron and forms ferric chloride (or maybe ferrous,
don't remember, but not important). This ferric chloride is highly
fugitive, and quickly escapes from the glaze, taking the iron with it
(this is also the cause behind your bricks and furniture turning brown
in a salt kiln).
On my pot, which exhibits fairly typical behavior, so much iron was
removed by the salt from the kaki glaze that it became an iron yellow.
When the iron is stripped from the black glaze, your other colorants
start to predominate. Since cobalt is likely the most powerful one
left, you get a bluish cast.
Any such effect will be lesser on the inside of your vessels, as the
salt atmosphere will not be as intense, but you will still likely
experience it. In order to have the best chance of black remaining
after the bleaching, I would use a combination of iron, cobalt,
manganese, and chrome (taking all necessary prophylactic measures, so
we don't need to start a thread about how nasty manganese or chrome
can be). An iron-and-cobalt-only glaze is almost definitely going to
be bluish in salt. I would tend to leave out copper to mitigate the
possibility of leaching since this will be a liner glaze (see
Ron/John's warnings).
For whatever it may be worth.
...James
James Freeman
"All I say is by way of discourse, and nothing by way of advice. I
should not speak so boldly if it were my due to be believed."
-Michel de Montaigne
http://www.jamesfreemanstudio.com
http://www.flickr.com/photos/jamesfreemanstudio/
http://www.jamesfreemanstudio.com/resources
June on sat 20 mar 10
Temmoku would be my choice. In fact, my black liner for soda/salt at Cone 1=
0 is temmoku.
Other black formulas would have things like chrome, manganese, iron and/or =
cobalt in various combinations - some of which I would not want to use in a=
liner glaze for safety reasons.
Just google "Cone 6 temmoku recipe", or "Cone 6 reduction temmoku recipe" ,=
and you should be able to find one or more recipes.
Regards,
June
http://www.shambhalapottery.blogspot.comcone
http://www.shambhalapottery.com
http://groups.yahoo.com/group/sodasaltfiring/
http://saltandsodafiring.ning.com/
http://ncclayclub.blogspot.com
Johanna San Inocencio on sun 21 mar 10
--=3D=3D=3D=3D=3D=3D=3DAVGMAIL-72EB1B5F=3D=3D=3D=3D=3D=3D=3D
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James, is the inside of the pot in the image black? I really like the
green/yellow combination.
Johanna
"A man is as free as he chooses to make himself,
never an atom freer."
The Raven, Lillith by George MacDonald
James Freeman wrote:
> On Sat, Mar 20, 2010 at 8:12 AM, Monica Wright =
wrote:
>
>> Looking for a good black that I can use as a liner on some large pots. =
I have several books/resources but none of them have any black glazes in th=
em. I suppose I could just add some RIO and some cobalt to a base glaze an=
d get a black but I always have hated the "blueish" tint that the cobalt gi=
ves. This is going to be in reduction/salt atmosphere, cone 6. Thanks.
>>
>>
>
>
>
> Monica...
>
> The salt atmosphere will "take apart" most black glazes. There is a
> salt-glazed pot on page three of my flickr site (address in my
> signature line below, or go directly to the picture here:
> http://www.flickr.com/photos/jamesfreemanstudio/3811437709/). The top
> of the vase is a glaze that is solid jet black in oxidation or
> reduction, but you can see what the salt does to it. Likewise with
> the yellow glaze on the body of the vase. It is, or at least was,
> actually an iron saturate/kaki/persimmon/tomato red glaze.
>
> As you are aware, most black glazes get their color from various
> combinations of cobalt, chrome, copper, manganese, and above all, lots
> of iron. Salt acts as a bleach where iron is concerned. The sodium
> combines with the iron and forms ferric chloride (or maybe ferrous,
> don't remember, but not important). This ferric chloride is highly
> fugitive, and quickly escapes from the glaze, taking the iron with it
> (this is also the cause behind your bricks and furniture turning brown
> in a salt kiln).
>
> On my pot, which exhibits fairly typical behavior, so much iron was
> removed by the salt from the kaki glaze that it became an iron yellow.
> When the iron is stripped from the black glaze, your other colorants
> start to predominate. Since cobalt is likely the most powerful one
> left, you get a bluish cast.
>
> Any such effect will be lesser on the inside of your vessels, as the
> salt atmosphere will not be as intense, but you will still likely
> experience it. In order to have the best chance of black remaining
> after the bleaching, I would use a combination of iron, cobalt,
> manganese, and chrome (taking all necessary prophylactic measures, so
> we don't need to start a thread about how nasty manganese or chrome
> can be). An iron-and-cobalt-only glaze is almost definitely going to
> be bluish in salt. I would tend to leave out copper to mitigate the
> possibility of leaching since this will be a liner glaze (see
> Ron/John's warnings).
>
> For whatever it may be worth.
>
> ...James
>
> James Freeman
>
> "All I say is by way of discourse, and nothing by way of advice. I
> should not speak so boldly if it were my due to be believed."
> -Michel de Montaigne
>
> http://www.jamesfreemanstudio.com
> http://www.flickr.com/photos/jamesfreemanstudio/
> http://www.jamesfreemanstudio.com/resources
> ------------------------------------------------------------------------
>
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