Eric Suchman on thu 17 aug 06
Try this:
Cream/Rust ^6
Custer feldspar 26.6
Strontium carbonate 3.3
Frit 3134 30.6
wollastonite 10.6
talc 2.3
EPK 8.4
Silica 18.2
-------
add rio 6.0
tin 13.0
Or:
Nutmeg ^6
Dolomite 23.3
Spodumene 23.3
Frit 3134 6.8
OM-4 23.3
Silica 23.3
------
add rio 1.07
yellow ochre 3.24
tin 4.85
I hope that this helps.
Eric in Oceanside
On Aug 17, 2006, at 4:28 PM, Jami Bishop wrote:
> I am looking for some technical information on White Tin
> Glazes. I have
> several books with recipes, but none seem to answer my question. I
> have
> seen pictures of white tin glazes on stoneware with lovely iron flecks
> coming through from the clay. I believe that the iron flecks only
> come
> through the glaze when the piece is fired in reduction, and yet
> most recipes
> that I have seen are cone 1 or lower. I have heard that some White
> Tin
> Glazes can be fired to cone 6. When I have attempted various
> recipes, I
> have had trouble with the white glaze turning to grey and crazing
> or the
> oxides burning out. So my question is how can I retain the iron
> flecks when
> firing? Do I fire up to cone 6 in my downdraft gas kiln without
> reduction
> wherein there will still be a slight enough reduction to bring
> forth the
> iron flecks, or is it possible to fire same in my electric kiln and
> still
> get iron flecks. Or for best results should I fire at lower temp,
> and if
> so, which kiln? Also, with regard to the overglaze decoration, I am
> interested in using cobalt, and red iron, but can anyone tell me
> what I can
> use to obtain green or pink for floral decoration that will not
> burn out?
> Last of all, if anyone can recommend a good tin white recipe with
> temperature and telling if oxidation or reduction I would be eternally
> grateful!
>
> Jami Bishop
> jamianne@charter.net
> Rogue River, Oregon
>
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Stephani Stephenson on thu 17 aug 06
Jami,
these are partial answers at best, and hopelessly general in nature !
but may fit in with other info you come across.
the iron flecks in iron bearing clay bodies do interact with the glaze
and
you can get this to happen at lower than stoneware temps.
A lot of chrome tin glazes are used in the majolica techniques on red
clay earthenware.
also I have seen some lovely examples on red clays up to cone 3.
Other factors may be the thickness of the applied glaze, the makeup
of the base glaze
and the makeup of the clay body which determines all of this.
For example a thick coating of a very stiff opaque glaze may not give
you the effect , as you
will want the clay body to look as if it is bleeding up through the
glaze, just a bit.
also the composition of the clay body..i have seen some hearty red
bodies provide the
effect you describe , which is very attractive...just the right
clay/glaze combo.. and application..
I wonder too if a granular manganese or iron could be added to the
glaze or perhaps to the clay body or even added as an underglaze slip
to promote the speckling. just brainstorming.
as to the green and pink , ahhhh
just try to make something green and it will go pink for you!!!
my problem with tin white glazes for awhile was that everything ended
up flashing pink!!!!
chrome plus tin will give many shades of pink and crimson.
So test your colorants...chrome -free greens for green
or copper, or perhaps nickel silicate stains?.
and then chrome colorants added to the base glaze for your pinks
or you may have a chrome green which stays green but goes pink when it
overlaps the tin glaze.
This is a rich area for experimentation and a way to make the effect
your own.
Stephani Stephenson
steph@revivaltileworks.com
http://www.revivaltileworks.com
Jami Bishop on thu 17 aug 06
I am looking for some technical information on White Tin Glazes. I have
several books with recipes, but none seem to answer my question. I have
seen pictures of white tin glazes on stoneware with lovely iron flecks
coming through from the clay. I believe that the iron flecks only come
through the glaze when the piece is fired in reduction, and yet most recipes
that I have seen are cone 1 or lower. I have heard that some White Tin
Glazes can be fired to cone 6. When I have attempted various recipes, I
have had trouble with the white glaze turning to grey and crazing or the
oxides burning out. So my question is how can I retain the iron flecks when
firing? Do I fire up to cone 6 in my downdraft gas kiln without reduction
wherein there will still be a slight enough reduction to bring forth the
iron flecks, or is it possible to fire same in my electric kiln and still
get iron flecks. Or for best results should I fire at lower temp, and if
so, which kiln? Also, with regard to the overglaze decoration, I am
interested in using cobalt, and red iron, but can anyone tell me what I can
use to obtain green or pink for floral decoration that will not burn out?
Last of all, if anyone can recommend a good tin white recipe with
temperature and telling if oxidation or reduction I would be eternally
grateful!
Jami Bishop
jamianne@charter.net
Rogue River, Oregon
Ron Roy on mon 21 aug 06
The expansion for the first glaze is OK - but the expansion for Nutmeg is
very low and could be a problem with some clay bodies.
I have reformulated it - if anyone cares to fire both - I would appreciate
it you would let me know how close my revision is.
Revised Nutmeg for higher expansion - RR
Dolomite - 22.5
G200 - 19.5
Spodumene - 10.0
Frit 3134 - 7.0
OM#4 - 22.5
Silica - 18.5
Total - 100.0
Probably not a stable glaze by the way - just not enough boron for a good
melt at cone 6.
RR
>Try this:
> Cream/Rust ^6
>
> Custer feldspar 26.6
> Strontium carbonate 3.3
> Frit 3134 30.6
> wollastonite 10.6
> talc 2.3
> EPK 8.4
> Silica 18.2
> -------
> add rio 6.0
> tin 13.0
>
>Or:
>
> Nutmeg ^6
>
> Dolomite 23.3
> Spodumene 23.3
> Frit 3134 6.8
> OM-4 23.3
> Silica 23.3
> ------
> add rio 1.07
> yellow ochre 3.24
> tin 4.85
>
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
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