Stephani Stephenson on thu 14 nov 02
Dan wrote:
" I use a cone 04 (1985F) base glaze fired in oxidation that produces a
glossy finish.
I am spraying it on whiteware with an airbrush.
Could someone suggest how I might make this glaze totally matte but
still maintain
good adhesion & fit?
Cone 04 Glossy Glaze
39 grams frit 3134
39 grams frit 3195
2 grams flint
6 grams pioneer kaolin"
Dan
This is just off the cuff... so I imagine you will get more specific
info, but
thinking of what can matte a glaze I think of the following
1. cooling cycle: often the difference between a glossy and a matte
effect with the same glaze is simply the rate at which the kiln cools.
if you can slow the cooling significantly, this will give crystals the
opportunity to form. These crystals interfere with the light penetrating
and bouncing back up through the glaze... so the glaze looks matte.
These types of matte glazes are often lovely, luminous mattes, rather
than dry looking mattes.
this slowing down of the cooling cycle can make a difference whether
you use an electric or gas kiln.
2. One thing I notice is that you have a lot of frit 3195, which is a
pretty hard clear gloss at cone 04....you could try decreasing the 3195,
ether subbing with another frit with higher melting point or with a
frostier or more opaque appearance at 04 (3134, 3124, 265,233.....) or
subbing a higher % of other ingredients, some of which follow...
3. introduction of 'mottling' or crystal inducing ingredients into the
glaze: at this temperature this could be zinc oxide or titanium
dioxide....
4. In my own layman terms, matting also occurs also when certain
ingredients precipitate out of the melt and out of solution. Generally
these are categorized as calcium mattes, (excess calcia or magnesia),
alumina mattes (excess alumina) or silica mattes (excess silica) . At
this temperature you might doing a line blend with something like
whiting, dolomite, (for calcium matte) or EPK (silica/alumina) . Whiting
in particular might be useful.
4. you could also raise the melting point of the glaze a bit as well as
add some matting ingredients by adding something like EPK, Neph Sy.,
Feldspar, silica, (though sometimes this has the opposite effect), or
alumina.....or lessening the % of frit in relation to the other
ingredients.
5. Barium carb is also useful but due to it's toxicity may not be
something you want to introduce into the studio or onto the ware.
of course some of this might mess with the fit of the glaze... but those
are some possible directions.
As an example,
a cloudy satin matte from Chappel , ssg-49
is
Neph sy 37.5
frit (try 3134) 54
whiting 7.2
bentonite 2
cmc 1
of course a lot depends on your clay......
anyway...happy matting to you ,
these are just my own suggestions, I look forward to learning more
about this myself from others further along the road!
sincerely
Stephani stephenson
steph@alchemiestudio.com
Carlsbad CA
Dan Saultman on thu 14 nov 02
I use a cone 04 (1985F) base glaze fired in oxidation that produces a
glossy finish.
I am spraying it on whiteware with an airbrush.
Could someone suggest how I might make this glaze totally matte but
still maintain
good adhesion & fit?
Cone 04 Glossy Glaze
39 grams frit 3134
39 grams frit 3195
2 grams flint
6 grams pioneer kaolin
I add 4g cobalt ox for a dark blue.
I use a "spray on wipe off" technique.
By the way, here is an excellent white opaque glossy glaze that will
even cover over
terracotta.
Cone 04 White Glossy Opaque (oxidation)
10 g talc
39 g frit 3134
39 g frit 3195
8 g EPK (Edgar plastic koalin)
4 g flint
Add 12 g zircopax
Dan Saultman in rainy Detroit.
June Perry on fri 15 nov 02
Dan, by eliminating the silica and upping the EPK to 25, you will lower the
Silica:Alumina ratio down to the 5+ range, but because of the high boron
content you will probably get a more satiny finish.
Another variation to try is. to again, eliminate the silica, lower the EPK to
8 and add 15 Calcined Kaolin. This will lower the Silica:Alumina ratio a bit
more.
Both variations will still keep you within the C04 limits for Silica and
alumina.
Regards,
June Perry
http://www.angelfire.com/art2/shambhalapottery/index.html
Ababi on fri 15 nov 02
Let me first round the numbers:
GLOSSY 04
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 04 1060 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
FRIT 3134 45.00
FRIT 3195 45.00
Flint 2.00
EPK Kaolin 7.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.324 7.62%
CaO 0.672 14.28%
MgO 0.004 0.06%
Al2O3 0.212 8.19%
P2O5 0.000 0.02%
B2O3 0.801 21.14%
SiO2 2.136 48.66%
TiO2 0.001 0.03%
K2O 0.001 0.02%
Na2O 0.323 7.60%
Al:Si 10.07
Expan. 8.28
ST 296.57
The easiest way to change a frit
GLOSSY 04
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Cone 04 1060 deg.C. -
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
FRIT 3124 45.00
FRIT 3195 45.00
Flint 2.00
EPK Kaolin 7.00
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Seger Weight%
KNO 0.314 8.57%
CaO 0.683 16.46%
MgO 0.004 0.06%
Al2O3 0.370 16.19%
P2O5 0.000 0.02%
B2O3 0.722 21.62%
SiO2 1.435 37.06%
TiO2 0.001 0.03%
K2O 0.015 0.60%
Na2O 0.299 7.97%
Al:Si 3.88
Expan. 9.03
ST 317.79
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
Anther way to play with the EPK ( or your kaolin)
10 TESTS
Cone 04 Glossy Glaze
39 grams frit 3134
39 grams frit 3195
2 grams flint
8% 10% 12% 14% 16% 18% ............ grams pioneer kaolin and so on until you are
happy
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 ----------
>Dan wrote:
>" I use a cone 04 (1985F) base glaze fired in oxidation that produces a
> glossy finish.
> I am spraying it on whiteware with an airbrush.
> Could someone suggest how I might make this glaze totally matte but
> still maintain
> good adhesion & fit?
> Cone 04 Glossy Glaze
> 39 grams frit 3134
> 39 grams frit 3195
> 2 grams flint
> 6 grams pioneer kaolin"
>Dan
>This is just off the cuff... so I imagine you will get more specific
>info, but
>thinking of what can matte a glaze I think of the following
>1. cooling cycle: often the difference between a glossy and a matte
>effect with the same glaze is simply the rate at which the kiln cools.
>if you can slow the cooling significantly, this will give crystals the
>opportunity to form. These crystals interfere with the light penetrating
>and bouncing back up through the glaze... so the glaze looks matte.
>These types of matte glazes are often lovely, luminous mattes, rather
>than dry looking mattes.
>this slowing down of the cooling cycle can make a difference whether
>you use an electric or gas kiln.
>2. One thing I notice is that you have a lot of frit 3195, which is a
>pretty hard clear gloss at cone 04....you could try decreasing the 3195,
>ether subbing with another frit with higher melting point or with a
>frostier or more opaque appearance at 04 (3134, 3124, 265,233.....) or
>subbing a higher % of other ingredients, some of which follow...
>3. introduction of 'mottling' or crystal inducing ingredients into the
>glaze: at this temperature this could be zinc oxide or titanium
>dioxide....
>4. In my own layman terms, matting also occurs also when certain
>ingredients precipitate out of the melt and out of solution. Generally
>these are categorized as calcium mattes, (excess calcia or magnesia),
>alumina mattes (excess alumina) or silica mattes (excess silica) . At
>this temperature you might doing a line blend with something like
>whiting, dolomite, (for calcium matte) or EPK (silica/alumina) . Whiting
>in particular might be useful.
>4. you could also raise the melting point of the glaze a bit as well as
>add some matting ingredients by adding something like EPK, Neph Sy.,
>Feldspar, silica, (though sometimes this has the opposite effect), or
>alumina.....or lessening the % of frit in relation to the other
>ingredients.
>5. Barium carb is also useful but due to it's toxicity may not be
>something you want to introduce into the studio or onto the ware.
>of course some of this might mess with the fit of the glaze... but those
>are some possible directions.
>As an example,
>a cloudy satin matte from Chappel , ssg-49
>is
>Neph sy 37.5
>frit (try 3134) 54
>whiting 7.2
>bentonite 2
>cmc 1
>of course a lot depends on your clay......
>anyway...happy matting to you ,
>these are just my own suggestions, I look forward to learning more
>about this myself from others further along the road!
>sincerely
>Stephani stephenson
>steph@alchemiestudio.com
>Carlsbad CA
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