Cone 6 Reduction Glazes

Préparation du document



Glaze It Forward
by Diana Pancioli
WHY USE CONE 6 REDUCTION?
First of all Cone 6 saves money. Some say it costs less by almost a third compared to
Cone 10. Secondly, it helps preserve the kiln; Cone 6 is much easier on kilns than
Cone 10. Thirdly, less gas used means less carbon emissions produced and a greener
planet for polar bears and humans. Lastly, a reduction atmosphere makes beautiful
glazes, whatever the temperature.
The development of cone 6 Reduction glazes was originally an attempt to insure that
our expensive new gas kiln would last a long time. It has. Extending its life was my
major goal ten years ago; saving fuel and reducing emissions were secondary, until
now.
Having fired cone 10 R for many years, I also thought that it might be fun to add
something to the literature by developing reduction glazes for a lower temperature. After
several years of firing a handful of glazes at 6R, I applied for a summer grant to develop
a better palette. I tested hundreds of glazes—anything I could find that was written for
mid-range. The 22 glazes chosen for Glaze Forward are the product of that summer!s
research. (Thank you Eastern Michigan University.)
My first goal was to lower the temperature of traditional Cone 10R glazes-- celadon,
temmoku, iron saturate, shino, copper red, etc. I revised some favorite formulae to the
new lower temperature. The remainder were selected from many tests; I hoped to
provide a range of colors, surfaces, and bases that would satisfy many tastes and
encourage experimentation by others.
I have provided a list of the sources of these glazes. You will recognize some of them
from cone 10. I renamed all the glazes according to their surface qualities so that (a)
they would not be mistaken for their cone 10 versions and (b) their names would give
my students a clue about each glaze!s color and appearance.
I sent some glazes to the Alfred Analytical Testing Laboratory for leach testing. The
results are reported in the notes at the bottom of each glaze page. Some testing still
needs to be done.
John Hesselberth has been generous in allowing me to use a version of his software
“GlazeMaster” to present the glaze recipes, their photos, and their chemical analyses
for you. (Thank you John.)
Diana Pancioli
Glaze Forward
January, 2009
Recipe Name
Ingredients
Cone
Firing
Cornwall Stone
Whiting
Feldspar--Custer
Feldspar--Kona F4
Barium Carbonate
Dolomite
Add
6
Green Gloss
Reduction
Test Sample IDs
Ball Clay--Old Mine #4
Silica
Surface
% or
Amt.
38.0
14.0
11.0
10.0
11.0
3.0
5.0
8.0
Totals 100.0
Glossy
Recipe Set
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Al 2 O 3
B 2 O 3
Fe 2 O 3
Color
True Green
Pancioli ^6 Reduction
Unity
0.125
0.102
0.053
0.544
0.176
0.227
1.000
0.351
0.003
Weight
%
2.75
3.43
0.76
10.85
9.63
6.17
27.42
12.74
0.18
Date Created
5/1/2008
Mole
%
3.01
2.47
1.29
13.14
4.26
5.48
24.16
8.49
0.08
Date Printed
12/20/2008
SiO 2
TiO 2
2.776
0.003
59.34
0.10
67.08
0.08
P 2 O 5
0.004
0.21
0.10
Glaze Photo
Si:Al
Exp Coeff
Comments
L.O.I.
Derived from Cone 10 “Dimig Green”
7.90
79.82
11.28
Recipe Cost, $ / lb
0.91
This beautiful glossy green stays green unless the reduction is too heavy. Sometimes a pink blush will highlight
one side of the piece. This glaze crazes. (Probably more flint will fix it). It is a stronger green with 5% copper but
also leaches more. Becasue of the high copper content and the barium it is not useful as a liner. Strontium
substitution for the barium doesn’t work. It helps fix the crazing but the color changes to a muddy pink.
At 4% copper carbonate it leached 23.2 mg/l copper
At 5% it leached 43.1 mg/l copper and 14.2 barium. Thin to medium application
Recipe Name
Ingredients
Cone
Firing
Feldspar--Custer
Whiting
Talc
Frit--Ferro 3134
Kaolin--EPK
Silica
Add
Cobalt Carbonate
Copper Carbonate
Titanium Dioxide
Bentonite
6
Denim Blue
Reduction
Test Sample IDs
Surface
% or
Amt.
40.0
16.0
9.0
9.0
10.0
16.0
Totals 100.0
1.2
1.2
2.0
2.0
Semiglossy
Recipe Set
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Al 2 O 3
B 2 O 3
Fe 2 O 3
SiO 2
TiO 2
P 2 O 5
Color
medium blue
Pancioli ^6 Reduction
Unity
0.099
0.123
0.194
0.584
0.222
1.000
0.297
0.085
0.003
2.715
0.001
0.000
Weight
%
2.39
4.48
3.03
12.68
6.87
22.58
11.72
2.29
0.19
63.16
0.03
0.01
Date Created
5/2/2008
Mole
%
2.43
3.00
4.73
14.23
5.42
24.38
7.24
2.07
0.07
66.20
0.03
0.01
Date Printed
12/20/2008
Glaze Photo
Si:Al 9.15
Exp Coeff 74.11
Comments
L.O.I. 9.17
Recipe Cost, $ / lb
0.90
This is a Val Cushing glaze; the master has done it again. This glaze is probably stable enough to pass a leach
test, which means you can use it at these colorant levels on the interiors of vessels for food use.
Leach test results not yet completed.
Thin to medium application
Recipe Name
Ingredients
Cone
Firing
Feldspar--Kona F4
Barium Carbonate
Dolomite
Frit--Ferro 3110
Kaolin--EPK
Silica
Add
Bentonite
Zircopax
Iron Oxide--Red
6
Cold Yellow
Reduction
Test Sample IDs
Surface
% or
Amt.
34.0
20.0
16.0
10.0
8.0
12.0
Totals 100.0
2.0
10.0
2.0
Semiglossy
Recipe Set
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Al 2 O 3
B 2 O 3
Fe 2 O 3
SiO 2
TiO 2
P 2 O 5
Color
yellow
Pancioli ^6 Reduction
Unity
0.166
0.053
0.219
0.294
0.267
0.220
1.000
0.263
0.010
0.002
2.004
0.001
0.000
Weight
%
4.47
2.19
3.83
7.18
17.85
6.66
35.52
11.65
0.30
0.16
52.31
0.03
0.01
Date Created
5/1/2008
Mole
%
5.06
1.63
6.66
8.98
8.15
6.69
30.49
8.01
0.30
0.07
61.09
0.02
0.01
Date Printed
12/20/2008
Glaze Photo
Si:Al
Exp Coeff
Comments
L.O.I.
Derived from Cone 10 “Alfred Yellow”
7.62
85.18
12.99
Recipe Cost, $ / lb
0.98
This cold yellow glaze goes to pale blue where thick and warm brown where thin. Strontium does not work as a
substitute for barium in this glaze. The yellow color is completely lost with strontium.
This is not a liner glaze. It leaches barium at 7.25 mg/l.
Thin to medium application.
Recipe Name
Ingredients
Cone
Firing
Feldspar--Kona F4
Whiting
Frit--Ferro 3134
6
Dark Satin
Reduction
Test Sample IDs
Ball Clay--Old Mine #4
Kaolin--EPK
Flint
Add
Iron Oxide--Red
Cobalt Carbonate
Bentonite
Surface
% or
Amt.
48.0
16.0
6.0
12.0
7.0
11.0
Totals 100.0
5.0
3.0
2.0
Semiglossy
Recipe Set
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Al 2 O 3
B 2 O 3
Fe 2 O 3
SiO 2
TiO 2
P 2 O 5
Color
Pancioli ^6 Reduction
Unity
0.219
0.089
0.008
0.684
0.308
1.000
0.516
0.068
0.005
3.135
0.007
0.000
Weight
%
4.41
2.73
0.11
12.47
7.14
19.71
17.09
1.54
0.24
61.22
0.18
0.01
teal, green, black
Date Created
5/3/2008
Mole
%
4.63
1.88
0.17
14.45
6.51
21.14
10.90
1.44
0.10
66.27
0.15
0.00
Date Printed
12/20/2008
Glaze Photo
Si:Al
Exp Coeff
Comments
L.O.I.
Derived from E. Cooper’s “Matt Iron”
6.08
77.82
10.06
Recipe Cost, $ / lb
1.00
A textured satin with variegated color. The attractive teal/green/black color mix will change to a smooth satin
black with more dark colorants but may also then be in danger of leaching. A dark glaze should contain no more
than 2 to 3 percent cobalt if it is to be used as a liner. This glaze is more colorful on an iron-bearing clay body.
At 6% cobalt (twice as much as the recipe calls for) it leached 0.1 mg/l of cobalt.
Thin to medium application.
Recipe Name
Ingredients
Cone
Firing
Nepheline Syenite
Whiting
Talc
Frit--Ferro 3110
6
Satin Celadon
Reduction
Test Sample IDs
Ball Clay--Old Mine #4
Silica
Add
Iron Oxide--Red
Bentonite
Surface
% or
Amt.
34.0
20.0
5.0
2.0
19.0
20.0
Totals 100.0
1.5
2.0
Semiglossy
Recipe Set
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Al 2 O 3
B 2 O 3
Fe 2 O 3
SiO 2
TiO 2
P 2 O 5
Color
Celery
Pancioli ^6 Reduction
Unity
0.181
0.058
0.124
0.638
0.238
1.000
0.394
0.002
0.005
2.775
0.009
Weight
%
4.21
2.04
1.88
13.44
6.25
21.57
15.12
0.06
0.31
62.66
0.26
Date Created
5/2/2008
Mole
%
4.31
1.38
2.97
15.24
5.69
23.89
9.43
0.05
0.12
66.30
0.21
Date Printed
12/20/2008
Glaze Photo
Si:Al
Exp Coeff
Comments
L.O.I.
Derived from E. Cooper’s “Clear Pale Olive”
7.03
75.65
11.77
Recipe Cost, $ / lb
0.26
A lovely satin celadon (more celery colored, not blue). The addition of more silica will make it shinier and move
toward correcting the crazing (which is only visible if you stain it). But I don’t like the glaze as well with the silica
addition. I added a little frit to give it a slight sheen.
This glaze settled out more than the others despite the addition of bentonite so I added a small amount of
Epsom salts to keep it in suspension
Not as nice on porcelain.
Recipe Name
Ingredients
Cone
Firing
Nepheline Syenite
Frit--Ferro 3134
Talc
Whiting
Kaolin--EPK
Silica
6
Textured Blue
Reduction
Test Sample IDs
Surface
Semiglossy
Recipe Set
Color
Curdled blues
Pancioli ^6 Reduction
Date Created
5/2/2008
Date Printed
12/20/2008
Al 2 O 3 0.276 12.89 7.85
Totals 100.0 B 2 O 3 0.156 4.99 4.45
Add
Fe 2 O 3 0.002 0.17 0.06
Zircopax
10.0
Rutile
3.0 SiO 2 2.074 57.15 59.09
Cobalt Carbonate
0.5 TiO 2 0.001 0.04 0.03
Copper Carbonate
1.0 P 2 O 5 0.000 0.02 0.01
Glaze Photo
Bentonite
2.0
Si:Al 7.53
Exp Coeff 75.59
Comments
L.O.I. 7.47
Recipe Cost, $ / lb
0.88
This is Marcia Selsor’s Waxy White base with a number of colorants added. This variation is derived from a 50/50
color blend with rutile incorporated in the base for texture. There are other nice combinations with rutile but this
one remains a favorite. Gloes glossy on interiors and breaks beautifully over textures.
Medium application.
% or
Amt.
30.0
20.0
17.0
10.0
13.0
10.0
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Unity
0.192
0.036
0.302
0.470
0.228
1.000
Weight
%
5.47
1.55
5.59
12.09
7.02
24.70
Mole
%
5.48
1.02
8.61
13.39
6.50
28.50
Recipe Name
Ingredients
Cone
Firing
Feldspar--Kona F4
Whiting
Dolomite
Zinc Oxide
Frit--Ferro 3134
Silica
Add
Bentonite
6
Chun or Jun
Reduction
Test Sample IDs
Surface
% or
Amt.
34.0
10.0
6.0
3.0
17.0
30.0
Totals 100.0
2.0
Semiglossy
Recipe Set
Li 2 O
Na 2 O
K 2 O
MgO
CaO
SrO
BaO
ZnO
PbO
Subtotal
Alkalis
Total
Fluxes
Al 2 O 3
B 2 O 3
Fe 2 O 3
SiO 2
TiO 2
Color
Pancioli ^6 Reduction
Unity
0.186
0.049
0.089
0.572
0.104
0.235
1.000
0.186
0.159
0.001
2.843
Weight
%
4.42
1.76
1.37
12.28
3.23
6.19
23.07
7.26
4.23
0.07
65.36
Bright textured white
Date Created
5/2/2008
Mole
%
4.45
1.17
2.12
13.65
2.48
5.62
23.87
4.44
3.79
0.03
67.87
Date Printed
12/20/2008
P 2 O 5
Si:Al
Exp Coeff
Comments
L.O.I.
MarciaSelsor’s “Jun”, unchanged.
15.28
73.37
7.23
Glaze Photo
Recipe Cost, $ / lb
0.59
This is a beautiful bright marshmellow-like white textured semi-gloss. I tried adjusting this formula but it didn’t
come out as well as the original. (You might want to try to take out the zinc.) The difficulty is that to make this
glaze more stable one has to destroy an important quality--its ability to run and hold itself in beautiful fat drips.
(Don’t use near the foot.)
I accept that it might not last as long with the dishwasher use (although after 3 years of use I can’t see any
changes). Application depends on where you want the glaze to form drips. (It is good lightly tinted too, with small
amounts of iron or nickel.)