Wednesday, November 3, 2010

Cone 6 Oxidation results Group 2

Cone 6 Oxidation results Group 2
by Terry Rorison
To see explanation and Group 1 click on the link below:

 47 over 48

47 Floating Blue C/5

Gillespie Borate 0.26

Neph Sye 0.48

EPK 0.06

Flint 0.2

Cobalt Carbonate 0.02

Rutile 0.04

Red Iron Oxide 0.02

48 Oribe type c/5

Standard Ceramic Cone 6 glaze #1125 1

Black Copper Oxide  0.052

Rutile  0.02


52 Raspberry Semigloss C/6

Gillespie Borate 0.21

Neph Syenite 0.16

EPK 0.11

Whiting 0.2

Silica 0.32

Tin Oxide 0.05

Chromium Oxide 0.0075


53 Cranberry C/6

Neph Syenite 0.18

Frit 3134 0.14

Whiting 0.2

OM#4 Ball Clay 0.18

Silica 0.3

Tin Oxide 0.038

Chromium Oxide 0.002


54 Jeannie's Purple Semigloss C/6

Neph Syenite 0.18

Frit 3134 0.14

Whiting 0.2

OM#4 Ball Clay 0.18

Silica 0.3

Chromium Oxide 0.002

Tin Oxide 0.038

Cobalt Carbonate 0.006

55 Goodrich Raspberry C/6

Gillespie Borate 0.21

Neph Syenite 0.16

EPK 0.11

Whiting 0.2

Silica 0.32

Tin Oxide 0.05

Chromium Oxide 0.0015

59 Matt Yellow C/6

Strontium Carb (Toxic) 0.1579

Whiting 0.1053

Zinc Oxide 0.1053

Minspar (f-4) 0.5262

Tenn Ball Clay 0.1053

Rutile 0.03

Nickel Oxide 0.015


63 Speckled Blue Gray C/6

Gillispie Borate 0.2

Custer Spar 0.2

Frit 3110 0.15

Tenn Ball Clay 0.15

Silica 0.3

Cobalt Oxide 0.01

Red Iron Oxide 0.015

Titanium Dioxide 0.05

64 Off White Satin Matt C/6

Barium Carb 0.05

Whiting 0.19

Custer Spar 0.54

EPK 0.16

Silica 0.06

Zinc Oxide 0.09

Rutile 0.05

67 Plum Glaze C/6

Gillespie Borate 0.13

Whiting 0.087

Custer Spar 0.609

EPK 0.087

Silica 0.087

Red Iron Oxide 0.115


71 Waxwing Brown C/6

Frit 3134 0.345

Talc 0.095

OM4 Ball Clay 0.25

Silica 0.31

Red Iron Oxide 0.15

Titanium Dioxide 0.0015

72 Waterfall Brown C/6


Frit 3134 0.335 167.5

Frit 3195 0.26 130

OM4 Ball Clay 0.17 85

Silica 0.235 117.5

Red Iron Oxide 0.125 62.5

Rutile 0.001 0.5

77 Raw Sienna C/6

Frit 3195 0.23

Wollastonite 0.28

Neph Syenite 0.04

EPK 0.28

Silica 0.17

Rutile 0.06

Red Iron Oxide 0.06


86 Zinc Semimatte/Glossy Base Glaze Blue C/6

Neph Syenite 0.36

Wollastonite 0.13

Zinc Oxide 0.1

EPK 0.1

Silica 0.31

Copper Carbonate 0.05

Rutile 0.06

116 Transparent - T5 C/6 Orange

Minspar 0.56

Bentonite 0.02

Dolomite 0.065

Lithium Carb 0.037

Whiting 0.082

Zinc Oxide 0.041

Silica 0.195

Yellow Stain Standard's K83 0.06

Red Stain Standard's #487 Red 0.06


117 Transparent - T8 C/6 Yellow

Minspar 0.373

Bentonite 0.02

Dolomite 0.066

Lithium Carb 0.037

Whiting 0.118

Zinc Oxide 0.041

Silica 0.345

Yellow Stain Standard's K83 0.1


  1. I have been struggling with #53 Cranberry. It comes out grayish w/tints of reds. I have a Skutt 1027 kiln and glaze to cone 6. Every other glaze I have made from recipes works like a champ except tones of reds. We are using a medium dark stoneware. I tried increasing the chrome ox 1/2 again as much to .03% I have been making 500 gram batches and I have a scale that measures down to the 0.1g. Any ideas or help would be greatly appreciated.

    1. It has to be thick enough.

    2. Are you adding enough chrome oxide? The percentages in the recipes above are expressed in decimals. Likely what happened was that the percentages were entered into a spreadsheet and the percentage symbol included; this converted them to decimals. Move the decimal two spaces to the right for all numbers. This will give you, for example, 21% Gillespie borate and 0.15% chrome oxide. This is a much larger amount than you started with if you are only increasing to 0.03%. I think you might have mis-converted the very low number for chrome oxide. Also, when this glaze is thin, it will tend to be white from the tin. I have had success with this on white clay. It turned out darker red than the colour on my monitor, so I'm considering trying again with less chrome.

  2. Darci, rather than increasing the chrome you might try decreasing it slightly. With the other two reds above the ratio of tin to chrome is much higher than #53. I would also try the glaze on a lighter clay body to see if it comes red for you. I fired the three reds above on a white stoneware and a buff stoneware and all three worked well. I just fired another batch of the three today to see what effect a slower cooling rate would have on the glazes. I have a new kiln controller and also have replaced the thermocouple but today the witness cones read cone 6 flat and glossy so I suspect the kiln went to at least cone 7. However, all three reds came out fairly nice. It seems like the cone 6 reds with tin and chrome require a low amount of Chrome to create red so going higher with the chrome won't likely give you what you are looking for. Are you sure you are using frit #3134? Also, have you tried either of the other two reds above?

  3. Does anyone know if Goodrich Raspberry C/6 is a transparent glaze?

    1. I would think so in looking at the formula. It has a little bit of opacifier (tin ox) but try it without the tin and chrome ox and see what you get.

  4. Hello Terry, I have been searching for a green celadon in the cone 6 range. Similar to the celadon cone 10 we had at the Manchester Craftsman's Guild? Do you know of any?

  5. I have been working with oxidation firing and effects. Producing a pale green celadon without reduction is a challenge which I have not yet solved. the pale green reduction celadon is the result of the reduction of red iron oxide. I have gotten red iron green effects but not anything close to a pale celadon. Anyone out there that has produced a pale green at cone 6 in oxidation?