Cone 6 Oxidation results Group 1

Cone 6 Oxidation Results Group 1

by Terry Rorison

Since I have made the decision to concentrate on firing at Cone 6 oxidation rather than Cone 10 reduction, I have begun glaze tests to build a palette of colors and finishes to choose when glazing pieces.  I also have the desire to produce the variation in the glazes that is similar to the effects  of reduction on the glazes while retaining the brightness that is possible in oxidation firing.  

Thus far I have batched between 80-100 different glazes, the formulas for which have been found from publicly available sources.  After firing these tests in an electric kiln to Cone 6, I have photographed each and am making them available to potters with the accompanying formulas.

Since this is my second attempt to post this (having lost hours of work due to some glitch in Blogspot), I am breaking the postings down into smaller groups to minimize risk if a posting gets lost or deleted.  I will make a more detail explanation of my methodology at a later time.  All tiles were photographed with a Nikon D60 in a light tent with two outside lights and flash.  Each photo was cropped but otherwise not altered by software.  

As always, comments and input are desired and welcome.  The results are posted in a random fashion and this first batch was fired in a programmable kiln with a two hour pre-heat at 200 degrees and a program that ramped up the temperature to Cone 6 with the kiln being shut off and cooled normally.  I will produce a set later with a slower cool down rate to promote crystal grow.

Formulas are shown in decimal format with 0.1 being equivalent to 10%.  Two clay bodies were used and glazes were fired on each.  The fit and visual difference produced by the two different bodies was very slight.  A white stoneware from Standard Ceramic #181 was used and a studio mixed stoneware body that is an adaptation of Val Cushing's Cone 10 Wheel Wiz.  The stoneware has low iron and fires out to a buff color at Cone 6 oxidation.

Tip:  Click on each photo to enlarge.  Then click again to enlarge some more.  There is a lot of detail to be seen.

2

2	Jen's Juicy Fruit Variation (Red Matte) C/6             Totals 100%
	EPK	8
	Gillespie borate	7.2
	Nepheline syenite	39.2
	Flint	9.6
	Whiting	8.8
	Lithium carbonate	7.2
	Standard Ceramic's Red Stain	8.0
	Soda ash	8.0
	Titanium dioxide	4.0

4

4 Tomato Red #13 C/6 Frit 3134 0.108 Nepheline syenite 0.231 Bone ash 0.1 Magnesium carb 0.062 Whiting 0.077 EPK 0.21 Flint 0.212 Bentonite 0.02 Red Iron Oxide 0.1
5 5 Tomato Red #13 Pumpkin Orange C/6 Frit 3134 0.108 Nepheline syenite 0.231 Bone ash 0.1 Magnesium carb 0.062 Whiting 0.077 EPK 0.21 Flint 0.212 Bentonite 0.02 Red Iron Oxide 0.1 Rutle 0.02  6 6 Tomato Red #13 with spodumene C/6 Frit 3134 0.11 Spodumene 0.112 Bone ash 0.079 Magnesium carb 0.063 Whiting 0.079 EPK 0.216 Flint 0.217 Neph Syenite 0.118 Bentonite 0.02 Red Iron Oxide 0.1  8 8 Jen's Juicy Fruit Variation (Red Matte) Cone 6      Totals 100% EPK 8.26 Gillespie borate 7.44 Nepheline syenite 40.5 Flint 9.92 Whiting 9.09 Lithium carbonate 7.44 Soda ash  8.26 Titanium dioxide 4.13 Black Iron Oxide 4.96
12   12 Jen's Juicy Fruit Variation Whiting C/6 EPK 0.09 Gillespie borate 0.1 Nepheline syenite 0.5 Flint 0.07 Wollastonite 0.15 Lithium carbonate 0.09 Soda ash  0.1 Titanium dioxide 0.05 Black iron oxide 0.06
17 17 Randy's Red C 5/6 Flint 0.3 EPK 0.05 G200 0.2 Talc 0.15 Gillespie Borate 0.3 Red Iron Oxide 0.15
18 18 Jade Green C 5/6 G200 0.381 Barium Carbonate 0.19 EPK 0.096 Flint 0.095 Gillespie Borate 0.095 Zinc Oxide 0.094 Copper Carbonate 0.049
21 21 Emily's Satin Matt C/6 Kona F-4 Spar 0.52 Whiting 0.19 EPK 0.14 Zinc Oxide 0.09 Flint 0.06 Copper Carbonate 0.06
36 36 Blue Green cone 6  Gillespie Borate  0.22 Strontium Carbonate  0.04 Whiting 0.11 Custer Feldspar  0.38 Flint 0.25 Cobalt Carbonate  0.005 Chrome Oxide  0.01 Bentonite 0.02

39

39	Clear Base Blue C/6
	Feldspar G-200	0.2
	Frit 3134	0.1
	Wollastonite	0.2
	Flint	0.185
	EPK	0.2
	Talc	0.115
	Cobalt Carbonate	0.01
	Copper Carbonate	0.0075
	Red Iron Oxide	0.03
	Rutile	0.06

 43

43	Kaki with Gillespie Borate C/6
	Gillespie Borate	0.27
	Flint	0.253
	Custer Spar	0.169
	Talc	0.118
	EPK	0.042
	Red Iron Oxide	0.128
	Bentonite	0.02

Red Rust Bottle

Red Rust Bottle - # 147 Rusty Bronze cone 6 over all of it,  with #55 Raspberry Red over top part to middle, #140 Hansen White over the neck to line at bottom of neck all cone 6 oxidation.  Red shows as a nice blush on the surface.  Glazes were applied by dipping with no special treatment.