C10R TEST TILES

GROUP 5

****NOTE:   Many raw materials used in ceramics are toxic and one should thoroughly acquaint ones self with these materials and their proper handling and usage.  Some glazes, such as those with high barium and high copper content, or other high concentrations of coloring oxides or other toxic materials  should not be used for items intended for food, or even anything that someone might inadvertently be able to use to cook, store or serve food. Many glazes may be lacking in their base formulation, the minimum amounts of silica and/or alumina to properly hold the oxides in solution, making for a glaze that may be potentially unstable and potentially harmful when  on functional pottery.

Most clay bodies listed on this page were either from Laguna Clay in southern California, or Georgies in Portland, Oregon.

RECIPES

Top row, far left tile is #6054 Glick  Blue on Windsor porcelain. This is a nice buttery gloss, in a deep, quiet blue -- the color of new unbleached denim jeans.  The upper left corner is not a color change. It's just glare from the scanning. The scan is showing it a bit deeper than it is. This base is within C10 copper limits.  The expansion is 7.43

ADD: Rutile 1%, Red Iron 2%, Cobalt Oxide 0.5%

Top row, second tile from the left is # 1163 Carlton Ball Barium Blue Base, my  color G This is definitely not a "food safe" glaze with it's high barium and lithium  content. This would only be suitable for the exterior of boxes or sculptures or other decorative type pieces that would not in any way be used to serve, cook or store food.  You can try versions of this with 1% Cobalt Oxide or 1-4% Copper Carbonate or a combination of both  for some interesting barium  blues.

Color G, ADD: Cobalt Oxide 1%, Rutile 4%                                              

Top row third tile from the left is #3072 June Perry Celadon base. Color B on Danish White Stoneware. Next time I test this glaze I'm going to lower the cobalt to 0.25% and strain it through a 200 mesh screen or ball mill it to avoid the cobalt specking. I might do another version with 2% black iron oxide and 0.25% Cobalt Carbonate.  I was looking to get a hint to blue to the celadon, but it is not quite what I was hoping for. This glaze has a low expansion (6.31). If you need it a bit higher, lower the Grolleg to 15 and the Silica to 28. That would raise the expansion to 6.5 keeping the alumina/silica ratio almost the same. Both versions are within the Insight Software's Version 5 limits for a copper bearing C10 glaze with the exception of the Calcium, which is 0.78 (0.70 is the limit given). If you lower the whiting to 8.5 it brings it to the 0.70 calcium limit.

32.92 Silica

Color B, ADD: Red Iron oxide 1%, cobalt carbonate 0.5%

26.70 Silica

Color E, ADD: Cobalt Carbonate 0.6%, Zinc Oxide 5%

  2.6 Tin Oxide

ADD: 2% Bentonite

Color B, ADD: 6% Rutile

Color A (no tile shown)  ADD:3.2% Rutile, 2% Powdered Illmenite. This is a beautiful light rutile blue on an iron bearing stoneware.

Color C, ADD: Rutile 3%, Copper Carbonate 0.25% Purplish/pink/red on stoneware, Lavender/beige on porcelain.

Color D, ADD: Rutile 1.5%, Copper Carbonate 0.25% for red.

Second row from the top second tile from the left is #7010 Dan's Copper Teal on Tom Coleman porcelain. This is a lovely, rich, transparent teal blue that showed a bit of rolling at a full cone 10. I did not like this glaze on Amador, an iron bearing stoneware. This is definitely not a glaze for functional ware. It is too low in silica and alumina for a C10 copper bearing glaze. Also, the high barium and high copper in such a glaze would probably cause leaching of the copper in the presence of certain foods. I've created a similar base but with much more silica and alumina to bring to C10 copper bearing limits and also, I've made it with a frit to replace the Gerstley which is no longer being mined. See #8303 June Perry's glossy base

  9.0 Barium Carbonate (this may also work if you substitute 6.75 % Strontium Carbonate for the Barium).

Color A, ADD: Copper Carbonate 6.3%, Cobalt carbonate 0.5%

#8303 June Perry's Glossy base (This is within C10 limits for a copper bearing glaze). It is only theoretical and hasn't been tested. I'd appreciate any feedback if you try this base. If using  this glaze on functional ware that is used to serve or store food, try it with the strontium carbonate subbing for the barium carbonate.  Only testing would tell is the barium and/or copper etc. won't leach in the base.  You can try both versions and then make a third by mixing 1/2 of each.  With 1/2 and 1/2 I think the barium would be low enough to be OK in this base; but always have functional glazes tested for leaching of suspect ingredients! A small amount of barium (5-6% or less), in a well balanced glaze should not present problems, but it's always wise to be safe and have glazes tested for leaching.

35.90 Custer Feldspar

20.20 Silica

Color A, ADD: Copper Carbonate 6.3%, Cobalt Carbonate 0.5% Teal (should no use on food without testing because of the high copper content)

Color B, 4 Copper Carbonate, 1 Cobalt Carbonate (I'd still have this one tested as well. I think there's enough silica and alumina and balance to the glaze that it might be OK)

Color D, ADD, Copper oxide 4, Cobalt Oxide 0.5% . Same color as B but bit deeper. 

Color E, ADD, Copper oxide 3.5 , Cobalt Oxide .4%, chrome oxide 0.25%

Second row from the top, third tile from the left is #375 Magnesia Matt  (Transparent blue gloss on a porcelain body at Cone 10)This base would lend itself to other oxides or stains. It has a flawless surface on this clay body. This is a C8-10 glaze and would be matt at C8, but as you can see, at C10 it is a nice gloss. The color was  best at C9. Don't apply this glaze too thickly.  This glaze is a bit low in silica for a C 10 glaze.  I have designed a new magnesia matt,  very similar to this one but within C 10 limits. It's #8304 and I'll list it just below this recipe.

11.1 Silica

ADD: Cobalt carbonate 0.7%, Copper Carbonate 1%.

Color A, ADD: Cobalt Carbonate 0.75, Copper Carbonate 1.2%

Second row from the top, far right tile is #317 Lewis Yellow Matt C 9-10 R on a porcelain body. Very nice matt. The color is the palest celery showing a lovely red orange blush at the edges on the porcelain body. This is definitely not a food safe glaze with all this barium. Save this one for the exterior of boxes or vases, or sculptural pieces. This would be a stronger yellow on an iron bearing body or over an iron engobe. If you want a stronger yellow over a porcelain or white stoneware you might try upping the iron  oxide to 4%.

ADD: Zircopax 18.9%, Red Iron Oxide 3%

Third row from the top, far left tile is #13 Shaner Gold base,  June Perry Color A Very lovely waxy surface. Clay is an iron bearing stoneware. I'm listing the original Shaner Gold which is a beautiful glaze that has a lot of texture, and a rich pumpkin orange with proper reduction. My version A has 6% iron oxide and Rutile (Unfortunately I lost my work sheet, but I believe the Rutile was 4-6%)  I would try the 4% first. The higher  rutile (6%) will give a deeper orange tone to the glaze.  I was attempting to get it to be more of a reddish orange than the original which was more orange.

 6.5 Rutile

Third row from the top, second tile from the left is #1211 Moonlight blue using my Color A variation on an iron bearing stoneware. The original Moonlight blue is a beautiful rutile blue. My color version  A, is  as rich as it looks deep rutile blue and deep red orange -- a beautiful  glaze. I don't think I tested this on a white body. It might be a lovely light rutile blue. 

 1.9 Zinc Oxide

Color A, ADD: 4% Red Iron Oxide, 3.2% Rutile

Third row from the top, third tile from the left is June Perry's  base  #1620 J Color on an iron bearing stoneware. Glaze is actually more gold with an orange tint,  than yellow as shown, with some rutile blue inclusions. With more reduction, you should get more blue on this glaze. This recipe has some soluble ingredients, so only add as much water as you need to make a working glaze. If you add too much water to the glaze, don't pour it off or you'll lose these soluble fluxes. Just let the excess water evaporate before using.   I'm listing some other colors; but there are no pictures for them.  This is within C10 limits, but if you add an extra 7.5 silica to this recipe, it will be within C10 copper bearing glaze limits and it will also have a better expansion on 7.12 and Alumina/Silica ratio is 1 to 6.93.  Without the extra silica the expansion is 7.42 making it a bit more prone to crazing, particularly on a porcelain body; and the alumina/silica ratio is 1 to  6.08

51.71 Custer Feldspar

10.80 Silica

Color J, ADD: Rutile 3.2%, Powdered Illmenite 2%.

Color E, ADD: 3% Rutile, 0.25% Copper Carbonate, 0.25% Cobalt Carbonate Lovely light teal blue on Hopkins White clay body.

Color H, ADD: 2% Black Iron Oxide for rich amber honey.  (it may be different with more reduction). I fired this in an old California kiln without the best reduction. I'd love feedback if you test this with proper reduction.

Third row from the top, far right tile is #1595 Vivika's Porcelain base Color A.  This glaze is also less yellow than shown. The true color is more of a light golden yellow instead of the lemon yellow as copied with my new scanner. See C10R Glaze Group #2 for this base glaze recipe.

Color A, ADD: .91% Red Iron oxide.  (Try one test with .91%Iron and 3.4% Rutile). I made an error in my paper work and show two "A" versions. I'm listing both since I don't know which one is on this tile! I suspect it may be the first one, without the rutile. Both are nice colors either on porcelain or iron bearing bodies.

Bottom row, far left tile is June Perry's textured matt base #2475 Color B on Amador clay body. This glaze has a lot of textured and a buttery matt surface. The horizontal lines are some cobalt oxide and stains test that I ran across the front.  This is a lovely grey color with a hint of blue. This same version on a darker stoneware came out a stronger teal blue tone.

19.32                 19.32  Silica

Color B, ADD: Zinc oxide 3.26, Grey Stain #6319, 2.17%

Color A: ADD: Tin Oxide for White

Color G (no picture) ADD: 0.125% Cobalt Carbonate, 1% Manganese Carbonate, 3% Tin oxide - Lt. grayed powder blue. Up the Cobalt Carbonate to 0.25% -0.5% for more blue color.

Original Tan recipe: ADD: 11.7% Rutile, 2.2% Bentonite

Bottom row, third tile from the left, is  #2514 June Perry Black Oil Spot glaze C10-11 OX on Sasuga Porcelain. This tile was fired to C11  oxidation.

 2 Cobalt oxide

Bottom row, far right tile is #1034 Carlton Ball Chun Base Color A on Calico, a dark stoneware.  This was supposed to be a rutile blue and I wound up getting a lovely  brown on this dark stoneware. I don't think I made a mistake in the color addition. I'd love feedback if someone tries this on another body. This will definitely run at a full C10. It's probably best at C9 or  C10 just starting.  The alumina and silica in this glaze are low for minimum C10 limits. I'm listing a chun base (#8302) that I just created, that is within limits. I'll post it below this recipe.

40.1 Custer Feldspar

  2.5 Tin Oxide

Color A, ADD: 6% Rutile

Color B, ADD: 4% Rutile, 3.5 %Yellow Ochre, 1/4% Ben a gel or 1-2% Macaloid or Bentonite. This is a gorgeous pink/blue/lavender rutile glaze on a white body.

(No tile available) June Perry's Chun Base # 8302. This base is within C10 limits. Since Gerstley Borate is no longer being mined, I'm using a Ferro boron frit to satisfy the boron content. The Expansion ( 6.83) on this glaze is lower than the Carlton Ball base which should make it less prone to crazing.  The alumina/silica ratio on this is 11.22.

21.8 Custer Feldspar

29.60 Silica

ADD: Tin Oxide 2.6%

You can use the colors given in the Carlton ball chun recipe #1034, and #1210  listed above this one. The higher clay will make suspension and application a little easier as well.  I haven't tested this, so any feedback would be greatly appreciated. If it seems too stiff, you can try mixing with 1/2 and 1/2 with one of the other Chuns on this page to find a middle ground. The limits should be OK mixed 1/2 and 1/2 with 1210 but may be a bit low mixed with the #1034.

**** I'd appreciate any feedback on your results with any of these glazes.

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