6383 – Cobalt Aluminate
Q. I purcahsed a color in the past or I see a color on the color chart that is not listed, were some colors discontinued?
A. In 2008 Mason changed their color chart to reflect only the most popular colors. Currently there are approximately 92 colors in the color chart and Krueger Pottery Supply keeps them all in stock. Some colors are a blend of two or more colors and in the past Mason had chips of them available as well. If you are looking for a color you don't see check the BLENDED COLOR RECIPE SHEET to find out which stains to purchase to match your favorite stains from the past.
Q. Why do I not get good pinks or crimsons at Cone 06/2/5/10, etc.?
A. Mason’s chrome-tin pink series, #6000 to #6006, are stable from Cone 06 (normal "low" temperature) to Cone 12 (normal "high" temperature). This type of pigment requires the correct glaze chemistry in all temperature ranges, in order to maximize the "color value". High calcium content is most important, and zinc & magnesia must be low to zero. Boron should not be too high. A major complication is that these rules do not necessarily apply when "fast-firing" techniques are used. Second, these pigments need an oxidizing atmosphere throughout the firing cycle.
Q. When I use black stains to make gray shades they turn green/brown/blue/pink, etc. Why are they not simply gray?
A. Do not use black stains to make gray shades by using small amounts in the glaze. Blacks are made of combinations of cobalt, iron, nickel, chromium, manganese, etc., and if low percentages are used the resulting color is often that of the predominant oxide in any particular black pigment. Again, care should be taken to use the correct glaze chemistry to avoid combinations that create color problems. It is better to use the gray pigments that we offer.
Q. Why does my green glaze turn brown or has brown edges?
A. This is usually due to the presence of zinc. Remove any zinc from the formula, because it turns chromium brown in most situations. Additional calcium may help.
Q. Why does my glaze appear "milky"?
A. Too much boron in the frit or glaze formula, under-firing, or the presence of opacifier in amounts greater than 2%.
Q. Why is my purple/lilac/violet glaze turning blue?
A. Some of these pigments are made of chrome-tin pink and cobalt. (See Q. #1). Sufficient calcium is needed to support the "red" side of the mixture.
Q. How do I make a nice red-brown using your regular brown pigments?
A. The base glaze should contain from 3-5% zinc. This supports the red side of the stain.
Q. My blue under-glaze runs, creating a "fuzzy" appearance. How can I prevent this?
A. Cobalt silicate is very soluble in the glaze, so it is better to use cobalt aluminate, or a combination of both. Too high a temperature can also cause this effect.
Q. Can I mix pigments to make my own color palette?
A. Yes, in most instances. However, some stains are incompatible with others, so if you do not achieve the result you want you should phone the Mason laboratory for further information.
Q. Do your pigments contain lead compounds?
A. No. Lead compounds are not used in Mason pigments.
Q. What are "encapsulated" pigments? Are they safe to use?
A. Encapsulation is a special, patented, manufacturing process designed to incorporate certain metallic oxides into the crystals of zirconium oxide. They are also referred to as "inclusion" pigments. They are safe to use, and are now widely used in ceramic manufacture around the world. Obviously, as with all finely dispersed powders, care should be taken to keep operations as dust-free as possible.
Q. Can Mason help me with technical problems, glaze formulas, etc?
A. Yes, most certainly. Mason's technical support staff will offer advice on all ceramic manufacturing problems, and will be happy to supply body , glaze and engobe formulas on request. Obviously, no guarantees or warranties are expressed with such information since all ceramic operations differ in crucial ways, but we will try to help you with your difficult problems. www.masoncolor.com
Q. Where can I find Material Saftey Data Sheets for the products you offer?
A. We now offer all of our MSDSs online for download. You can find them here.
|Pinks and Crimsons|
|Old No.||Al||B||Ca||Cd||Co||Cr||Fe||Mg||Mn||Ni||Pr||Si||Sn||Ti||V||Zn||Zr||Zx||Se||See Ref.|
|Reds & Oranges|
|6030||Mango *Coming Soon!|
|Good Refractory Additives|
|6110||7710||Violet of Iron||X||X||X||X||3,6,7|
|6254||64||Dk. Teal Grn.||X||X||X||X||X||1,3,6,8|
|6790||1390||White for Matting||X||X||3,6|
|6020||Mn Al Pink|
|6069||Fe Zr Coral|
|6268||Cr Co Green|
|6319||Mn Al Co Lavender|
|6434||Fe Zn Yellow|
|6485||Cr Sb Ti Yellow|
Reference Notes From Mason
NOTE FROM MASON: The recommendation made herin are based on our research and the research of others, and are beleived to be accurate. No guarantee of their accuracy is made. The products discussed are sold without warranty, expressed or implied, and upon such condition, purchasers shall make their own tests to determine the suitability of such products for their particular purposes. Likewise, statements concerning the possible use of these products are not intended as recommendations to use these products in infringement of any patent. For safety and handling questions, please refer to your MSDS sheet that is available here or available upon request. The swatches in this guide are as accurately represented as the color printing and screen display process will allow.
LEAD IS NOT USED IN THE MANUFACTURING OF ANY MASON PRODUCTS
REFRENCE NUMBER GUIDE:
1. Can be used as a 'body stain' in porcelain at high temperature. All of the brown colors can be used as 'body stains' but will vary in shade considerably depending on the composition of the body and temperature at which it is fired.
1a. Use obly as a 'body stain'
1b. Do not use as a 'body stain'
Firing Temperatures can only be a rough guide. Firing at 2200 F on a slow schedule may give the equivalent maturing as firing at 2300 F on a fast schedule. The cycle, atmosphere, and rate of cooling will affect the color.
2. Max. firing limit 2156F (1180C)
3. Max. firing limit 2300F (1260C)
4. Max. firing limit 1976F (1080C)
Zinc Oxide influences the color in a glaze more than any other element. Generally, zincless glazes should not contain magnesium oxide. Some colors containing zinc are to be used in a zincless glaze. The zinc in the color is in combined form and will not harm the color, but free zinc oxide in the glaze can destroy the color.
5. Do not use zinc in glaze.
6. May be used with or without zinc
7. Zinc not necessary, but gives better results.
8. Best results with no zinc.
Calcium Oxide content as calcium carbonate should be between 12-15% for best color development. Adding the molecular equivalent of calcium oxide with wollastonite, a natural silicate, often gives better uniformity. The increased silica from the wollastonite must be subtracted ir the glaze will have a poor surface.
9. Glaze must contain 6.7 - 8.4% CaO (12-15% CaCO3)