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Norm Stuart

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  1. Dropping the 3% lithium carbonate raises the COE from 7.65 to 7.66, an insignificant change. My best guess is leaving out the Lithium Carbonate should produce virtually the same identical glaze. Adding barium carbonate would provide no advantage I'm aware of and could possibly cloud the clear glaze. Without the lithium, this clear glaze might react somewhat differently with colorants, but probably not. Frankly I don't understand why 3% lithium carbonate was added to this recipe. The addition of the 5% zinc oxide is making this clear glaze into something of a zinc semi-matte.
  2. It could be that too much lead has evaporated from these ^6 glazes if you fire too slowly. I found a ceramics journal from 1904 which quantifies the percentage of the lead in a glaze, fired in a sagger, which vaporized per hour. Journal of the Society of Chemical Industry, Volume 23 - Society of Chemical Industry (Great Britain) 1904 http://books.google.com/books?id=lkLOAAAAMAAJ&pg=PA470&dq=kiln+firing+%22lead+glaze%22+loss+per+hour&hl=en&sa=X&ei=qhTnUpKpAYPvoASxlIGoCw&ved=0CDsQ6AEwAA#v=onepage&q=kiln%20firing%20%22lead%20glaze%22%20loss%20per%20hour&
  3. Metallic Rain, which I have not tried, is similar in chemistry to Spectrum Metallic Mirror and Amaco Palladium. Amaco says their leaded Palladium is not dinnerware safe, but Spectrum says leaded Metallic Mirror is food-safe based on the glassy non-leeching finish of the glaze "Contains some heavy metals and/or cadmium compounds but passes test for lead and cadmium release.". You need a small amount of lead to create this type of look. But they don't use enough lead to make these glazes reliable. I think you'd be far happier with a standard ^05 lead-manganese glaze like these s
  4. That's the amazing thing about ceramics. Humans have been doing this for so long, like Chris Campbell asked - is anything original? I actually emailed with Jon Singer three years ago about his results with rare earth colorants like Europeum when I was try to develop a different path to pink. At the time I thought I understood a lot of the rare earths fluoresced under black light. But it looks like it's probably a lot of the same materials to create photo luminescence where the element absorbs light then gives it off over time as the excited electrons drop back into their lower orbitals (
  5. The missing ingredient I left out is water - with 100 grams of course easily measured out as 100 ml. We use clear squeeze bottles from a restaurant supply store. This is the actual mixing procedure. 475 $4.43 100.0% Color Bottles - per bottle 100 $0.00 22.2% Water 50 $4.17 11.1% Mason Stain ($8.48 to $37.50) $4.17 average cost per bottle Pour above into bottle and shake 100 $0.17 22.2% Gerstley Borate 200 $0.00 44.4% Water 25 $0.09 5.6% Zircopax (not for Black, Grey or Taupe - but this caution has been ignored and
  6. We make mason stain color bottles with 2/3 water and 22% gerstley borate, mixed and sieved. To this we add 11.1% mason stain plus 5.6% zircopax for colors other than blacks or greys. The zircopax essentially gives us a white canvas to pain the bright colors on, rather than making red into a pink. Everyone at our studio much prefers this mix to under-glazes as they never blister or change color. The clay-like properties of gerstley borate also prevent the stain from bleeding into the bisque beyond where you apply it, just as John Baymore mentions adding PVA (white glue) to achieve the s
  7. I think a lot of commercial ware has to be made using Metal Vapor Deposition in a vacuum like Canadian artist Trudy Golley outlines in her article. Thanks so much for sharing this. It seems obvious in retrospect. It's how mylar is aluminized for tinsel and emergency blankets. Hardly a surprise that Golley learned how to do this in the ceramic village of Jingdezhen. I'm beginning to find that village annoying - what haven't they perfected there? Am I going to have to move there to satisfy my vexation end envy? Titanium and Chrome are certainly less expensive and more durable th
  8. I mix the cobalt oxide with gerstley borate, which also typically eliminates the need for adding the PVA (Elmers white) glue. If you can think of a use for it you can also make a cobalt tape which is flexible and can be cut with scissors or hole punches then applied. Cobalt tape uses 24 grams of PVA (polyvinyl acetate) glue (Elmers White) with 30 grams of Glycerin. You can mix this with up to 70 grams of dry material like cobalt oxide, gerstley borate or boric acid, or frit or clay. Once it's "dry", it a flexible plastic-like wrap. Attach it the the bisque by wetting the back side an
  9. I prefer using 40% less dark blue cobalt oxide which looks closer to how it will fire, with the added advantage of not having to fire off the carbon dioxide.
  10. If the heating elements are fine, then one or more of the relays needs to be replaced.
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