glazenerd Posted February 5, 2016 Author Report Share Posted February 5, 2016 Interesting Tyler: Still puzzled as to why, when I mix it with straight colorants like cobalt, copper, nickel, iron, and even rare earth oxides there is little effect other than color intensification. It is only when TiO2 is added in higher quantities that the above extreme reactions occur. Puzzles me. Nerd Link to comment Share on other sites More sharing options...
Magnolia Mud Researdh Posted February 5, 2016 Report Share Posted February 5, 2016 After doing a series of test, I have concluded that CaS reacts strongly with TiO2 (titanium dioxide).. [snip].. with 1% CaS addition. Note: Cadmium is highly toxic and should not be handled unless full safety precautions are observed. Ok... The Cement industry defines CaS as Calcium Silicate. An inorganic chemist defines CaS as calcium sulfide. What is your definition of CaS? You mentioned that cadmium is a hazardous material. Cadmium is uses the Cd as its symbol. Your description of the glaze does not indicate that cadmium was used as an ingredient. What's going on here? LT Link to comment Share on other sites More sharing options...
glazenerd Posted February 5, 2016 Author Report Share Posted February 5, 2016 What is going on? A typo.... corrected to CdS Cadmium sulfide.. sorry about that. Nerd Cadmium sulfide is a hazardous material; full safety measures should be observed. Link to comment Share on other sites More sharing options...
Tyler Miller Posted February 5, 2016 Report Share Posted February 5, 2016 I suspect an increase in crystal nucleation sites caused by the increase in titania would be at least part the reason, but that's a guess. The green is definitely coming from a reaction between Cd and Zn. Link to comment Share on other sites More sharing options...
Benzine Posted February 5, 2016 Report Share Posted February 5, 2016 I keep trying to follow this topic, but then I start reading all the chemical jargon/ formulas, and my nose starts bleeding... Link to comment Share on other sites More sharing options...
High Bridge Pottery Posted February 5, 2016 Report Share Posted February 5, 2016 It is strange that zinc/cad makes green but it doesn't without titanium. I started reading a few glass colouring articles but all they say about cadmium is that it's toxic and not much elaboration on that. Link to comment Share on other sites More sharing options...
Tyler Miller Posted February 5, 2016 Report Share Posted February 5, 2016 I think there's a piece of the puzzle yet to fall into place. But I think it's one of those things best left a mystery. The other tiles posted which included cadmium, in glazenerd's gallery show a muddy greenish yellow as well. Given that it's so toxic, and that crystalline glazes are so leachable, I think it's a wise conclusion to say that CdS and the resulting ZnCdS are unsuitable additives and colorants. There are other, less toxic ways to get green. Link to comment Share on other sites More sharing options...
glazenerd Posted February 5, 2016 Author Report Share Posted February 5, 2016 I can assure you that the Cadmium is only for my own experimentation: not one piece will ever leave the shop. I have the safety equipment to deal with it, would not advise anyone to use it unless they fully understand and are equipped to do so. The experiments have nothing to do with colorants, as Tyler stated easy to get greens from safe sources. What I am looking for is enhancers, chemicals that will promote crystal growth and control population. Going to run a few more tests to check a few things: then the remaining CdS will be mixed with some frit and solidified. Then I will play with some Selenium for awhile, then some carbides and perhaps some zirco. I enjoy the experiments more than I do making tiles. Have long felt that something is being overlooked in crystalline glaze; will keep looking until I find it. Ytrrium is also in the same classification as Titanium, will look at that as well. Nerd Joel: what is even stranger is that both the test tiles have the same colorants. I would expect the Cadmium to alter or deepen the color; but to change it entirely? I think people forget in my earlier post the cadmium was rendered into a paste- so at this point there is no air borne dust. "The Dictionary of Glass," by Charles Bray A&C Black, London : "cadmium is used to produce brilliant yellows in glass." It is also used in conjunction with selenium to produce ruby reds. Link to comment Share on other sites More sharing options...
Tyler Miller Posted February 6, 2016 Report Share Posted February 6, 2016 Glad to know it's for experimentation only. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted February 6, 2016 Report Share Posted February 6, 2016 GlazeNerd, FYI........ http://community.ceramicartsdaily.org/topic/5586-seeding-glaze-with-small-crystals/?p=51606 best, ...................john Link to comment Share on other sites More sharing options...
glazenerd Posted February 7, 2016 Author Report Share Posted February 7, 2016 John: As you always state: " it depends." My philosophy " all of the above." Until testing disproves otherwise- will try this as well. Nerd Tyler: I have zero interest in exposing others to possible harm. Link to comment Share on other sites More sharing options...
Guest JBaymore Posted February 7, 2016 Report Share Posted February 7, 2016 John: As you always state: " it depends." My philosophy " all of the above." Until testing disproves otherwise- will try this as well. Nerd Tyler: I have zero interest in exposing others to possible harm. Nerd (hate to write that! ), I watched Charles do it all the time. So it works. Sometimes. Thought you'd maybe be interested. best, .......................john Link to comment Share on other sites More sharing options...
Tyler Miller Posted February 7, 2016 Report Share Posted February 7, 2016 glazenerd, I think I gave the wrong impression. Didn't mean to imply you'd knowingly use a toxic ingredient in a careless way. Sorry for my poor choice of words. -Tyler Link to comment Share on other sites More sharing options...
glazenerd Posted February 7, 2016 Author Report Share Posted February 7, 2016 John: My supplier in St.Louis assigned the GlazeNerd nickname. He went so far as having company T-shirts made with the Glaze Nerd name tag. You will find me immediately at KC, bright red T-Shirt with "GlazeNerd." Like I told him, after 42 years in the construction business, and being called every name in the book: Nerd is a cakewalk. Tyler-- we're good. Nerd Link to comment Share on other sites More sharing options...
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