Grace W Posted August 21 Report Share Posted August 21 (edited) Hi there! New in town but not to pottery. I am wondering if anyone has ever used cobalt oxide as a clay colorant? I love the look and have been experimenting with it for a few years now but I am wondering about the safety of throwing with it. I do a .5 - 1% ratio with a white clay body and it creates really beautiful results but wondering if I should be wearing gloves when wedging and throwing (wearing gloves while throwing seems terrible?) I would be open to using a stain or something less caustic if I could get similar results, but I inherited some materials so have just been using what I have. Thanks! Edited August 21 by GraceKW Quote Link to comment Share on other sites More sharing options...
PeterH Posted August 21 Report Share Posted August 21 34 minutes ago, Grace W said: but wondering if I should be wearing gloves when wedging and throwing (wearing gloves while throwing seems terrible?) Hope it doesn't come to that, but related thread. Grace W 1 Quote Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted August 21 Report Share Posted August 21 If you’re concerned, using a stain going forward might be a good idea. Sure wouldn’t hurt, anyways. The cobalt can be used in glazes and is unlikely to go to waste. Grace W, Jeff Longtin and Rae Reich 3 Quote Link to comment Share on other sites More sharing options...
Mark C. Posted August 21 Report Share Posted August 21 There is a lot of folks doing this just google it up Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Grace W Posted August 21 Author Report Share Posted August 21 1 hour ago, Mark C. said: There is a lot of folks doing this just google it up Helpful! I can only find information on adding it to slips and glazes really, which is why I am asking here. Hulk 1 Quote Link to comment Share on other sites More sharing options...
Min Posted August 21 Report Share Posted August 21 Cobalt is a transition (heavy) metal. Adding it to a claybody, working with with bare hands, trimming plus dealing with the dry scraps are all going to expose you to it. There are numerous articles on cobalt toxicity, many are dealing with cobalt in it's metallic form. As potters we are dealing with the oxide and carbonate for the most part, unless you use cobalt salts and that's a whole other issue. Route of entry into the body can be through skin, only very very slighly, broken skin, much higher rates of absorpion, ingestion, not likely, and inhalation. I'm one of those people with skin sensitivities, if you can avoid even getting that from cobalt exposure it would be a plus. We also have to consider total body burden and the "doseage" exposed to. Given there are alternatives that are known to be safer, ie stains, I would use those instead. I found conflicting articles on the toxicity as it pertains to how we are exposed to it. The European Chemical Agency, dated Dec 2023, has this to say about it: https://echa.europa.eu/substance-information/-/substanceinfo/100.013.777 Rae Reich and Grace W 2 Quote Link to comment Share on other sites More sharing options...
PeterH Posted August 21 Report Share Posted August 21 2 hours ago, Grace W said: Helpful! I can only find information on adding it to slips and glazes really, which is why I am asking here. You might start with: HOW TO COLOR CLAY WITH MASON STAINS http://www.ccpottery.com/colored-clay-lessons--chris/how-to-color-clay-with.html Callie Beller Diesel, Bill Kielb and Rae Reich 3 Quote Link to comment Share on other sites More sharing options...
PeterH Posted August 22 Report Share Posted August 22 (edited) 11 hours ago, Grace W said: Helpful! I can only find information on adding it to slips and glazes really, which is why I am asking here. A useful search term is body stain ... which tries to restrict the search to stains that are specifically recommended for use in clay bodies You can tighten the search by adding the name of a major stain manufacturer, such as body stain Mason If you want to restrict the search to this site try community.ceramicartsdaily.org body stain Better yet, if you are using google try site:community.ceramicartsdaily.org body stain ... which is how I found a thread that mentioned Chris Campbell's work. Which I then searched for with Chris Campbell body stain Be aware that some stains have unfortunate colour reactions with some glazes (and possibly some bodies). PS Bold used for emphasis only. Edited August 22 by PeterH Hulk, Callie Beller Diesel and Grace W 3 Quote Link to comment Share on other sites More sharing options...
Grace W Posted August 22 Author Report Share Posted August 22 16 hours ago, Min said: Cobalt is a transition (heavy) metal. Adding it to a claybody, working with with bare hands, trimming plus dealing with the dry scraps are all going to expose you to it. There are numerous articles on cobalt toxicity, many are dealing with cobalt in it's metallic form. As potters we are dealing with the oxide and carbonate for the most part, unless you use cobalt salts and that's a whole other issue. Route of entry into the body can be through skin, only very very slighly, broken skin, much higher rates of absorpion, ingestion, not likely, and inhalation. I'm one of those people with skin sensitivities, if you can avoid even getting that from cobalt exposure it would be a plus. We also have to consider total body burden and the "doseage" exposed to. Given there are alternatives that are known to be safer, ie stains, I would use those instead. I found conflicting articles on the toxicity as it pertains to how we are exposed to it. The European Chemical Agency, dated Dec 2023, has this to say about it: https://echa.europa.eu/substance-information/-/substanceinfo/100.013.777 Thank you so much! Quote Link to comment Share on other sites More sharing options...
Grace W Posted August 22 Author Report Share Posted August 22 20 hours ago, PeterH said: Hope it doesn't come to that, but related thread. I took a class with a woman who threw in gloves, I have tried it before when I have a cut on my hand and it's definitely tricky but I can see getting used to it if I needed to. Quote Link to comment Share on other sites More sharing options...
Mark C. Posted August 22 Report Share Posted August 22 There was woman for years here that does colored claty workshops-Her Name is Chris Campbell if I recall -look up her posts on this subject say 6-10 years ago. Quote Link to comment Share on other sites More sharing options...
PeterH Posted August 22 Report Share Posted August 22 52 minutes ago, Mark C. said: There was woman for years here that does colored claty workshops-Her Name is Chris Campbell if I recall -look up her posts on this subject say 6-10 years ago. Is there anything specific you're thinking of, we've already referenced her colored clay web page. http://www.ccpottery.com/colored-clay-lessons--chris/how-to-color-clay-with.html @Grace W The search function on this site only examines "active" threads. To search the whole site for contributions by Chris Campbell ... for google site:community.ceramicartsdaily.org Chris Campbell for other search engines community.ceramicartsdaily.org Chris Campbell PS Note that Chris just happened to register here as Chris Campbell, most people use shortened forms or pseudonyms. Babs 1 Quote Link to comment Share on other sites More sharing options...
Mark C. Posted August 23 Report Share Posted August 23 Thanks Peter for posting this.Its all been covered well here in the past as you noted Quote Link to comment Share on other sites More sharing options...
Babs Posted August 23 Report Share Posted August 23 On 8/22/2024 at 5:50 AM, Grace W said: Helpful! I can only find information on adding it to slips and glazes really, which is why I am asking here. Google neriage work, Chris Campbell coloured clays http://www.ccpottery.com/ Only consideration that I can see is $$$ when you get hooked on the cobalt and need to buy some more... A body stain would be a lot less expensive. PeterH 1 Quote Link to comment Share on other sites More sharing options...
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