allenc27 Posted June 25, 2020 Report Share Posted June 25, 2020 Hi, I recently come across with flambe Jeff's red, it contains 4.4 barium. I've heard barium and copper may cause some toxicity issue for functional ware. Can anyone confirm and how much of barium is safe? Is Jeff's red not recommended for functional ware? Custer feldspar 41.9 Whiting 8.4 Silica 26.2 Gerstley borate 8.7 Dolomite 8.7 Barium carbonate 4.4 Zinc oxide 1.7 Tin 2.6 Copper carbonate 0.5 Bentonite 1 Thanks Link to comment Share on other sites More sharing options...
Bill Kielb Posted June 25, 2020 Report Share Posted June 25, 2020 33 minutes ago, allenc27 said: Hi, I recently come across with flambe Jeff's red, it contains 4.4 barium. I've heard barium and copper may cause some toxicity issue for functional ware. Can anyone confirm and how much of barium is safe? Is Jeff's red not recommended for functional ware? Custer feldspar 41.9 Whiting 8.4 Silica 26.2 Gerstley borate 8.7 Dolomite 8.7 Barium carbonate 4.4 Zinc oxide 1.7 Tin 2.6 Copper carbonate 0.5 Bentonite 1 Thanks Most potters don’t use things like lead, vanadium pentoxide, barium .... because the possibility exists that it can be toxic. Without testing every piece that goes out the door or on the table from dishwashing to a wide variety of foods most potters just don’t use those glaze components out of an abundance of caution. Some can be toxic in handling and firing as well so there is that. Link to comment Share on other sites More sharing options...
Leaman Pottery Posted June 30, 2020 Report Share Posted June 30, 2020 There was once a rule that anything recipe less than 5% barium carbonate was safe. Is that no longer true? Link to comment Share on other sites More sharing options...
Bill Kielb Posted June 30, 2020 Report Share Posted June 30, 2020 Not sure where that rule would originate or the basis for it since testing over the lifespan of the product would be the only way to confirm with 100% certainty. Again, out of an abundance of caution, many if not most don’t even have in there store of glaze materials. Link to comment Share on other sites More sharing options...
CactusPots Posted June 30, 2020 Report Share Posted June 30, 2020 My understanding of the source of the evidence of barium's toxicity was a kibbutz in Israel that substituted barium for baking soda. There has to be an acceptable level of toleration, otherwise we fall into the "no measurable level" camp. Science is really good as measuring things like lead in drinking water and there is in fact measurable lead in your water. I doubt a spoon full of red iron oxide would be any good for you. I don't get the idea of not having barium in your store of glaze ingredients. As for exposing users to it, that's what liner glazes are for, right? As for it being a risk to the potter, it's your choice, but it doesn't seem to me like much of a risk as choices in life go. I question the idea that most potters don't use barium at all. Link to comment Share on other sites More sharing options...
liambesaw Posted June 30, 2020 Report Share Posted June 30, 2020 Here's why barium is not recommended. If barium is fired without carbon monoxide, it doesn't enter the glaze melt. Instead it acts as an opacifier and stays outside of the melt. When it is underfired or fired in oxidation, it leaches barium oxide which is... That's right! Toxic! And most barium glazes are oxidation cone 6 glazes that use the barium as a refractory/matting agent or opacifier. Which is exactly the wrong application. It's one of those ingredients that when properly used by industry, are invaluable. But when left to the hands of hobbyists and craftsmen, it's better to avoid it altogether. Same with lead oxides. Lead is still used by the dinnerware industry in their glazes, but it's engineered to be done safely. I don't see anyone recommending people use lead in their glazes because it can be done safely, so why barium? How about cadmium, is there an acceptable limit to that? Vanadium? Uranium? Yes there are! But not for everyone. Link to comment Share on other sites More sharing options...
Mark C. Posted June 30, 2020 Report Share Posted June 30, 2020 I have one barium glaze in a cone 10 glaze-I use it on the surfaces that do not contact the food--I do not out it on the inside of saya mug are the lip either-just the part you see on the outside not where you use the liquid or food. Link to comment Share on other sites More sharing options...
liambesaw Posted June 30, 2020 Report Share Posted June 30, 2020 32 minutes ago, Mark C. said: I have one barium glaze in a cone 10 glaze-I use it on the surfaces that do not contact the food--I do not out it on the inside of saya mug are the lip either-just the part you see on the outside not where you use the liquid or food. Cone 10 reduction is also exactly where barium would be functional. What is the barium used for in the glaze? Link to comment Share on other sites More sharing options...
Mark C. Posted July 1, 2020 Report Share Posted July 1, 2020 Its the usual robin egg blue (turquoise) color that crows swoop in to pick up. Link to comment Share on other sites More sharing options...
liambesaw Posted July 1, 2020 Report Share Posted July 1, 2020 Ahh. If it's for coloration I usually just do the strontium swap Link to comment Share on other sites More sharing options...
Benzine Posted July 1, 2020 Report Share Posted July 1, 2020 17 hours ago, liambesaw said: How about cadmium, is there an acceptable limit to that? Vanadium? Uranium? Yes there are! But not for everyone. Now you tell me! What am I going to do with all this surplus Uranium I have sitting around?! Link to comment Share on other sites More sharing options...
Mark C. Posted July 1, 2020 Report Share Posted July 1, 2020 (Ahh. If it's for coloration I usually just do the strontium swap) I tested the swap and it wqas not the same-a tad greener Link to comment Share on other sites More sharing options...
Pres Posted July 1, 2020 Report Share Posted July 1, 2020 Said it before, and will say again, barium is too dangerous for me to have, broken bag, or container, and contamination is really difficult to clean up safely. Why have it in you studio if it can be absorbed in so many ways. . . think of a Coronavirus that attacks through skin, absorbed by mouth and breathing. . . . what a killer! I realize that there are some out there that use it, and are responsible, but I would not allow it in my HS studio, or in my own. Ben. . . .get rid of those old Yellow copper enamels! best, Pres Link to comment Share on other sites More sharing options...
Babs Posted July 1, 2020 Report Share Posted July 1, 2020 7 hours ago, Benzine said: Now you tell me! What am I going to do with all this surplus Uranium I have sitting around?! There may be a market for that out there, and stop cleaning your paint brushes in your mouth! Link to comment Share on other sites More sharing options...
Benzine Posted July 4, 2020 Report Share Posted July 4, 2020 On 7/1/2020 at 5:35 PM, Babs said: There may be a market for that out there, and stop cleaning your paint brushes in your mouth! Van Gogh did it, and he turned out fine... Link to comment Share on other sites More sharing options...
Pres Posted July 4, 2020 Report Share Posted July 4, 2020 Alas Ben, Van Gogh died, mad or insane, and alone. Greater painter he was, a rebel too, but it wasn't till many years later that his stroke of genius even though born of madness and depression was revered. So clean your brushes between your teeth, not worrying about lead or cadmium, but plastic and other inorganics. 'Nough said. Don't fool around when other art teachers are watching! best, Pres Link to comment Share on other sites More sharing options...
Babs Posted July 4, 2020 Report Share Posted July 4, 2020 1 hour ago, Pres said: Alas Ben, Van Gogh died, mad or insane, and alone. Greater painter he was, a rebel too, but it wasn't till many years later that his stroke of genius even though born of madness and depression was revered. So clean your brushes between your teeth, not worrying about lead or cadmium, but plastic and other inorganics. 'Nough said. Don't fool around when other art teachers are watching! best, Pres Ben and Pres have given me my giggles for the day. Good therapy. Link to comment Share on other sites More sharing options...
Benzine Posted July 6, 2020 Report Share Posted July 6, 2020 On 7/4/2020 at 5:06 PM, Pres said: Alas Ben, Van Gogh died, mad or insane, and alone. Greater painter he was, a rebel too, but it wasn't till many years later that his stroke of genius even though born of madness and depression was revered. So clean your brushes between your teeth, not worrying about lead or cadmium, but plastic and other inorganics. 'Nough said. Don't fool around when other art teachers are watching! best, Pres Oh I know Pres. I go over quite a bit about Van Gogh with students, as he is one of my favorite painters/ artists. We talk about his style, about how he wasn't recognized in his time and how he sold one painting and now they are worth many millions of dollars. We also talk about how he was likely schizophrenic, or at least has some type of mental health issue (seizures, heavy metal poisoning from his paints, or potentially syphilis, which I don't name specifically...) We also discuss how one or a combination of these likely shaped his work. I'm definitely not a rebel, unless we are talking about specific professional development items... Link to comment Share on other sites More sharing options...
Pres Posted July 6, 2020 Report Share Posted July 6, 2020 Didn't call you a rebel, Van Gogh. Who wouldn't get testy over professional development meetings, and requirements. best, Pres Link to comment Share on other sites More sharing options...
Benzine Posted July 6, 2020 Report Share Posted July 6, 2020 11 hours ago, Pres said: Didn't call you a rebel, Van Gogh. Who wouldn't get testy over professional development meetings, and requirements. best, Pres Those, who create them! Our current Curriculum Director is around my age, used to be a former teacher, and is someone I get along well with. I told her that I appreciated the fewer early out PD meeting days, that we had on the calendar. She said that she thought we needed more. I bluntly said, "No we don't!" She did not like that answer. I explained, that time with the students, is more valuable than pretty much anything we are going to do in PD. Link to comment Share on other sites More sharing options...
Pres Posted July 6, 2020 Report Share Posted July 6, 2020 When I was DC for our department and Music, I arranged trips to local art museums and other venues at least for one or 2 of the required meetings. Other times we invited in or visited other SD departments for PD. Back to the subject though, Latest teacher in my district found Barium in the supplies. . . asked about it, I told him to dispose of it with the Chem department as they had legal ways to dispose of materials. best, Pres Link to comment Share on other sites More sharing options...
Benzine Posted July 6, 2020 Report Share Posted July 6, 2020 10 minutes ago, Pres said: When I was DC for our department and Music, I arranged trips to local art museums and other venues at least for one or 2 of the required meetings. Other times we invited in or visited other SD departments for PD. Back to the subject though, Latest teacher in my district found Barium in the supplies. . . asked about it, I told him to dispose of it with the Chem department as they had legal ways to dispose of materials. best, Pres I am my District's Visual Arts "Data Team Leader". Each grade level/ department has been collecting the data of their choosing for the past several years, in an effort to improve on a part of our practice, benefiting our student's learning. Not a bad concept, it can just be difficult to implement for many reasons, that I won't get into here. Like you, I pushed for visits to other districts. We took a couple, and found them to be quite beneficial, as much of the PD is never aimed at the elective courses. We haven't been able to do it the past two years though. Maybe again in the future?.. I am glad I have never had to deal with any materials that were overly toxic. I have some glazes that I inherited that do contain lead. I pulled them from student use, mixed them together and have been gradually coating "leftover" pieces in it, firing them, then tossing in the trash. The most toxic thing in my room, is the questionable dark spots on the ceiling tiles, from where the HVAC line drips condensate. Link to comment Share on other sites More sharing options...
Callie Beller Diesel Posted July 8, 2020 Report Share Posted July 8, 2020 On 6/30/2020 at 3:41 PM, liambesaw said: If barium is fired without carbon monoxide, it doesn't enter the glaze melt. Instead it acts as an opacifier and stays outside of the melt. Hey Liam, do you have an article I can link to on this? I’ve got someone asking about it in a FB group. Link to comment Share on other sites More sharing options...
Magnolia Mud Research Posted July 8, 2020 Report Share Posted July 8, 2020 48 minutes ago, Callie Beller Diesel said: On 6/30/2020 at 4:41 PM, liambesaw said: If barium is fired without carbon monoxide, it doesn't enter the glaze melt. Instead it acts as an opacifier and stays outside of the melt. Hey Liam, do you have an article I can link to on this? I’ve got someone asking about it in a FB group I too would like to know the source of Liam’s statement re carbon monoxide and barium carb and/or barium oxide. Link to comment Share on other sites More sharing options...
liambesaw Posted July 8, 2020 Report Share Posted July 8, 2020 https://digitalfire.com/4sight/material/barium_carbonate_86.html Link to comment Share on other sites More sharing options...
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