Maybe I'm wrong, but the answer might be very simple. glazes, when applied thinly, as you applied your lead based "glaze," sort of soak into the clay and come out matte. Try doing 3-4 coats. Worth a shot, if you are still interested in this.
This is a interesting video. I spent years to remove lead paint from houses and I often wondered how the lead was incorporated into the paint. Thanks for sharing
Hi Andy. I saw an article about making sulfur soluble for use in gardening by oxidizing it at 200C. If you are able to heat your ground galena to 800C, well above the oxidation temperature of 200C. Then regrind the resultant puck, you might be able to dissolve / flush the sulfur out of your reground galena with water. The article also mentioned soaking in an acid to increase the sulfur's solubility in water. At the time this glaze started showing up they would of had access to uric acid. Perhaps you might know of a chemical engineer that might be able to offer a simpler way of removing the sulfur. If enough people start thinking about this, the cat won't have a fur coat, cheers.
There was a surge of interest in colonial art and craft and country decor in the seventies, and part of it was a Pennsylvania German style of redware that was rolled out, had white slip applied, cut into circles, and eventually formed into shallow pie plates by slapping it down on a mold. The shape was like a typical Mimbres bowl, as if a clay disc was dropped and pressed on a bowling ball. The edges were then "coggled" with a rotary tool, and the final touch was to dust the inside with pulverized white lead (as I recall). I can't spare the time to check my references or research from other sources, but the result was a think, clear glaze that sealed the low fire terra cotta. It was essentially glaze, and was lead of some sort. This may provide a clue or research path for you to pursue. Lead was a more popular glaze ingredient before its toxicity was so well known. The clear glaze we used seemed to get a similar result, and sealed the clay without any drips or cloudiness that made us aware that glaze had been applied, unless we were curious potters with some professional interest. Kemper Vallejo Currently remote studying some exciiting pottery traditions through Solano Community College, which led me to your site last fall.
Gee this got interesting and had me ask "how do you oxidize lead ore" and then here I am reading an article from 1976 OXIDATION OF LEAD SULPHIDE Peter John that says to 2 PbS you add 3 O2 to get out 2 PbO and 2 SO2 out... that was by page 9 of 231... Grind it up, use lower temps, and wave air in don't let it heat without fresh air flowing is what I think I am reading ...
Interesting your results. I have a sherd from I think lead paint that has a reddish hue in the polished paint areas deep under the black shiney surface , I have wondered how much red iron or rhyolite was part of paint mixture. This stuff drives you crazy but what fun !
Oh well I guess I assumed it went without saying. Don’t eat lead, don’t breathe lead dust, don’t breath lead fumes from a firing. Don’t eat or drink from lead glazed pottery.
I'm not sure about the metal detector. It has a definite glassy texture that is unlike burnishing, wherever the paint does not form a glaze it is vert matte in texture.
Thank you and yes, I remember that. Still there does not seem to be a technological bridge between the 700 Rosa and the 1270 Pinedale. So perhaps Rosa is a technological isolate, not connected to the larger White Mountain/Zuni/Rio Grande glaze phenomenon.
Maybe, I ground it up and then roasted it so it would be impossible to do with powdered gelena. But this might work for a solid chunk of galena. I am also mixing the lead with other minerals like manganese and copper to make black glaze paint.
Lead isn’t inherently dangerous like uranium you know. You have to ingest it to be poisoned by it. I have other lead things in my house that haven’t poisoned me yet, lead fishing weights, lead bullets. Why should I be scared of lead pottery paint as long as I am not eating out of this pot?
@@AncientPottery Well, ingesting is only part of it. Inhaling lead dust & fumes is a much more effective way to get lead poisoning. For children, a single grain-salt sized grain of lead is enough to give them lead poisoning for life (often resulting in retardation and a whole complex of health issues). Inhaling lead dust damages the brain and the reproductive system, among much else. Even if you wear a mask while making these, dropping & breaking a bowl can be very hazardous to children and harmful for adults.
Go back to your blog, Tamara Rubin. Nobody's getting lead poisoning off of this man's pots and your fear mongering on every comment section in the world is more agitating than ingratiating. You're not a materials scientist and your roleplaying as one is not convincing.
I can't wait to see the test tile results. Thanks for sharing these priceless knowledge with us.
You are welcome, I’m glad you enjoyed it.
Maybe I'm wrong, but the answer might be very simple. glazes, when applied thinly, as you applied your lead based "glaze," sort of soak into the clay and come out matte. Try doing 3-4 coats. Worth a shot, if you are still interested in this.
Yes I am still experimenting with this and have had some clues that thicker paint equals better glaze. Thanks for the tip
This is a interesting video. I spent years to remove lead paint from houses and I often wondered how the lead was incorporated into the paint.
Thanks for sharing
I think lead house paint is different, it certainly was not fired and never produced a glaze.
Absolutely beautiful! ❤️
Thanks
Hi Andy. I saw an article about making sulfur soluble for use in gardening by oxidizing it at 200C.
If you are able to heat your ground galena to 800C, well above the oxidation temperature of 200C. Then regrind the resultant puck, you might be able to dissolve / flush the sulfur out of your reground galena with water.
The article also mentioned soaking in an acid to increase the sulfur's solubility in water.
At the time this glaze started showing up they would of had access to uric acid.
Perhaps you might know of a chemical engineer that might be able to offer a simpler way of removing the sulfur.
If enough people start thinking about this, the cat won't have a fur coat, cheers.
Thanks for that tip, I might just try washing it, I've got nothing to lose.
There was a surge of interest in colonial art and craft and country decor in the seventies, and part of it was a Pennsylvania German style of redware that was rolled out, had white slip applied, cut into circles, and eventually formed into shallow pie plates by slapping it down on a mold. The shape was like a typical Mimbres bowl, as if a clay disc was dropped and pressed on a bowling ball. The edges were then "coggled" with a rotary tool, and the final touch was to dust the inside with pulverized white lead (as I recall). I can't spare the time to check my references or research from other sources, but the result was a think, clear glaze that sealed the low fire terra cotta. It was essentially glaze, and was lead of some sort.
This may provide a clue or research path for you to pursue. Lead was a more popular glaze ingredient before its toxicity was so well known. The clear glaze we used seemed to get a similar result, and sealed the clay without any drips or cloudiness that made us aware that glaze had been applied, unless we were curious potters with some professional interest.
Kemper Vallejo Currently remote studying some exciiting pottery traditions through Solano Community College, which led me to your site last fall.
Cool, thanks for sharing.
Amazing process, congratulation for this achievement.
Thank you very much!
Gee this got interesting and had me ask "how do you oxidize lead ore" and then here I am reading an article from 1976 OXIDATION OF LEAD SULPHIDE Peter John that says to 2 PbS you add 3 O2 to get out 2 PbO and 2 SO2 out... that was by page 9 of 231... Grind it up, use lower temps, and wave air in don't let it heat without fresh air flowing is what I think I am reading ...
Good stuff, thanks for sharing.
Interesting your results. I have a sherd from I think lead paint that has a reddish hue in the polished paint areas deep under the black shiney surface , I have wondered how much red iron or rhyolite was part of paint mixture. This stuff drives you crazy but what fun !
Yes, definitely fun. I think the Pueblo potters from northern New Mexico produced red glaze paint.
Looks nice!
Thank you
Fascinating. You don't mention if there's any health safety concerns about lead based glazes.
Oh well I guess I assumed it went without saying. Don’t eat lead, don’t breathe lead dust, don’t breath lead fumes from a firing. Don’t eat or drink from lead glazed pottery.
@@AncientPottery It's self-evident to someone like me, old enough to have lived in houses with lead pipes. ;)
I wonder what would happen if you put it in a regular pottery kiln to see if extra heat would make a difference? The journey continues.
If you can reach 1115 C or whatever galena melts at, you could do it easily in a modern kiln.
I'd like to know the recipe for your red glaze - mine all turn brown using oxides to color the slip.
The red is not a glaze but a burnished yellow clay slip.
Is it just the shine, or how can you identify that pottery has lead glazed paint? Do you think a metal detector would identify it?
I'm not sure about the metal detector. It has a definite glassy texture that is unlike burnishing, wherever the paint does not form a glaze it is vert matte in texture.
Nice try. FYI, Rosa B/w was a Colorado lead-glazed pottery type produced ca 700 AD, well before it showed up in AZ.
Thank you and yes, I remember that. Still there does not seem to be a technological bridge between the 700 Rosa and the 1270 Pinedale. So perhaps Rosa is a technological isolate, not connected to the larger White Mountain/Zuni/Rio Grande glaze phenomenon.
But you are correct, WMRW was not the first glaze paint in the SW.
@@AncientPottery "Everybody knew everything, distance was nothing..." Steve Lekson
What if instead of a paint, you used the roasted lead like a pencil and just draw on the jar?
Maybe, I ground it up and then roasted it so it would be impossible to do with powdered gelena. But this might work for a solid chunk of galena. I am also mixing the lead with other minerals like manganese and copper to make black glaze paint.
nice Video :)
Thanks!
I think you need to burn off all the sulfer.
Yes, that is exactly what I am trying to do by pre-roastin the galena.
What a tounge breaker, "lead based glaze paint"... But a cool experiment / journey!
Thanks, yeah I tripped over that a few times. I could make a blooper reel of all those.
Umm isn’t lead toxic?
Umm, yeah, don't eat it
Why in the world would you want to, and promote, getting lead poisoning from your silly hobby?
Lead isn’t inherently dangerous like uranium you know. You have to ingest it to be poisoned by it. I have other lead things in my house that haven’t poisoned me yet, lead fishing weights, lead bullets. Why should I be scared of lead pottery paint as long as I am not eating out of this pot?
@@AncientPottery Well, ingesting is only part of it. Inhaling lead dust & fumes is a much more effective way to get lead poisoning. For children, a single grain-salt sized grain of lead is enough to give them lead poisoning for life (often resulting in retardation and a whole complex of health issues). Inhaling lead dust damages the brain and the reproductive system, among much else. Even if you wear a mask while making these, dropping & breaking a bowl can be very hazardous to children and harmful for adults.
Go back to your blog, Tamara Rubin. Nobody's getting lead poisoning off of this man's pots and your fear mongering on every comment section in the world is more agitating than ingratiating. You're not a materials scientist and your roleplaying as one is not convincing.