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Searching For Discontinued Glaze - Help? Also Lead Questions

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Hello everyone! I'm new here, and I've been reading some threads. I was wondering if anyone might know of anyone or might have stashed somewhere, the Blue Marble glaze from Mayco Jungle Gems. This glaze was discontinued in the early 2000s because of its lead content. I just recently discovered it when someone had a tiny amount for me to glaze a pinch pot. I glazed it at cone 6 instead of 06 (oops) but it came out AMAZING! (Turns out Jungle Gems CAN be fired at cone 6!). The Mayco rep contacted me about my inquiry and is sending me a package of glazes to play around with to see if I can recreate it, but I would really like to find something very similar or some that someone isn't using. I will pay a reasonable amount for this! :)

 

Questions:

 

Is touching a piece made with lead glaze harmful?

Once a lead glaze is fired is it still dangerous?

post-62628-0-64006800-1392920227_thumb.jpg

post-62628-0-64006800-1392920227_thumb.jpg

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neilestrick    1,379

There are two types of safety labels on glazes. First, the toxicity label (non-toxic, toxic, etc). This usually features the code ASTM D-4236, which is the code by which art materials must be labeled for health hazards. The toxicity label only applies to the form in which you purchased the glaze. If you purchase a wet mixed glaze, then the label only applies to the wet mix. Once it's dry on the pot, the label no longer applies. This is important to know because dry glazes will never be labeled as non-toxic because silica, and many of the other ingredients in our glazes, are known carcinogens. You do not want to breathe clay or glaze dust for this reason.

 

If a glaze is labeled as toxic, that doesn't mean you shouldn't use it. The toxic rating may be due to the level of copper or cobalt, both of which can be handled safely with common sense. Just use good hygiene practices when working with glazes. Don't sweep. Instead, mop or sponge clean to keep the dust to a minimum. Don't eat or drink when handling glazes. Wash your hands when you're done. Again, use common sense. Read the label and follow directions. Toxic glazes should not be used by children under a certain age, and the label should tell you this.

 

The second safety label will tell whether or not the glaze is safe to use on surfaces which come into contact with food. A toxic glaze can be food safe. A non-toxic glaze can be non-food safe. They have nothing to do with each other. A glaze with lead in it can be food safe. You'll have to read the label. Make sure you fire at the temperature that is recommended by the manufacturer. A glaze that is said to be food safe at cone 06 may not be at cone 6.

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There are two types of safety labels on glazes. First, the toxicity label (non-toxic, toxic, etc). This usually features the code ASTM D-4236, which is the code by which art materials must be labeled for health hazards. The toxicity label only applies to the form in which you purchased the glaze. If you purchase a wet mixed glaze, then the label only applies to the wet mix. Once it's dry on the pot, the label no longer applies. This is important to know because dry glazes will never be labeled as non-toxic because silica, and many of the other ingredients in our glazes, are known carcinogens. You do not want to breathe clay or glaze dust for this reason.

 

If a glaze is labeled as toxic, that doesn't mean you shouldn't use it. The toxic rating may be due to the level of copper or cobalt, both of which can be handled safely with common sense. Just use good hygiene practices when working with glazes. Don't sweep. Instead, mop or sponge clean to keep the dust to a minimum. Don't eat or drink when handling glazes. Wash you hands when you're done. Again, use common sense. Read the label and follow directions. Toxic glazes should not be used by children under a certain age, and the label should tell you this.

 

The second safety label will tell whether or not the glaze is safe to use on surfaces which come into contact with food. A toxic glaze can be food safe. A non-toxic glaze can be non-food safe. They have nothing to do with each other. A glaze with lead in it can be food safe. You'll have to read the label. Make sure you fire at the temperature that is recommended by the manufacturer. A glaze that is said to be food safe at cone 06 may not be at cone 6.

 

 I really appreciate this help! I suppose, just to be safe, I will assume (and tell whoever ends up with my work) that my pieces aren't food safe, as to get the effects that I like, I've been firing 06 at 6. I really think I need to be more careful around the glazes. I haven't been taking it as seriously as I should be.

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It's possible that I'm a glaze snob, but I will not touch commercial glazes when I can help it. I've come across too many instances of poor glaze chemistry to be 100% comfortable with anything I'm not formulating myself... 

 

If you took a shot at reproducing those effects, I would suggest using a really active alkali flux like lithium or sodium, and dropping the maturity point a bit lower than you intend on firing to. Rutile, Copper, and Iron will be your go-to colorants.

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Thank you Colby! :) I am just now beginning my ceramics adventure (can't you tell by the shape of that pinch pot?!) and am opting to learn the basics of clay and firing first. I am easily overwhelmed, and I have all the time in the world. I haven't bought a home yet, thus no studio. :( However, I do take a pottery class for fun at the community college and use their created glazes. I much prefer them except for these gem glazes when they run! Beautiful!

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Benzine    609

"Don't eat or drink when handling glazes. Wash your hands when you're done. Again, use common sense."

 

Don't forget, no smoking Neil!  I always chuckle, when I read that on a label, mainly because I'm in my classroom, when I read it.  I just hate that I have to break that to the students, "Alright kids, you'll have to put out your cigarettes, before you start glazing, the label makes this quite clear!"

 


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Benzine    609

Also, in regards to the glaze in question, I got a similar look, by dripping an Amaco Dark Yellow over Amaco Frosted Jade.  The Frosted Jade, is not food safe, I think due to the texture or crazing it produces.  Though, the glaze you have in that photo, also looks to be crazed a bit.

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Benzine    609

I totally forget about smoking! I haven't been around cigarettes for so long that I don't even think about it. Great point!

 

 

That's one reason I think it's funny.  I just can't really see anyone glazing, with a cigarette hanging out of their mouth.

 

Of course, I grew up in a time, where all of society, didn't feel they had to be smoking constantly.

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ayjay    119

 

Is touching a piece made with lead glaze harmful?

Once a lead glaze is fired is it still dangerous?

 

It's turned your fingernails blue. ;)

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Is touching a piece made with lead glaze harmful?

Once a lead glaze is fired is it still dangerous?

 

It's turned your fingernails blue. ;)

 

 

 

I was just as shocked as you are!!! Hahaha! I woke up and my thumb was blue and my other fingernails were BLACK!

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"Don't eat or drink when handling glazes. Wash your hands when you're done. Again, use common sense."

 

Don't forget, no smoking Neil!  I always chuckle, when I read that on a label, mainly because I'm in my classroom, when I read it.  I just hate that I have to break that to the students, "Alright kids, you'll have to put out your cigarettes, before you start glazing, the label makes this quite clear!"

 

 

 

 

You teach art as well?? :) That's awesome! I have Kindergarten kids who are terrible chain smokers!

 

I don't smoke...but I'll remember the drinking part. It's so easy to just have a cup or bottle sitting nearby as I work and take a drink every now and then.

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Also, in regards to the glaze in question, I got a similar look, by dripping an Amaco Dark Yellow over Amaco Frosted Jade.  The Frosted Jade, is not food safe, I think due to the texture or crazing it produces.  Though, the glaze you have in that photo, also looks to be crazed a bit.

 

It is crazed a bit. It was fired at 6 instead of 06. But with the Jungle Gems, you can do that...I guess it's just the price paid?

 

While we're on this topic...crazed work....is it frowned upon? I happen to love the look...but I know that my standards aren't going to align to the professional community's idea of worthy. LOL.

 

Another question....

 

Can you be a successful potter using commercial glazes? Do you just not tell anyone? Haha! It's just my only option right now...hopefully in the next year I can buy a house with a studio or buy a house and BUILD a studio. Around here, though, most houses have studios because of the large number of artists.

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Benzine    609

 

You teach art as well?? :) That's awesome! I have Kindergarten kids who are terrible chain smokers!

 

I don't smoke...but I'll remember the drinking part. It's so easy to just have a cup or bottle sitting nearby as I work and take a drink every now and then.

  

 

I do indeed teach Art, high school.

 

 

It is crazed a bit. It was fired at 6 instead of 06. But with the Jungle Gems, you can do that...I guess it's just the price paid?

 

While we're on this topic...crazed work....is it frowned upon? I happen to love the look...but I know that my standards aren't going to align to the professional community's idea of worthy. LOL.

 

Another question....

 

Can you be a successful potter using commercial glazes? Do you just not tell anyone? Haha! It's just my only option right now...hopefully in the next year I can buy a house with a studio or buy a house and BUILD a studio. Around here, though, most houses have studios because of the large number of artists.

Crazed work, may be frowned upon by some, but others really like the look. John will be the first to tell you that, as Japanese work has a good deal of crazing.

He, and others, would also point out, that a lot of glazes craze, even if we can't see it. This is why you have to be careful using low fire wares. They don't fully vitrify, and the glaze, which CAN seal them from seeping, could fail to do so, because of the crazing.

 

There is nothing wrong with using commercial glazes, as a professional. A lot of people will make the comparison, "Not all painters mix their own paints.". It's very true. It's all on how you use them.

I too, am slowly getting my studio together. i plan to mix my own glazes, because it will be cheaper than buying commercial. I use commercial glazes in the classroom, because I don't have the time to mix my own, nor do I have the space to keep the raw ingredients.

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You teach art as well?? :) That's awesome! I have Kindergarten kids who are terrible chain smokers!

 

I don't smoke...but I'll remember the drinking part. It's so easy to just have a cup or bottle sitting nearby as I work and take a drink every now and then.

  

 

I do indeed teach Art, high school.

 

 

It is crazed a bit. It was fired at 6 instead of 06. But with the Jungle Gems, you can do that...I guess it's just the price paid?

 

While we're on this topic...crazed work....is it frowned upon? I happen to love the look...but I know that my standards aren't going to align to the professional community's idea of worthy. LOL.

 

Another question....

 

Can you be a successful potter using commercial glazes? Do you just not tell anyone? Haha! It's just my only option right now...hopefully in the next year I can buy a house with a studio or buy a house and BUILD a studio. Around here, though, most houses have studios because of the large number of artists.

Crazed work, may be frowned upon by some, but others really like the look. John will be the first to tell you that, as Japanese work has a good deal of crazing.

He, and others, would also point out, that a lot of glazes craze, even if we can't see it. This is why you have to be careful using low fire wares. They don't fully vitrify, and the glaze, which CAN seal them from seeping, could fail to do so, because of the crazing.

 

There is nothing wrong with using commercial glazes, as a professional. A lot of people will make the comparison, "Not all painters mix their own paints.". It's very true. It's all on how you use them.

I too, am slowly getting my studio together. i plan to mix my own glazes, because it will be cheaper than buying commercial. I use commercial glazes in the classroom, because I don't have the time to mix my own, nor do I have the space to keep the raw ingredients.

 

 

I'm at the Elementary/Middle level now, but I'm hoping to be moving up for next year! :) The kids are really excited about my work, regardless of age...so that keeps me going when I get a piece that doesn't turn out how I want or when I make a goof like I did with the load that started this post.

 

I really like the look of crazed work, so it makes me feel good that at least SOME people also do. :) I definately do not have the room in my classroom as of now...and even if...my older audience is really limited as far as students go! It wouldn't be worth the school's investment. BUT I want my own space at home! :)

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neilestrick    1,379

I know several full time potters that use all commercial glazes. The 2 main problems with using commercial glazes are that it's very difficult to impossible to tweak a glaze to make it work better for you, so you have to make adjustments to your firings and such in order to accommodate their particular traits. For instance, some work best at cone 5, some at cone 6. So instead of being able to just alter the glaze formula a bit to make them work at the same temperature, you end up doing two different firings. The other issue is that they are expensive compared to mixing your own. I can mix a 5 gallon bucket of clear glaze for about the same price as buying 1 gallon.

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Babs    385

IF using for food bacteria can flourish in the cracks of the glaze. Also interesting if you put beetroot in the dish!

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JBaymore    1,432

IF using for food bacteria can flourish in the cracks of the glaze. Also interesting if you put beetroot in the dish!

 

If that were a really major issue........ millions of Japanese and Koreans would be ill or dying every day from it.

 

It CAN happen,........ but how often does it happen?  This is not as big an issue as many make it out to be.

 

I'm working on a study to address this question. 

 

best,

 

...................john

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Benzine    609

 

IF using for food bacteria can flourish in the cracks of the glaze. Also interesting if you put beetroot in the dish!

 

 

If that were a really major issue........ millions of Japanese and Koreans would be ill or dying every day from it.

 

It CAN happen,........ but how often does it happen?  This is not as big an issue as many make it out to be.

 

I'm working on a study to address this question. 

 

best,

 

...................john

Isn't the bigger issue on low fire ware, where the bacteria and mold get through the crazed glaze, and into the porous clay body?

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neilestrick    1,379

Isn't the bigger issue on low fire ware, where the bacteria and mold get through the crazed glaze, and into the porous clay body?

 

Restaurants aren't allowed to use non-vitrified ware for this reason. All dishes and utensils used for cooking and serving must be non-porous. No earthenware, no wooden bowls or spoons, no wood cutting boards or counter tops. Of course, their definition of vitrified is pretty vague- they don't give a specific absorption rate.

 

However, people have been cooking with and eating off of crazed glazes and earthenware pots for centuries, and as far as we know people weren't dying from it in any great numbers, or at all. Could be that all those stomach aches come from it, though.

 

Personally, I have seen black gunk growing underneath a crazed earthenware glaze. Pretty nasty. I swore from that moment I would never use earthenware for functional pots.

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Babs    385

 

IF using for food bacteria can flourish in the cracks of the glaze. Also interesting if you put beetroot in the dish!

 

If that were a really major issue........ millions of Japanese and Koreans would be ill or dying every day from it.

 

It CAN happen,........ but how often does it happen?  This is not as big an issue as many make it out to be.

 

I'm working on a study to address this question. 

 

best,

 

...................john

 

No big issue John, just a comment.

I don't use antibacterial spray in my kitchen either

:) Living on a rural property I'd hate to see what I have inadvertently ingested over my time here!

Local doc said my kids were healthy because of what they had ingested in the way of bacteria. Seemed immune to many gastros hitting the school population.

My favourite mug wouldn't pass the no craze test. :o

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