[Clayart] Toxic chemicals.

ronroy at ca.inter.net ronroy at ca.inter.net
Thu Aug 22 13:58:56 EDT 2019

Hi Paul,

The real problem happened when potters decided they did not want to  
understand the technical aspects of our craft. The guy who taught me  
was a Alfred grad. He was very encouraging when I was being creative.  
When I asked about certain technical problems he could not answer them  
- and discouraged me from being interested in that part of pottery.

That attitude was rampant then. The writers of the time (Rhodes,  
Leach, and Cardew - etc.) were trying their best to help the situation  
but - the pictures were what most potters wanted.

Because most of us were essentially dumb about clay and glazes we were  
easy meat for clay and glaze companies. Some even hired people who  
would simply deny any mistakes.

There were - and still are - glazes that change colour when in contact  
with food. Clays that produce unwanted cristobalite, clays that leak  
at the advertised proper temperature and still clays that have a 4  
cone range.

I think all this has an effect on sales - and I also think those  
functional potters who solve the problems have a much better chance of  
making a go of it.

I hope more potters will educate themselves - it's not only useful -  
it is a great stimulus for the brain. Do I sound like I enjoy it?


Quoting Paul Gerhold <gerholdclay at gmail.com>:

> In the real world you would have to demonstrate that your tests are  
> correlated to actual usage and that the results have health  
> implications. And that also applies to supposedly safe glazes.
> Be real. We as potters don't actually have the resources to do the  
> real testing required and in ten or twenty years we may find we  
> missed something obvious.
> Cigarettes used to be safe. Leaded gasolines used to be safe.  
> Fluorocarbon aerosols used to be safe. Roundup used to be safe.  
> Margarine used to be better than butter. MSG used to be everywhere.
> Face the fact. If you are really paranoid the best thing is to use  
> clay to make art, not functional work that comes into contact with  
> food.
> Just messing with you all, but think about it.
> Paul
>> On Aug 21, 2019, at 1:42 PM, ronroy at ca.inter.net wrote:
>> Thanks Sumi,
>> It does no harm to apply some rational thinking to this subject.
>> I agree that we live in an increasingly polluted world - much of  
>> which we cannot avoid. It's also true that many more people are  
>> becoming aware and concerned.
>> While I don't think we as potters are great contributors to the  
>> problem, I do think we can benefit by paying attention to what  
>> clays and glazes we use.
>> When John and I decided to write our book we both had this problem  
>> in mind. Our glazes are still the only tested glazes published. We  
>> hoped that more authors and glaze producers would follow our  
>> example. This has not happened except for a few exceptions.
>> On the brighter side, many potters Like Sumi have made the  
>> adjustments and are benefiting from that.
>> There are some who still think that being concerned about toxic  
>> materials leaching out of glazes is overkill. There are those who  
>> will not or cannot change. Many are simply too lazy to learn the  
>> skills necessary to understand our craft.
>> I have no idea what the balance of those who are concerned against  
>> those not concerned is. I do know it is changing for the better.
>> RR
>> Quoting sumi <sumi at herwheel.com>:
>>> Antoinette
>>> Interesting point. We (with the help of Ron and John) are trying  
>>> to be responsible by telling our students how to make stable  
>>> glazes that won't poison their loved ones. I try to make sure all  
>>> the glazes in my classroom are labeled according to whether they  
>>> are liner glazes, stable glazes, or, in the case of a couple, not  
>>> to be used on surfaces that will come into contact with food. The  
>>> result of our increasing knowledge and care is that people are  
>>> increasingly scared! I think it's throughout the culture in every  
>>> industry, though. I stopped using a brand of very nice seaweed  
>>> because California made them put a "prop 65" warning on the  
>>> package to tell me the seaweed may contain trace amounts of  
>>> cadmium or mercury, to which as it happens I have high levels of  
>>> antibodies and therefore really must avoid them. Yes, all seafood  
>>> probably has trace amounts of these heavy metals. Without prop 65  
>>> I just wouldn't know.
>>> People are suffering from the pervasive toxins in the environment  
>>> (herbicides, pesticides, heavy metals, BPA, etc.) and doing  
>>> everything they can to avoid any toxic exposure. So, the truth is,  
>>> some people probably really shouldn't buy a house that had glaze  
>>> materials in the basement. In fact, it's possible I should be  
>>> avoiding glaze chemicals but I just try to be very careful. At  
>>> least I understand enough to be appropriately careful.
>>> Sumi
>>>> Hi guys. I am still alive and well. Read more and take more note of
>>>> your notes here at this time, since I had a very busy year this far.
>>>> I know we talked about the ?big scare for  ceramics materials? before;
>>>> to the point that some colleges want/or already closed ceramic
>>>> programs,  but I thought of bringing it up again, since it looks like
>>>> it is really becoming an issue. Young potters are scared to the point
>>>> that they do not want to mix glazes themselves, which ironically takes
>>>> all control out of their hands of what they are actually working with
>>>> and no lesser hazard.
>>>> There is an incident that a person reported about a house sale that is
>>>> falling through, because they did not declare that they worked with
>>>> ?toxic chemicals? in their basement studio.
>>>> I am just shaking my head; we know responsible handling and knowledge
>>>> is key. Maybe something to pay more attention to in class setups.
>>>> Best wishes,
>>>> Antoinette Badenhorst
>>>> www.porcelainbyAntoinette.com
>>>> www.TeachinArt.com
>> Ron Roy
>> ronroy at ca.inter.net
>> Web page ronroy.net

Ron Roy
ronroy at ca.inter.net
Web page ronroy.net

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