Hank Ray on fri 13 nov 98
Years ago... when we were just starting out... we made alot of earthenware
dishes... with bright colorful underglazes... with a "food safe" clear glaze
over it all...
we have been eating off of these dishes for years...... just did a lead
test on them ..... and it was positive.......
Pete... in oklahoma
Donn Buchfinck on fri 13 nov 98
A lot of commercial industrial potteries still use lead in their glazes
Duncans Diamond clear is a lead glaze, and is rated food safe
I even think lenox china is lead
and lead crystal is still sold
lead is out there
the English potters still use it
I'm not condoning it, I am just saying it is still being used.
and what the govt. Deems safe a few years ago they do not think they are safe
now. So if you made some dishes years ago, it is a good bet that they
release lead. And this is what the problem is all about,
how much lead is released
lead glazes leach lead
firing raw lead glaze in a kiln can contaminate the next load even if the
glazes are not lead.
but the comercial glazes are using a frit, that is the lead has already been
fired and locked with silica.
my question is
if it is so bad for us why is it still legal to use lead in food safe glazes
from companies like duncan
Donn Buchfinck
Bill Amsterlaw on sun 15 nov 98
------------------
Hi Pete:
You wrote:
=3C=3C Years ago... when we were just starting out... we made alot of =
earthenware
dishes... with bright colorful underglazes... with a =22food safe=22 clear =
glaze
over it all... we have been eating off of these dishes for years...... =
Just
did a lead test on them ..... and it was positive. =3E=3E
Many questions come to mind....
Regarding the people who have eaten off these dishes:
1. Anyone with vague symptoms that could be caused by chronic lead =
poisoning?
2. Anyone with an elevated serum lead level?
(I'm hoping that your serum lead level is normal=3B I would love to have an
anecdote like that to counter some of our glaze ingredients paranoia.)
Regarding the glaze and underglaze:
1. Is the lead coming from the underglaze, the clear glaze, or both?
2. Is the glaze crazed, worn, thin, dull, or underfired?
Regarding liability:
1. Could you be sued by a customer with lead poisoning?
2. Do you have product liability insurance that would cover you?
3. How do you feel about the possibility of doing harm with your pots?
- Bill Amsterlaw (wamster=40slic.com)
Plattsburgh, NY
Ron Roy on sun 15 nov 98
It is possible to make a glass - with lead that is food safe - it is even
possible to make a frit with lead that is food safe within the regulations
- I suppose - thats a lot of surface area to expose to an acid test.
What is wrong with the following is: When you use a lead frit to make a
glaze you are able to unlock any toxins in it by poor formulation. The frit
is melted into the glaze - you can describe the glaze as a new frit if you
like with it's own characteristics - one of which can be not enough silica
for the cone fired to.
Couple that with the fact that lead is volatile in kilns and is easily
reduced to the pure metal - which aids in more even more lead in the
atmosphere.
I am surprised that any company still sells a lead glaze recommended food
safe in NA - very much depends on how this type of glaze is fired to
maintain it's integrity never mind adding stuff like copper to it.
RR
>----------------------------Original message----------------------------
>but the comercial glazes are using a frit, that is the lead has already been
>fired and locked with silica.
>my question is
>if it is so bad for us why is it still legal to use lead in food safe glazes
>from companies like duncan
Ron Roy
93 Pegasus Trail
Scarborough, Ontario
Canada M1G 3N8
Tel: 416-439-2621
Fax: 416-438-7849
Web page: http://digitalfire.com/education/people/ronroy.htm
Randall Moody on tue 17 nov 98
>... with a "food safe" clear glaze
>over it all... we have been eating off of these dishes for years......
Just
>did a lead test on them ..... and it was positive. >>
>
Regarding all of the 'lead safe' posts, I am now wondering if anyone has a
positively lead safe clear glaze for the 04 range? I am starting to do
sculpture in this firing range but would like to be able to use the same
body for my functional pieces. The body I am using is 50/50 OM4 ball
clay/Talc. Yes, I wear a good respirator when mixing and clean up well after
myself. (I have to. I am in a university setting)
Frank Gaydos on wed 18 nov 98
Randall,
Here are two clears that use no lead. They work on the 50/50 clay body but
the color is not bright white, most likely because of the ball clay.
Good Luck
NEW CLEAR-Cone 04-Ox.
Frit 3195--42.50
Gerstley Borate--25
F-4 Feldspar--17
EPKaolin--8
Flint(Silica)--5
Frit 3110--2.50 (can also substitute for silica here instead)
Add: Lithium Carbonate 1%
Bentonite 3%
Clear 3195-Cone04-Ox.
Frit 3195--85
Frit 3110--5
EPKaolin--10
add: Bentonite 3%
-----Original Message-----
From: Randall Moody
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, November 17, 1998 9:59 AM
Subject: Re: Lead test results....
----------------------------Original message----------------------------
>Regarding all of the 'lead safe' posts, I am now wondering if anyone has a
positively lead safe clear glaze for the 04 range?
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