Gayle Bair on sun 20 may 07
John and all,
Duncan is also guilty. They have several low fire glazes with 27% lead.
One was recalled but I think Diamond Clear is still in use. Those are also
favored by the "Paint your own" shops.
This is from Duncan's site:
"Learning About Duncan Diamond Clear and Dipping Glazes
Basic Instructions
1.Duncan Diamond Clear's smooth, creamy consistency makes application of 2-3
flowing coats easy. Apply to shelf cone 04 bisque only.
2.Duncan Diamond Clear has a wide firing range, from shelf cone 06 to 6 for
porcelain and stoneware.
Tips & Techniques
1. Because crazing may occur on some clay bodies, we recommend that you make
a small fired test on the particular porcelain or stoneware body you plan to
use.
Health & Safety
1. Duncan Diamond Clear glaze is safe for use on food containers.
2. Caution. Contains lead. Conforms to ASTM D-4236."
So can anyone tell me how Duncan can claim # 1 under Health and Safety
when it probably is not vitrified at 06 and has 27% lead and an over the
counter
test I did turned the test stick a bright pink.
Some interesting reads:
http://www.dhs.ca.gov/childlead/tableware/twregs.html
This one is by our very own Edouard Bastarache
http://www.ceramicstoday.com/articles/lead2.htm
http://www.health.state.ny.us/environmental/lead/handbook/phc2.htm
there are many more articles.
Gayle Bair
Bainbridge Island, WA
Tucson, AZ
http://claybair.com
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG]On Behalf Of John Post
Sent: Sunday, May 20, 2007 5:11 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re :Lead Frits (Kid Pots)
One of the most irresponsible uses of lead glazes is on kid pots.
If you browse through the Amaco catalog you will see that many of their
cone 05/06 glazes contain lead and or cadmium.
Art teachers here in Michigan are not required to take any courses about
the possible material hazards they will encounter on the job.
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1:52 PM
Ric Swenson on mon 21 may 07
Okay, lets talk....about lead and heavy metals....again.
=20
It's what we older potters and teachers would call 'common knowledge' about=
lead in glazes.....but maybe not so common?? frita are more safe...the sol=
ubility of the lead is decreased by the fritting process....melting and que=
nching ... ( look it up)
=20
The warnings on packaging....today are conspicuous....or should be.....in m=
ost States.......lead in most forms has a bad effect on 'young brains' espe=
cially. ....absorbing of lead or heavy metals .....in developing brains =
are affected in terrible ways...adults can more easily pass the lead out of=
their systems.... as I remember reading about the effects at Dartmouth Med=
. School at Baker Library... in the 1970s.....=20
=20
Please Remember that acidic solutions like citric and other acidic food can=
cause leaching of lead into foods...vinegar one of the worst leachates. =
=20
=20
The BIG example of the orange juice mixed each night in a Mexican pitcher b=
y a California physician for his child caused the child to die...eventually=
...in the 1960s I think. Imagine his angst?
=20
Soaking or boiling....pieces in vinegar can minimize lead leaching...but wh=
o wants to take the chance that it might cause brain damage in a child??
=20
It caused us all (then...) to be aware of the lead dangers....and cadmium =
and some other heavy metals....
=20
of course fritting helps...makes then less soluble.....in acid solutions...
=20
also in 1970s ....lead in house paint and the 'picas'...who sought the sw=
eet taste of lead in paint from window sill paints.... what shall we do to=
re-iterate these dangers?
=20
A new generation of potters and teachers should know and understand these g=
laze features....and dangers..
=20
The warnings on current glazes should be enough to warn teachers today....o=
r can't they READ??
=20
Que Lastima!
=20
Sometimes common knowledge is not so COMMON?? yes....teachers are exposed =
over MANY years to toxic materials and dust...students are exposed over a s=
horter period.
=20
beware.
=20
RR?
=20
=20
Regards,
=20
Ric
=20
=20
"...then fiery expedition be my wing, ..." Wm. Shakespeare, RICHARD III, Ac=
t IV Scene III Richard H. ("Ric") Swenson, Teacher, Office of International=
Cooperation and Exchange of Jingdezhen Ceramic Institute, TaoYang Road, Ea=
stern Suburb, Jingdezhen City JiangXi Province, P.R. of China. Postal code=
333001. Mobile/cellular phone :13767818872 +86-0798-8499600 (ofc.) +86-079=
8-8499012 (fax) E-Mail: RicSwenson0823@hotmail.com=20
> Date: Sun, 20 May 2007 20:10:47 -0400> From: johnpost@WIDEOPENWEST.COM> S=
ubject: Re :Lead Frits (Kid Pots)> To: CLAYART@LSV.CERAMICS.ORG> > One of t=
he most irresponsible uses of lead glazes is on kid pots.> > If you browse =
through the Amaco catalog you will see that many of their> cone 05/06 glaze=
s contain lead and or cadmium.> > Art teachers here in Michigan are not req=
uired to take any courses about> the possible material hazards they will en=
counter on the job.> > I was doing a throwing demonstration at a local K-12=
school and noticed> that none of their kilns were vented and that most of =
their glazes were> Amaco lead glazes. When I discussed this with the teache=
rs there,> neither had ever heard of the problems posed by lead and when I>=
recommended they switch to lead free glazes, they couldn't imagine doing> =
it since the kids liked the colors and textures of the lead glazes, and> ho=
w could they possibly get along without their favorite red?> > I told them =
that as teachers they would be the ones to suffer the> greatest exposure to=
lead over time but even this didn't seem to register.> > Amaco complies wi=
th the laws in labeling these products but not too many> teachers I have ru=
n across read the fine print in the catalog about> which glazes are lead fr=
ee and which are not. They shop purely by color.> > John Post> Sterling Hei=
ghts, Michigan> > > > >> >Just have some mugs tested for lead and cadmium -=
there are lots of labs> >around that will do this for about $35.> >> >I wo=
uld not fire either it in my kilns.> >> >RR> >> >> >> >> >> >> >> >> > ____=
__________________________________________________________________________>=
Send postings to clayart@lsv.ceramics.org> > You may look at the archives =
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