Lily Krakowski on sun 10 aug 03
This has been done to death, but it is better to do something to death than
die from it.
Lead bisilicate is a frit. Frits were developed in the 19th century for two
very good reasons. One was to make lead "safer" IN THE RAW STATE, to save
lives in factories, and the other was to put water soluble materials
insoluble.
Touching and handling raw lead, breathing it in etc killed people. By
INCORPORATING
IT IN A GLASS the lead was made safer to handle in the raw state.
BUT MELTING THE GLASS/FRIT IN A GLAZE STARTS A WHOLE NEW "PRODUCT" In other
words a glaze that includes a lead frit or lead bisilicate still is a lead
glaze and all the cautions about lead glazes remain. Not 100% accurate, but
close enough: a glaze made with raw lead and a glaze to the same molecular
formula but with lead frits will result in the same lead glaze.
DON'T DO IT. STAY AWAY.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage....
Paul Lewing on mon 11 aug 03
on 8/10/03 8:00 AM, Lily Krakowski at mlkrakowski@CITLINK.NET wrote:
> Lead bisilicate is a frit. Frits were developed in the 19th century for two
> very good reasons. One was to make lead "safer" IN THE RAW STATE, to save
> lives in factories, and the other was to put water soluble materials
> insoluble.
>
> Touching and handling raw lead, breathing it in etc killed people. By
> INCORPORATING
> IT IN A GLASS the lead was made safer to handle in the raw state.
Actually, we're not even sure that's the case. It's true that during the
Industrial Revolution, when it was realized that lead poisoning was a
problem in china factories, fritted lead was introduced and the incidence of
lead poisoning went down. However, at the same time, factories were made
cleaner, with better ventilation and hygiene, people started to do things
like wear masks and overalls, and a bunch of other basic common sense
practices. Nobody's really sure if any of these reforms was more important
than any other in reducing lead poisoning. It was almost undoubtedly the
combination that did it.
We can easily test whether the same molecular formula made with fritted or
unfritted lead will leach less. We're not likely to ever see a test done
that will test whether breathing one form of lead is less hazardous than
another.
In some Early American potteries, it was common practice for the potter to
take a cheesecloth bag of raw lead oxide, hold it over the wet pot on his
wheel, and shake it till enough lead dust settled on the wet pot to make a
sort of glaze when it was fired. No mask, of course- not that it would have
helped! Just think about that for a minute.
Paul Lewing, Seattle
Lily Krakowski on tue 12 aug 03
Thank you Paul. Much I did not know.
One does not have to go to the 19th century. WE in the 1940s-1950s handled
raw lead barehanded. Handled it in glaze room, handled it in painting
class. Red lead in particular was fun as it is SO pretty. And printmakers
handwiping lead-ink inked plates...(I know of one said to have died of elad
poisoning. My s-i-l the prinmaker had it....)
And we DID not wear gloves and masks and we DID NOT get out of our glaze
clothes right away, and we DID NOT wash those clothes instanter...etc.
Actually I wonder how much illness and death were caused, or brought on
sooner by the LIVING conditions of workers. A bath once a week in a tub,
fresh clothes only once a week, dirty, dust covered overalls hanging in the
mudroom, dust moved every time a door slammed.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage....
John Hesselberth on tue 12 aug 03
I remembered that when the subject of lead came up earlier this summer
I promised I would dig up some info from a book I have (I was traveling
at the time) when I got a chance. I found this book fascinating. It was
written by William James Furnival in 1998 and is titled Research on
Leadless Glazes. It is dedicated "To all who ardently desire and are
working for the betterment of mankind". In the introduction Furnival
goes over some of the evidence of lead poisoning in England at the
time. For example:
"Sir Mathew White Ridley, replying to a question in the House of
Commons, on the 14th of July, 1898, is reported to have said: 'There
are many recorded instances which amply prove that in the pottery
trade, as elsewhere, the occurrence of lead-poisoning in the mother is
capable of producing grave effects on the children. The total number of
reported cases of lead poisoning among women and girls engaged in the
manufacture of earthenware and china, during the two and a half years
since the Act of 1895 came into force is--women, 528; girls, 63; or a
yearly average of about 230'."
Also:
"Mr Bertram Wilson, in the Hanley Labour Church report on
lead-poisoning, refers to the inquests upon the bodies of two young
boys, fourteen and fifteen years old, who had worked in the dipping
house only six and twelve months respectively. Of 156 cases reported to
them, twelve resulted in total blindness, two of these being paralyzed
and insane, three of them died since having been reported; of nine
cases liable to go blind, three of them..." and on it goes.
Mr. Furnival goes on to castigate those who are so selfish that they
won't share the results of their own leadless glaze research. He names
names and takes no prisoners. He must have been fired up like Gayle was
with her school board mission.
So some things have improved over the years--if we are smart enough to
heed the lessons from the past.
Regards,
John
>
http://www.frogpondpottery.com
http://www.masteringglazes.com
John Hesselberth on tue 12 aug 03
Ooops, I meant 1898. So much for my proof reading skills today.
John
On Tuesday, August 12, 2003, at 01:57 PM, John Hesselberth wrote:
> It was
> written by William James Furnival in 1998
>
>
http://www.frogpondpottery.com
http://www.masteringglazes.com
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