Teresa Speakman on sun 6 feb 00
I read somewhere that Spain produces much lead glazed pottery,
but they pretreat it before use. I can't remember exactly how, but I
think they boiled vinegar(?) water a few times in the vessel, and this
was supposed to leach the majority of available lead out. Did I read
it in Joaquim Chavarria's Big Book Of Ceramics? I can't remember. Has anyone
anyone else heard of this? I don't know chemistry well enough to
understand if this makes sense.
-Teresa in Ohio
Don & Isao Morrill on mon 7 feb 00
Teresa>- Sounds to me as useful as putting a silver coin in wild mushrooms
to check their possible toxicity.
As for reducing lead content in ceramics,one would require a hell
of a lot of vinegar and a very long boiling time......poor economics and
even then virtually impossible to oxidize any but a miniscule amount of
surface lead.
I realize I repeat my message but, it is not the drinking from one
lead vessel once a week that poisons us but the accumulation of minute
quantities of lead from hundreds of sources in our society over time. I'm
quite sure there is lead in my system from childhood when we had lead pipes
in our house. I suspect that parts of Europe where lead has been used for
many purposes such as soldering, for centuries (and leaded gasoline for
nearly 100 years) would show higher levels of lead than much of Africa and
probably, N.America.
Don & Isao Sanami Morrill
e-Mail:
Cindy Strnad on mon 7 feb 00
Teresa,
I read something like this in Kardew's Pioneer Pottery. Don't remember for
sure if he recommended boiling vinegar, specifically, or just water. I
expect vinegar would work better because of its acidity, but I wouldn't
trust either method to remove all leachable lead. The only way to be sure
would be to have the piece tested. In any case, boiling out the lead doesn't
protect the potter.
Cindy Strnad
earthenv@gwtc.net
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
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