paul wilmoth on wed 17 dec 97
Hi Everyone,
Can anyone give me limits for lithium and strontium in an 04 glaze? I am
working on an alkaline matt, but am having leaching problems. I want to
stay away from soda and potassium as much as possible because of thermal
expansion problems, therefore I am looking toward lithium and strontium
for the alkaline quality.
TIA Paul Wilmoth
Paul Lewing on thu 18 dec 97
Paul,
I looked all over at one time for limit formulas for Li and Sr, as
well as Pb, and couldn'tfind anything in any of my books. I finally
did find those limits in Michael Zakin's book, "Mastering the Craft.
But I only wrote them down for c5 and c10. Look there for c04 limits.
Paul Lewing, Seattle
PS The limits for Li at c 3-7 were .05-.2, and for c8-10, .05-.2. For
Sr they were c3-7, 0-.4, c8-10, 0-.7. Pb was .2-.5 for c3-7, and, of
course, no listing for c8-10.
Tim Stowell on thu 18 dec 97
Beware of Strontium. I have not been able to find very much out about the
toxicity of strontium carbonate. I do know that other strontium compounds
are extremely toxic. There have not been very many studies involving
human exposure to strontium. My brother is a toxicologist for a major
chemical company and he looked up strontium carbonate for me using their
computers. I was asking him about using strontium carbonate as a
substitute for barium carbonate...His advice to me was stick with the
devil you know and avoid strontium in any form.
Tim
Tim Stowell Gerard Stowell Pottery
Stacey Gerard 290 River Street
tstwll@juno.com Troy, NY 12180
(518)272-0983
Tom Buck on fri 19 dec 97
Tim S. Such blanket statements you made on this topic seem a rather poor
way of seeking information.
How can one say what you do about Strontium Carbonate? Strontium
compounds are widely used in medicines, eg, in a brand of toothpaste to
counter sensitivity in tooth enamel. My reading of the literature leads me
to say that Strontium ions, unlike Barium ions, are well tolerated by the
body, and do not pose a hazard to potters who use SrCO3 in their glazes.
This topic has been covered before, and Monona Rossol's texts go into
detail. Please refer to them.
Tom Buck ) tel: 905-389-2339
& snailmail: 373 East 43rd St. Hamilton ON L8T 3E1 Canada
(westend Lake Ontario, province of Ontario, Canada).
Craig Martell on fri 19 dec 97
At 04:09 PM 12/17/97 EST, Paul wrote:
>----------------------------Original message----------------------------
>Hi Everyone,
>
>Can anyone give me limits for lithium and strontium in an 04 glaze? I am
>working on an alkaline matt, but am having leaching problems. I want to
>stay away from soda and potassium as much as possible because of thermal
>expansion problems, therefore I am looking toward lithium and strontium
>for the alkaline quality.
Paul:
I'm not sure if limits for either of these have been published. Lithium has
similar expansion properties with zinc and magnesia. The limits for ZnO and
MgO at 04 are .10 to .15. You might use this as a starting point.
Strontium has some of the same properties as BaO and CaO. Barium has a
lower limit due to toxicity but CaO is .30 to .60.
That's all I can tell you. Craig Martell-Oregon
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