Alisa Liskin Clausen on thu 4 jul 02
Dear Clayart,
With the great loss of David Shaner and the talk of his use of manganese =
in glazes, I paid particular attention to the following:
I am reading a Studio Handbook that is copyrighted 2001.
The author, Claus Domine Hansen, is a graduate of the very respected =
Glass and Ceramics School on Bornholm. The book is wonderful and =
demonstrates the wide know how Claus has about process, decoration and =
materials. I have seen some techniques in this book I have never seen =
elsewhere. His work, and the others illustrated, is very exciting, =
ranging from non functional to quality design and function.
But, here comes the but. The book was published one year ago. There are =
recipes included that call for=20
Terracotta base glaze
75 Lead Frit. There is a caution not to use on functional ware, and it =
could be subbed with another frit but the color would be more boring.
Silkemat base glaze cone 5
25 Barium Carb.
6 Lithium Carb.
Mat base glaze cone 5
40 Barium Carb.
Bronze Glaze cone 5
49 Manganese dioxide=20
Bronze glaze cone 6
43 Manganese dioxide
Bronze glaze cone 6
43 Manganese diox.
Clear base glazes cone 6
19 to 36 Barium Carb.
PHOOEY
After I look at all of the great work and read up on techniques, I am =
going back to Mastering Glazes for the surfaces.
In all seriousness, I also think about the only purely pottery school =
here now wanting to introduce more "individual projects and art". How =
many graduates of these programs are produced and expect to make livings =
without a good background in glaze safety and chemistry?
Which leads me to Marianne's post of a glaze fault being all right to =
use. People do that all the time, but they call it an effect. I =
personally have nothing against effects that I like, but would not want =
to smooth over the rim of a mug with my lips over that stuff. The puffy =
mouth look minus the cost of collagen injections because one is being =
sawed to pieces by shivering!
I have very rough, chunky glazes that I like on some bigger pots. They =
are a fault on mugs and plates because they crawl and chip. But on the =
non functional pots that they look good on, they are an effect. Name =
game?
Clayart is a (large) part of my continuing education. I think it is =
very important to stay current and aware no matter what discipline one =
has, whether it is medicine or clay. Clay can also be life threatning =
if one continues outdated or uninformed practices.
On a lighter note, I hope everyone is enjoying some summer days.
regards from Alisa in Denmark. Should stop raining next week.
Jeff Tsai on thu 4 jul 02
Hi,
I've never seen the book in question or how it speaks about manganese use and
firing in glazes, or barium or any of the other chemicals you listed.
I guess judgment on whether the book is outdated or irresponsible would
depend on how the author also explained the problems with working with these
chemicals. If he failed to give proper warning, then that's bad, but if he
warns you that lead should not be used for functional work, and care must be
taken with manganese in firings, etc. etc. then he or she has probably done
his or her job.
I am not the most careful person in the world, but I read about the dangers
before I do a work, that's a personal responsibilty as well as a
responsibilty of an author. If I saw a cake recipe that called for arsenic, I
wouldn't simply add the ingredient and not think, well, I know that's a
chemical of some kind but I won't make sure it won't kill me.
Let's face it, lots of our materials are hazardous. Silica is bad for us,
Chrome is possibly a carcinogin. It's as much our responsibilty to learn
about our chemicals as it is to depend upon the pages of just one book.
-jeff
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