Ivor and Olive Lewis on sat 13 jan 07
Dear Friends,
Those who wish to investigate Ball Milling of Ceramic Raw materials =
might like to read :
Michael Cardew , "Pioneer Pottery". Appendix 7. Ball Mills. pp 375-285. =
Ten information packed pages
Harry Davis. "The Potters Alternative". Index has a paragraph of =
entries.
Stephen Harrison, "Thoroughly Modern Milling." Discussion paper covering =
technology and working plans for the construction of a Ball Mill (six =
sheets).
Gem Tumblers are not designed to process ceramic materials and render =
them into impalpable powders. Their barrel rotational speed is =
calculated so that the charge does not quite cascade. Lightly abrasion =
is the Keyword (See Sinkankas "Gemstone Cutting")
Ball Mills are designed to pulverise the charge, not abrade and polish. =
Speed of barrel rotation is just sufficient to allow the charge to =
cascade but not so high as to kept it in contact with the barrel wall by =
centrifugal force.=20
Percussive impact is the best way to describe the process
At Sunderland School of Art (Ryhope Road), operation of a ball mill was =
essential learning. But that was in the days before students were hand =
fed the best materials manufacturers could provide (1965). I still have =
a pot from those days. Used Durham Dolomite with Wood Ash and white =
clay. I broke and milled the Dolomite.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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