Tom Buck on wed 6 sep 06
Lee Love:
You requested the recipe of mine in John Britt's book; and got two
-- the eastern North American version and the western N.A. version.
In the east most potters use as potspar, G200 feldspar, while in
the west most potters use Custer feldspar. the two spars are close in
analysis but not dead-on, so one tends to make a minor adjustment.
now comes the other difference, wollastonite for whiting. If you
run a fast fire to Cone 10, and cool quickly, with whiting you likely get
pinholes aplenty. so you change to wollastonite (calcium silicate) and
avoid the outgassing of Calcium Carbonate (CaCO3 goes to CaO and CO2). but
there is a change in the way the glaze may look depending on the way you
fire etc.
with whiting, the glaze is low on silica so the glaze will
probably grab some from the body. not so with wollastonite. both versions
give a low COE suitable for porcelain.
good tests. peace Tom B.
Tom Buck ) -- primary address.
"alias" or secondary address.
tel: 905-389-2339 (westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street, Hamilton ON L8T 3E1 Canada
Lee Love on wed 6 sep 06
Thanks Tom!
It is good to be able to look at the recipe. You always feel left
out (like an inside joke) when folks are talking about a recipe and aren't
sharing the subject of the discussion.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
| |
|
