Dov Katz on sat 20 jul 96
Hi,
I'm trying to source some materials for a porcelain glaze recipe (from
Peter Lane's book "Contemporary Porcelain"). The recipe uses "Cornish
Stone" (feldspathoid containing feldspar, quartz, kaolinite, mica and a
small amount of fluorospar). Can anyone recommend a supplier that may
carry this? Local suppliers carry "Cornwall Stone", is this the same
thing? "Cornwall Stone" is described as a feldspar in the suppliers
literature. Doesn't sound like the same thing.
Any help appreciated as I'm new to this :) !
Thanks,
Dov Katz
email: dov_katz@horizon.bc.ca
David Hewitt on mon 22 jul 96
In general terms Cornish Stone and Cornwall Stone are the same.
The following Cornish Stone formula is taken from Cookson's catalogue,
the main UK supplier, and is typical. The Cornwall Stone recipe is as
given to me by Ron Roy, and I understand is typical of what you may
obtain. I would substitute the same amount of Cornwall Stone for the
Cornish Stone in your recipe and try it.
Percent Analysis
Oxide Cornish Stone Cornwall Stone
K2O 4.40 3.68
Na2O 3.44 3.68
CaO 1.47 1.99
Al2O3 15.3 15.9
Fe2O3 0.13 .14
SiO2 73.2 72.56
TiO2 0.06 .07
P2O5 0.47 .5
LOI 1.53 1.48
David Hewitt
David Hewitt Pottery Caerleon, Newport, Gwent, UK.
URL http://digitalfire.com/magic/hewitt.htm
| |
|
