crafts - INFORMATION porcelain/pottery

You want to post this on the the clayart list
http://lsv.ceramics.org/scripts/wa.e...D1=clayart&A=1 (if you don't
belong)
or to the yahoo
http://groups.yahoo.com/group/potterybasics/

There are experts here who could answer you question in more detail but it
has been extremely quiet of late. I can give my opinion but it is not one
you would want to post.

Porcelain first came to us from China. It is made primarily from a clay
called Kaolin (or China clay). Europeans tried to copy the ware out of
China, eventually discovering their own sources of white clay but none of
them quite compare to what came out of China. For one thing what we have is
not as plastic (making it harder to throw). We do however have some kaolins
that are more 'pure'.

Although you can get what is labeled as mid fired porcelain that vitrifies
(melts and forms glass as part of the body) by the use of fluxes and other
ingredients (ball clay for example) it is not to me a 'real' porcelain. In
general porcelain is made up of 50% white clay, 25% free silica and 25%
felspar. The feldspar used matters because to make the porcelain
translucent it has to be fired high enough for the body to melt but not to
slump. The feldspar 'holds' it up in its fluid state.

As I said, don't trust what I say. Ask and look elsewhere.

Donna

"Ron" rower$$$start.no.replacedollarswith@ wrote in message
...
Hi,

I have been googling quite some time for information about the ingredients
and processes involved in making contemporary porcelain/pottery. But I am
still not satisfied.

It seems as if there are several different opinions about the EXACT
definition of what porcelain is.

The ingredients seem pretty obvious: clay/kaolin/feldspar/quartz.

Some sources say that ALL the ingredients melt into the flux (feldspar),
while others speak about the flux sintering the other ingredients
together,
only partly dissolving them.

Can anybody direct me to a website with a comprehensive
description/classification of the different types of porcelain/pottery. Or
if somebody wants to write down an explantion in this group I would
obviously be extremely grateful!

I would also like to learn more about the enamel.

The information -if satisfactory- would be used in a museum display about
feldspar.

Any help is greatly appreciated!

Ron
Norway