Ron Roy on wed 29 sep 99
Hi Steve,
I don't mean this as a complaint against your statement. But I think we
have to discriminate here and realize that not changing clay recipes can
lead to problems as well.
As you may know I consult to two clay companies - my job is to look over
the clays that are to be mixed next - check the test data and make changes
that are necessary to keep the shrinkage and absorbency within bounds. The
changes are made are to prevent problems - and do not cause them.
We get individual complaints from potters and we help them isolate the
factors that are the problem but they are not from the careful maintenance
of our clays.
It is also true that we must get in the habit of testing the clays we buy -
it takes so little time - and it saves so much in the long run - a couple
of bars in the next firing along with a few cylinders to see if our glazes
still fit. Look at it this way - if your supplier is not testing - and you
are - you will soon be in a position to advise that clay company - think
about it - you will have information they need.
If your supplier is not testing - and after many complaints - the body is
changed - without test data to understand what happened - you have to guess
what the problem is. You might then have to make drastic changes - with no
check on what those changes do to the expansion of the body - of course it
can lead to big problems.
I also have to add - creating a data base for clays has it's own problems.
It is my experience that potters generally - know about as much about body
building as the clay makers. Couple that with lack of testing data and
someone to keep an eye on at least the raw materials and what do you have?
I do favour the sharing of glazes and clays - as you all know but - the
important part is how to evaluate the raw materials and provide the
technical data that will make this kind of thing better than what we have
now?
If all you want to do is start passing around your clay bodies - good luck.
RR
>Now at long last, after many vigorous denials, they have started
>supplying virgin grogs in their clays. Now perhaps we can concentrate on
>getting them to tell us when they change the recipes, without consulting
>anyone!
>
>Steve
Ron Roy
93 Pegasus Trail
Scarborough
Ontario, Canada
M1G 3N8
Evenings 416-439-2621
Fax 416-438-7849
| |
|
