Randy McCall on wed 28 dec 05
I have been using a commerical clay that I use at cone 6 that I like. It
does fine for small pieces under 5 or 6 lbs, but when I make anything over
6lbs I a having a much higher percentage of cracking problems even though I
put it in a drying cabinet and take a month to dry it. I also fire in
electric and gas. I guess it could be from some uneven throwing in the
walls, but I am looking for a clay that would be more forgiving.............
Thanks for any suggestions.
Randy
Pottery Web Site
members.tripod.com/~McCallJ/index.html
South Carolina
David Beumee on wed 28 dec 05
Randy,
Time to let go of this particular body. Try to get some samples of every cone 6 clay you can lay your hands on, and make both small and larger forms from each clay, keeping close watch on a similar weight of moist clay for each form. As you throw each piece, write a small note as to the body used and put it by each piece, and keep track throughout the trimming and drying process, writing the body on the bottom of each piece. No need to baby the drying time. Just put all the thrown pieces in your cabinet and allow a reasonable amount of time to let them get leather hard for trimming. A body will emerge that you can use for larger forms that doesn't need to be babied with a month of drying time. If this doesn't work, contact me off list and we'll figure something out.
David Beumee
Lafayette, CO
www.davidbeumee.com
-------------- Original message ----------------------
From: Randy McCall
> I have been using a commerical clay that I use at cone 6 that I like. It
> does fine for small pieces under 5 or 6 lbs, but when I make anything over
> 6lbs I a having a much higher percentage of cracking problems even though I
> put it in a drying cabinet and take a month to dry it. I also fire in
> electric and gas. I guess it could be from some uneven throwing in the
> walls, but I am looking for a clay that would be more forgiving.............
>
> Thanks for any suggestions.
>
>
> Randy
>
> Pottery Web Site
> members.tripod.com/~McCallJ/index.html
> South Carolina
>
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Ron Roy on thu 29 dec 05
Hi Randy,
I too think you need to consider finding another clay - it sounds like you
may be using a clay with too much shrinkage - or perhaps not enough.
If you would like to test that clay for shrinkage and absorbency let me
know and I will send you some testing information.
RR
>I have been using a commerical clay that I use at cone 6 that I like. It
>does fine for small pieces under 5 or 6 lbs, but when I make anything over
>6lbs I a having a much higher percentage of cracking problems even though I
>put it in a drying cabinet and take a month to dry it. I also fire in
>electric and gas. I guess it could be from some uneven throwing in the
>walls, but I am looking for a clay that would be more forgiving.............
>
>Thanks for any suggestions.
>
>
>Randy
.
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Phone: 613-475-9544
Fax: 613-475-3513
Ivor and Olive Lewis on wed 4 jan 06
Dear Randy McCall,
I cannot think of a technical reason why a clay should behave perfectly =
when used in small quantities but mis-behave when you increase the =
weight of the pot beyond a few pounds.
If you were to describe the cracking problems in more detail perhaps you =
might get someone to come to the table with an answer.
By the way, are you absolutely certain that the smaller pots contain no =
cracks or is it that because the pots are smaller the flaws are so =
insignificant that you cannot see them?
What does the manufacturer have to say about your problem?
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Cheryl Weickert on thu 5 jan 06
I have to wonder if Randy is using more water and taking a long time to
throw the larger pieces. If he/she has water sitting in the bottom of the
pot for quite a while it could cause the cracks on the bottom of the pot
when it dries, I had this problem when starting out. Sorry, just found
this conversation, so not sure if Randy's been throwing for a while and
this is a new problem of if he/she is a beginner and just starting to
throw larger amounts of clay.
Pinky in MN... enjoying the winter's quiet.
On Wed, 4 Jan 2006 15:02:17 +1030, Ivor and Olive Lewis
wrote:
>Dear Randy McCall,
>
>I cannot think of a technical reason why a clay should behave perfectly
when used in small quantities but mis-behave when you increase the weight
of the pot beyond a few pounds.
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