iandol on thu 12 apr 01
Dear Logan Oplinger,
I have been wondering about other factors which might be influential in =
inducing this defect. Do you know if anyone has gone beyond the idea of =
it only being stress, induced in wedging which is the prime cause?
I ask because I am working on this topic this week.
Best regards,
Ivor Lewis. Redhill, South Australia
tomsawyer on fri 13 apr 01
Ivor,
I don't have the answer to your question but I do have an additional
question. Why is cracking less common and different in pressed slabs than on
thrown slabs? I suspect that with pressed/rolled slabs the orientation is
parallel and with thrown slabs it is concentric but what does this have to
do with frequency and shape?
Tom Sawyer
tsawyer@cfl.rr.com
Tony Ferguson on fri 13 apr 01
Iandol,
S cracks, based on my experience with them when I was
learning how to throw, has to do with inadequate
compression when you are making your bottom. This
will also happen when throwing off the hump. Becasue
I make sure I compress my bottoms, I haven't had an S
crack for years. Knock on wood. I also don't just let
my pots air dry right after trimming--like I used to
when I S cracked. I wait a day to let the moisture
even out and then leave them un covered. None the
less, I think S cracking has more to do with
compression then anything else.
Tony Ferguson, Duluth, MN
| |
|
