Rlucas on sat 26 mar 11
I have some 7/8" thick shelves (they are 1/2 shelves) for my Skutt KM 1027=
.
They have not been used much but they are cracking all the way through on
the straight edge about 3 or 4 inches in. They are 5 sided 1/2 shelves.
First of all I cannot imagine what caused them to do this and I wonder if
they will continue to crack all the way to the end.
If they would do that of course it would be disastrous. the only thing I
can think of to do is put a stilt where the crack is.
I have replaced my shelves several times since I purchased the kiln but
these have been sitting unused for 5 years because
I was not working with clay.
Any input would be appreciated.
Thanks
Verna
rlucas@centurytel.net
William & Susan Schran User on sun 27 mar 11
On 3/26/11 9:15 PM, "Rlucas" wrote:
> I have some 7/8" thick shelves (they are 1/2 shelves) for my Skutt KM 10=
27.
> They have not been used much but they are cracking all the way through o=
n
> the straight edge about 3 or 4 inches in. They are 5 sided 1/2 shelves.
> First of all I cannot imagine what caused them to do this and I wonder if
> they will continue to crack all the way to the end.
> If they would do that of course it would be disastrous. the only thing I
> can think of to do is put a stilt where the crack is.
> I have replaced my shelves several times since I purchased the kiln but
> these have been sitting unused for 5 years because
Verna,
Though you don't write what type of shelves these are, I will assume they
are cordierite. You write they are 7/8" thick, but I have never run across
shelves this thick. Usually they are 5/8" or 3/4" thick. 5/8" thick shelves
are usually the size supplied fro your 7 cu. ft. kiln.
Why would they crack? Several answers come to mind and it is difficult to
say definitively what the answer is. I've seen batches of kiln shelves crac=
k
from manufacturing faults. Usually I see warping, but I imagine they might
crack from high firing with heavy loads. You wrote they had been stored for
5 years. Were they laying on dirt or concrete floor where moisture
absorption is possible? Were they laying flat with other stuff on top of
them? Were they possibly hit while stored or dropped/knocked into something=
?
You also wrote you have replaced shelves several times since purchase of
kiln - why, what happened to the shelves?
I have had shelves develop cracks and I continued to use them for many
years.
If concerned, you certainly could place posts lined up with the cracks, jus=
t
don't forget to place post under bottom shelf where you will line up the
ones above.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
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