William & Susan Schran User on fri 22 aug 08
Folks,
Besides testing shelves in ^10 reduction firings, this past summer I was
also testing a 15" octagonal Corelite shelf in our raku firings. We fire in
a IFB bottom, fiber lined metal mesh top updraft kiln. After the kiln gets
going our firing cycle is usually around 20 minutes.
The Corelite shelf broke after about 20 firing cycles, so I am not
recommending this brand shelf for raku firing.
After a few back & forth messages I finally got this response from the
technical sales support rep from Resco, the parent company making these
shelves:
"Thank you for putting the CoreLite shelf we donated to you at NCECA through
the Raku process. Your experience has helped us to better understand how
they perform in in that application. Although we were a little disappointed
that you didn't get that many firings with, I can't say we were really
surprised. We felt that a higher temperature material would be more
universally beneficial to ceramists, and as such the CoreLite shelves
contain substantially more mullite than a standard cordierite shelf. This
gives much better performance at cone 10 temperatures, but we sacrifice a
small amount of thermal shock resistance as a result. Mullite has a thermal
expansion coefficient higher than cordierite. The thermal gradient imposed
by the cores may have contributed, testing a pure cordierite shelf may
answer that question."
"Thanks again for your valuable input, if we decide to further develop a
better Raku shelf, can we send you one?"
Eric Nedreberg
Technical Sales Support Representative
I still suggest this shelf for ^6 electric kiln firings due to their lighter
weight, lower thermal mass and cost.
I'm continuing my testing at ^10 reduction and they seem to be holding up
well.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
jonathan byler on sun 24 aug 08
So I guess I have to go to NCECA to get them to give me free shelves
too??? ;)
Thanks for posting the info bill. Always interesting to see how the
competing technologies pan out.
jon byler
3-D Building Coordinator
Art Department
Auburn University, AL 36849
On Aug 22, 2008, at 4:01 PM, William & Susan Schran User wrote:
> Folks,
>
> Besides testing shelves in ^10 reduction firings, this past summer
> I was
> also testing a 15" octagonal Corelite shelf in our raku firings. We
> fire in
> a IFB bottom, fiber lined metal mesh top updraft kiln. After the
> kiln gets
> going our firing cycle is usually around 20 minutes.
>
> The Corelite shelf broke after about 20 firing cycles, so I am not
> recommending this brand shelf for raku firing.
>
> After a few back & forth messages I finally got this response from the
> technical sales support rep from Resco, the parent company making
> these
> shelves:
>
> "Thank you for putting the CoreLite shelf we donated to you at
> NCECA through
> the Raku process. Your experience has helped us to better
> understand how
> they perform in in that application. Although we were a little
> disappointed
> that you didn't get that many firings with, I can't say we were really
> surprised. We felt that a higher temperature material would be more
> universally beneficial to ceramists, and as such the CoreLite shelves
> contain substantially more mullite than a standard cordierite
> shelf. This
> gives much better performance at cone 10 temperatures, but we
> sacrifice a
> small amount of thermal shock resistance as a result. Mullite has
> a thermal
> expansion coefficient higher than cordierite. The thermal gradient
> imposed
> by the cores may have contributed, testing a pure cordierite shelf may
> answer that question."
> "Thanks again for your valuable input, if we decide to further
> develop a
> better Raku shelf, can we send you one?"
>
> Eric Nedreberg
> Technical Sales Support Representative
>
>
> I still suggest this shelf for ^6 electric kiln firings due to
> their lighter
> weight, lower thermal mass and cost.
> I'm continuing my testing at ^10 reduction and they seem to be
> holding up
> well.
>
> Bill
>
> --
> William "Bill" Schran
> wschran@cox.net
> wschran@nvcc.edu
> http://www.creativecreekartisans.com
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