"Duane Kimball (by way of Duane Kimball on sun 16 feb 97
My new skutt 1027 has survived its first bisque...yahoo. But i am wondering
whether firing glazes to cone 5/6 rather than 9/10 will lengthen the life of
the elements? Of course, it is meant to go that high, but has anyone found
that this lower firing translates into a larger number of possible firings?
Dave and Pat Eitel on mon 17 feb 97
>----------------------------Original message----------------------------
>My new skutt 1027 has survived its first bisque...yahoo. But i am wondering
>whether firing glazes to cone 5/6 rather than 9/10 will lengthen the life of
>the elements? Of course, it is meant to go that high, but has anyone found
>that this lower firing translates into a larger number of possible firings?
Absolutely! By a huge amount, I'd guess.
Later...Dave
Dave Eitel
Cedar Creek Pottery
Cedarburg, WI
pots@cedarcreekpottery.com
http://www.cedarcreekpottery.com
Greg Lamont on mon 17 feb 97
At 11:19 AM 2/16/97 EST, you wrote:
>----------------------------Original message----------------------------
>My new skutt 1027 has survived its first bisque...yahoo. But i am wondering
>whether firing glazes to cone 5/6 rather than 9/10 will lengthen the life of
>the elements? Of course, it is meant to go that high, but has anyone found
>that this lower firing translates into a larger number of possible firings?
>
Hi Duane,
I was just discussing this topic with Pete Pinnell the other day. I have a
L&L J-230 Kiln which I fire to cone 6. Pete fires to Cone 04. He said that
I should expect to quadruple my element life overfiring at cone 10. (not to
mention reducing the stresses on the rest of the kiln!). He estimates that
by firing at earthenware temps his elements should last 40 times over what
they would last at cone 10. I'm no whiz at this but Pete's been in thsi
business for a long time and, like Dr. Science says, "He knows more thatn I
do!"
Kurt Unterschuetz on mon 17 feb 97
Duane Kimball (by way of Duane Kimball ) wrote:
>
> ----------------------------Original message----------------------------
> My new skutt 1027 has survived its first bisque...yahoo. But i am wondering
> whether firing glazes to cone 5/6 rather than 9/10 will lengthen the life of
> the elements?
Hi Duane or Mrs. Duane?
I fire a km 1027 skutt kiln to cone 5-6 and have to replace elements
once per year. Last year I counted 275 firings. Of course some are
bisque firings.
Kurt Unterschuetz
SchatziBoyz Pottery
Marengo, IL
Curt Heuer on tue 18 feb 97
>But i am wondering whether firing glazes to cone 5/6 rather than 9/10 will
>>lengthen the life ofthe elements?
I seem to remember from Grad school a figure of 1500 hours as the life of
an element fired only to ^05, but a life in the range of only 600 hours of
so when fired to ^9. I'm sure the tech people at Skutt can give you a
definitive answer.
Curt Heuer
UW-Green Bay
Tom Buck on wed 19 feb 97
Since there have been several questions relating to element life, perhaps
this quote from the developer of Kanthal alloys is appropriate:
Life of KANTHAL alloys
"The life of a resistance material is directly dependent on service
conditions, i.e. furnace atmosphere, ceramic ,ountings, temperature,
radiation possibilities, surface loading, frequency of switching, and the
construction of the lement.
"For practical reasons the manufacturer of resistance materials
must, during the manufacturing process, use a system of testing which will
give quick results with sufficient accuracy. For this reason,
Kanthal resistance materials are given a life test as specified by the
American Society for Testing Materials. The Kanthal tests wires are
suspended in a U shape between two adjacent contacts, without any
additional weight, and are energized. Most of the tests are performed at
1200 degrees C (2190 F).
"The test wire has a diameter of 0.0285" (0.72mm). The necessary
current and voltage are controlled by resistors in series until the
desired wire emperature, as tested with an optical pyrometer, is reached.
By intermittent current application, the wire is alternately cooled and
heated so that it expands and contracts. The material is therefore
subjected to more stringent demands than in normal operations, thus
accelerating the test."
The results of this testing are then displayed in a graph. For Kanthal A1
alloys (the usual element material), the graph shows a lifetime of almost
800 firings to 1150 C, 2100 F, and 360 firings to 1200 C (2192 F), 200
firings to 1250 C 2280 F, 110 firings when going to 1300 C 2370 F, 80
firings when reaching 1350 C 2460 F, 60 firings at 1375 C 2500 F.
These results are under the best test conditions at Kanthal, and hence may
be looked upon as the top number of firings to be expected when going to
the specified temperature. Lower lifetime will be obtained if the firinbgs
conditions cause damage to the surface of the element wire.
Cheers Tom.Buck@freenet.hamilton.on.ca
Hamilton, Ontario, Canada
On Tue, 18 Feb 1997, Curt Heuer wrote:
> ----------------------------Original message----------------------------
> >But i am wondering whether firing glazes to cone 5/6 rather than 9/10 will
> >>lengthen the life ofthe elements?
>
> I seem to remember from Grad school a figure of 1500 hours as the life of
> an element fired only to ^05, but a life in the range of only 600 hours of
> so when fired to ^9. I'm sure the tech people at Skutt can give you a
> definitive answer.
>
> Curt Heuer
> UW-Green Bay
>
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