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replacing coils??

updated mon 19 jul 99

 

John Tiemann on fri 16 jul 99

I have started teaching ceramics at a High School in Missouri, and I'm =
firing
two Skutt kilns. I found several new packages of element coils (top, =
middle,
bottom) but I'm not sure if I really need to change them now or not. I =
don't
know the last time the teacher before me had replaced them. What are the =
usual
signs that would let me know that the coils need replaced? If they do need
replaced, can anyone refer any handouts or books that would guide me through
this process? I've heard that after the coils have been replaced, the kiln
should be fired empty to =5E4 so a coating can form on the coils.... I am
interested in any comments about this. I appreciate any advice from you =
pro's=21=21

Thanks in advance=21

John

Mike Bailey on sun 18 jul 99

In message , John Tiemann writes
>----------------------------Original message----------------------------
>I have started teaching ceramics at a High School in Missouri, and I'm =
>firing
>two Skutt kilns. I found several new packages of element coils (top, =
>middle,
>bottom) but I'm not sure if I really need to change them now or not. I =
>don't
>know the last time the teacher before me had replaced them. What are the =
>usual
>signs that would let me know that the coils need replaced? If they do need
>replaced, can anyone refer any handouts or books that would guide me through
>this process? I've heard that after the coils have been replaced, the kiln
>should be fired empty to =5E4 so a coating can form on the coils.... I am
>interested in any comments about this. I appreciate any advice from you =
>pro's=21=21
>
>Thanks in advance=21
>
>John
>
Dear John,

A couple of thoughts.

You only need to replace the elements when the kiln fails to make
temperature - or is beginning to take too long to get to temperature.
All elements age and will eventually need replacing. The higher you fire
the more wear and tear there is on the elements and the more often
they'll need replacing.

Theory says that if one element breaks you should replace the full set -
just replacing one element unbalances them as the resistance of the
remaining old ones will be less than the new one. However, expediency
and lack of cash often dictate what one does!

You are correct about the firing of any new element up to red heat with
the kiln empty. This does increase their life-span.

Cheers,

Mike.
--
Mike Bailey. Bath. U.K.