Joan Conklin on wed 24 may 06
Should I be concerned? I just did a clean up of the inside of my electric kiln which included the removal of the kiln shelf that I had raised 1 inch above the kiln floor. I noticed three cracks which do not run along the lines of the brick lines. My kiln is 4 years old a Scutt 1027 with thicker walls and envirovent (factory drilled holes in lid and floor). It runs well and maintains cone temperature exactly as I want through slow cooling. I use Ron and John's firing with a slow cool. But what about these cracks! It sits on cement floor.
Joan
Arnold Howard on wed 24 may 06
Joan, those cracks are probably minor and nothing to be
concerned about. Insulating firebricks go through tremendous
stresses every time you fire them. It is amazing how well
they hold up. Small cracks are normal.
You mentioned the cement floor. I am assuming that your kiln
sits on a kiln stand. It should not be directly on a cement
floor.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
----- Original Message -----
From: "Joan Conklin"
> Should I be concerned? I just did a clean up of the inside
> of my electric kiln which included the removal of the kiln
> shelf that I had raised 1 inch above the kiln floor. I
> noticed three cracks which do not run along the lines of
> the brick lines. My kiln is 4 years old a Scutt 1027 with
> thicker walls and envirovent (factory drilled holes in lid
> and floor). It runs well and maintains cone temperature
> exactly as I want through slow cooling. I use Ron and
> John's firing with a slow cool. But what about these
> cracks! It sits on cement floor.
Snail Scott on wed 24 may 06
At 05:47 AM 5/24/2006 -0700, you wrote:
>>>>
Should I be concerned?...kiln floor...three cracks which do not run along
the lines of the brick lines. My kiln is 4 years old a Scutt 1027...what
about these cracks! It sits on cement floor...
<<<<
Not directly, right? It's on a stand or on blocks
or something?
As for the cracks, don't sweat 'em. It's normal
to have a few. Kilns flex and brick is brittle.
That said, I realized a few years ago that I'd
really shortened the life of my kiln bottom by
resting my full weight on the rim when loading
the bottom. All that weight, carried straight
down the wall to the edge of the floor, where the
floor is NOT supported directly by the stand.
That's shear force and deflection, on a cantilever.
Didn't realize how bad it had gotten (exacerbated
by thousands of miles in the back of a U-Haul)
until I unstacked it to replace the bottom element.
Always considered the steel band on the bottom
to be sort of irrelevant until then, but that's
literally all that was holding it together!
If you're as short as I am, consider shortening
your kiln stand a bit(over concrete, it's fine),
or building a loading platform anound the kiln.
Some minor cracking is unavoidable, though, and
will do no real harm at all. It's fine.
-Snail
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