Helen Lovell on thu 7 feb 02
First - thanks to all for your thoughtful commentary on the importance =
of craftsmanship. I am psyched to improve - Going to attend more =
workshops - and Brown University offers free space at their annual =
crafts show in November - so aiming for that.=20
'Nother topic: What kinds of kiln rehab should I do? Are there symptoms =
that your elements are going or do they just cut out? I don't want to =
risk underfiring. If something is underfired can you fire it again? I'm =
sure this has all been discussed before - so, in your opinion, what is =
the best book for this type of info?
Here's the current situation: I bought a used Skutt kiln. It has 3 =
sections and an optional 4th with no elements, low, med and high =
settings - no controller. The junior cone holder is busted. 2 or 3 =
bricks are pretty chewed up around the lid to a depth of, say, 3/4 inch. =
One of the peep hole stuffers (don't know its proper name) is gone. It =
has a fan at the bottom and I have never closed the top peep anyway. It =
came with used elements (and a new extra set!). I have fired it up (cone =
6) about 10 times with no problems (related to the equipment).
I spoke with the ITC people - that seems to be a good idea but I am =
nrerous about the application process and don't want to screw up the =
kiln. Any advice?
TIA -
Joan Lovell
Cindy Strnad on thu 7 feb 02
Dear Joan,
As long as your kiln is firing well, there's no
need to change out the elements. Unless one of
them actually breaks, they will fail gradually and
you will notice slower and slower firings. If a
firing ends up incomplete, you can usually
re-fire, but much depends on how your glazes react
to this treatment. If you do re-fire, be sure to
take the kiln up very slowly, as previously-fired
ware is slow to exhaust gasses and will explode if
fired too quickly.
You can't easily ITC the elements that are already
installed (unless there's some info I've missed?),
and with such a small kiln, I don't think the ITC
is going to make that much difference in your
firing. From what I've heard, it will give your
elements some protection. You can dip the new ones
before installing, but be sure to get the right
kind of ITC. They make one especially for the
elements. At that point, you can also spray the
kiln if you like, but repair the fire bricks
first.
So how are you firing with the junior cone holder
busted? Just propping the master switch up and
using shelf cones? Get a new junior cone holder.
They can't cost that much--simple as they are, but
even if they do, get one. A local ceramics shop
(even the kind with the pink unicorns) may be able
to help you find the part. If not, phone the
kiln-sitter manufacturer and ask them or call
Euclids--not sure if they carry this sort of
thing, but you can ask. This is a very handy
device to have, though it doesn't preclude the
necessity to keep an eye on your kiln. It's an
important safety back-up and you really shouldn't
be firing an electric kiln without it or something
similar. Your insurance company would undoubtedly
object as well.
Cindy Strnad
Earthen Vessels Pottery
RR 1, Box 51
Custer, SD 57730
USA
cindy@earthen-vessels-pottery.com
http://www.earthen-vessels-pottery.com
Snail Scott on thu 7 feb 02
At 06:35 AM 2/7/02 -0500, you wrote:
>...What kinds of kiln rehab should I do? Are there symptoms that your
elements are going or do they just cut out? I don't want to risk
underfiring. If something is underfired can you fire it again?
If your elements are going, you will notice an incease in the time needed to
reach tempearature. Depending on the temperature you are trying to reach, you
may still be able to get there, but it will take longer. (Even with many bad
elements, you may still be able to bisque, for example, but because ^10 is so
close to the designed maximum temp of these things, even one iffy element may
prevent reaching temperature.) Just keep an eye on your witness cones. If the
elements are so bad that you can't reach your intended temperature, just shut
the poor thing down, replace the elements, and refire the stuff. You can
almost
always refire.
To see which elements might be your trouble, turn it on, turning the knobs up
in 5 minute increments. After it's been on High for about 20 minutes, look
through the peepholes. Elements which are totally black may be broken, or
maybe it's just a bad connection. Elements which glow, but show black (not-
glowing) patches need to be replaced.
>Here's the current situation: I bought a used Skutt kiln. It has 3
sections and an optional 4th with no elements, low, med and high settings -
no controller. The junior cone holder is busted. 2 or 3 bricks are pretty
chewed up around the lid to a depth of, say, 3/4 inch. One of the peep hole
stuffers (don't know its proper name) is gone. It has a fan at the bottom
and I have never closed the top peep anyway. It came with used elements
(and a new extra set!). I have fired it up (cone 6) about 10 times with no
problems (related to the equipment).
Sounds great! (No kidding!) All those problems are very fixable, especially
on a Skutt. Replacing broken bricks is easy on a Skutt, since every brick
is accessible without removing any others. The top-rim bricks are especially
easy. Pull the pins holding the elements to the broken bricks, and ease the
elements out of the grooves. Old elements can be brittle, but will soften if
you heat them with a little propane torch. Then loosen the hose clamps
holding
the steel jacket, pull the broken brick up and out and slide a new brick in.
Tuck the elements back in the groove, heating again if necessary, and pin
them.
If you plan to use ITC, just pull out all the old elements, apply the ITC,
then install the new elements. Old ones are often too brittle to survive
being
pulled and reinstalled, and since you've got to pull them out anyway to apply
the ITC, and you've already got a repacement set, seize the opportunity to
start fresh. The only really tough part of this process is crimping down the
connectors to the elements - ordinary pliers or crimpers aren't really studly
enough, and you need to get them tight!
What's broken on the kiln sitter? If it's just the support prongs, that's
easy.
If it's the rod that sits on top, that's pretty easy, too. If the ceramic
tube
is actualy broken, that's a bit more work, but still a do-it-yourself job.
If it was me, I'd replace any elements that were actually bad and leave the
rest, and pack a few chunks of kaowool into the lid gap. I'd replace the
sitter tube next (if that's what's wrong), but fire with witness cones in
the meantime. I'd make a peephole plug from a scrap of softbrick. I'd save
doing the ITC 'til after I win the lottery. (That's the 'I'm broke' approach)
If you can afford it, though, go ahead and do all the repairs and ITC; it
will be better than new afterward.
-Snail
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