search  current discussion  categories  kilns & firing - manufacturers 

duncan kiln: good news!

updated tue 14 jun 05

 

Steve Slatin on fri 27 may 05


Marianne --

Bet that 5x20'll work really well now!

One of the reasons why people often use two (or more)
ways of checking their firings is that nearly
everything is subject to some variation or error.
With cones, placement can be critical. With a timer,
you can let it go for as long as it took last time,
but if your elements are deteriorating or your power
company's running the voltage a little off you could
miss by quite a bit.

The thing with kilnsitters may be that the sitter is
mis-adjusted or that you didn't place the cone as
anticipated (did you use bar cones or the
pyramid-shaped ones? They're hard to seat properly).
Typically what the sitter does, though, is to turn off
too late (overfiring) if the sitter isn't in perfect
condition, or too early (if you use, say, a #6 cone
for a #6 firing, the weight of the bar on the sitter
will deform the cone before the temperature is
actually reached). I don't like sitters for that
reason.

Thermocouple-based pyrometers also deteriorate over
time, as the exposure to high heat alters the
efficiency of the thermocouple. I'd suggest measuring
each firing by as many different means as you can --
record the time, how heavy the kiln load is, when you
adjust to the various heat levels, using the sitter
and using cones in different parts of the kiln.

Please also be careful about looking in -- use goggles
or something similar to protect your eyesight from the
intense infra-red radiation. Cones are the most
accurate measure, but if you put cones at different
places in a kiln, even a well-controlled kiln, you'll
probably find a quarter or a half-cone range in
achieved firing, and likely more if you pack your
glaze firing tight.

Best wishes -- Steve Slatin (computer-controlled kiln,
cones, and length of firing in all segments)


--- marianne kuiper milks
wrote:

> Hello,
>
> I apologize for not responding sooner to the Duncan
> kiln issue, but i had to try a few things first.
>
> I ran the kiln three times since I first wrote about
> it.
> I didn't realize that I could physically "look" at
> the
> cones, as with the gaskilns etc at the U.studios.
>

Steve Slatin --

Some men will do here for diamonds what some men will do here for gold



__________________________________
Discover Yahoo!
Find restaurants, movies, travel and more fun for the weekend. Check it out!
http://discover.yahoo.com/weekend.html

marianne kuiper milks on fri 27 may 05


Hello,

I apologize for not responding sooner to the Duncan
kiln issue, but i had to try a few things first.

I ran the kiln three times since I first wrote about
it.
I didn't realize that I could physically "look" at the
cones, as with the gaskilns etc at the U.studios.

I ordered self-supporting cones 5,6 and 7. Since i
used 3 shelves, I put identical cones on each shelf
and on the bottom as well.I ran a load and, when the
kiln sitter went off (about 4 hrs later) I saw that
the cones were just as cute as when I put them in. I
turned the kiln back on, checking from time to time,
and when the cones went down (5 all the way, 6 half, 7
just the tip) I shut off the kiln. It took about 4
hours longer! Surprise: I had glazes! (Didn't like
them, but they had matured!

I ran the kiln twice more to be sure. The kilnsitter
obviously doesn't work, except in "0" cones (bisque
etc). So i "eye-ball" it and, with scorched eyebrows
and lashes, I am much happier. Now working on better
colors.

Thank you!! Marianne

__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com

Arnold Howard on wed 1 jun 05


It sounds like either your Duncan Kiln Sitter is either out of adjustment or
needs a new sensing rod. You can find out by checking the adjustment of the
release claw with a firing gauge.

By the way, Duncan manufactured its own version of the Kiln Sitter. Either
Dawson or Duncan will be printed on the faceplate of the Kiln Sitter. Most
of the parts are not interchangeable between these two brands.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
arnoldhoward@att.net / www.paragonweb.com

----- Original Message -----
From: "marianne kuiper milks"
> I apologize for not responding sooner to the Duncan
> kiln issue, but i had to try a few things first.
>
> I ran the kiln three times since I first wrote about
> it.
> I didn't realize that I could physically "look" at the
> cones, as with the gaskilns etc at the U.studios.
>
> I ordered self-supporting cones 5,6 and 7. Since i
> used 3 shelves, I put identical cones on each shelf
> and on the bottom as well.I ran a load and, when the
> kiln sitter went off (about 4 hrs later) I saw that
> the cones were just as cute as when I put them in. I
> turned the kiln back on, checking from time to time,
> and when the cones went down (5 all the way, 6 half, 7
> just the tip) I shut off the kiln. It took about 4
> hours longer! Surprise: I had glazes! (Didn't like
> them, but they had matured!
>
> I ran the kiln twice more to be sure. The kilnsitter
> obviously doesn't work, except in "0" cones (bisque
> etc). So i "eye-ball" it and, with scorched eyebrows
> and lashes, I am much happier. Now working on better
> colors.

Arnold Howard on mon 13 jun 05


Marianne mentioned that the Kiln Sitter on her Duncan kiln was off by about
two cones. Since that post, I have found additional information about Duncan
ASDs (automatic shut-off devices):

The Duncan ASD and Dawson Kiln Sitter switch blocks are not interchangeable,
because Dawson uses bolts, spacers and nuts for assembly. Duncan, instead,
uses bolts that fasten into threaded holes.

The Dawson Kiln Sitter sensing rod, claw, and cone supports can be used on a
Duncan ASD, but the Duncan sensing rod, claw, and cone supports cannot be
used on a Dawson Kiln Sitter. This is due to a difference in size between
Dawson and Duncan.

Sincerely,

Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
arnoldhoward@att.net / www.paragonweb.com

From: "marianne kuiper milks"
> I ran the kiln twice more to be sure. The kilnsitter
> obviously doesn't work, except in "0" cones (bisque
> etc). So i "eye-ball" it and, with scorched eyebrows
> and lashes, I am much happier. Now working on better
> colors.