John Hesselberth on sun 13 jul 03
On Sunday, July 13, 2003, at 04:27 PM, martha rosenfeld wrote:
> Do any of you out there have thoughts on the pros and cons of manual
> vs. automatic electric kilns?
Hi Martha,
I will never buy another manual kiln. Having a controller is the
easiest and best way to control your cooling rate which is critical to
getting the best out of your glazes. As to why the automatic kiln you
worked with overfired--well it wasn't programmed properly. That is a
very simple problem to fix--shame on the person who tolerated that.
You can't just punch the Cone Fire setting and expect it to work
correctly. You still have to make sure it is adjusted correctly before
you commit important work to it.
Regards,
John
http://www.frogpondpottery.com
http://www.masteringglazes.com
martha rosenfeld on sun 13 jul 03
I am in the happy position of getting ready to turn my big garage into a year-round studio, and need to replace my electric kiln. I do all my firing electric, including glaze. I have worked at cone 6, but currently am working around cone 3 with earthenware. For examples, go to http://martharosenfeld.womanmade.net .
I have always used a good ol' manual kiln with switches and a kiln sitter. While working in a group studio in Chicago I had access to a programmable electric and it way overfired my stuff, the few times I used it. It was convenient, but I feel I have more control with a manual.
Do any of you out there have thoughts on the pros and cons of manual vs. automatic electric kilns? I would love to hear your perspective. I am a bit of a Luddite, and don't want to miss the boat by ordering another manual kiln without hearing some other points of view. Also, if you have particular brands/models you think are the best, contact me off list with your recommendations. My last kiln was an Olympic oval, about 12 cubic ft. I'm going to get something smaller this time, around 8 to 10 cubic feet. Cost is an issue but not the primary issue.
Thanks, y'all. I have enjoyed lurking while in transition from Chicago to Louisville, KY, and I think this group is aces.
Martha Rosenfeld mudfish2@hotmail.com
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Arnold Howard on mon 14 jul 03
An advantage of a digital kiln is that it saves time. Once the kiln is =
firing to your satisfaction, you can do repeat firings easily and =
accurately without having to pay close attention to the kiln. This is =
wonderful for slow cool-downs and difficult glazes such as crystalline.
If you get a digital kiln for cone 6 firings, you should get a Type-S =
thermocouple. (The thermocouple senses temperature inside the kiln.) The =
Type-K does not last long at that temperature. The Type-K also has =
temperature drift at higher temperatures, which means the firing results =
gradually change as the thermocouple ages. The Type-S is extremely =
stable over its life, which can be years. Economically, it makes =
absolutely no sense to use the Type-K for cone 6 firings.
An advantage of the manual kiln is that problems are easier to diagnose. =
If an element isn't firing, it is usually due to a burned out switch or =
element. On a digital kiln, the problem can be the switch box fuse, =
controller, transformer, relay, or element. Nevertheless, once you =
understand how a digital kiln is wired, it, too, is not difficult to =
diagnose.
Sincerely,
Arnold Howard
Paragon Industries, L.P.
www.paragonweb.com
Do any of you out there have thoughts on the pros and cons of manual =
vs. automatic electric kilns? I would love to hear your perspective. I =
am a bit of a Luddite, and don't want to miss the boat by ordering =
another manual kiln without hearing some other points of view. =20
Martha Rosenfeld mudfish2@hotmail.com
Brad Sondahl on mon 14 jul 03
Programmable kilns are quite a bit costlier, so unless you are working
with glaze processes which require holding or slow cooling, (such as
crystalline glazes), they are a nice convenience but not a necessity.
They are also good for people who can't remember to turn the kiln up as
needed. I might fit in this latter category, but I've never used a
programmable kiln, yet. I did have a thermocouple shut off device once,
but found I had to replace the thermocouple yearly, which was $25.00 I'd
rather not have to spend. Perhaps if the thermocouple's coated with ITC
coatings, that could be avoided.
Brad Sondahl
siding with the luddites
--
For original art, music, pottery, and literature, visit my homepage
http://sondahl.com
Pottery sales page http://sondahl.freeyellow.com
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Miriam on mon 14 jul 03
--- In clayart@yahoogroups.com, martha rosenfeld wrote:
>
A programmable kiln was the most expensive error I ever made in Clay...Repair costs were phenomenol... It stood unused for two & half months during my busiest season... whilst the WONDERFUL manual kilns just hummed happily along!!!!!!
The stupid repairmen were the only people delighted with the continued problems with the kiln... they walked away each time with jingling pockets.
In great despair I finally phoned the maker of the kiln... several times.... the entire box was removed, shipped back to them, a new one sent... it "seemed" to work...it was easy to re-install. I instantly sold it & bought a lovely new manual kiln with no parts on it but what "I" can replace... & am the happiest camper imaginable in this area of Tarpon Springs, Florida!!!!!!
Never ever, in my lifetime...
Miriam
Bob Nicholson on mon 14 jul 03
>Do any of you out there have thoughts on the pros and cons of manual
>vs. automatic electric kilns? I would love to hear your
>perspective. I am a bit of a Luddite, and don't want to miss the
>boat by ordering another manual kiln without hearing some other
>points of view. Also, if you have particular brands/models you
>think are the best, contact me off list with your recommendations.
>My last kiln was an Olympic oval, about 12 cubic ft. I'm going to
>get something smaller this time, around 8 to 10 cubic feet. Cost is
>an issue but not the primary issue.
The big advantage of a kiln controller is that it allows you to
control the firing ramp.
Slowly through certain temperature ranges - quickly through others -
hold at certain
points. It's a very valuable tool, but like any other tool, it needs
to be properly used.
If a kiln with controller was "consistently over firing," then it was
not calibrated
correctly or was not programmed correctly. The controllers have provisions for
adjusting various parameters, to compensate for any problems you're having
in the firing. When I first got my current kiln (a Cone Art with a
Bartlett controller),
I spent about a month running tests, experimenting, and calibrating.
That was probably
overkill, but I learned a lot about what the controller can do, and
how to spot and
correct problems. (I still use cones to confirm that the kiln is
firing correctly.)
Anyway, if you're buying a new kiln, I'd HIGHLY recommend a controller.
Regards,
Bob Nicholson
william schran on mon 14 jul 03
Martha asks: cons of manual vs. automatic electric kilns?>
I think, in some ways, this is like the difference between automatic
and manual transmissions in cars. For many folks it's a matter of
convenience, for some it's what they learned on and yet others think
it will solve their particular problem.
I have a manual, at school we have 5 manuals. Next kiln we get for
school may be ordered with the automatic program controller - mainly
to teach my students how they work.
I sincerely believe whatever kiln is purchased, witness cones should
still be used and nobody should ever go off and rely on a kiln to
shut itself off.
Bill
Chuck Wagoner on tue 15 jul 03
We like all seven of our controller kilns. They are set up so they can
be bypassed at the contactors so they can be switched back to manual,
although that would be a rare occasion. None of them are "built into the
kiln" which I guess is a drawback not to mention they get awful hot when
they are that close. Mounted on the wall is better. We keep back up
units on hand and extra thermocouples. We still use large visual cones
in every firing and that helps keep the calibration right on as changes
in units progress....not to mention gives us a real idea of "work/time"
that a controller cannot.
In my opinion the big mistake is if one were to expect to just leave the
kiln alone and not monitor it. We still "hang" with my kilns at certain
points in the firings. But it sure is nice to be able to know that the
kiln will reach temp at a certain time within a few minutes this way or
that.
Controllers are also good as an indicator of temperature rise and fall
when soaking and general firing. Otherwise one would need a pyrometer.
After the sinter of the glaze begins we do not like the kiln to go much
faster then a certain amount depending on the glazes we are firing in a
particular firing. Or when experimenting with different schedules the
controller gives us a fairly precise idea of the ramp up and down.
I suppose if we were only firing one kiln it would not be as important,
but when many kilns are on at once it is great to be able to make pots
and not have to be checking on four or five kilns and keeping close
notes on firings. It is a big help to production level and general state
of mind.
Chuck
...west of Indy where it has been so humid and wet that the pots are
piling up waiting to dry.
martha rosenfeld on wed 16 jul 03
Thanks, everyone, for the responses to my manual/digital kiln question. There were good arguments on both sides of the issue, so I have a few things to think about. And since I am about to convert my garage into a studio, I am reading the posts on planning a studio with great interest. Thanks again.
Martha Rosenfeld
Louisville, KY
mudfish2@hotmail.com
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