Michael Wendt on wed 10 nov 04
Many kiln designers use higher wattage elements at the top
and bottom.
This is done because the top and bottom present extra
unheated area.
If a middle element was placed either at the top or bottom,
that ring
would run a little cooler. Could this have happened?
A multimeter can be used to measure the resistance of the
elements
(power disconnected of course) and if the bottom element
shows a higher resistance, then I would either swap the
elements or order a new bottom element and install it.
You might also order a middle element and replace it as well
since elements become brittle after use and can easily break
if bent cold.
That's why the experts advise you to heat used ones to above
red heat
with a propane torch before bending.
Regards,
Michael Wendt
Dawn Candy on wed 13 jul 11
Hello,
I recently changed out all the elements in an older manual olympic electr=
=3D
ic=3D20
kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and put =
=3D
witness=3D20
cone packs in front of the peeps. The kiln sitter tripped it before I wa=
=3D
s able=3D20
to shut it down manually, but the middle and top reached a nice solid con=
=3D
e 6=3D20
and yet the bottom barely hit cone 5. Is this normal with brand new=3D20
elements? I'm firing all the bottom shelf ware again tomorrow and am pla=
=3D
nning=3D20
to graduate the firing so that the bottom is on high for longer (although=
=3D
this=3D20
option is limited as the switches are the high, medium, low kind with no =
=3D
in=3D20
between) and hope that it works to even out the kiln, but I'm perplexed a=
=3D
t=3D20
such a large discrepancy between the middle and bottom. Has anyone=3D20
encountered this before?
Larry Kruzan on thu 14 jul 11
Hi Dawn,
I don't know about Olympic kilns, but my Skutt kilns have specific elements
for the top and bottom. These get a little hotter to offset these cooler
locations. Any chance this may be the problem?
Larry Kruzan
Lost Creek Pottery
An armed man is a citizen. An unarmed man is a subject.
-----Original Message-----
From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of Dawn Candy
Sent: Wednesday, July 13, 2011 10:53 PM
To: Clayart@LSV.CERAMICS.ORG
Subject: underfiring manual electric kiln
Hello,
I recently changed out all the elements in an older manual olympic electric
kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and put
witness
cone packs in front of the peeps. The kiln sitter tripped it before I was
able
to shut it down manually, but the middle and top reached a nice solid cone =
6
and yet the bottom barely hit cone 5. Is this normal with brand new
elements? I'm firing all the bottom shelf ware again tomorrow and am
planning
to graduate the firing so that the bottom is on high for longer (although
this
option is limited as the switches are the high, medium, low kind with no in
between) and hope that it works to even out the kiln, but I'm perplexed at
such a large discrepancy between the middle and bottom. Has anyone
encountered this before?
William & Susan Schran User on thu 14 jul 11
On 7/13/11 11:52 PM, "Dawn Candy" wrote:
> I recently changed out all the elements in an older manual olympic electr=
ic
> kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and put
> witness cone packs in front of the peeps. The kiln sitter tripped it be=
fore
I was able
> to shut it down manually, but the middle and top reached a nice solid con=
e 6
> and yet the bottom barely hit cone 5. Is this normal with brand new
> elements? I'm firing all the bottom shelf ware again tomorrow and am pla=
nning
> to graduate the firing so that the bottom is on high for longer (although=
this
> option is limited as the switches are the high, medium, low kind with no =
in
> between) and hope that it works to even out the kiln, but I'm perplexed a=
t
> such a large discrepancy between the middle and bottom. Has anyone
> encountered this before?
Does the Olympic kiln have elements of different resistance for top and
bottom like Skutt kilns? If so, might you have installed those elements in
the bottom section?
Do you know how to over ride the kiln sitter so you can turn the kiln back
on so you can continue firing?
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
Arnold Howard on thu 14 jul 11
On 7/13/2011 10:52 PM, Dawn Candy wrote:
> I recently changed out all the elements in an older manual olympic electr=
ic
> kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and put =
witness
> cone packs in front of the peeps. The kiln sitter tripped it before I wa=
s able
> to shut it down manually, but the middle and top reached a nice solid con=
e 6
> and yet the bottom barely hit cone 5.
Dawn, how evenly did the kiln fire before you changed the elements?
Years ago I test-fired Paragon's first SnF-series automatic kiln. I
discovered that changing the resistance of an element by even one ohm
could change the kiln's heat distribution. Is it possible that you
installed the wrong bottom element?
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
Rob Haugen on thu 14 jul 11
Dawn,
Some models of Olympic kilns do indeed have different elements in the top &
bottom vs. the center of the kiln. It is possible that the elements have
been installed in the wrong order. I need to know your model number and I
can tell you for sure.
Rob Haugen
Olympic Kilns
-----Original Message-----
From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of Dawn Candy
Sent: Wednesday, July 13, 2011 11:53 PM
To: Clayart@LSV.CERAMICS.ORG
Subject: underfiring manual electric kiln
Hello,
I recently changed out all the elements in an older manual olympic electric
kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and put
witness
cone packs in front of the peeps. The kiln sitter tripped it before I was
able
to shut it down manually, but the middle and top reached a nice solid cone =
6
and yet the bottom barely hit cone 5. Is this normal with brand new
elements? I'm firing all the bottom shelf ware again tomorrow and am
planning
to graduate the firing so that the bottom is on high for longer (although
this
option is limited as the switches are the high, medium, low kind with no in
between) and hope that it works to even out the kiln, but I'm perplexed at
such a large discrepancy between the middle and bottom. Has anyone
encountered this before?
Snail Scott on thu 14 jul 11
On Jul 13, 2011, at 10:52 PM, Dawn Candy wrote:
> ...The kiln sitter tripped it before I was able=3D20
> to shut it down manually, but the middle and top reached a nice solid =3D
cone 6=3D20
> and yet the bottom barely hit cone 5. Is this normal with brand new=3D20=
=3D
> elements?
Nope. You need to check what's going on. The bottom=3D20
element might not be firing properly due to a bad=3D20
connection. A multimeter will tell you a lot, but even=3D20
if you haven't got one you can do some checking.=3D20
Set the empty kiln to 'high' and leave it for 15-20=3D20
minutes, then check the color of the elements. Is=3D20
the bottom element (or next-to--bottom) darker than=3D20
the rest? Does it have any dark patches? Dark=3D20
patches are more typical of an old element, as they=3D20
are indicative of damage, but an element that looks=3D20
somewhat darker (not glowing as brightly) may show=3D20
that there's not enough current running through it,=3D20
and you would need to check your connections.=3D20
Also, it's possible, even if you were careful, to have=3D20
accidentally installed a 'middle' element in the bottom=3D20
channel and vice-versa, which would cause uneven=3D20
heating. Top and bottom elements for many kiln=3D20
brands are made to run hotter, to compensate for=3D20
heat loss through the lid and floor.
Another factor: how was the kiln loaded? Clay soaks=3D20
up heat - that's how firing works, after all. If the bottom=3D20
region of the kiln was tightly packed and the top was=3D20
mostly empty, the result you described would be quite=3D20
typical. Even if you have a partial load, distribute it=3D20
evenly throughout the kiln or mostly in the middle to=3D20
get the most even firing results.
-Snail=3D
paul gerhold on thu 14 jul 11
Dawn,
I have a Skutt, a Paragon and an L&L and they all seem to fire slightly (
about a cone) cooler very close to the bottom. Suspect this is universal
which is probably why elements are now showing up in the bottom of the kiln=
.
I will put pots with broader range glazes or slightly lower firing glazes a=
t
the bottom, Or, if this not possible I will set my bottom shelf up about 4
inches or fire toward the top of the glaze range.
Note, that this occurs even with the correct higher heat elements in the
bottom of the Skutt.
Paul
On Thu, Jul 14, 2011 at 8:30 AM, Arnold Howard wrot=
e:
> On 7/13/2011 10:52 PM, Dawn Candy wrote:
>
>> I recently changed out all the elements in an older manual olympic
>> electric
>> kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and put
>> witness
>> cone packs in front of the peeps. The kiln sitter tripped it before I w=
as
>> able
>> to shut it down manually, but the middle and top reached a nice solid co=
ne
>> 6
>> and yet the bottom barely hit cone 5.
>>
>
> Dawn, how evenly did the kiln fire before you changed the elements?
>
> Years ago I test-fired Paragon's first SnF-series automatic kiln. I
> discovered that changing the resistance of an element by even one ohm
> could change the kiln's heat distribution. Is it possible that you
> installed the wrong bottom element?
>
> Sincerely,
>
> Arnold Howard
> Paragon Industries, L.P., Mesquite, Texas USA
> ahoward@paragonweb.com / www.paragonweb.com
>
John Post on thu 14 jul 11
If it turns out your elements are installed correctly, you could try
using half inch or one inch shelf posts underneath your bottom kiln
shelf. If you aren't already doing this it could help. It lets heat
move around the bottom of the shelf and may help to even out your
firing.
John Post
Sterling Heights, Michigan
http://www.johnpost.us
Follow me on Twitter
https://twitter.com/UCSArtTeacher
On Jul 13, 2011, at 11:52 PM, Dawn Candy wrote:
> Hello,
> I recently changed out all the elements in an older manual olympic
> electric
> kiln. When firing it to cone 6 I put a cone 7 in the kiln sitter and
> put witness
> cone packs in front of the peeps. The kiln sitter tripped it before
> I was able
> to shut it down manually, but the middle and top reached a nice
> solid cone 6
> and yet the bottom barely hit cone 5. Is this normal with brand new
> elements? I'm firing all the bottom shelf ware again tomorrow and
> am planning
> to graduate the firing so that the bottom is on high for longer
> (although this
> option is limited as the switches are the high, medium, low kind
> with no in
> between) and hope that it works to even out the kiln, but I'm
> perplexed at
> such a large discrepancy between the middle and bottom. Has anyone
> encountered this before?
Dawn Candy on thu 14 jul 11
Thanks so much to everyone who replied!=3D20=3D20
The kiln model is a 2327h and I bought elements that were labelled top/bo=
=3D
ttom=3D20
or centre. I am fairly certain that I installed them in the correct plac=
=3D
e (when I=3D20
switched them all on to make sure they were all connected and getting pow=
=3D
er=3D20
the top and bottom elements glowed much more quickly than the rest of the=
=3D
m=3D20
in the centre).=3D20=3D20
The bottom shelf height was only about 7" or so, I will definitely make i=
=3D
t taller=3D20
this time and pack it a bit more loosely.=3D20=3D20
I do not know how to override the kiln sitter, though- I was considering=3D=
20=3D
putting in a cone 8 to give me a bit more leeway as I think that my sitte=
=3D
r=3D20
(which is in the middle of the kiln) might be a bit trigger-happy, but if=
=3D
there is=3D20
a way to keep firing for a bit after it has tripped I'd be interested to =
=3D
try that=3D20
as well.
Dawn
Pottery by John on thu 14 jul 11
Dawn Candy remarked: if there is a way to keep firing for a bit after it
has tripped I'd be interested to try that as well.
Dawn,
Assuming your Olympic has a Dawson Kiln Sitter, you can lift up the lever
device on the sitter that swings down to shut off the kiln, push in the
butoon to power up again, and then gently lower the lever device. You are
then powered on until you eother turn off the koln with switches, lift and
drop the lever device again, or your kiln melts and shorts out the wiring (=
I
do not recommend choise three.) You will need to hang out after a while to
monitor the cones inside and shut off the kiln.
You can also fire down your kiln this way if you need to develop a glaze by
slower cooling than the normal crash cool of an electric with thin wals. I
do this frequently for iron reds, mattes and some other effect glazes I use=
.
Good firing and watch those cones...
John Lowes
Sandy Springs, Georgia
http://wynhillpottery.weebly.com/
Rob Haugen on thu 14 jul 11
Dawn,
You can check the resistance of the elements with an ohm meter. The very
top and the very bottom element should read 21.5 ohms. The 4 center
elements should read 32.9 ohms. You may also want to check and make sure
that all of your element connections are tight. The final thing to check i=
s
to make sure that the elements are wired correctly to the switch. To do
this turn all the switches to medium. The bottom element of each pair
should get hot, while the top element remains cold. Next turn all of the
switches to high and you should get heat out of both elements.
Rob Haugen
Olympic Kilns
-----Original Message-----
From: Clayart [mailto:Clayart@LSV.CERAMICS.ORG] On Behalf Of Dawn Candy
Sent: Thursday, July 14, 2011 1:17 PM
To: Clayart@LSV.CERAMICS.ORG
Subject: Re: underfiring manual electric kiln
Thanks so much to everyone who replied!
The kiln model is a 2327h and I bought elements that were labelled
top/bottom
or centre. I am fairly certain that I installed them in the correct place
(when I
switched them all on to make sure they were all connected and getting power
the top and bottom elements glowed much more quickly than the rest of them
in the centre).
The bottom shelf height was only about 7" or so, I will definitely make it
taller
this time and pack it a bit more loosely.
I do not know how to override the kiln sitter, though- I was considering
putting in a cone 8 to give me a bit more leeway as I think that my sitter
(which is in the middle of the kiln) might be a bit trigger-happy, but if
there is
a way to keep firing for a bit after it has tripped I'd be interested to tr=
y
that
as well.
Dawn
Snail Scott on thu 14 jul 11
On Jul 14, 2011, at 12:16 PM, Dawn Candy wrote:
> ...I do not know how to override the kiln sitter...
I run my ^6 firings with a ^8 in the sitter, and shut
it down using witness cones if the glaze is fussy.
The ^8 gives me the latitude to do that without
having to re-set the sitter, though it's pretty easy
to do: just lift the deadfall back up and tuck the
hook back over it. Friction will hold it fine. The ^8
acts as a failsafe, though, if I can't be there - for
any reason - to shut it off manually. I find is easier to
put in a higher cone than to recalibrate the sitter.
Every sitter is adjusted differently, though, so my
^8 (or ^6) may not be yours.
-Snail
Snail Scott on thu 14 jul 11
On Jul 14, 2011, at 8:28 AM, paul gerhold wrote:
> I have a Skutt, a Paragon and an L&L and they all seem to fire =3D
slightly (
> about a cone) cooler very close to the bottom. Suspect this is =3D
universal
> which is probably why elements are now showing up in the bottom of the =
=3D
kiln...
I put extra insulation under my floor, in the=3D20
form of my old 'beater' kiln's lid. Fires even=3D20
and true, now, and the extra insulation let=3D20
me lower my stand, even more than needed=3D20
to compensate for the extra thickness.
-Snail
Fredrick Paget on thu 14 jul 11
>Thanks so much to everyone who replied! =3D.....snip
> if there is a way to keep firing for a bit after it has tripped I'd
>be interested to
>try that as well.
>
>Dawn
Dawn
If you look at the outside face of the KS there is a button of
plastic .You can see it above the swinging weighed thingy that falls
down when the KS trips and a spur on the back of the thingy pushes in
another button below its hinge point and turns off the switch and
thus the kiln.
That top button is the on switch and the lower button is the off
switch button of an old fashion wall switch they used in houses 100
years ago to turn on/or off - the room lights.
If you want to turn the kiln back on after the KS tripped what you
have to do is push in the on button (the top one).
To do it hold the thingy up a bit and push in the top button and
then carefully lower the thingy so the spur on its back doesn't punch
in the off switch. Leave the thingy resting lightly and the switch
will stay on. To turn it off again gently push the thingy so its spur
trips the off button.
That will turn on the kiln again and you are on your own then - no
safeguard so watch it!
--
Fred Paget
Twin Dragon Studio
Mill Valley, CA, USA
fredrick@well.com
Charter Member Potters Council
Anita Rickenberg on thu 14 jul 11
I had the same problem with an Olympic 2827 kiln I bought used. I =3D
replaced
the elements before firing (they were in bad shape). The elements were
replaced correctly and testing indicated everything was OK but the =3D
bottom of
the kiln was always 1 cone below the rest (cone 6 in this case). I =3D
adjusted
the firing schedule and finally got it where it fires evenly. Hours =3D
1-3:
all 3 on low. Hours 3-4: top on low, bottom 2 on medium. Hours 4-5: top =
=3D
2
on medium, bottom on high. Hours 5+: all on high. =3D20
If you want to try this route you could probably shorten the 3 hrs. on =3D
low
since the 2327 is 7 cu. feet compared to 10 cu. feet for mine.
Anita
Steve Mills on fri 15 jul 11
Can I add to John's very clear instruction on Dawson Kiln Sitter over-ridin=
g=3D
and recommend you turn off the main switch befor pressing in the switch bu=
t=3D
ton; the Kiln Sitter switch is a very simple contact, and operating it "Li=
v=3D
e" will cause arcing. This can cause pitting on the plain metal contacts an=
d=3D
is not at all good for them. It can occasionally lead to them "welding" to=
g=3D
ether.=3D20
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my Ipod touch
On 14 Jul 2011, at 19:51, Pottery by John wro=
t=3D
e:
> Dawn Candy remarked: if there is a way to keep firing for a bit after it
> has tripped I'd be interested to try that as well.
>=3D20
> Dawn,
>=3D20
> Assuming your Olympic has a Dawson Kiln Sitter, you can lift up the lever
> device on the sitter that swings down to shut off the kiln, push in the
> butoon to power up again, and then gently lower the lever device. You ar=
e=3D
> then powered on until you eother turn off the koln with switches, lift an=
d=3D
> drop the lever device again, or your kiln melts and shorts out the wiring=
(=3D
I
> do not recommend choise three.) You will need to hang out after a while =
t=3D
o
> monitor the cones inside and shut off the kiln.
>=3D20
> You can also fire down your kiln this way if you need to develop a glaze =
b=3D
y
> slower cooling than the normal crash cool of an electric with thin wals. =
I=3D
> do this frequently for iron reds, mattes and some other effect glazes I u=
s=3D
e.
>=3D20
> Good firing and watch those cones...
>=3D20
> John Lowes
> Sandy Springs, Georgia
> http://wynhillpottery.weebly.com/
| |
|
