William & Susan Schran User on fri 1 jul 05
On 7/1/05 3:15 PM, "Carole Fox" wrote:
> If you accidentally miss the event of the cone sitter tripping off your
> kiln, come back (after picking up your kids at from their summer program)
First - just what the heck are you doing leaving your kiln unattended while
firing? Boy girl, you are asking for trouble!
>and find the kiln still hot (bright cherry red) but the shelf cone 6
>straight as an arrow...can you just turn the kiln back on?
Yes, you can turn it back on.
>And...if you soak the kiln at medium temperature at the end of a firing, can
>you cause the glazes to become more fluid or do they just cool slower?
The glazes will be more fluid/melted - some glazes may benefit from this
others not so much - depends on the glaze.
>It is near impossible to put some large bowls in the
>center of the kiln shelf and I'm getting big time warping.
Position the large bowls in the center of shelves without cones and surround
by smaller pots to help with heating/cooling changes.
--
William "Bill" Schran
Fredericksburg, Virginia
Snail Scott on fri 1 jul 05
At 03:15 PM 7/1/2005 -0400, you wrote:
>If you accidentally miss the event of the cone sitter tripping off your
>kiln...but the shelf cone 6
>straight as an arrow...can you just turn the kiln back on?
Nearly always, yes. Go ahead. Just restart it and
finish up according the the cone reading.
>And...if you soak the kiln at medium temperature at the end of a firing, can
>you cause the glazes to become more fluid or do they just cool slower?
GLazes can 'refreeze' at different temperatures, I think
and holding it at a liquid temperature can give a glaze
more time to melt and run, but I expect that turning it
to 'medium' will mainly slow the cooling, not extend the
melt time enough to cause added fluidity. (I turn mine to
'low' for cooling, personally. YMMV)
>
>Also- I feel like I load my kiln so inefficiently for glaze firings because
>the cone pack takes up a whole lot of space if it is positioned so that
>there is nothing in front or behind it...
Just put your big bowls in the middle. You can try
various other cone-viewing remedies instead. I just
stick with blowing into the peephole if I truly can't
see the cones at all, but usually I can make them out
OK if I use a dark lens. Some folks put a stripe of
iron oxide on a surface behind the cones. I don't do
it, but if it works for you, just make your cone packs
with a 'back wall' for the iron stripe.
-Snail
Carole Fox on fri 1 jul 05
I don't understand some stuff about electric firing...
If you accidentally miss the event of the cone sitter tripping off your
kiln, come back (after picking up your kids at from their summer program)
and find the kiln still hot (bright cherry red) but the shelf cone 6
straight as an arrow...can you just turn the kiln back on? Will the cones
behave differently? Is the term cone freeze applicable here?
And...if you soak the kiln at medium temperature at the end of a firing, can
you cause the glazes to become more fluid or do they just cool slower?
Also- I feel like I load my kiln so inefficiently for glaze firings because
the cone pack takes up a whole lot of space if it is positioned so that
there is nothing in front or behind it (so that it is easy to see shadowed
by the elements). It is near impossible to put some large bowls in the
center of the kiln shelf and I'm getting big time warping.
Do you have some advice for me?
xo,
Carole
Carole Fox
Silver Fox Pottery
Elkton, MD
silverfoxpottery@comcast.net
Hank Murrow on fri 1 jul 05
On Jul 1, 2005, at 12:15 PM, Carole Fox wrote:
> I don't understand some stuff about electric firing...
Dear Carole;
Great place to start!
>
> If you accidentally miss the event of the cone sitter tripping off your
> kiln, come back (after picking up your kids at from their summer
> program)
> and find the kiln still hot (bright cherry red) but the shelf cone 6
> straight as an arrow...can you just turn the kiln back on? Will the
> cones
> behave differently? Is the term cone freeze applicable here?
I use the kiln sitter as a fail safe, and read the shelf cones for
final turn off. For bisque I let the Sitter do the shutoff.
>
> And...if you soak the kiln at medium temperature at the end of a
> firing, can
> you cause the glazes to become more fluid or do they just cool slower?
I have only done this in my gas kiln but the theory is the same. If you
do the soak around 150 degrees or more lower than the final cone the
glaze will not run or change except for matting and more color in the
case of crystalline matts.
> Also- I feel like I load my kiln so inefficiently for glaze firings
> because
> the cone pack takes up a whole lot of space if it is positioned so that
> there is nothing in front or behind it (so that it is easy to see
> shadowed
> by the elements). It is near impossible to put some large bowls in the
> center of the kiln shelf and I'm getting big time warping.
Can't you see the cones against the surface of the bowl?
Cheers from Hank in Eugene!
Rick Hamelin on fri 1 jul 05
miss the the cone sitter tripping off your kiln, come back and find the kiln bright cherry red but cone 6 straight as an arrow...can you just turn the kiln back on? Your sitter cone should be similar in temp to your spy cone. Why did the sitter cone prematurely fail? Is it because it is faulty (I have had a few in the past be bad for a number of reasons). Yes you can turn the kiln back on, but if you restart the kiln, will you be there to shut it off when the spy cone drops? Will you properly monitor it?
Will the cones behave differently?
Cones react to heat work, something that I think of this way. You can take a whole bunch of vegetables, chop them up and put them in a big pot of water. You can boil them on high and get them to mush faster than if you steep them at a lower temp over time but mush will eventually happen. The melting of a glaze is affected by heat over time as well as reaching temp. And...if you soak the kiln at medium temperature at the end of a firing, can you cause the glazes to become more fluid or do they just cool slower? Fluidity could occur depending on the glaze at hand but soaking (read Clayart archives) is recommended to help clear the glaze and improve gloss.
the cone pack takes up a whole lot of space . Buy two pyrometers so that you can calibrate them over time or assess any changes. Use the spy cones to sort of judge the accuracy of end temp of the pyrometer but rate of firing affects cone drop. Put pyrometer probes through spy holes and put your kiln post next to the spy hole to minimize lost space and prevent the thermocouple from hitting a pot.
warping. Instead of stilts, rest your pot on small bisque slabs. Keep off the coil by at least an inch.
Good luck
Rick
"Many a wiser men than I hath
gone to pot." 1649
Carole Fox on sat 2 jul 05
From: "William & Susan Schran User"
>
>> If you accidentally miss the event of the cone sitter tripping off your
>> kiln, come back (after picking up your kids at from their summer program)
>
> First - just what the heck are you doing leaving your kiln unattended
> while
> firing? Boy girl, you are asking for trouble!
Bill-
I thought I would be back in time for the end of this firing. I left the
kiln on at a lower temperature (numbers 10 and 8 on my manual dial) hoping
to slow the firing so that I WOULD be home for the end of the firing.
Apparently, I left it on this setting long enough for the heatwork to melt
the sitter cone. I always finish off my firings by checking the shelf cones.
In this case, I turned the kiln back up when I got home- but after two hours
of HI temp firing, I got nervous that the cones were not telling me the true
story and I turned it back to medium for a soak.
The glazes all look fine, but I'm trying to learn from my experiences. I
have a cone sitter and a timer to shut off the kiln in emergencies.I know
this isn't 100 percent reliable, but with two teens that need to be picked
up and driven somewhere everyday, it is impossible to always be near the
kiln for a firing.My timing was off this time- am I forgiven?
Carole Fox
Silver Fox Pottery
Elkton, MD
silverfoxpottery@comcast.net
----- Original Message -----
Earl Brunner on sat 2 jul 05
By some of these people? Never......
Earl Brunner
Las Vegas, NV
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Carole Fox
Sent: Saturday, July 02, 2005 6:40 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: electric firing questions
From: "William & Susan Schran User"
>
>> If you accidentally miss the event of the cone sitter tripping off your
>> kiln, come back (after picking up your kids at from their summer program)
>
> First - just what the heck are you doing leaving your kiln unattended
> while
> firing? Boy girl, you are asking for trouble!
The glazes all look fine, but I'm trying to learn from my experiences. I
have a cone sitter and a timer to shut off the kiln in emergencies.I know
this isn't 100 percent reliable, but with two teens that need to be picked
up and driven somewhere everyday, it is impossible to always be near the
kiln for a firing.My timing was off this time- am I forgiven?
Carole Fox
Silver Fox Pottery
Elkton, MD
silverfoxpottery@comcast.net
Jo Smith on sat 2 jul 05
Hank,
No, I am only able to see the cones when there is a glowing element behind
the cones. This has always worried me because if I ever get the gas kiln
hooked up how am I ever going to see the cones? Are my eyes dysfunctional?
Jo
----- Original Message -----
From: "Hank Murrow"
To:
Sent: Friday, July 01, 2005 5:08 PM
Subject: Re: electric firing questions
>
>
> Can't you see the cones against the surface of the bowl?
>
> Cheers from Hank in Eugene!
>
>
____________________________________________________________________________
__
Hank Murrow on sat 2 jul 05
On Jul 2, 2005, at 3:33 PM, Jo Smith wrote:
> Hank,
> No, I am only able to see the cones when there is a glowing element
> behind
> the cones. This has always worried me because if I ever get the gas
> kiln
> hooked up how am I ever going to see the cones? Are my eyes
> dysfunctional?
Probably not. However, they will function better and longer if you
obtain a safety frame with Didymium lenses mounted in them. Glass
blowers' supply houses carry them, as do welding supply places
sometimes. They are pink, and filter most of the infra red. I never
look in my kiln without them.
Cheers, Hank
www.murrow.biz/hank
Jennifer Boyer on sun 3 jul 05
Hi All,
Besides using safety glasses it helps to put something dark behind the
cone pack. My favorite solution is to put 2 plate setter posts (painted
with iron oxide wash) behind the cones. They are 1.5"/2"/.5" and I get
them from Bailey's, catalogue # C-178-14.
http://www.baileypottery.com
They are .70 each or so and l like having a pile of these around to use
along with my kiln posts for stacking my kiln. How many times have YOU
needed an extra .5 inch??
Bailey's also has the Didymium glasses.
Jennifer
On Jul 2, 2005, at 9:07 PM, Hank Murrow wrote:
> On Jul 2, 2005, at 3:33 PM, Jo Smith wrote:
>
>> Hank,
>> No, I am only able to see the cones when there is a glowing element
>> behind
>> the cones. This has always worried me because if I ever get the gas
>> kiln
>> hooked up how am I ever going to see the cones? Are my eyes
>> dysfunctional?
>
> Probably not. However, they will function better and longer if you
> obtain a safety frame with Didymium lenses mounted in them. Glass
> blowers' supply houses carry them, as do welding supply places
> sometimes. They are pink, and filter most of the infra red. I never
> look in my kiln without them.
>
> Cheers, Hank
> www.murrow.biz/hank
>
> _______________________________________________________________________
> _______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
>
************************
Jennifer Boyer
Thistle Hill Pottery
Montpelier, VT
http://thistlehillpottery.com
Jo Smith on sun 3 jul 05
I have some welding lenses, so dark one cannot see unless looking in the
kiln...Jo
> Probably not. However, they will function better and longer if you
> obtain a safety frame with Didymium lenses mounted in them. Glass
> blowers' supply houses carry them, as do welding supply places
> sometimes. They are pink, and filter most of the infra red. I never
> look in my kiln without them.
>
> Cheers, Hank
> www.murrow.biz/hank
>
>
____________________________________________________________________________
__
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
>
bonnie staffel on sun 3 jul 05
Hi Clayarters,
Don't know if I broke a cardinal rule, but I have brushed the leading edge
of my cones with a bit of iron oxide. I am able to see the cones in my
electric kiln very easily. In the back of my mind, sort of recall that this
was a no no, but all things considered, I have a very forgiving glaze and so
far all is well.
Regards,
Bonnie Staffel
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
Charter Member Potters Council
Jane Murray-Smith on sun 3 jul 05
Why is this a no-no?....I do it every time...the iron oxide is just wet
enough to go on...it makes sense not to get the cone wet, but is there
another reason?
thanks, Jane
----- Original Message -----
From: "bonnie staffel"
To:
Sent: Sunday, July 03, 2005 8:56 AM
Subject: electric firing questions
> Hi Clayarters,
>
> Don't know if I broke a cardinal rule, but I have brushed the leading edge
> of my cones with a bit of iron oxide. I am able to see the cones in my
> electric kiln very easily. In the back of my mind, sort of recall that
> this
> was a no no, but all things considered, I have a very forgiving glaze and
> so
> far all is well.
>
> Regards,
>
> Bonnie Staffel
> http://webpages.charter.net/bstaffel/
> http://vasefinder.com/bstaffelgallery1.html
> Charter Member Potters Council
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
Hank Murrow on sun 3 jul 05
On Jul 3, 2005, at 10:47 AM, Jane Murray-Smith wrote:
> Why is this a no-no?...(brushing the leading edge of the cones with
> iron oxide).
> I do it every time...the iron oxide is just wet
> enough to go on...it makes sense not to get the cone wet, but is there
> another reason?
Dear Jane;
If you were firing in reduction, there would be the reason that iron in
reduction acts as a flux and might................just might(anyone
want to do a test of this side by side?) cause the cone to retire
early. In oxidation or neutral firings, I doubt that it would make any
difference.
Cheers, Hank
www.murrow.biz/hank
dannon rhudy on sun 3 jul 05
The iron oxide is a flux. It may affect the bending of the
cone. It's hard to imagine such a minute amount of iron
along only the edge would significantly affect the temp
at which the cone bends. But all the text books I ever had
said "don't do it". I've not tested it, personally. But if you
always do it, and it works, then - don't worry about someone
else's "no no".
regards
Dannon Rhudy
> Why is this a no-no?....I do it every time...the iron oxide is just wet
> enough to go on
Carole Fox on mon 4 jul 05
Carole - I use wire cone holders in my electric kiln. When I view the
cones with welding glasses, I can see the contrasting outline of the
horizontal wire across the cone, which makes it easier to see the profile
of the cone's edge. These wire cone holders are available from Bailey's as
well as other suppliers. They last pretty much forever. If you fire a
cone flat, you will need to whack it once with a chisel to get it off the
holder, but that's easy enough.
I sympathize with your problem in being chauffeur to a couple of teens.
However, I don't leave my kiln unattended while it's firing.
Good luck!
the other Carole Fox
in sunny Dayton, OH
bonnie staffel on mon 4 jul 05
My recollection of the no-no was that it reacted in some way as to interfere
with the correct bending of the cone. I was hoping that there would be some
knowledge out in clayart land who would have the answer so that newbies
would not be sent off on the wrong track.
Bonnie Staffel
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
Charter Member Potters Council
Snail Scott on mon 4 jul 05
At 10:47 AM 7/3/2005 -0700, you wrote:
>Why is this a no-no?....I do it every time...the iron oxide is just wet
>enough to go on...it makes sense not to get the cone wet, but is there
>another reason?
It changes the chemical composition of the
cone surface in that spot. It's a particular
issue with reduction firing, since reduced
iron is a flux. If done exactly the same
every time, so that consistent, predictable
results are obtained, it can work, but
repeatability is important if you need precise
results. It doesn't really matter whether it
shows a 'true' ^5 or ^10 or whatever, as long
as you know how it correlates with your
intended firing temperature.
If you stick a ^10 in at a weird diagonal, in
front of a cold draft, with fluxes all over it,
it doesn't matter if it drops at ^3, AS LONG
AS the treatment is the same every time, for
the same results every time, and it tells you
what you need to know. It's easier to use cones
as directed than to make potentially variable
alterations each time, but if you like your
results, then that's your business. The only
true measure of proper practice is the success
of the work.
-Snail
Earl Brunner on mon 4 jul 05
My recollection is that a lot has been SPECULATED about this, but I have
never seen hard data. And even if there is hard data that were to say for
example that a cone 10 with iron on it in reduction bends at cone 9, then
you would just have to know that figure accordingly......
Earl Brunner
Las Vegas, NV
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of bonnie staffel
Sent: Monday, July 04, 2005 8:05 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: electric firing questions
My recollection of the no-no was that it reacted in some way as to interfere
with the correct bending of the cone. I was hoping that there would be some
knowledge out in clayart land who would have the answer so that newbies
would not be sent off on the wrong track.
Bonnie Staffel
http://webpages.charter.net/bstaffel/
http://vasefinder.com/bstaffelgallery1.html
Charter Member Potters Council
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
Arnold Howard on tue 5 jul 05
H. L. Bouton Co. makes didymium glasses. Twelve years ago they sent me a
pair and told me that didymium glasses do not completely filter infrared
radiation. They recommended their green #3 for infrared radiation.
Sincerely,
Arnold Howard
Paragon Industries, L.P., Mesquite, Texas USA
ahoward@paragonweb.com / www.paragonweb.com
----- Original Message -----
From: "Hank Murrow"
if I ever get the gas
>> kiln
>> hooked up how am I ever going to see the cones? Are my eyes
>> dysfunctional?
>
> Probably not. However, they will function better and longer if you
> obtain a safety frame with Didymium lenses mounted in them. Glass
> blowers' supply houses carry them, as do welding supply places
> sometimes. They are pink, and filter most of the infra red. I never
> look in my kiln without them.
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