Roeder on mon 24 feb 97
Hi all,
I'm going to be involved in a group pit firing session. I usually do my pit
firing in a brick enclosure (or pit dug in ground) with sawdust, wood, and
assorted "stuff" thrown in.
The challenge here is, at the location of this upcoming firing, there are no
bricks available, and a pit cannot be dug into the ground. There is an
"electric kiln skeleton" which can be used. I'm wondering how to adapt this
"shell" for pitfiring, so that adequate air circulation can take
place....how to approximate that which I'm used to.
Any ideas out there?
This old kiln is a sectional one, BTW.
Thanks,
Candice Roeder
Michigan
Marcia Selsor on tue 25 feb 97
Dear Candace,
I'd put the skeleton up on a frame or bricks and punch a few small holes
in the bottom, and sides. Make some plugs for the holes. As firing, you
can adjust the air by opening the holes and heat up cold spots. My oil
drum smoker has about 36 1 inch holes in it.
Marcia in Montana
Roeder wrote:
>
> ----------------------------Original message----------------------------
> Hi all,
>
> I'm going to be involved in a group pit firing session. I usually do my pit
> firing in a brick enclosure (or pit dug in ground) with sawdust, wood, and
> assorted "stuff" thrown in.
>
> The challenge here is, at the location of this upcoming firing, there are no
> bricks available, and a pit cannot be dug into the ground. There is an
> "electric kiln skeleton" which can be used. I'm wondering how to adapt this
> "shell" for pitfiring, so that adequate air circulation can take
> place....how to approximate that which I'm used to.
>
> Any ideas out there?
>
> This old kiln is a sectional one, BTW.
>
> Thanks,
>
> Candice Roeder
> Michigan
--
Marcia Selsor
http://www.imt.net/~mjbmls/
mjbmls@imt.net
lynne on tue 25 feb 97
>----------------------------Original message----------------------------
>Hi all,
>
>I'm going to be involved in a group pit firing session. I usually do my pit
>firing in a brick enclosure (or pit dug in ground) with sawdust, wood, and
>assorted "stuff" thrown in.
>...snip
>The challenge here is, at the location of this upcoming firing, there are no
>bricks available, and a pit cannot be dug into the ground.
>...snip
>Any ideas out there?
>
>Thanks,
>
>Candice Roeder
>Michigan
Hi Candice,
Have you considered galvanized garbage cans for your pitfiring? I have four
cans with nail holes for air circulation and am able to fire my high school
students' work on a weekend, firing approximately 140 pots in two firings.
Also, using several cans makes it possible for the participants to get
involved in the loading. The cans are lightweight, portable, easily
transported, and give great flashing with the right combustibles. I use a
combination of sawdust, sun-dried, powdered horse manure, banana peels, and
whatever I rake up from under the trees. I wrap the pots loosely in
newspaper, preferably the Wall Street Journal (a potter friend told me their
ink is the best for pitfiring). I first bisque the pots at school at ^012
to make them easier to transport and handle. Be sure to bring along the
lids or any metal covering for smothering the fires somewhat. Good luck-and
toss in a kiln god or two!
(I fire at night, so no one can see where the smoke is coming from...a fire
engine flew by once with sirens blazing but they never found us).
Lynne Gingerich
Tucson, Arizona, where some of my flowers are still blooming.
Bruce Lenore on wed 26 feb 97
hi Candice, That old kiln should work fine. If you can ,space the
sections apart with fiber ,or small pieces of brick, posts will work
or even better ,small pieces of kiln shelves. The air flow is
important, but it is the variables that make it interesting. Good
luck! Bruce Lenore
Dannon Rhudy on wed 26 feb 97
Candice,
The garbage can idea does work; be sure there are plenty of holes
for air or it just smolders. Sometimes garbage-can firings do not
get very hot (relatively speaking) so you get a lot more black and
a lot less other stuff. Another possibility is to just
make a heap of pots and combustibles, cover the whole thing with
lots of wood, and light it. This will burn hot, but relatively
quick. You can continue to feed the fire periodically to keep it
going longer. A fire of this kind will not get much hotter than
the temperature at which the wood burns, since there is nothing
to hold the heat in. Temp will vary, depending upon the wood used,
by 200 -300 degrees. You can make a paper kiln (there was an
article some 3-4 years ago in CM re: paper kilns). You do this
by making a heap of pots/combustibles/fuel. Then, using long
pieces of wood or sticks, make a tipi sort of affair around the
work. Cover this "tipi" with layers of slip covered newspaper
(take the paper, dip it in a bucket of thin slip, lay across
support sticks/wood). Use several layers of paper. When you
have finished your paper kiln, (leave a hole in the top for a
chimney), light it from the bottom. As it burns, the slip
bisques, makes a thin shell over the work, holds in a little
extra heat. Main problem is that it becomes unwieldy in size
if there is a lot of work to fire. Also, in my experience, they
don't hold enough initial fuel, and are hard to feed because
of the jumble of work inside. Possibly you could put a grate
in, supported by a few bricks or stones, put the work on top of
the grate, and feed the fire by pushing wood beneath the grate,
build up more heat that way. It is rather fun, but wet and messy
while you are building the kiln.
Dannon Rhudy
potter@koyote.com
-------------------------Original
message----------------------------
>----------------------------Original
message----------------------------
>Hi all,
>
>I'm going to be involved in a group pit firing session. ....
challenge here is, ...no bricks available, and a pit cannot be dug
into the ground......
>...snip
>Any ideas out there?
>
>Thanks,
>
>Candice Roeder
>Michigan
Hi Candice,
Have you considered galvanized garbage cans for your pitfiring? I
have four
cans with nail holes for air circulation and am able to fire my
high school
students' work on a weekend,
Richard Ramirez on wed 26 feb 97
Hi Lynne,
I'll tell you what I've used in the past. An old trash can. With air holes
drilled all over it. Lined the bottom with several inches of saw-dust, and
stack your pots along with a couple of inches of saw-dust to the top , light
with newspaper and top off with a metal sheet damper. Depending on the size
of the load, depth, size of saw-dust, it usally makes about 6-8 hrs. of
smoldering. Be prepared for plenty of smoke! Maybe under a vented stack might
be better, heatlh, and fire-marshrall safe. Blacks to moltten(sp) tans, can
do greenware if very dry, soft bisque is safest. Hope this helps, let me know
what you use, and how it works.
Richard Ramirez, " the clay stalker",R12396
David Donica on fri 28 feb 97
I've got a 55 gal drum that I got for free somewhere that I'm going to
drill some 1/2" holes in a do a firing someday soon. You have to be
careful what was stored in the drum obviously. The lid needs to be cut off
of mine- the best way to do that is to fill the drum with water in the
event there are combustible fumes that would ignite with the welding torch.
Maggie Shepard
FireWorks Pottery
Mt. Shasta, Calif.
Clay on sat 1 mar 97
At 07:09 AM 2/25/97 EST, you wrote:
>----------------------------Original message----------------------------
>>----------------------------Original message----------------------------
>>Hi Candice Roeder
>>Michigan
Get a electric kiln , Fire to orange color (your pots) take them out like
raku.Put them in to sawdust or what ever burn,BINGO, you get the black
silver you want .
>>
>>I'm going to be involved in a group pit firing session. I usually do my pit
>>firing in a brick enclosure (or pit dug in ground) with sawdust, wood, and
>>assorted "stuff" thrown in.
>>...snip
>>The challenge here is, at the location of this upcoming firing, there are no
>>bricks available, and a pit cannot be dug into the ground.
>>...snip
>>Any ideas out there?
>>
>>Thanks,
>>
>>Candice Roeder
>>Michigan
>
>Hi Candice,
>Have you considered galvanized garbage cans for your pitfiring? I have four
>cans with nail holes for air circulation and am able to fire my high school
>students' work on a weekend, firing approximately 140 pots in two firings.
>Also, using several cans makes it possible for the participants to get
>involved in the loading. The cans are lightweight, portable, easily
>transported, and give great flashing with the right combustibles. I use a
>combination of sawdust, sun-dried, powdered horse manure, banana peels, and
>whatever I rake up from under the trees. I wrap the pots loosely in
>newspaper, preferably the Wall Street Journal (a potter friend told me their
>ink is the best for pitfiring). I first bisque the pots at school at ^012
>to make them easier to transport and handle. Be sure to bring along the
>lids or any metal covering for smothering the fires somewhat. Good luck-and
>toss in a kiln god or two!
>(I fire at night, so no one can see where the smoke is coming from...a fire
>engine flew by once with sirens blazing but they never found us).
>Lynne Gingerich
>Tucson, Arizona, where some of my flowers are still blooming.
>
Cindy on tue 4 mar 97
>
> Get a electric kiln , Fire to orange color (your pots) take them out like
> raku.Put them in to sawdust or what ever burn,BINGO, you get the black
> silver you want .
? Is this practice hard on the electric kiln, or just dangerous? (because
of awkwardness removing ware, etc.) I have an electric kiln and would like
to try raku, but don't want to risk damaging my kiln and would like to be
aware of advisable precautions.
Cindy
June Perry on wed 5 mar 97
Reaching into an electric kiln with Raku tongs can get someone a quick and
earlier than anticipated trip to the pearly gates! Even with the kiln turned
off it can present a danger.
May try that technique instead with a gas kiln.
Regards,
June
Clay on wed 5 mar 97
Hi Cindy,
Ask those student from Ontario Collage of Art, That is the only option they
have if they like raku.
I Didn't see any damage there,but people tense to drop glaze on their kiln
when they are rakuing(sure it is school equipoment that 160 students can
have access to it).
However, they chance thier kiln lid.They were using a lifted up(like cabbage
can type)lid & use fiber flex insted of bricks to minimize the damage.
Have fun.Need more info?
Clay@Tomigi.com
Ian Chung
At 06:58 AM 3/4/97 EST, you wrote:
>----------------------------Original message----------------------------
>
>>
>> Get a electric kiln , Fire to orange color (your pots) take them out like
>> raku.Put them in to sawdust or what ever burn,BINGO, you get the black
>> silver you want .
>
>
>? Is this practice hard on the electric kiln, or just dangerous? (because
>of awkwardness removing ware, etc.) I have an electric kiln and would like
>to try raku, but don't want to risk damaging my kiln and would like to be
>aware of advisable precautions.
>
>Cindy
>
Sandra Dwiggins on wed 5 mar 97
June---
As I said---my friend uses very long tongs, and much physical protection
such as asbestos aprons, long leather gloves on her arms as well as
asbestos mits, and good hair cover. This is not a technique for people
who are careless about their safety!!!
Also, one cannot put things in the kiln haphazardly---you have to
carefully figure how you are going to remove the pieces you place in the
kiln. I probably should have mentioned this. My friend uses this
technique very successfully, but she is a super-cautious
attentive-to-details artist where personal safety and environmental
safety are concerned. Forewarned is fore-armed or four-armed...
Sandy
Phil Davenport on thu 6 mar 97
Try using metal garbage cans. Drill holes in the can to provide air. My
firings usuallly take 1/2 day.
On Mon, 24 Feb 1997, Roeder wrote:
> ----------------------------Original message----------------------------
> Hi all,
>
> I'm going to be involved in a group pit firing session. I usually do my pit
> firing in a brick enclosure (or pit dug in ground) with sawdust, wood, and
> assorted "stuff" thrown in.
>
> The challenge here is, at the location of this upcoming firing, there are no
> bricks available, and a pit cannot be dug into the ground. There is an
> "electric kiln skeleton" which can be used. I'm wondering how to adapt this
> "shell" for pitfiring, so that adequate air circulation can take
> place....how to approximate that which I'm used to.
>
> Any ideas out there?
>
> This old kiln is a sectional one, BTW.
>
> Thanks,
>
> Candice Roeder
> Michigan
>
Gavin Stairs on fri 7 mar 97
Hi All,
This business of safety in firing raku in an electric...
There are two issues: safety for the kiln and safety for the operator.
As for the kiln, I would expect a little bit of wear and tear from thermal
shock and accidents. What should be expected will depend on the workmanship
and materials in the kiln. May vary from brand to brand, or kiln to kiln,
but we've already had testimony from Ian and Candace that it can be done.
As for the potter safety, the main thing is to turn the kiln off before
opening it. In most kilns, the elements are safely behind the firebrick
face, so the likelihood of touching one with tongs is slight, with a little
care. Also, elements are oxide covered. Nevertheless, your mother told you
not to poke forks into the toaster, right? And then she pulled the plug and
went after that end slice herself, didn't she? There's no danger (to the
potter) from an element that is OFF. So make sure: unplug it, or flip the
big wall switch.
As for long tongs, etc. This is no protection from electricity. A shock
will run up tongs of any length. Thermal protection is another matter.
However, thick gloves are a good protection from electric shock, provided
they are dry (as opposed to sweaty wet). Also rubber boots or shoes. But
turn it OFF anyway.
I wouldn't try to reduce in the electric kiln. Element life is greatly
reduced in a true reducing atmosphere. I'd use the garbage can technique.
Gavin
June Perry on fri 7 mar 97
I'm glad your friend is careful. But as I said before, putting anything metal
in an electric kiln while it's on, or having just been turned off is a
disaster waiting to happen. One touch of those tongs on an element can cause
her to have her fillings flying out of her teeth!
Regards,
June
Estelle Renberger on fri 7 mar 97
I reach into my electric kiln w/raku tongs..after unplugging it of
course!!....hey!! it works!!June Perry wrote:
>
> ----------------------------Original message----------------------------
> Reaching into an electric kiln with Raku tongs can get someone a quick and
> earlier than anticipated trip to the pearly gates! Even with the kiln turned
> off it can present a danger.
> May try that technique instead with a gas kiln.
>
> Regards,
> June
June Perry on sat 8 mar 97
Unplugging the electric kiln before reaching in with the tongs is definitely
a good idea but it may not necessarily prevent a disaster. I once read an
article or perhaps it was a posting here on Clayart (perhaps some of our
kiln gurus who have more knowledge of electricity can either confirm or deny
this) that there could still be a chance of electrocution if one
inadvertently touches an element, in a kiln that has just been turned off,
with any metallic object.
I would love to hear from those in the know if the above has any basis in
truth.
Thanks!
June
Gavin Stairs on sun 9 mar 97
At 08:24 AM 08/03/97 EST, you wrote:
>----------------------------Original message----------------------------
>Unplugging the electric kiln before reaching in with the tongs is definitely
>a good idea but it may not necessarily prevent a disaster. I once read an
>article or perhaps it was a posting here on Clayart (perhaps some of our
>kiln gurus who have more knowledge of electricity can either confirm or deny
>this) that there could still be a chance of electrocution if one
>inadvertently touches an element, in a kiln that has just been turned off,
>with any metallic object.
>I would love to hear from those in the know if the above has any basis in
>truth.
>
>Thanks!
>June
>
Hi June,
There is no danger of an electric shock from an element which has just been
properly disconnected. Electric current, which in this case is the danger,
does not persist after the element has been disconnected from the supply.
Now I need to say that this depends on the element being properly
disconnected. It is possible to connect a one-side switch on the wrong side
of the element, so that the line voltage still appears on the elements.
This is probably the danger that you refer to. This situation is not good
practice, and should not be considered safe under any circumstances. If you
are unsure whether this is the case with your kiln, you should have it
tested by an electrician, or someone competent to discover this circumstance
and correct it. A simple ground fault or voltage measurement is all that is
required.
It is the possibility of this fault which prompts me to say that you should
turn the kiln off at the junction box into which it is plugged. Most
electrical codes require that equipment drawing large currents, like kilns,
be connected to the supply mains through a fused disconnect. This is that
biggish box on the wall with a lever switch on its side, to which the kiln
is connected by a flexible cable. Turning that box off will disconnect all
of the voltage supply lines.
If you have any doubt about the safety of any of these measures, get your
equipment inspected! If the wires are wrongly connected, or if there is a
deficiency in the safe design of your installation, do not wait for raku
tongs to tell you. Such equipment is unsafe even when you are unloading it
cold.
This situation differs from other cases, like television sets, computer
monitors, and, to a lesser extent, other electronic apparatus where a high
voltage is stored in various capacitances of the power supply and picture
tube. These devices do pose some danger after the power is disconnected.
All well designed equipment of this nature is designed to bleed these
voltages away relatively quickly. However, some experience in these matters
is essential for safety, and untrained maintenance is discouraged in most cases.
I hope this clarifies the question. Again, if you have any doubt about the
safety of your equipment, get it checked. This is not optional: it is
required both for your safety, and that of others who may use the equipment,
whether they are doing raku or ordinary electric kiln firing.
Lest this be too alarming, I would like to point out that the UL and CSA
seals, among others, are intended to indicate that the equipment bearing
them has passed adequate inspection in respect of this and other dangers,
and is safe to use in the manner intended. This includes use for raku
firing, if the kiln is turned off before the tongs are inserted. If you
know that equipment bearing seals has been properly installed by competent
people, and has not been tampered with by anyone you don't trust, then you
have reasonable assurance of safety.
Finally, if you have a voltmeter, and want to test your own equipment, and
you don't know how to do it, or think you do, but aren't certain, DON'T. It
is possible to fool yourself into thinking unsafe equipment is safe, which
is worse than being frightened. As someone who knows your particular case
to show you how, or to do it for you. Wiring can be confusing. And lastly,
the elements are coated with a thin film of oxide, which can cause a wrong
reading. Don't ever measure there: measure at the connection block.
Sorry to run on like this. I hope this helps.
Gavin
Paul Monaghan on sun 9 mar 97
June Perry wrote:
>
> ----------------------------Original message----------------------------
> Unplugging the electric kiln before reaching in with the tongs is definitely
> a good idea but it may not necessarily prevent a disaster. I once read an
> article or perhaps it was a posting here on Clayart (perhaps some of our
> kiln gurus who have more knowledge of electricity can either confirm or deny
> this) that there could still be a chance of electrocution if one
> inadvertently touches an element, in a kiln that has just been turned off,
> with any metallic object.
> I would love to hear from those in the know if the above has any basis in
> truth.
>
> Thanks!
> June
Hi June,
there's absolutely no chance of electrocution if AND ONLY IF The main
circuit breaker is thrown and breaks all wires leading to the kiln. let
me explain. If you turn the kiln off at the kiln or say from the kiln
sitter it is posible that one side of the circuit is still connected to
the elements. But since one side is open (Disconnected) there isn't a
completed path and the electricity stops flowing. However, if you reach
in with metal tongs (or your fingers) touch the elements and happen to
be grounded (against a cold water pipe or metal object etc) the circuit
can be completed and electricity will flow. Unfortunately you are now
part of the circuit and the power is flowing through you. If both sides
of the circuit are broken with a switch or circuit breaker than you can
even lay your tongue on the elemnts (hope there cool) and you won't have
any danger of being electrocuted (might get poisone from some glaze
residue though).:-) I hope this helps.
Paul
--
Paul J. Monaghan email: paul@web2u.com
WEB2U Productions --- http://www.web2u.com
The "COOLEST" Site on the WEB
"The Computer Secrets are hidden at www.web2u.com/secret"
Vivian Mills on mon 10 mar 97
June Perry wrote:
>
June:
I don't understand why Touching an electric elememt after it is turned
off is so dangerous, except for the heat part, of course----please
explain.
The only thing I can think of is that there might be some residual
charge in the wire, sort of like a TV set, but I wouldn't think the kiln
wires would have hold a charge, because there are no electrical
components in a kiln, similar to a TV---????
Can you explain? Thanks!
Vivian
> ----------------------------Original message----------------------------
> I'm glad your friend is careful. But as I said before, putting anything metal
> in an electric kiln while it's on, or having just been turned off is a
> disaster waiting to happen. One touch of those tongs on an element can cause
> her to have her fillings flying out of her teeth!
>
> Regards,
> June
Ellen Barrosse on tue 11 mar 97
> June Perry wrote:
> >
> June:
> I don't understand why Touching an electric elememt after it is turned
> off is so dangerous, except for the heat part, of course----please
> explain.
>
> The only thing I can think of is that there might be some residual
> charge in the wire, sort of like a TV set, but I wouldn't think the kiln
> wires would have hold a charge, because there are no electrical
> components in a kiln, similar to a TV---????
The residual charge in a TV set comes from a capacitor, which is designed
to hold a charge so the TV screen will come on quickly without having to
warm up first. to work on the innards of a TV or computer monitor, you have
to unplug it, then drain away the charge using a special tool. (Or you can
leave it unplugged for a few days, which will also drain it--or so I've
heard.)
I can't imagine why there would be a capacitor in a kiln.
Roger King on wed 12 mar 97
While I have never heard of/ seen/ tried what you advocate doing, I
must say that as a physics student I am taught that if the power supply
is taken away, the current ( no matter haw many amperes, volts, or
whatever) ceases to exist. Electron induction through the elements will
stop immeadiately upon power supply loss, however there is perhaps a
buffer ( delay?) mechanism on the kiln that could keep current for a
VERY short time in the resistors ( elements). This tiem theoretically
could not exceed one second, but for all intents and purposes, over fire
one cone, then let the kiln shut off and cool to the desired temp. Then
take the ware out and solve all the problems.
Kevin King
June Perry wrote:
>
> ----------------------------Original message----------------------------
> Unplugging the electric kiln before reaching in with the tongs is definitely
> a good idea but it may not necessarily prevent a disaster. I once read an
> article or perhaps it was a posting here on Clayart (perhaps some of our
> kiln gurus who have more knowledge of electricity can either confirm or deny
> this) that there could still be a chance of electrocution if one
> inadvertently touches an element, in a kiln that has just been turned off,
> with any metallic object.
> I would love to hear from those in the know if the above has any basis in
> truth.
>
> Thanks!
> June
Roger King on wed 12 mar 97
Ellen,
You're probably right in not being concerned, but the possible presence
of a capacitor ( a device used to store electrical potential) to
compensate for short brownouts during firing ( do these exist on
kilns????) could be intact, in which case you would draw 30 amps of
current and never see the light of day again, thus better safe than
sorry.
Kevin
P.S. solution= overfire enough to give time after unplugging for all
reasonable doubt of danger to dissapear as the kiln cools to desired
removal temp, then you have circumvented the problem.
Ellen Barrosse wrote:
>
> ----------------------------Original message----------------------------
>
> > June Perry wrote:
> > >
> > June:
> > I don't understand why Touching an electric elememt after it is turned
> > off is so dangerous, except for the heat part, of course----please
> > explain.
> >
> > The only thing I can think of is that there might be some residual
> > charge in the wire, sort of like a TV set, but I wouldn't think the kiln
> > wires would have hold a charge, because there are no electrical
> > components in a kiln, similar to a TV---????
>
> The residual charge in a TV set comes from a capacitor, which is designed
> to hold a charge so the TV screen will come on quickly without having to
> warm up first. to work on the innards of a TV or computer monitor, you have
> to unplug it, then drain away the charge using a special tool. (Or you can
> leave it unplugged for a few days, which will also drain it--or so I've
> heard.)
>
> I can't imagine why there would be a capacitor in a kiln.
Paul Monaghan on wed 12 mar 97
Ellen Barrosse wrote:
>
> ----------------------------Original message----------------------------
>
> > June Perry wrote:
> > >
> > June:
> > I don't understand why Touching an electric elememt after it is turned
> > off is so dangerous, except for the heat part, of course----please
> > explain.
> >
> > The only thing I can think of is that there might be some residual
> > charge in the wire, sort of like a TV set, but I wouldn't think the kiln
> > wires would have hold a charge, because there are no electrical
> > components in a kiln, similar to a TV---????
>
> The residual charge in a TV set comes from a capacitor, which is designed
> to hold a charge so the TV screen will come on quickly without having to
> warm up first. to work on the innards of a TV or computer monitor, you have
> to unplug it, then drain away the charge using a special tool. (Or you can
> leave it unplugged for a few days, which will also drain it--or so I've
> heard.)
>
> I can't imagine why there would be a capacitor in a kiln.
There Ain't. And it Ain't true. :-))
I have a feeling that another "Electrical Folklore" thread is about to
start.
--
Paul J. Monaghan email: paul@web2u.com
WEB2U Productions --- http://www.web2u.com
The "COOLEST" Site on the WEB
"The Computer Secrets are hidden at www.web2u.com/secret"
Irish Jim on fri 14 mar 97
The explaination I received about why you never touch an element is; The
oils on your hands could transfer to the element and at the next firing
burn out the element. Never saw this happen but makes sense.
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