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raku kiln not up to temp.

updated mon 14 jul 03

 

mcgowan cathleen on fri 4 jul 03


Can Anybody HELP!???

I have made a raku kiln using Piepenburg's propane
flange burner. The kiln is fiber blanket lined 30
gallon trash can. The problem is, it doesn't get up
to temperature. I have a raku party to fire at in a
couple weeks and am PANICKING!
I don't have a regulator of any kind as I cannot fit
the high pressure regulators to the propane tank due
to right hand/left hand thread mismatches. Does
anyone have any suggestions? Do I need the high
pressure regulator?
I fired the burner into a hole cut into the bottom of
the trash can. I couldn't fit a brick in and so the
flame is just going through the kiln.

Thanks,
Cathleen
ayiloda@yahoo.com




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william schran on sat 5 jul 03


>Cathleen - We'll need some more information to come up with a
>solution. Is the burner positioned in the hole or set back away a
>little (should be set back an inch or two)? How large is the flue
>opening?
How high is the shelf propped up from the floor(may need to be
higher)? I suspect you may be suing too much pressure. Are there
flames coming out the flue (check at night, it's easier to see)? This
might be an indication of too much pressure. More info please.
Bill

>
>I have made a raku kiln using Piepenburg's propane
>flange burner. The kiln is fiber blanket lined 30
>gallon trash can. The problem is, it doesn't get up
>to temperature. I have a raku party to fire at in a
>couple weeks and am PANICKING!
>I don't have a regulator of any kind as I cannot fit
>the high pressure regulators to the propane tank due
>to right hand/left hand thread mismatches. Does
>anyone have any suggestions? Do I need the high
>pressure regulator?
>I fired the burner into a hole cut into the bottom of
>the trash can. I couldn't fit a brick in and so the
>flame is just going through the kiln.
>
>Thanks,
>Cathleen
>ayiloda@yahoo.com
>
>
>
>
>__________________________________
>Do you Yahoo!?
>SBC Yahoo! DSL - Now only $29.95 per month!
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>______________________________________________________________________________
>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.

Cindy Gatto on sat 5 jul 03


Cathleen:
Hi, One quick question- do you have a flue hole cut in the top Of the
kiln? Believe it or not it is very important to have a large enough flue hole.
Having to small or no flue hole at all can be very detrimental to temperature
rise.
It may sound strange but whatever you put into the kiln (meaning gas volume)
must be able to get out (meaning spent fumes) I read one time that a Raku kiln
is more like a heat exchanger more than anything.
The first time I fired our Raku kiln I had the same problem,
everything was correct everything was good I had checked everything except it would get
so hot then it would stall, and get no hotter. It wound up simply that my
flue hole was not large enough and therefore the gas could get in but spent fumes
could not get out. Thus no temperature rise.
I hope this is of some help to you.
Cindy & Mark
The Mudpit
228 Manhattan Ave
Brooklyn, NY 11206
718-218-9424
mudpitnyc@aol.com
www.mudpitnyc.com

Marcia Selsor on sat 5 jul 03


I don't know this burner, but I will check my Piepenburg books.
It could be you have the burner in too far. Try keeping the tip
of the burner outside the kiln. None of the burner should be in the kiln
at all. If your port is the right size there should be sufficient
secondary air to help heat the flame. How thick is your insulation? I
hope this helps you reach temperature. What is the lid like? do you have
a sufficient size exit for the flame?
I have sprayed my two fiber kilns with ITC. For my raku workshop last
weekend, it costs $12 for 2 days of firing these kilns. (First day we
only did horse hair so that is cooler.
Marcia

mcgowan cathleen wrote:
> Can Anybody HELP!???
>
> I have made a raku kiln using Piepenburg's propane
> flange burner. The kiln is fiber blanket lined 30
> gallon trash can. The problem is, it doesn't get up
> to temperature. I have a raku party to fire at in a
> couple weeks and am PANICKING!
> I don't have a regulator of any kind as I cannot fit
> the high pressure regulators to the propane tank due
> to right hand/left hand thread mismatches. Does
> anyone have any suggestions? Do I need the high
> pressure regulator?
> I fired the burner into a hole cut into the bottom of
> the trash can. I couldn't fit a brick in and so the
> flame is just going through the kiln.
>
> Thanks,
> Cathleen
> ayiloda@yahoo.com
>
>
>
>
> __________________________________
> Do you Yahoo!?
> SBC Yahoo! DSL - Now only $29.95 per month!
> http://sbc.yahoo.com
>
> ______________________________________________________________________________
> 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.
>

John Post on sat 5 jul 03


Hi Cathleen,

My guess is that your flu exit hole is not large enough.
If you have a removable lid on the kiln, you can try propping it open a bit.
If the temperature rises, this will tell you that you need to make the flu
larger.
If you make a larger flu, you can use a brick across the top of it to
control reduction in the kiln.

Steve Branfman's book has good information about this topic.

Cheers and good luck,

John Post

>>>Can Anybody HELP!???

I have made a raku kiln using Piepenburg's propane
flange burner. The kiln is fiber blanket lined 30
gallon trash can. The problem is, it doesn't get up
to temperature. I have a raku party to fire at in a
couple weeks and am PANICKING!
I don't have a regulator of any kind as I cannot fit
the high pressure regulators to the propane tank due
to right hand/left hand thread mismatches. Does
anyone have any suggestions? Do I need the high
pressure regulator?
I fired the burner into a hole cut into the bottom of
the trash can. I couldn't fit a brick in and so the
flame is just going through the kiln.

Thanks,
Cathleen
ayiloda@yahoo.com

Arnolds Home Improvements on sat 5 jul 03


Cathleen

Check the size of your exit flue. I had the same problem and increasing the
size from 3x3 to 4x4 solved the problem for me.

Gene Arnold
mudduck@advi.net

mcgowan cathleen on sat 12 jul 03


Thanks for the suggestions. Yes, I have a 5" diameter
hole at the top of the kiln for the flue.


--- Cindy Gatto wrote:
> Cathleen:
> Hi, One quick question- do you have a flue
> hole cut in the top Of the
> kiln? Believe it or not it is very important to have
> a large enough flue hole.
> Having to small or no flue hole at all can be very
> detrimental to temperature
> rise.
> It may sound strange but whatever you put into the
> kiln (meaning gas volume)
> must be able to get out (meaning spent fumes) I read
> one time that a Raku kiln
> is more like a heat exchanger more than anything.
> The first time I fired our Raku kiln I had
> the same problem,
> everything was correct everything was good I had
> checked everything except it would get
> so hot then it would stall, and get no hotter. It
> wound up simply that my
> flue hole was not large enough and therefore the gas
> could get in but spent fumes
> could not get out. Thus no temperature rise.
> I hope this is of some help to you.
> Cindy & Mark
> The Mudpit
> 228 Manhattan Ave
> Brooklyn, NY 11206
> 718-218-9424
> mudpitnyc@aol.com
> www.mudpitnyc.com
>
>
______________________________________________________________________________
> 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.


=====
"Reality is merely an illusion, albeit a very persistent one."
- Albert Einstein

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