Sherry Becker-Gorby on tue 9 oct 01
Hi Folks
I too am a long time lurker and have enjoyed as well as benefited =
immensely from all the good advice shared. =20
I recently built a small portable fiber raku kiln. It is about the size =
of a 30 gallon garbage can just a little shorter. I use 25 lb propane =
tank to fire. I do not seem to be able to get it up to temperature to =
melt the glazes. I have fired for three hours and longer. I keep =
pressure at about 10 lbs. I appreciate any advice I can get on this. =20
Sherry Becker-Gorby
Ababi on wed 10 oct 01
As it is pretty hard for me to convert your measurements I will try
another way.
I think the size is like mine.
Perhaps the ceramic fiber must be thicker?
Perhaps you do not have enough presure?
I think we use"Butan - gas".
What will happen if you will use maximum pressure?
Try this way.
put the pressure valve on maximum.
Now the gas faucett near the kiln :
The first ten minutes fire on low, how much? Half turn.
Than up to the maximum.
When there are flames, adjust the pressure valve, to the maximum
possible- blow the flames, do not have flams in the kiln but have high
fire. there is another way, to add reassure every 10 minuets, but this
way here will help you to adjust your maximum pressure.
To make this every ten minuts raising of firing, you make the pressure
on makximum, just turn the near the kiln faucet more and more
Ababi Sharon
Kibbutz Shoval- Israel
officially Glaze addict
sharon@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
http://www.israelceramics.org/
---------- Original Message ----------
>Hi Folks
>I too am a long time lurker and have enjoyed as well as benefited
>immensely from all the good advice shared.
>I recently built a small portable fiber raku kiln. It is about the
>size of a 30 gallon garbage can just a little shorter. I use 25 lb
>propane tank to fire. I do not seem to be able to get it up to
>temperature to melt the glazes. I have fired for three hours and
>longer. I keep pressure at about 10 lbs. I appreciate any advice I
>can get on this.
>Sherry Becker-Gorby
>_______________________________________________________________________
_
>______
>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.
Lamar, Luke on wed 10 oct 01
Hi Sherry,
What kind of burner do you have? You might have a problem with your fuel/air
mix or burner size. I have a 6 cu. ft. fiber kiln, use a 25 lb propane
tank, and fire with a pressure of 8psi and I reach temperature between 30
and 50 minutes depending on the glaze and current temperature of kiln. I can
do 5 firings with about 4 to 4.5 pounds of LPG. For regular firing, not
reduction, I try to adjust the fuel/air mix to get a nice blueish flame with
a minimum amount of sputtering.
Check the archives for burners and fuel/air mixtures. Also, Marc Ward at
Ward Burner Systems is extremely knowledgeable on this subject. Hope this
helps!
Luke Lamar
llamar@bacweb.org
-----Original Message-----
From: Sherry Becker-Gorby [mailto:meadowview@1ST.NET]
Sent: Tuesday, October 09, 2001 7:03 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Firing Fiber Raku Kiln
Hi Folks
I too am a long time lurker and have enjoyed as well as benefited immensely
from all the good advice shared.
I recently built a small portable fiber raku kiln. It is about the size of
a 30 gallon garbage can just a little shorter. I use 25 lb propane tank to
fire. I do not seem to be able to get it up to temperature to melt the
glazes. I have fired for three hours and longer. I keep pressure at about
10 lbs. I appreciate any advice I can get on this.
Sherry Becker-Gorby
____________________________________________________________________________
__
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.
Arnolds Home Improvements on wed 10 oct 01
Sherry
I had the same problem with my first raku kiln. It would stall out at 1700
degrees no matter how long or how much gas, still only 1700 max. My problem
was the opening in the top of the kiln was too small,which would not allow
the kiln to get any more air and it would stall.
This may or may not be your problem but it worked for me.
I enlarged the hole to 4.5 inches from 3 inches.
There is probably a formula to figure the size needed for this opening,I
kind of go by the seat of my pants being a beginner.
Gene Arnold
mudduck@advi.net
playing in the mud in N.C.
Sherry Becker-Gorby on thu 11 oct 01
Hi Gene
Thanks for the advice. Actually the plan I used to build my kiln has no
openings at the top, only 2 side openings. The side openings are about 4" X
4" Perhaps I should try to put an opening at the top
Sherry
----- Original Message -----
From: "Arnolds Home Improvements"
To:
Sent: Wednesday, October 10, 2001 4:53 PM
Subject: Re: Firing Fiber Raku Kiln
> Sherry
>
> I had the same problem with my first raku kiln. It would stall out at 1700
> degrees no matter how long or how much gas, still only 1700 max. My
problem
> was the opening in the top of the kiln was too small,which would not allow
> the kiln to get any more air and it would stall.
>
> This may or may not be your problem but it worked for me.
>
> I enlarged the hole to 4.5 inches from 3 inches.
>
> There is probably a formula to figure the size needed for this opening,I
> kind of go by the seat of my pants being a beginner.
>
> Gene Arnold
> mudduck@advi.net
> playing in the mud in N.C.
>
>
____________________________________________________________________________
__
> 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 Baymore on thu 11 oct 01
I recently built a small portable fiber raku kiln. It is about the
size of a 30 gallon garbage can just a little shorter. I use 25 lb
propane tank to fire. I do not seem to be able to get it up to
temperature to melt the glazes. I have fired for three hours and
longer. I keep pressure at about 10 lbs.
Sherry,
Without a little more information it is hard to diagnose from afar.......=
.
but as crazy as this seems...... you might try running the gas pressure t=
o
your burner quite a bit LOWER. In order to climb in temperature, the hea=
t
energy from the gas needs to be realized in the chamber. It is possible
that one reason it is not getting hot is that you are not actually
combusting the fuel in the chamber. Common problem with raku kilns that
are "overpowered".
This is assuming that the BTU rating of your burner was appropraite or hi=
gh
to start with, that the kiln flues are correctly sized, that the burner i=
s
adjusted properly for primary air, and so on.
Now on to some "pain in the butt" questions..........
What type of burner is it? What's the BTU rating? How is it set up to
introduce the flame into the kiln chamber? What size are the burner port=
s
and the exit flue? How much fiber is the kiln made out of? What rating
and density? When you fire, what color is the flame at the burner port? =
What color is the flame in the chamber? If there is flame at the exit
flue, what color is it?
Best,
..............................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JohnBaymore.com
JBaymore@compuserve.com
John.Baymore@GSD-CO.com
"Earth, Water, and Fire Noborigama Woodfiring Workshop 2002 Dates TBA"=
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