Francoise Melville on sun 13 oct 96
Marc, I see that you do not recommend the use of weed-burners for
raku kilns and you are certainly right in saying that there are more
appropriate burners for this kind of work. However, two summers ago, I
designed and built my own small fiber-lined garbage can kiln which I
regularly fire using a Tiger Torch weed-burner, a 20lb propane tank and a
Fisher regulator (the most expensive component in the set-up). My first
load of the day takes about 30 minutes to fire with subsequent firings being
considerably quicker if the raku piece is not too voluminous and thick. I
keep a garden hose dripping gently over the top of the tank - avoiding the
valve - throughout the firings and my tank not only never freezes, but can
be used to the very last ounce of gas. My kiln is very small - about 24"
high by 14" diameter - and I can usually manage up to 13 one-pot firings
with one 20lb tank, so really I have no complaints about wastage or
inefficiency. However, the regulator is a must, and I keep the Tiger Torch
about one inch OUTSIDE the burner port after a few minutes initial warm-up.
A piece of firebrick in the middle of the kiln floor ensures that the flame
from the burner is evenly dispersed.
So, for those of you who can't afford a real kiln-burner, go for a weed-burner!
Francoise
Indalo Pottery
Port Edward, B.C.
Canada
WardBurner@aol.com on sun 13 oct 96
Francoise,
I'm sorry I didn't make myself clearer....plus you illustrated my point.
Most all weed burner setups use the same or similar burners that Raku
systems use, they just don't have a regulator. Because of this, they are weed
burners. You did the right thing by putting on the regulator. Your
experiences would have been much different if you hadn't spent the extra
money. Now you have a kiln burner instead of a weed burner! Again I'll say
what I said before, "it's the cheap person that spends the most".
Folks, please don't run any gas fired burner system without a regulator. You
wouldn't think of driving a car that has no gas pedal and ran as fast as it
would go and only slowed down when it started running out'a gas.
Marc Ward
Ward Burner Systems
PO Box 333
Dandridge, TN 37725
USA
423.397.2914 voice
423.397.1253 fax
wardburner@aol.com
Francoise wrote:
Marc, I see that you do not recommend the use of weed-burners for
raku kilns and you are certainly right in saying that there are more
appropriate burners for this kind of work. However, two summers ago, I
designed and built my own small fiber-lined garbage can kiln which I
regularly fire using a Tiger Torch weed-burner, a 20lb propane tank and a
Fisher regulator (the most expensive component in the set-up). My first
load of the day takes about 30 minutes to fire with subsequent firings being
considerably quicker if the raku piece is not too voluminous and thick. I
keep a garden hose dripping gently over the top of the tank - avoiding the
valve - throughout the firings and my tank not only never freezes, but can
be used to the very last ounce of gas. My kiln is very small - about 24"
high by 14" diameter - and I can usually manage up to 13 one-pot firings
with one 20lb tank, so really I have no complaints about wastage or
inefficiency. However, the regulator is a must, and I keep the Tiger Torch
about one inch OUTSIDE the burner port after a few minutes initial warm-up.
A piece of firebrick in the middle of the kiln floor ensures that the flame
from the burner is evenly dispersed.
So, for those of you who can't afford a real kiln-burner, go for a
weed-burner!
Francoise
Indalo Pottery
Port Edward, B.C.
Canada
Karl David Knudson on sun 13 oct 96
On Sun, 13 Oct 1996, Francoise Melville wrote:
> ----------------------------Original message----------------------------
> I regularly fire using a Tiger Torch weed-burner, a 20lb propane tank and
> a Fisher regulator (the most expensive component in the set-up).
------------------------------------------
> However, the regulator is a must,
-----------------------
> So, for those of you who can't afford a real kiln-burner, go for a weed-burner
I think that Marc's problem with the weed burner was that it was
unregulated. You're own setup mentions that buying a regulator was not
only expensive but a must. Fire without one and you run into all of the
problems that Marc mentioned. So it would be more informative had you
closed with a sentence like "for those of you who can't afford a real
kiln-burner, go for a weed-burner, and a good regulator, and hook it up
properly. For those of you who can afford the extra $3.00 or so that a real
burner will cost, you would be better served to do so." IF you cant
afford this, try raku firing with wood, it'll take a bit longer but may
result in some interesting reduction flame patterns...
Karl
Jeff Lawrence on sun 13 oct 96
Francoise writes:
>So, for those of you who can't afford a real kiln-burner, go for a weed-burner!
>
My Red Devil weedburner is a fired out hulk after a mere five hours. But it
worked great until something gave out! Think twice.
Jeff
Jeff Lawrence
jml@sundagger.com
505-753-5913 vox/fax
Francoise Melville on mon 14 oct 96
First of all, Marc, I always enjoy your very helpful and informative
posts, and I appreciated your gracious reply to mine.. The real reason
for my buying a humble weedburner was that my suppliers near Vancouver do
not stock any 'real kiln burners' and advised me to get a weedburner plus
regulator. These are available locally and my 'Westorch', made in Alberta I
believe, and CGA approved, cost around $35 Canadian. I said the regulator
was the most expensive item and so it was, at under $50. As they were not
available, I have no idea of the cost of a 'real' raku burner. My burner
allegedly gives out 220.000 BTUs at 30 psi but I never have to use it at
full power.
Karl, sorry if I expressed myself poorly. Yes, indeed, you may
consider me 'cheap and stingy' - not so, I am merely pecuniarily challenged
:) I did construct a small, wood-fired raku kiln before getting the
weedburner, but never managed to get it up to the necessary temperature
before being doused with rain, and could never find enough dry wood to fire it.
Finally, Jeff. I do not know the Red Devil burner, maybe it is not
a good one, or it could be that you had it too far into your burner port,
causing it to overheat and burn itself out. My torch has been firing for
several hours every ten days or so, winter and summer, ever since I
installed it over a year ago.
Francoise, who lives in the rainiest part of sodden, NW Canada :( (How
about a solar-powered raku kiln?)
ZALT@aol.com on tue 15 oct 96
I have to support the statement that one should never, never, never use a gas
burner with out a proper regulator. My experience was when I was serving
with the UN in the middle east. We used butagas for our cooking stoves and
we could never get a hot flame. When visiting a friend at his outpost I
noticed that his flame was hot. I asked how he did it. He explained that
he simply took the regulator off the bottle. I thought that this was a great
idea. That was until he lite the oven of his stove. BOOM!!!. I was
thrown across the room and he was without hair and eyebrows. He also spent a
week in hospital. Lesson Learned.
Terrance Frank Lazaroff
Harvey Sadow on tue 15 oct 96
Regarding Francoise's request for a solution to pressure drop and tank
freeze up problems when using a small tank and "weed burner" for raku
firing, I would like to offer this. In 1974, I was living in a cabin in the
Wisconsin woods, a mile and a half from the road and a long way from the
last place that a propane truck could hope to reach. Of course, I built my
raku kiln on the hill beside the cabin. The old local veteran gas dealer
insisted that if all us potters would just listen to him, we'd all be a lot
better off. He begged me to try using a 100 lb. liquid withdrawal cylinder,
which I could haul up to the cabin on a toboggan or a garden cart, depending
on the season. He had me hook a regulator to the cylinder, and a high
pressure hose to the regulator and use a "tar burner", another name for a
liquid withdrawal burner. I was able to fire that kiln, a rolling floor
beauty measuring 27" x 22 1/2" x 40" inside to 1800F in four minutes.
Needless to say, I've never used anything else since. A liquid withdrawal
system take the LP from the bottom of the tank, vaporizes it in the line,
superheats it in the burner and sounds like the concorde taking off! It is
a little hard on the regualtor, I am on my third one, but I am still using
the same burner all these years later. More importantly, each tank of gas
gets drained to the bottom, never loses pressure and ends up saving time,
money and gas. This is how those road crews in the tundras keep the tar
pots hot when they are fixing pot holes in -20 weather. this solution may
not help you, Francoise, having already purchased other equipment, but may
be of interset to the next person considering this issue.
Harvey Sadow on tue 15 oct 96
Regarding my previous message, I keep the pressure down on the tar burner,
so the kiln doesn't fire so fast that I can't get my reduction choreography
ready. It runs quietly at low pressure, though not as quiet as a venturi
burner. The burner, by the way, is 500,000 BTU. You can buy much smaller
ones, too, and they are available through most LP dealers. I don't get any
commission...
WardBurner@aol.com on tue 15 oct 96
Francoise,
Again you prove my point...I guess I'm not making myself clear. There is no
such thing as a "real kiln burner" as oppossed to a humble weed burner. The
Venturi burner I sell for many Raku systems is a MR750. It costs about the
same as the burner you bought and is used in weed burners and portable fish
cookers. When you added the regulator it became a "real" kiln burner. I got
tied up in this loose thread so I could STRONGLY warn people not to fire weed
burners without a regulator.
Marc Ward
Ward Burner Systems
PO Box 333
Dandridge, TN 37725
USA
423.397.2914 voice
423.397.1253 fax
wardburner@aol.com
Francoise wrote:
<<<<< The real reason
for my buying a humble weedburner was that my suppliers near Vancouver do
not stock any 'real kiln burners' and advised me to get a weedburner plus
regulator. These are available locally and my 'Westorch', made in Alberta I
believe, and CGA approved, cost around $35 Canadian. I said the regulator
was the most expensive item and so it was, at under $50. As they were not
available, I have no idea of the cost of a 'real' raku burner.>>>>
Mary Hays on fri 18 oct 96
Ward,
1) What's the difference in a weed burner and a raku burner? (just a
regulator?)
2) Price wise, how much does a "real" raku burner cost?
3) Is there any special regulator to use with a weed burner?
4)What do you set/adjust your regulator to?
5) What propane tank works best, (so it doesn't freeze over), do you need a
20lb., 40lb., 100lb. propane tank.
6)What does it mean when the tank freezes over? how do you correct this?
I know, I sure ask alot of questions. By the way, I want to thank all members
of clay art for all the valuable info. It's pretty incredible to be able to
talk to artist's across the country!
Thanks for your help!
jhaysbsmo@aol.com (Mary Hays) in Blue Springs, MO.
WardBurner@aol.com on fri 18 oct 96
Mary Asked these questions:
Ward,
1) What's the difference in a weed burner and a raku burner? (just a
regulator?)
2) Price wise, how much does a "real" raku burner cost?
3) Is there any special regulator to use with a weed burner?
4)What do you set/adjust your regulator to?
5) What propane tank works best, (so it doesn't freeze over), do you need a
20lb., 40lb., 100lb. propane tank.
6)What does it mean when the tank freezes over? how do you correct this?
Answers:
1) Weed burners generally do not have regulators, air shutters, and valves.
2) Again, there is no such thing as a "real" Raku burner. Systems that I sell
that are designed for Raku start at $165.00. All the Raku kilns we make use
this same burner system. Added safety systems, more or different burners,
hookups for multiple tanks, ect., all increase the price.
3) Any adjustable high pressure PROPANE regulator in the 0-30 PSI range will
work such as a Fisher 67, a Rego 567, or a Shen 7000-30. Don't use regulators
designed for welding.
4) No specific answer. Depends on the burner used and the size of the kiln
being fired. Play around with it.
5) Again, no specific answer. It depends upon how much gas you withdraw in
relation to the total amount of gas in the tank and how fast this happens.
The amount of liquid surface area is more important that volume. In other
words, two 20lb tanks hooked together work better that one 40lb tank. Same
volume, but the two 20's have twice the surface area.
6) There are actually two types of freezing conditions that affect Raku
firing. The least common is regulator freezeup from moisture in the fuel. Ice
forms in the regulator and plugs it up. Shouldn't happen if you get "good"
propane with a drying agent. The most common form of freezeup is seen on the
outside of the tank. This has to do with "gas laws". You scuba divers out
there know why cylinders are filled with air while in a tub of cold water.
For the rest of you that don't like to breath underwater, scuba tanks are
filled in cold water because the cylinders get hot as they're filled or
pressurized. When pressurized gas is released, the opposite happens, they get
cold. The quicker they are drained, the colder they get. No big deal in
scuba, but propane tanks have liquid in them. This liquid needs to boil, like
any other liquid, to turn into a gas. As the tank gets colder from rapid
withdrawal, the liquid inside doesn't boil as much so you don't get as much
gas. You turn it up to get more...it gets colder-less gas...you turn it up
even more....it gets even colder-a greater reduction in gas....you're
finished firing whether you like it or not. The liquid inside gets to be way
below the freezing temperature of water and this cause the moisture in the
air to condense on the sides and turn to ice. The answer to the problem is a
bigger tank or small tanks hooked together so that the percentage removed is
smaller. Propane tanks are not designed to be submerged in water like scuba
cylinders. If you run water over them while firing or put them in a tub of
water, you are not curing the problem....you're alleviating the symptoms
while reducing the life and possible integrity of the tank.
Mary, feel free to call or write for a catalog. Pictures sometimes tell a
better story.
Marc Ward
Ward Burner Systems
PO Box 333
Dandridge, TN 37725
USA
423.397.2914 voice
423.397.1253 fax
wardburner@aol.com
ZALT@aol.com on sun 20 oct 96
In a message dated 96-10-18 18:50:50 EDT, you write:
<< in >>
Lets be careful out there. It is a big thing to release the air out of a
scuba tank quickly. The release causes a moisture build up, through
condensation, in the tank which causes problems when you breath future air
fills.
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