I was cooking yesterday on the old classic (model 424) coleman green suitcase stove for about 20 minutes when suddenly fire /gas spurted out onto the black plastic fuel valve and was lit and burning on top of the fuel tank. It had been working fine for 20+ minutes with no problem.

I moved the food and while I was looking at it thinking of my next move someone came over with a water bottle. I said "No" as he started to pour water on it. Predictably the water carried some fuel (now lit) onto the concrete floor (we were in a barn like structure). Fortunately he only did a little water as my message got through and that fire was minimal. Another guy was getting a fire extinguisher as I am there standing in front of it thinking how am I going to turn the fuel valve off without getting burnt. I saw some pliers like hot tongs and was turning the valve off when the water guy grabbed some all purpose flower and dumped it onto the flames. That and my shutting off the fuel worked and the fire was out.

I took apart the generator pipe and did not see much corrosion on the needle, which I cleaned anyway.

So any thoughts on what might have caused the fire especially after the stove had been working well for 20 + minutes?

If I can't find a plausible cause and fix it, I am going to trash the stove.

Thoughts?

Sounds to me since you had it going for 20 minutes that the fuel bottle became hot and was causing the fuel inside to expand and thus maybe come out.
I take it the fuel was coming out in liquid form.
Also as to using flour to extinguish a liquid fuel or grease fire is NOT a good idea as flour dust is flammable. That is why they have had explosions in grain mills. You want to use baking soda, which is what is basically in a ABC type fire extinguisher.
FYI I have 30 yrs of professional firefighting experience.

quote OldFingers57: "Sounds to me since you had it going for 20 minutes that the fuel bottle became hot and was causing the fuel inside to expand and thus maybe come out.
I take it the fuel was coming out in liquid form.
Also as to using flour to extinguish a liquid fuel or grease fire is NOT a good idea as flour dust is flammable. That is why they have had explosions in grain mills. You want to use baking soda, which is what is basically in a ABC type fire extinguisher.
FYI I have 30 yrs of professional firefighting experience.
"

thanks for the reply. The fuel reservoir was not hot. Agree that flour is not the best option and that it is flammable when it is "aersolized", but this was more of a dump of flour and it worked. I think the key was to get the valve shut down.

Was it a large pot on the stove...? Maybe cap was a tad bit loose? The older caps had a screw in the top for tightening the gasket (I think) and maybe leaking through there? Packing around the valve gasket going bad or that nut that tightens the packing loose? I would set it up in a safe area and try to reproduce the same thing. Maybe even use one the those butane starters around the tank area or soap the fitting to see it you have any leaks? I have a friend who burnt down his tent on a hunting trip..... Someone went to light the stove on a cold morning and it lit with a 9' (that is 9 feet) flame... The valve had not been shut off completely the night before....no one got hurt but that took care of their 3 room canvass tent and the trip.... Guess there is a reason for that label about 'no flames in tent'

In deals like that as long as everyone stays cool about the situation things usually turn out OK. Worst is a grease fire in the kitchen and the person pours water on it or tries to carry the whole thing to the sink

dr bob

I would think that you would not have to trash the whole stove but just replace the fuel tank and generator part.
Where was the fire located on the stove precisely? I wonder what would cause the fuel to start leaking out if the tank is not warm or hot. I would pressure test the tank and see if it has a leak someplace. Pump it up and see if it leaks with out any fire or flames around it.

I would cook with smarter guys. At least they did not have access to gasoline.

So I took apart the valve and what I found was a bunch of the graphite packing nut had come apart, made a powder that was partially encircling the area shown by the probe. I am not 100% sure that is what the problem was, but I have put it back together and it seems to be working. We'll see.

quote drnatus: "So I took apart the valve and what I found was a bunch of the graphite packing nut had come apart, made a powder that was partially encircling the area shown by the probe. I am not 100% sure that is what the problem was, but I have put it back together and it seems to be working. We'll see.


"

An alternative to your "powder packing" material (in lieu of a purpose-built part), you might replace it with a rubber "O" ring. (You can find them at Lowes and Home Depot.) You'd need to find one that fits tightly and is marginally larger than the orifice of the receiver. You might want to slightly lubricate the O-ring.

I'd go back to a graphite ring if your are planning to use the stove in cold temperatures.

dd

BTW: I've used O-rings for home-built compression fire pistons so they withstand at least short durations of intense heat. But in any case, you probably want to select an O-ring with heat tolerant properties.

Coleman Collectors Forum
A reply at the bottom links, Old Coleman Parts might be the part, small and large listed. Part linked may also be packing for the air control eccentric.

A proper sized Viton o-ring (or simmilar fuel resistant), could be another mod fix, as mentioned by DD.

butthead

PS: Baking soda works great but not always at hand a wet towel will smother the flame and allow removing the stove to a safer place to fight any residual burning. bh

quote dentondoc: "

quote drnatus: "So I took apart the valve and what I found was a bunch of the graphite packing nut had come apart, made a powder that was partially encircling the area shown by the probe. I am not 100% sure that is what the problem was, but I have put it back together and it seems to be working. We'll see.



"

An alternative to your "powder packing" material (in lieu of a purpose-built part), you might replace it with a rubber "O" ring. (You can find them at Lowes and Home Depot.) You'd need to find one that fits tightly and is marginally larger than the orifice of the receiver. You might want to slightly lubricate the O-ring.


I'd go back to a graphite ring if your are planning to use the stove in cold temperatures.


dd


BTW: I've used O-rings for home-built compression fire pistons so they withstand at least short durations of intense heat. But in any case, you probably want to select an O-ring with heat tolerant properties.
"

My company sells industrial pumps, and many use o-ring static seals. If you can find Viton o-rings, they are good to about 350 deg F. Buna rubber is only good to the 200-225 deg F range. Not much cost difference between them, and both are compatible with most fuels. I've found that Ace Hardware has a good selection of little things like o-rings and screws and bolts. If they don't have them, WW Grainger has about every o-ring you can imagine, and they have the o-ring dimensions listed. On the con side, you may have to buy 5 or 25 of them. Use some lube oil of some sort when you install them. Makes it a lot easier for them to move around to the right spot. Vaseline will work as well. O-ring sizes are defined by the "dash number", e.g. -23.

So, with this information, you have all my "extensive" knowledge of o-rings. The original part could have been made of a material called "carbon graphite", which is quite brittle, and I could see that material shattering. Or, it could have been made of graphite impregnated Teflon aka packing. Packing is flexible and will not shatter.

Tomster

Let me clarify.

The pointer does point to that groove, but as far as I can tell, it is supposed to be empty, no o-ring nor any packing in it. the brass washer you see slides up to that point. So I think there was material there that was not supposed to be there.

Please correct me if I am wrong.

quote drnatus: "Let me clarify.
The pointer does point to that groove, but as far as I can tell, it is supposed to be empty, no o-ring nor any packing in it. the brass washer you see slides up to that point. So I think there was material there that was not supposed to be there.
Please correct me if I am wrong. "

Been looking for a decent parts diagram of the Powerhouse 424.
ClassicCampStoves reference is the best so far but does not show the fuel valve, My 425 is different as the grove you point to has a brass ring and collar among other differences.

butthead

Just found some photos and description,

from, Rebuilding a Two or Three Burner Stove

Hope this helps some.

butthead

quote butthead: "Just found some photos and description,


from, Rebuilding a Two or Three Burner Stove


Hope this helps some.


butthead"

Yes that second photo is it. the silver piece is the graphite packing nut that I think rubbed off and created the debris that caused a leak by not letting the brass washer seat properly.

For some reason, the pix that Butthead posted on line are really tiny on my computer. There is another material, carbon based, called grafoil, which is designed for really hot temps, e.g. > 550 deg F. It is not at all flexible and it is quite fragile, so there is no way you would be able to slip it into a spot where an o-ring might seat. It is used as a type of packing for rotating shafts. We sell some for use in really hi-temp applications, such as for hot oil heating systems used to heat asphalt pumps.

Going way off topic, as I usually do, do you remember the Challenger shuttle explosion? The story I heard was that the sections of the outboard rockets were sealed with a type of elastomer that did not have the proper temperature range before failure. The solution was to use an elastomer called Kalrez, which is made by DuPont, which remains flexible over a very wide temperature range. Kalrez is really expensive. A single 2" diameter Kalrez o-ring is probably about $200. Maybe more.

Tomster

That's the way they posted Tom, click on them, then click on the photo to enlarge to full size.

butthead

Have had the same thing happen as the OP, easy fix in the field just tweaking the valve stem nut slightly tighter. That's why a 1/2 inch combination wrench always rides in my green suitcase.

quote schweady: "Have had the same thing happen as the OP, easy fix in the field just tweaking the valve stem nut slightly tighter. That's why a 1/2 inch combination wrench always rides in my green suitcase.
"

This seems to be especially prevalent after a few years of use without any maintenance. It seems like they work their way loose after a while.

I hope that I'm not too late to this thread.

I would suggest that you contact Coleman direcly about this problem.

A few years ago, my suitcase stove started spraying excessive gas from the discharge pipe and started a large fire in the case. It burned a lot of the green paint off before it finally conked out. I called Coleman and they quickly offered to replace the brass valve/discharge assembly free of charge. I installed it back on the red tank and have not had any trouble with it since. They did not ask how old the stove was or anything like that.

Worth a try.

SE