Earlier this summer I discovered that I had pinholes in my 1925 Coleman Model 2, two burner stove fount (fuel tank). As noted in my previous post about this stove’s generator rebuild, I was disappointed in the new pinholes making the stove unsafe to use, but I began working on a method to repair it. At first I thought I’d just solder the pins holes from the outside and continue using the stove. However, after some research, I decided that if there are a few holes, there are probably more on their way. To fix the fount in a more long-lasting and hopefully, less troublesome way I decided to disassemble the fount and stop more holes from destroying the fount. I was in for a surprise.
Disclaimer: I have been working on old stoves for several years, and what I do may not work for you. Please use this post as a reference only, which shows a process that I used. Given that old things can be in all states of disrepair you must use your own judgement when repairing your gas pressure appliances (GPA) and I cannot be responsible for something as serious as your repair of your old stove or other GPA. Proceed at your own risk!
The fount still had the original painted gold Coleman name on the fount and while I hoped that I could preserve it, I thought it be best to plan on it getting destroyed, so I took some photos of it, traced it onto some clear plastic sheet and tried to mark its location.
I emptied the fount and then rinsed several times with denatured alcohol. The idea was that I’d get most of the fuel out and then a couple of days in the hot sun would help dry the residual alcohol. The tank is difficult to empty due to the tube soldered to the filler opening/fitting which is there to prevent over-filling. Once empty and dry I removed the wing-nut fuel cap and the pump and set up the tank to remove the end cap which holds the pump and the check valve. With the help of my son and using two propane torches we heated the end and tried to remove the cap with some wide-grip pliers (Channel-lock type), but it wouldn’t budge. Eventually, with the solder flowing again I tried tapping it with a hammer and punch and was able to remove it.
What I saw inside made me a little sad, but also relieved that I decided to disassemble the fount. There was quite a bit of rust inside confirming that more pinholes were in the works.
The pitting was extensive on both ends of the fount and in some places there were sheets of rust. I used some muriatic acid to remove some of the rust, then after rinsing with water I followed up with a steel wire brush. I discovered 10 or more pinholes already existed, so it became obvious that since I’ve come this far I better remove the cap at the other end, too. Sure, enough, more holes.
What I decided to do next was remove as much rust as possible and them fill the pin holes as best I could with solder by heating from the outside and filling in some of the deeper rusted areas with solder.
Once I was satisfied I had soldered all of the holes, I chose to coat the entire inside of the fount with POR15 Fuel Tank Sealer (What I didn’t like about the product is that once opened all of the contents must be used. This quart sized fount used less than an ounce so most of the 8 ounce can is waste). This is a pretty expensive option but it seemed like the right thing to do, given that the fount cannot ever be fully emptied and would likely be rusting again in a short time. The process wasn’t too bad but it did make me somewhat uneasy. I re-soldered back on the end-cap at the fuel filling end so that the cleaner-degreaser, rust-remover and then sealer could be poured into the fount and be used as intended. I plugged the fount’s fuel puck-up tube, which cannot be removed, by clamping a piece of rubber over the fitting.
After the rust removing process, I noticed one more very small pinhole, however, the fuel tank sealer is supposed to be able to fill pinholes so I left it be. This may have been a mistake as you’ll see later. Overall, the sealer seemed to do its job as the pinhole appeared to be plugged after the sealer was applied. It needs to cure for 4 days before I could continue with the repairs.
Warning: be sure to blow air through the fuel line fitting to ensure that the pick-up tube remains open and doesn’t get sealed with the fuel tank sealer. Also, clean out the threads for the fuel line immediately.
While I waiting for the sealer to cure I began cleaning up the end-cap which holds the pump and check valve. As many people note, and you can see in the photos, the check valve is not a removable type so common to most Coleman GPAs (Gas Pressure Appliances). This is another reason I left this cap removed when sealing the fount.
What I didn’t realize was that there is a small rubber gasket which goes into the check valve, held in place by the hex fitting. This gasket, now burned to a crisp when I removed the end-cap with the torch, seals the check valve stem when opened so that air can be pumped into the fount. I didn’t know, but, whatever . . . I made a new one out of some Viton gasket material I have on the shelf from making other gaskets. The inner diameter of the gasket I made is approximately 4.5mm and the outer is 8mm (5/16″).
With that all ready to go and NOT installed, I soldered the end-cap on.
At this point it was time to pressure check the stove. But, before I could do this, I needed to re-install the fuel line and generator. Once completed, I pumped pressure into the tank and . . . FAILURE! Man, that’s disappointing. I discovered three pinholes which I did not get soldered, nor got filled by the fuel tank sealer. Sigh . . . . .
Unlike my backpacking stoves which have the burner sitting right on top of the fount which experiences lots of heat, this fount sits outside of the stove when in use and doesn’t get excessively hot, if hot at all. So, I decided I would try to patch solder from the outside of the fount. This appears to have worked well to this point with an air pressure test, so next, a lengthy pressure check overnight. This worked well.
Next, a water submersion. This showed no leaks, too. Looking good.
Finally, I reinstalled the whole assembly in the stove and rechecked all of the fittings, then added fuel.
Note: Like many early stoves, the On/Off valve is not right at the fount, so it is crucial that the fittings be checked for leaks before lighting. What I did was pressurize the fount and opened the valve to let some fuel into the generator, which means that fuel has now filled the fuel line and generator. I checked for leaks again, added more pressure and checked again. All was good. Actually, this is the reason I clean the parts so well. I want to be able to look at the gas fittings and not wonder . . . was that dark spot there before? Was it kinda’ wet looking? When it’s clean I know that anything less than the pristine, dry surface is not okay.
So, with everything set and fire extinguisher nearby I filled the preheat cup with fuel and warmed up the generator. Then, I moved the burners into position and lit the stove. Everything went perfectly. I ran the stove on a breezy evening and both burners were up and running fine. What a relief!
Next up will be some further testing, maybe three more operations, to confirm that everything is running well and that no new leaks appear. Finally, I’ll take the assembly back out of the stove, paint the fount black and add back the gold Coleman label using a stencil I made. But . . . that will be for another post.
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