A year or so back, I acquired a Svea 106 in very good condition--I did nothing to it but add fuel and it ran perfectly right away. The pump leather looks pretty beat up, but brings the tank up to pressure easily enough. The disassembled stove was stored in a can in an unheated part of my house over the winter. When I pulled it out the other day, preparatory to taking it on a canoe trip next month, some fuel had evidently dribbled out over the course of the winter. Not much--probably less than a teaspoon--but enough to concern me. I'm very much a novice at this type of stove, but my hypothesis is this: Over the winter, changes in temperature caused some pressure changes in the tank (these would have been considerable, since the loft temperatures probably varied from -10 F to +50 or so). This might have caused fuel to seep a bad seal in the reserve cap. Does that make sense? I had figured on replacing the seals all along, but it took this to motivate me to actual order the necessary kit from the Fettlebox. I suppose that a tiny leak in the fuel tank itself is another possibility, but that seems a lot less likely to me. Am I right to replace the seals and see what happens, or should I consider other possibilities as well?
Yep, IMHO leakage from fuel expansion as you guessed. Seals are probably fine, even my travelers had leakage problems. I leave air bleed open and cap a bit loose when storing with fuel. Best to store in leak proof pan because they still can leak from unregulated jet. Draining between using or traveling will help. Don't want Kero spill in car or canoe.
Some new and useful information for me, thanks. I assume that loosening the cap and/or air bleed as suggested above allows the pressure to gradually equalize when the stove is is storage. I had not done that. But isn't a stove designed to maintain its internal pressure? Isn't that what the seals are for? If so, and if--as Daryl has suggested--the seals are fine, what's the source of the leakage? Fuel is either getting past the seals, or oozing through a hole somewhere, correct? I can't think of any other possibilities.
You can check for leaks by leaving fuel cap loose, place in freezer for 10 or 15 minutes, filling a sink or large pot with hot water while waiting, then remove stove and tighten the cap, dunk in hot water with finger over the jet, quickly rolling around in the water. I’ve had a few stoves where all was closed or sealed and they still leaked, the ultimate test. I’ve repaired a few stoves that showed no air leakage, but later leaked kero, the for sure test. Duane
I know I must seem like an ignoramus, but is the takeaway here that a certain amount of leakage around seals is normal, expected, and can't always be prevented or corrected by replacing the seals? That one just has to live with it?
I know Doc has had no issues, but I no longer leave kero in a stove in my backpack. At home, I always empty kero out of a stove. Funny how no air will leak, but when tested with kero, you will notice the kero. This has been where I had to resolder a bung fitting or pump tube on a stove, so my fix may not have been very good. I have had some leakage on some lanterns, where if you look really close and for more than a few seconds, you can see a steady stream of very tiny bubbles, very hard to see, but my eyes are getting along in years. Duane
I have a number of kerosene stoves, such as the 00 in my avatar, that have never leaked in storage. I nonetheless put them with their tins in ziplock bags in case they might, especially in my pack.
Did you close the pressure relief valve (on the fuel cap) before storing the stove? Leaving it slightly open (with the stove upright) would allow air to leak out as it warmed. With it closed, the warm air expanding over the fuel would push the fuel up toward the burner. With your stove disassembled and the reserve cap on, this may mean you're getting leakage at the reserve cap, but the situation wouldn't have occurred with the relief valve opened (so long as the stove is stored upright). ....Arch
Yes, it appears to me that the leakage is coming from the reserve cap, although I base that on the "trail" of the kerosene on the tank, and have not yet done the undoubtedly more accurate dunk test others have described. My hope is that a new reserve-cap seal will prevent future leaks. That seems to me a reasonable goal, since none of my gasoline stoves have ever leaked in storage, and I would think that kerosene would be less likely to leak past seals than kerosene, given its lower viscosity. Of course, I will also replace the filler-cap seal at the same time.
Modern seals use to be very good for a very long time but they will start to leak because of ageing - pre-WW2 style seals are usually leaking/sweating a little already from new.
