compressed gas and cold

On my BP trip with Big foot it may may have dipped below freezing and never got above 35 degrees before we left camp. I was cooking on a compressed gas stove with Primus butane propane mix. The flames got pretty low as I heated about 12 ounces of water. I took the pan off the stove, turned the stove off and picked it up and to my surprise the pine needles under it were frozen to it around the edge. I wiped them off with my towel and set the fuel bottle into the warm water. ( NOTE DO NOT DO THIS IN REALLY HOT OR BOILING WATER) Then I relit the stove which now ran really well and finished my cooking. Perhaps setting it on an insulator would have kept it from chilling as quickly but I don't think so. You just have to get some water warm enough to warm the fuel bottle.
Jim

This happens to me, too. Even when temps are above freezing, things can freeze to the canister (like your fingers -- be careful!) As the canister cools, of course, the inside pressure drops and you get reduced output, so using an upright canister stove in cold weather is sort of a double whammy.

The putting-the-canister-in-water trick goes back a ways, and it only has to be liquid water, it doesn't have to be warm. The water keeps the canister from cooling off too quickly.

The other trick is to take off your gloves, blow on your hands, and wrap them around the canister while the stove is burning. You get an immediate increase in pressure and output. You also get really cold hands.

kbennet
The problem with keeping it in water is it requires another pan or something to hold the water, and actually the vaporisation point of normal butane is at the freezing point of water, and the water is cooled by the cannisters cooling, so in fact the water does have to not only be warm, it has to be kept warm. (but not real warm)
Jim

I put the canister inside my coat for 10-15 minutes to warm it up. Then I set it on a piece of CCF pad. I also use a windscreen that goes most (but not all) the way around the canister, which keeps it warm during use. This all worked fine on a couple of 18*F mornings last October, which is the coldest I've used the canister stove.

The main caveat with a windscreen on a canister stove is that you need to check frequently to make sure the canister is not getting too hot. A canister's blowing up from being overheated would definitely not make your day!

If I were going to winter camp a lot and melt snow for drinking water, I'd use a white gas stove like a Whisperlite. It's lots heavier and you have to pump the thing, but it doesn't have the cold weather issues that the isobutane canisters do.

White gas is hands down the way to go in the cold as it puts out some serious heat and is not finicky at all in the cold in my experience. I fall back on my indestructible whisperlite (not literally) for the cold. For whatever reason I also like the roar of the jet engine cranking out the BTU's on a cold morning.

-Skippy