I was wondering about a possible way to use a standard canister stove e.g. Pocket Rocket in cold conditions. It's not something I've had to do so may be impractical, but here goes!

Basically, all the idea is is to use one of those re-usable gel handwarmers (e.g.EZ Heat) to heat up the canister prior to and during use. The handwarmers get to ~50C and stay warm for 1/2 hour or so, and can be reactivated by boiling for a few mins if required.

Then make a 'cosie' for the canister from a suitable material, to keep the heat in and the handwarmer in good contact with the gas canister.

It's just an idea, I've not tried it myself, but if it works it may work out lighter than carrying a winter stove for an overnight trip, and also would mean you only had to buy one stove.

that kind of idea was mentioned in a forum article here a few years ago. I don't recall much discussion or the submitter giving detail on performance.

50C seems a little warm for that use ... I think I'd take some precautions when trying it .... but that isn't my area of expertise.

Edited by jcolten on 05/19/2008 06:52:59 MDT.

Personally, I would not place any heat source on the canister for that purpose, but would instead use my body warmth to heat it up in the morning before use. Or sleep with the canister in my sleeping bag.

I should also have remembered to ask your definition of cold conditions ... 35F is cold for some folks but very different than 0F. Also, which fuel?

On a recent BSA outing we were using a two burner canister stove (I don't know what fuel mix they brought, sorry). Morning temps were right at 30F and the stove was burning but with low output. Once we got the water slightly warm to touch (100F???) we put some in a small pan and set the canister in it. Instant and big improvement ... we didn't need to refresh the water (cooked for maybe 15 minutes that way.

I have a wide-mouth Nalgene water bag and I keep it in the sleeping bag with me in sub-freezing temps anyway just so it's not ice in the morning. The fuel canister I use is a cheap isobutane/n-butane mix and I just stick it through the opening and stand it up inside the water bag on cold mornings. The upright position causes more ablative cooling of the fuel in the canister than upside-down liquid feed, but the water bag holds 96oz and water has a very high specific heat. I've cooked over a strong butane flame in single digit Farenheit temps that way.

Oh, I forgot that you said you have a pocket rocket. The canister is pretty wide on those and it's not remote to the stove. Hm.

Jim's water-in-a-pan idea is a good one. You could try body-warmed water in a pan if you don't want to use fuel to heat the water to heat the fuel, and you could cover the pan a little to slow the cooling of the water.

Kapton film is not too hard to get. I used it for a stove project. It tolerates temperatures up to about 700 degrees F. You could get a Kapton bag or make a bag from Kapton film and use it to hold water around the canister instead of a pan. It would be lighter and it would lose less heat to the air.

The cold conditions I was thinking of were where it's too cold to use a canister top-mounted stove, I don't know what that temperature may be, I have just read of people saying they don't work well in cold conditions.

The idea was to extend the use of a summer stove so you only had to buy one bit of kit and not have to mess about with inverted canisters, water or other methods of canister warming which sometimes require a partially working stove in the first place, giving a method that warms the canister up the same amount reliably each time.

Also as it doesn't need the liquid fuel feed, would it use less gas than inverted canister systems? Shouldn't it then have a similar efficiency to summer use?

It would be more efficient than an inverted canister because it is hard to get full heat value as you bleed the inverted tube of liquid gas. However you have to factor in melting all the crystals in the warmer, in hot water. I expect that makes it a lot less efficient.
Efficiency is not everything.

Read the articles we have published on using canister stoves in winter!

Selecting a Canister Stove for Cold Weather Backpacking
Part I: Stove and Fuel Fundamentals
http://www.backpackinglight.com/cgi-bin/backpackinglight/selecting_stoves_for_cold_weather_part_1.html

Selecting a Canister Stove for Cold Weather Backpacking
Part II: Commercially Available Canister Stove Systems
http://www.backpackinglight.com/cgi-bin/backpackinglight/selecting_stoves_for_cold_weather_part_2.html

Lightweight Canister Stoves REVIEW SUMMARY and GEAR GUIDE OVERVIEW
http://www.backpackinglight.com/cgi-bin/backpackinglight/lightweight_canister_stoves_review_summary.html

Watch out for the warmers: 50 C is a bit warmer than desirable, and over that is outside specs.

> Also as it doesn't need the liquid fuel feed, would it use less gas than inverted canister systems?
Makes almost no difference while running at all: fuel is fuel. You will lose a couple of grams while priming and turning off maybe.

Cheers

http://www.backpackinglight.com/cgi-bin/backpackinglight/exploding_gas_canisters_the_hazard_of_overheating.html