Before you continue reading please note that I'm not telling you to do the following, I'm only telling you what has worked for me in the past. It is not recommended by any manufacturer, (it will in fact say not to do the following on your canister), to do what I do in order to prime pressurized fuel canisters.|
If you attempt any action found on this webpage then you do so at your own risk. I disclaim any liability for injury, injury resulting in death, any damages or loss of any kind by anyone attempting any action found on this webpage.
Over the years I've heard lots of ways people deal with pressurized fuel in the cold. Everything from holding lighters directly against the canister to creating canister warming devices by wrapping copper wire around the tank and into the flame. While these seemed either a bit too "edgy" or complicated for me the over all idea seemed sound, I needed to warm the canister some how.
For some time now I have successfully relied on a simple candle placed roughly 6-8" below my canister. After setting up my kitchen area I cut a small shelf in the snow below the stove area. I then take apart my avalanche shovel and use the shaft to create a vertical tunnel from the shelf to where my canister will be placed. I place the candle on the shelf directly in line with the vertical tunnel to allow slow, slight but steady heat up to the canister. In very cold temperatures (say below -20C) I have found placing the blade of my shovel over the opening of the shelf helps focus the heat upwards. Using this method I have never personally felt like I was in danger of blowing up the canister but again if you attempt to do something like this you do so at your own risk and manufactures advise against doing it.
Now you may be thinking that the extra weight of a candle is just another negative for me but I have found it to actually be a positive. First of all I already carry a couple of candles with me regardless of the trip. They provide warmth in a snow cave and provide an easy way to get a fire going with frozen wood, in the case I need extra warmth in an emergency. Candles also provide light while cooking and therefore saves headlamp battery time for when I really need it. I have found that one "mountaineering" candle usually provides priming for 2-3 days depending on water needs so weight it not much of a concern in the first place.
In the past my partners and I would take turns removing the moisture off the canisters by heating them with our hands and scraping the ice off with old ID cards. Then one day I came up with the idea to create a canister sleeve out of a closed cell foam camping pad. You can buy these usually blue or yellow closed cell foam pads for very cheap and with a little duct tape it is easy to create a tight and durable sleeve that will keep moisture off the top and sides of your fuel canister.|
Step 1: Cut a strip of foam to the height of the canister you are using. You want this strip of foam to rest slightly below where the canister starts to curve. If you go above this curve then you will have a small air pocket. Wrap the foam strip around the can and cut it to size. You want to make this piece fit as tight as possible around the canister to have a solid seal. Duct tape the foam strip around the canister using one long piece that overlaps onto itself.
Step 2: Keep the foam on the canister, place it onto a piece of foam and use it to draw a circle. Cut the circle out, this will cover the top of the canister.
Step 3: Turn the canister upside down and place it over the foam circle you just cut out. Make sure the canister is centered over the circle, press it into the foam and twist it a few times to imprint the nozzle into the foam circle.
Step 4: Cut the imprinted nozzle area out and make sure it fits nicely onto the canister.
Step 5: Duct tape the circle to the strip of foam already on the canister. Keep the foam on the canister while tapping in order to get a good solid product. When attaching the stove you will be twisting it onto the canister and there will be resistance between the stove and the foam so a little extra tape is a good idea.
I have made several different designs and this one is not only the simplest but provides tight contact between the canister and the foam.