Cold weather and wind can dramatically decrease the efficiency of a canister style stove. We have encountered dramatic shifts in weather even in summer that has included freezing or lower temperatures or even snow. Last year, on a trip early in September, we unexpectedly encountered several cold nights of temperatures in the upper twenties that lowered the efficiency of our canister stoves. Later in the year as the weather started to turn colder and winter began to take its hold on our climbing activities, we resisted carrying a liquid fuel burning stove because we wanted the convenience of the quick use and clean burning compressed gas canister. We wanted to be able to carry our canister stoves in most weather including during the fall or spring “shoulder” seasons. It forced us to look at how we could maintain the convenience, improve the efficiency and keep the weight to a minimum with some type of windscreen or added insulation around the canister.
- Stove stand moves the burner off of the canister.
Our first choice was the discovery of a light weight Stove Stand that Brunton makes that will work on any stove. The stand is a tripod that you can thread on any stove that uses standard threaded canisters and provides a flexible fuel line that moves the canister away from the burner allowing one to put a windscreen around the pot. The windscreen protected the burner from wind and directed most of the heat to the bottom of the pot.
- Stove stand and windscreen ready to use.
The screen worked very well on a larger pot used for group cooking and could be easily resized when cooking with a solo size of pot. The aluminum wind screen weighs a 5 oz. ounces and the stove base ads a 2 oz. more totaling only 7 oz.
Using the stove stand in the snow on a ski tour. While the windscreen helped to improve the heat transfer of the burner by protecting it from the wind and capturing heat by redirecting it to the pot, it did not solve the problem of cooling or ice forming on the canister as the fuel was being used (explained by something called the “Gas Law” if you took Atmospheric Science). The canister cooling effect is exacerbated by the surrounding cold air and cold conducting up from the ground.
Insulating the canister helps slow this process and improve fuel flow. Our first idea was to use chemical hand warmers placed under the canister in the dimple. It seemed like a reasonable idea and light weight, until I read the warnings on the package. Hand warmers can get as hot as 130 degrees and are not controllable. Most canisters carry warnings that they are not to be used above 120 degrees – a temperature that can easily be reached in a hot car during the summer. Since they can explode, I thought it was best to be careful. No one wants a spoiled trip that could have been avoided.
Canister warning cautions against using the canister on a stove in a windscreen because of the possibility of overheating.
We decided to go into the test and proto-type development center here at Cascade Alpinist world headquarters and try to solve the problem (read: went into the garage shop and rummaged around on the shelves to see what we could come up with). The solution was to build a durable light weight insulated base to be able to put the canister stove on while cooking or to use in combination with the stove stand to rest the canister. We found a piece of blue closed cell foam from an old foam pad, two 1/8 inch pieces of plywood, a roll of thin aluminum sheet stock and some duct tape.
- Spray adhesive, blue foam and 1/8th inch plywood (doorskin)
I started by cutting the plywood into two pieces 7 inches square and coating one side with spray-on contact adhesive used for mounting photos. I cut the ½ inch blue foam a little over sized and coated one side with the spray-on contact adhesive and let it dry. Pressed the coated side on to the coated plywood adhering them together, flipped them over and trimmed the foam to size. Sprayed the foam with the adhesive and after it was dry, carefully lined up the second piece of plywood and adhered it to the foam forming a composite sandwich of foam and wood.
- Glued together foam and plywood forming an insulated base.
To protect the “top” I cut a thin sheet of aluminum material (about 16 gauge almost foil like) to protect it. Wrapped the edges with duct tape and had a completed base for insulation. Total weight turned out to be 6 oz. You could probably get away with only doing one side with plywood and the “top” could just be the aluminum. I used “standard” duct tape; there is a real foil tape that is not susceptible to melting and getting gooey.
- Completed base with aluminum protective layer.
The composite square provides an insulated base to keep the stove or the canister when used with the stove stand off the ground, improving the efficiency. It also makes a nice flat base for the stove used normally and weighs about the same as a set of the clip-on tripod feet that attach to a canister. When the stove is burning, it does reflect heat down to the aluminum sheet warming the canister. Total weight of the stove stand, windscreen and insulated base is just less than 10 oz. A little bit more to carry, but it will improve the efficiency of your stove and if the weather turns cold could save time and fuel.
- Stove stand and insulated platform being used on the snow.
Woody, you guys are nuts! The prototype center. I think I can say that I’ve been there. It’s an elitist thing, not everyone will get it :) Rock on! J
Yeah, its all kind of how you look at it. Pretty interesting stuff can be invented in small spaces.