Cannister low limits.

Bored, with a pinched sciatic nerve keeping me from working this morning; I decided to run a little impromptu test for my own edification. I boiled 1 liter of water with my MSR Micro-Rocket and MSR Fuel in about 4 1/2 minutes in 7 degree F air temp. The cannister was around 60 when I started (I measured the temp of the can with my elec. tester probes) and I used a flame diverter between the ground and the cannister and a windbreak made of heavy foil wrapped about 3/4 of the way around and 2" from the side of the pot and stove. There wasn't much of a breeze, so wind wasn't much of a factor. I was pleasantly surprised at the very little loss in function. Since this set-up is light and compact, I may very well use it this weekend on an overnight instead of my liquid fuel stove. Has anyone had similar experience? I've been very hesitant to use it in single digits, but it seems as long as the cannister is pre-heated and care is taken to not overheat it, but reflect some heat back to it, it works pretty darn well. Sorry if this is one of those beat to death from 5 years ago topics.

Can you maybe post a picture of your setup? I'm not completely following what you're doing.

Am confident you know that if you can keep the fuel temp above 50 degrees or so you'll get normal performance from a vapor feed setup. If the fuel gets much below freezing, you'll use the propane fraction of the fuel first, perhaps losing functionality before the canister is empty. Of course there's no way of knowing this while it's burning happily.

Really, it's just a balancing act of capturing enough heat to keep the canister warm but with no risk of getting it hot. The simplicity of a canister-top stove is welcome in winter, when you'd really rather not be fiddling with a complex stove rig.

Good luck with that back! Cold weather seems to trigger all sorts of bodily maladies.

Cheers,

I used my Snow Peak Giga Power stove Christmas Eve to simmer dinner in temps in the mid 20F's. I used a hanging windscreen around the stove and part way up the sides of the pot, with the windscreen suspended off of the pot supports by two pieces of wire. I had trimmed it back a little more before using. The windscreen is only around 2.5" in height. With so much open space below it, I was still surprised at how much thermal feedback the canister received. After 15 minutes of use at a simmer setting, the top of the canister was still very touchable by hand and I could feel the coolness of the remaining fuel, which by then was maybe 1/3 full. I have no worries as I've had vintage gas stoves like a Optimus 8 have its fuel boiling and the SRV vent after bringing two pots of water to a boil, way beyond now I see of its capability. Canister fuel cools as fuel is used up. You just need to moniter fuel temps to operate safely.
Duane

Leave it outside overnight, then try make you a hot breakfast in the morning.. Then come tell us your result. :)I noticed performance issued with my canister when I slept in backcountry in 17 degrees weather. The first night there was no performance issue as I hiked in, but the next morning......sure did took a little more time to boil hot cocoa. I didn't put it in my sleeping bag nor a wool sock. I foolishly left it in my backpack letting the weather freeze the can.

I've used mine down to 18* F by warming the canister before use--putting the icy (!) canister in my armpit under my insulating jacket and doing a vigorous (!) "keep warm" dance for 10-15 minutes. You also need to keep the canister warm while the stove is burning, because the process of fuel vaporization chills the canister. (Remember "latent heat of vaporization" from high school physics?) Although officially not recommended, I use a windscreen that goes 3/4 of the way around and keep feeling the canister to make sure it isn't overheating. An exploding canister could ruin your day! A pan of warm water in which to place the canister is good, too, except that you somehow have to heat it up first. Although clunky, you may want to put the canister in the foot of your sleeping bag overnight along with your camera and water filter. Warming the canister prevents the more volatile propane from coming out first, leaving a very sluggish canister with nothing but isobutane.

If the temp is consistently below 20*F, you probably want the kind of stove that uses an inverted canister, such as the MSR Windpro II or (if you can find one) Kovea Spider. This configuration turns the canister into a liquid feed, but no pumping required. These have a generator tube which warms and vaporizes the fuel just before it gets to the burner. These inverted canister stoves, I've read, are good down to about zero F. Colder than that, you want liquid fuel. I've decided to invest in the MSR Windpro II not only for cold weather camping but also for group camping since it is much more stable with larger pots than the standard stove that screws into the top of the canister.

The diverter is a hollow piece of tin with holes in the sides meant to distribute heat evenly. They were commonly used on old gas stoves. I use it to make pancakes and burgers in lightweight frying pans. It does a good job of keeping the canister off the snow. As you can see, it's a very simple set up and the snow mound was used as a windbreak. The canister was near empty, so I'll assume it had the proper proportions of isobutane and propane remaining. I used this stove at 12,500' in the Sierra in Oct. on snow and it worked well at temps in the low 20's-high teens. In the Sierra, I constructed a rock well to place the stove in with snow packed around it. Even though it was very windy, nothing bothered the flame.

High elevation helps canister stoves work at lower temperature.

Your set-up looks pretty simple... and more important... pretty safe. Well done and thinks for the info. The reason this kind of thing isn't discussed more often is because if you get too much thermal feedback, you have built a bomb. People tend to be hesitant about giving advice on the internet which could kill somebody who isn't careful.

A good rule of thumb I have heard is: as long as you can comfortably touch the canister it is safe.

Thanks for posting the pic!

It is pretty safe! The can never got warm, just stayed cool, not cold. What I like about the can vs. my Whisperlite with its outboard bottle, is it stays in a compact space and you can easily build a windbreak with natural materials. I have seen people suggest cooking in vestibules. I watched a tent burn up , a VE24 and all its very expensive contents destroyed, outside the Harvard Cabin on Mt. Washington. Luckily, the lone occupant scrambled out with a minor burn. Overdid the pumping and priming on his stove and it flared badly. It was very cold and windy, but I was happy with a windbreak around my stove to cook outside.

Yeah, not Must have been like the big bad wolf with a flame thrower!

jimmby

I must admit to doing something near as foolish. From the mid 70's to early 90's I used an Optimus 8r that seemed very innocuous and never flared, especially if you placed the fuel in the warming cup with an eyedropper. One morning in pouring rain, I decided to use the vestibule to make some coffee. The o-ring on the fuel valve failed and it started to flare up from the leak. Luckily I shut it down and it never got worse than a few inch flame that burned out. First and last time for that . I may experiment with some reflectix and use it both as an outer wind break/chimney with the foil still inside and as a cozy for meal re-hydration with some glued on velcro to create an envelope. Once again, not enclosing the stove and canister, just putting a partial windbreak/reflector up. Saves the time clearing and packing snow, or piling rocks. If I make some sleeves in the reflectix I can use snow stakes to hold it in place.

I used a Primus Micron at 7500 ft at about 15F with a full small Snow Peak canister and it worked fine for heating water for tea and soup. Not sure how it would have fared if I had run it close to empty. I set it on a piece of blue closed cell foam cut from the familiar foam sleeping pad everyone seems to have had at one time or another. I could see ice forming on the canister as it cooled off while running.

Serendipitously, I recently bought a Kovea Spider (right off Amazon.com in fact, not like earlier when it was only on eBay).

I did a winter hike/campout on the side of Mt. Rainier last weekend and used it. Some learning curve required; I was trying to run it more full-throttle in inverted mode than I should have, and with temps at about 20F I'm not sure I should have even been inverting it.

But it seems well-built, and makes for a pretty small and light package for a canister type stove. No risk of exploding with the remote canister (for winter I had formerly wrapped copper wire around my snow peak canister stove and ran it up into the flame --- a little dicey and fiddly to setup and maintain, for me at least).

I don't miss my old whisperlite !