The Effect of Cold on Gas Canisters

I've tested boiling a liter of water om my Msr Dragonfly in "perfect conditions" (in my living room…) and the fuel consumption was 16 g of white gas. Note that I used the 2,1 l Primus Etapower pot with heat exchanger.

My canister stoves use about 10-12 g of fuel to boil a liter of water in the same pot.

After using MSR stoves for over thirty years, I would say that they are really good for boiling 1-4 quarts of water at a time.

I refer to the plate-roarer type of stoves, and not so much the quieter types.

–B.G.–

Hi Gaute

> 16 g white gas to boil 1 L
> 10-12 g canister to boil 1 L
Yep, that's about the ratio I find too. Canister stoves and fuel are far more weight-efficient.

Cheers

Roger, have you compared the cost of fuel for each liter of water boiled?

–B.G.–

> have you compared the cost of fuel for each liter of water boiled?

It is far less than the cost of the rest of my gear, and far less than the cost of the fuel required to get to the trackhead, far less than the cost of the food eaten on a trip, and (over quite a long period) less even than the cost of a liquid-fuel stove. That will do me.

Ymmv
Cheers

Many backpackers are cooking for only one or two mouths.

I've spent years leading and cooking for groups of 8, 10, or even 12 backpackers, so for those trips I like the relative economy of a white gas stove or two. This is especially true in the winter when more fuel is expended than in summer.

–B.G.–

Hi Bob

> cooking for groups of 8, 10, or even 12 backpackers
That's a hard life :-) Turns a hobby into a job.

Your situation is a bit outside my experience. Have you considered the weight economics of using a larger LPG cylinder and a larger stove, given the weight savings with the fuel? Just curious.

Cheers

When you write "LPG," I think Propane.

I think the cost economics won over weight economics. In the traditional backpacking world, and among the group leaders, white gas is the winner. As soon as I left that traditional world and made the zigzag turn into the ultralightweight world, the fuels of choice became butane blend, alcohol, or Esbit.

Propane has never been a good choice except for "car camping" where the weight of the heavy canister is not a factor.

When on a big mountain expedition, our group of fourteen was divided up into tent teams of 2 or 3 people, and every team was using white gas. Plus, nearly every other expedition on the mountain was using white gas. I don't know. Maybe it is an altitude thing.

–B.G.–

Hi Bob

Cost factor for commercial groups understood.

> nearly every other expedition on the mountain was using white gas.
Ha – you should what it is like in Nepal. One poor unfortunate porter gets to carry the keg of kerosene for the whole trip. Because they are too skint to afford decent reliable metal cans, they use cheap plastic containers which ALWAYS leak. Often the caps disintegrate. Poor guy.

Cheers

They were not commercial trips. They were shared-cost group trips for an outdoor club.

As for Nepal. Yes. Been there, done that, read the book, saw the movie.

On my first trek there in 1983, we had about 25-30 porters at the start of the trek. One poor guy carried the large kerosene container. You sure did not want to light a cigarette around him. However, back then, they were still allowed to burn some local firewood. By my 1997 trek there, firewood was not allowed to be burned because there was very little left.

–B.G.–

Hi Bob

> By my 1997 trek there, firewood was not allowed to be burned because there was very little left.
Yeah, I could see that coming all right.

They make their own kero stoves in the markets in Kathmandu: not so backward in technology.

Cheers

A friend of mine from the northeast made me a canister coozy this weekend for using canister stoves in the cold. He said that he used it all winter up north without issues. I was curious as to why I had never heard about this method before and why it isn't more common?

>A friend of mine from the northeast made me a canister coozy this weekend for using canister stoves in the cold. He said that he used it all winter up north without issues. I was curious as to why I had never heard about this method before and why it isn't more common?

YMMV, but the problem is that a coozy is just insulation. If you start with a warm canister and very cold air, then it will help preserve the original heat. But as you use the canister, it's going to cool down (PV~T). If you use sufficient gas, the canister temp will drop enough to cause problems, and the coozy doesn't help in this case (and works against you if ambient air temp is now warmer than the canister). Thus the recommendation to use a water bath (or packed-snow bath) to ensure the canister temp remains at or above 0C (32F).

Have you used a chemical hand warmer?

>Have you used a chemical hand warmer?

I'm not sure who you're asking, but that would really do the trick, especially with a coozy (or your hands) to hold it onto the canister. With a max temp ranging from 45-65C (110-150F) * it might be a bit on the hot side, but that's easily remedied in cold air. However, as the article mentioned, 0C (32F) or better is sufficient, and a water or snow bath is a zero-carried-weight item.

* http://www.wemjournal.org/article/S1080-6032(09)70081-X/abstract
( http://download.journals.elsevierhealth.com/pdfs/journals/1080-6032/PIIS108060320970081X.pdf )

I can remember years back Primus designed a chemical canister warmer that you would place in the void beneath their fuel canister stoves. These hand warmers needed to be boiled in water to gain the energy and by pushing a metal “plate” in the hand warmer activated the chemical agent absorbed the water energy, and thus releasing their energy. I think you can see the down side to this device as there is a downside to the “one shot" chemical hand warmers.

Water bath is still the best way to go OR use an external inverted fuel canister with a heat rod design to vaporize the liquid fuel as has been explained in the following article:

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

Ken, you refer to a sodium acetate phase change hand warmer. I have a couple, and they work fine.

Often, I don't have as much liquid water sitting around as you describe, so I simply warm the canister with a candle flame.

–B.G.–

I'd forgot about those (sodium acetate warmers); my EZ Heat (Pristech Products, Inc.) weighs 3.8oz. One drawback is that it must be boiled for about 10 minutes to ensure all the crystals melt, which requires more fuel than I'm willing to spend. And, worst, the one time I carried it, I found that I had accidentally snapped the metal plate or shocked it sufficiently to activate it, and when I needed it, it was hard and cold. Now it doesn't leave the house.

"Often, I don't have as much liquid water sitting around as you describe, so I simply warm the canister with a candle flame."

I would consider this advice Very carefully. Past performance is no guarantee of future longevity.

IMHO.

Oh, the candle flame is tried and true. First of all, we don't use a big candle, and we don't put the flame on a seam. Instead we warm the large metal surface initially, then save the candle for next time. We generally only need to do this when it is a very cold morning in snow country, and the fuel canister is cold.

As for the sodium acetate hand warmer, I carry mine in a durable plastic container, so it never gets set off accidentally. Boiling water will recharge mine in six minutes.

–B.G.–

…….and fuel to recharge that can be use for other uses.

When cold out i put my upright canister stove in a cup of warm water while using the stove. this works best if using small canister for they fit tight and it needs just a little bit of water. jet boil bottom cup or snow peak solo set has a cup also. Having this extra cup is still lighter than buying a remote canister stove. I tend to use a insulated cup for winter use.

So I have the Primus Spider remote can stove. I used it at around 10-15 deg F last week and it worked great upright, but when I inverted it, the fuel leaving the can made the valve freeze and it went out. I had to leave the can upright. The Jetboil Helios and others have an inversion canstand. Wouldn't they all freeze? I thought it was a winter stove designed to be inverted…

Thoughts?

It worked great upright, even at 15 deg, so I'm not worried, just wondering…

PS: the Caldera cone for a 1300mL upside down is THE BEST wind screen.

> when I inverted it, the fuel leaving the can made the valve freeze

This is possible, but rather hard to do deliberately. Normally the fuel goes down the hose as a liquid and vaporises in the preheat tube near the burner. For it to be vaporising at the valve on the canister is odd.

What to do if this happens? I'm not entirely sure as I have not had this problem more than once or twice. I THINK what I did was to open the valve up for a moment, to overload the system and force liquid fuel down the hose, then shut it down to a gentle flow again quite quickly. Once the hose is full of liquid fuel all seemed to be well.

But I am not recommending that you should do this, just saying what worked for me. Experimenting like this has a few hazards… big ones.

If the stove continues to behave like you described, I would return it for exchange, as it just may be that the hose is missing the filler cord which is meant to be inside it. Once again, I am not sure about this.

Cheers

Interesting…

It only took a few minute from when I first inverted it to when it started freezing. I held the valve in my hands and chemical warmers but it would still freeze (my chem warmers are horrible though). I tilted it back and forth changing whether or not liquid or gas was going in and it would make the stove roar then subside. I kinda lost the feel of when to have it be liquid or gas and it went out. Finally I just turned it upright and kept it going.