Best cold weather canister fuel?

[J C]

I work in an outdoor gear store (down under) and a colleague was trying to decide which canister fuel to take out in the snow. We had heard that the MSR IsoPro blend is supposed to be a good blend, with 80/20 Isobutane/propane, with a price to reflect its performance. However we also stock Kovea/GMA Elemental fuel canisters, which is much cheaper than Isopro.

I assumed that it would be an "inferior" blend, maybe with regular butane instead of isobutane. However, after a bit of online searching we discovered that the blend is not only isobutane/propane but a 75/25 blend – in theory a better cold weather blend than the 80/20 MSR Isopro, and far cheaper (at least in Australia).

Here's the manufacturer's page: http://www.gmaelemental.com.au/product-details.aspx?code=3101

[Daniel Cox]

My google-fu is weak tonight. I'm sure if Hikin' Jim sees this he can straighten it out.

I can tell you that somewhere on his page 'adventuresinstoving.com' is the information you seek. I've seen it, IIRC, in one of the articles about cold weather fuels.

That's about all I got, sorry.

[Five Star]

Led me to this:

http://adventuresinstoving.blogspot.com/2011/11/whats-best-brand-of-gas-for-cold.html

[J C]

I wasn't really asking for information, I just wanted to share some of my own.

All of my knowledge about cold weather stoving already comes from Jim's site. I just thought I would mention to people who are interested that we seem to have found a superior blend to any of those listed on Jim's site.

[Hikin’ Jim]

Regarding canister gas blends for cold weather, the US market is for whatever reason limited to a max 20% propane in a propane/isobutane mix. I assume this is to comply with DOT (US Department of Transportation) shipping requirements. This is why I included the proviso in my What's the Best Brand of Gas for Cold Weather? blog post, "data is for the United States of America. Brands and blends available elsewhere may vary."

Indeed, better blends are available outside the US. I've long been aware that Coleman PowerMax (sold as Coleman "Max" fuel in some countries) is a 35/65 propane/butane mix in the US but is a 40/60 propane/butane mix elsewhere. For standard threaded canisters, I believe a 30/70 propane/isobutane mix is available in some areas outside the US. Now, that would be a pretty decent winter blend. Of course 100% propane would be better still. More on that later, Jim said enigmatically.

HJ
Adventures In Stoving

[Jerry Adams]

I've never understood the logic of adding some propane.

If you use 80% iso and 20% propane, if it's cold, more propane will come out initially so the canister will gradually have a lower percentage of propane until it's almost totally iso at the end, so you have to have a system that runs on just iso.

If you used the canister some when it was very cold, then used the rest up when it was warmer, then having some propane initially would be useful. Maybe that's good enough reason to add 20% propane.

[Bob Gross]

Geez, Jerry, haven't we beaten that dead horse?

There are tricks and techniques where you can extend the blended butane fuel to work a little colder, and those have been discussed a lot. Some are more practical than others.

In the old days, we would go out on a winter ski tour for four or five days. Butane fuels could have potential cold problems, so we did our cooking inside the tent (four guys squished together in a three-man tent). We always put the newbie guy in the middle so that he was underneath the hanging stove. That way, he could hold a burning candle on the butane can just enough to warm it slightly and keep it functioning.

It was not elegant, but it worked.

–B.G.–

[Hikin’ Jim]

I've never understood the logic of adding some propane.

If you use 80% iso and 20% propane, if it's cold, more propane will come out initially so the canister will gradually have a lower percentage of propane until it's almost totally iso at the end, so you have to have a system that runs on just iso.

If you used the canister some when it was very cold, then used the rest up when it was warmer, then having some propane initially would be useful. Maybe that's good enough reason to add 20% propane.

Jerry,

This is a tricky point. The misconception is that the propane will all come out at once or all at the beginning. Not really.

The propane and isobutane blend and form in effect a unified liquid with a boiling point that is neither that of propane nor that of isobutane but rather somewhere in between. The net bottom line is that your boiling point will stay above the boiling point of pure isobutane for an extended period (not just at the very beginning as some people seem to think). If you are operating at a temperature where the isobutane alone might not vaporize enough to be sufficient to run a stove, then that propane will really be a major help.

Now, as the liquid boils (vaporizes and becomes a gas that you can run a canister stove off of), the propane does come out of the mixture at a faster rate than the isobutane, so your boiling point does change over time as the canister empties. However, as I said above, there's enough propane in the blend that stove performance is improved almost throughout the life of the canister. The last quarter or so of the canister will however be reduced to effectively pure isobutane. So the propane is a big improvement over the life of the canister but is not a cure all.

HJ
Adventures In Stoving

[Jan S]

See here. Even has pretty graphs. Well worth the read.

[Hikin’ Jim]

Hi, Jan,

Yep, that's pretty much the definitive article on the subject. Definitely worth a read.

I was trying to put it into accessible terms. Don't know how well I did there. :)

HJ
Adventures In Stoving

[Jan S]

"I was trying to put it into accessible terms."

No worries and a lot better then I could have. I think I hit the reply button before your answer though and still had to look for the article.

[Jerry Adams]

"Geez, Jerry, haven't we beaten that dead horse?"

ha, ha, ha – true enough

yet, the original question of this post was – is a 20/80 or 25/75 blend of propane/iso better?

and my answer was it doesn't matter that much at the end of the canister

if people quit asking the same questions then we wouldn't have to give the same answers

[James Marco]

Well, fuels are fuels. For most of the canister fuels we use backpacking, they are byproducts of the petrolium industry. These used to have no use beyond fuel because the processes involved in converting them to something differnt costs as much, or more, than using the byproduct…this is and has been changing over the last 30-40 years.

Anyway, isobutane, butane, and [rppane seem to be rather standard these days. We can look to these as continuing in the near future, minimally. They allow us to use very efficient stoves. And debate minor variences in fuel mixtures. MAPP gas is slightly better as a fuel. But, canisters would also need to be slightly heavier. A no-win situation.

So, As Jim was saying, there is only marginal differences in blends. I believe that canisters have reached a limit at the current technology. You will not do much better than a 1 to 1.5oz stove and a 4oz canister of fuel.

Unfortunatly Alcohol(as a fuel) and Canisters are withn about 10% of each other.
Canister:
110g(gas) is 3.8801oz
104g(can) is 3.6685oz
Total is 7.5486oz
At 1312.5/oz this gives us a total of heat of 5092.63125BTU per can. Dividing by the total weight we get about 674.6458BTU/oz.

For the same weight of 7.5486oz, we need a 1oz bottle to carry 6.5486oz of alcohol.
Heat of alcohol is only 12000BTU/lb or 750 per oz. We get 4911.45BTU for the weight or 650.6438BTU/oz.

Note that this is minimal even IFF you use the entire 4oz conister on a single outing AND you don't use a heavier stove than 1.5oz. Alcohol stoves are typically lighter. Esbit has slightly more heat at ~13000. You can crunch numbers for this if you are really interested. WG is much higher, but the stoves weigh a lot more. Kerosene is about the same as WG.

The point of all this is that it doesn't really matter. Heat sources for camping have about bottomed out using standard fuels. Roger, Jim and others have shown several methodes to use canisters in cold weather. Liquid water, albeit cold, inverted canisters, warming mechanism (wires and bars) preheat tubes, and, other methodes have been used succesfully.

What is needed is a better material for higher pressure canisters allowing better fuels. Hydrogen gas is a VERY good fuel source, but requres a very strong and expensive canister. Or perhaps a much stronger battery to generate electrical heat…
as needed.

[Roger Caffin]

Yeah, the MSR importer is ripping the consumer off.

But the real point is that for winter you should be using an inverted remote canister stove. Then quite a few propane/butane canisters will all work well, right to the end. That's what experienced ski tourers all do.

Cheers

[Stephen M]

I have used Primus winter gas in -13f with a remote canister stove and it worked fine, I also have used Jetboil gas winter gas at around 10f with no bothers.

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