Ah, I see where you're coming from. I just didn't want you to be disappointed if you didn't get to the "magic number" of 15ml of fuel for 500ml boiled. In colder weather, your pot, burner, windscreen, fuel, the water, etc. are all going to be colder and will absorb heat. Getting 500ml of cold, cold water to boil on only 15ml of fuel is a pretty good trick. None of my stoves can do it.

HJ

Three cheers for "Boy Scout juice," the best darned fire starter anywhere.

HJ

Excellent, thorough data gathering!


VERY interesting results.


Methanol does indeed have a higher vapor pressure. Methanol is usually the more practical fuel in cold weather for that very reason. Also, jetted stoves tend to burn a little stronger with methanol.

Lol. An Xtreme vs. an alcohol stove. NO comparison. But when it's cold, the Xtreme becomes your new best friend.

I bought every canister I could find when the local stores stopped carrying them.

HJ

I did one baseline test with less fuel as well, just to see what parameters made sense for additional testing. And for general practise and setup.
I used very cold water (just above freezing) to make it more of a challenge. Where I often camp (Canadian Rockies), the water temp is almost never above 10*C and often close freezing because of glacial melt.

I'm going to have to look at other types of stoves -- your article on efficient alcohol stoves has my interest peaked. I think I will build a couple more base on a smaller 8oz coke can. I don't like the idea of requiring a preheat pan, its just a bit clumsy. My stoves don't appear to be as efficient as I would like either.

Yeah the Xtreme with PowerMax fuel isn't playing fair but then again I still use this stove! I thought it would make a wide eyed comparison. I didn't think to weigh the cannister before and after to get the amount used. The Xtreme is also a lot noisier.

With cold weather and alcohol you may have to use a preheating pan. When I tried my penny stove the fuel on top would burn out before alcohol boils, but a very small amount of fuel in preheat pan made a big difference.

The Xtreme is a great stove, period. It has a lot of output, but you can burn through the fuel if you don't keep the flame down a bit.

For me, when I'm thinking cold temperatures, melting snow, etc, I much prefer the Xtreme over an alcohol stove, but I do know people that are alcohol "die hards" and use alcohol in all four seasons. To me, alcohol is a great choice above 10C/50F. Below that, I'm a gas or liquid fuel (petroleum based) kind of guy.

With regard to alcohol, if a stove needs priming in weather above 10C/50F, it's not the stove for me. Priming is by it's very nature inefficient. That fuel you're using for priming counts against your efficiency numbers. In colder temperatures, priming is a necessary evil.

This past weekend, I went out with (among other things) an alcohol stove made from 222ml mini Coke cans. The top opening was smaller than the inner wall of the stove and had a 1:1 ratio to the height of the burner. I was able to get efficiency numbers very close to the efficiency numbers of the commercially produced 12-10 alcohol burner. I ran my tests in a Clikstand set up. The windscreen/pot stand set up that you use makes a great deal of difference as does ground temperature.

My testing set up:


HJ

That's my experience as well. To really pre-heat, you've got to have a pan under the stove.

HJ

Speaking of priming, I just did a quick blog post on priming an alcohol stove.

Even if you don't normally have to prime your stove, in cold weather, you may. It's something that is generally a good idea for alcohol stove users to know how to and be prepared to do.

The post: Priming Alcohol Stoves

HJ