UKC

On the couch in London dreaming of higher and snowier days.

Been reading a bit about bigger expedition-style climbing - multi-day, higher altitude or winter, melting snow for water. Maybe Denali, similar.

I have no experience thereof although some ambition and idly musing. Say small group, 2-4 people, and perhaps a system that could also work on smaller trips where you might not be hauling (e.g. could get into a 40-50L climbing sack for bivi).

For those with experience of such, what systems have people settled on for stoves and pots?

The presumption seems to be towards white gas stoves e.g. Whisperlite/XGK type stoves in the US. Obviously Windburner/Reactor types are an option too. Am familiar with pros and cons of canisters in cold/at altitude and various tricks there, and of course the importance of seed water to start melting.

Assuming liquid fuel, what sort of size and material of pot? (Titanium doesn't conduct heat as well as aluminium but can be made thinner so perhaps nets off?) Steel an option I guess e.g. old school MSR Alpine pots but heavier and seems in the middle for conductivity.

2L pot at minimum I guess. (Maybe benefit in a bigger pot if hauling and if more than 2 people.)

Shape: low and wide or tall and narrow (boiler shape)?

Heat exchanger? I see some pots have one inbuilt and also separate ones available e.g. MSR or home made. Worth the weight in fuel savings and speed of boil?

Interested in anyone's thoughts.

From my experience, if having to carry in a rucksack, the size and weight of the windburner/reactor make are very handy.  If I have to carry, I'll almost always take my windburner, mostly for the small packsize as my rucksack is an AK57.  BUT, for Denali (or any other higher altitude) or temps consistenly lower than -10 C, I don't think gas stoves cut the mustard.

I have an XGK and Dragonfly, and for cold environments when solo I use them with a 2 litre pot (MSR quick 2) with my heat exchanger, which is also very handy for longer trips.  Pretty sure it offsets the weight in fuel savings, but only a feeling.  Wider pots are easier to keep filled with snow, but won't fit an MSR heat exchanger.

However, for snow melting, I wouldn't want a smaller pot than 2 litres just for me, so for 2-4 people I'd go bigger (in aluminium... I'd hate to drag around stainless steel) if possible.  When we had 3 of us melting snow in a 2.5 litre pot at altitude, it was a faff and making water was pretty much a full time job.

EDIT: By the way, for my last expedition, with a pulk (so no space worries), I made a proper stove board which was invaluable! Especially with the flarey fuel I had... 2 ft high fireball at one point with the XGK (which I find more flarey to prime than my Dragonfly), so could just move in and out of the porch easily.

About twenty years ago I did a big winter trip in the north Cascades in Washington state. We went 12 days between resupplies and did a lot of testing to see where we could save weight. We did a lot of white gas stove trials including with the wrap around heat exchanger as it was quite new then. But we didn't find it saved more than its equivalent weight in fuel using the pan sized to fit.  

We found the most efficient when snow melting, was the bigger of the aluminium pans (Complete with tight fitting lid) from MSR's guide set. The large base area seemed to capture the most heat, especially once a few mm of water had covered it. Sadly the Guide Sets don't seem to be in MSR's range any more.

I do a lot of cold unsupported stuff, at to just over 2 weeks.

If there's a basecamp and more than 4 people then liquid fuel is the most efficient for things like melting snow (though still carry gas stoves for the climbing). In which case I use Soto stoves that are MUCH safer to get going.

Otherwise, gas stoves nowadays are good to above 6000m and cold stuff so long as you get a remote cannister one with a vaporizing tube. I really like the Fire Maple Blade II (rebranded by Alpkit in the UK). Puts out more heat than a Jetboil, less CO issues, reliable).

Yes pots are 50% of the equation. For 2-3 going light I use the pot off a Reactor, beyond that a 2L from Fire Maple. The exchanger on the base is what matters, capturing more available fumes, and well worth the weight. The Reactor pot is nice and robust, can dig with it.

I wouldn't put all your eggs in one basket for four people, if climbing what happens if you drop your stove (or sack with it in), or can't all shelter together, so for 4 people two stoves.

Same applies if you are permanently relying on melting snow for hydration at lower elevations, where there will be no one else around, and no way to walk out to water in the event of stove loss/failure. For that reason most polar expeditions even if they are just individuals going solo take two stoves.

Generally base camp in cold conditions and lots of snow melting a petrol stove, climbing gas unless very cold.

Base camp, or pulking big wide pans are best for snow melting 3+ litres, and protecting from wind more critical that additional heat exchanger.  If weight isn't an issue and permanently on snow a stove base (can be just a sheet of plywood) is very handy; increases stability reduces spillage. Obviously you can use a snow shovel to stop the stove melting in, but generally thats always a bit faffy and not level.