Fuel Calcs for melting snow with a moulder strip/canister stove
Jan 4, 2021 at 4:43 pm #3692142Chris ABPL Member
Understanding there are many factors at play here (temps, stove brand, canister size, wind, etc), I’m curious if anyone has some rough calculations for fuel consumption when melting snow for water with a canister stove setup with a Moulder strip.
I’ve used my BRS 3000 with a strip in cold weather with good success for heating water. I have a Pocket Rocket Deluxe that I am planning to use with a Moulder strip on an upcoming trip in the Whites and trying to gauge my fuel needs for melting snow.
Thanks for any help!Jan 4, 2021 at 5:06 pm #3692148
I’ve used moulder strip with BRS3000 and it worked very good
I’ve used moulder strip with a Soto Windmaster and it didn’t work very good. I think it’s because it’s taller, so the strip is longer, so it doesn’t conduct heat to the canister as good. When I boil water when it’s cold, the flame slows down until it’s barely working.
I haven’t read anyone that confirms this, maybe something else explains my experience. It would be interesting to hear your experience.
It takes about the same amount of fuel to melt water, as it does to heat it from 32 F to 212 F. About the same amount of fuel to melt, as it takes to boil. 334 joules/gram is the latent heat of water – amount to melt. 4.2 joules/gram/degree C – specific heat. 420 joules/gram to heat from 0 C to 100 C.Jan 4, 2021 at 10:00 pm #3692197Eric BlumensaadtBPL Member
@danepackerLocale: Mojave Desert
And which brands of “winter” iso-butane/propane mixes work best?
I’m going to try the Fire Maple Blade 2 remote canister stove I got my grandsons because it has a vaporizing loop for using an inverted canister. I may take it to my Spring Mountains this winter to check out how well it actually works.Jan 5, 2021 at 2:16 am #3692208
which brands of “winter” iso-butane/propane mixes work best?
Once you restrict your choices to a 30%/70% mix, and nothing less, then the only other factor is how much dirt is in the canister. That dirt can and does block jets.
Assuming clean gas, NO brand outperforms any other brand. They all come from a just a couple of filling plants in Asia anyhow. Claims that a Brand X stove should only be used with Brand X canisters are pure marketing fluff. One or two Western Stove brands come to mind …
In my experience, most canisters do have a little bit of dirt in them, although certain Chinese brands have spadefuls. What this means is that the first time you invert a new canister, you may get some blockage of the jet. After you have cleaned the jet a couple of times the dirt seems to have been flushed out and the rest of the canister runs smoothly.
I find the French Campingaz to be about the cleanest, after the old Coleman Powermax canisters.
CheersJan 5, 2021 at 6:17 am #3692214Jan RezacBPL Member
@zkoumalLocale: Prague, CZ
This is something that strongly depends on your specific setup, mode of use and conditions. Start with taking more fuel than needed, take notes and calculate your own numbers. Only then, you can reduce the margin safely. Here are my numbers gathered over the years (on mostly 4-day trips):
I use a remote-canister stove (which likely has a better windscreen than upright stoves) coupled with either heat-exchanger 1.5 l pot or larger pots without heat exchanger for melting the snow and cooking for two or three. My recent setup is here. Snow melting only, no liquid water sources. Larger part of the water is heated only to lukewarm for drinks consumed immediately, warmer warm for drinks stored for the day and only small part is boiled for rehydrating meals – this has very large impact on the fuel consumption when we melt up to 5 liters per person per day. Average temperatures a few degrees C below freezing, cooking outside in reasonable weather / in a mid when too windy. The average fuel consumption is around 20g/liter. Apart from the factors already listed, it would be worse with a smaller pot without HE, and better if the stove was running at lower power (if the weather is good). We run it at high power to save the time.
Finally, on a longer trip it’s wise to have some means of checking how much fuel did you use so that you can adjust your consumption and avoid running out of fuel. For a multi-day trip and cooking in a group, just counting the empty canisters is enough.Jan 5, 2021 at 7:27 am #3692218
MSR Isopro is 5% n butane or less, so, at least 95% isobutane (or others like propane). That’s a good brand. About the same price as anyone else.
There are other brands that also have a similar percentage of isobutane. If it says it has 5% n butane or less, it’s good. If it doesn’t give a spec it’s probably not what you want.
Not that any manufacturer spec can be trustedJan 5, 2021 at 7:27 am #3692219
+1 to what Jan saidJan 5, 2021 at 7:49 am #3692221Gary DunckelBPL Member
I think that under winter conditions one wants a fuel canister that contains almost NO n-butane, which tends to not vaporize at temperatures much below +30* F. Jetboil and Olicamp (marketed by Liberty Mountain) are essentially identical, except that Olicamp is a bit cheaper. Both contain 25% propane and 75% iso-butane. The best bang for your buck is with the 8 oz. canisters, as there is a bit less fuel in the 4 oz. canisters due to the high proportion of propane. I assume that the 4 oz. canisters are structurally weaker than the more burly 8 oz. ones.
I have also learned that it is a bit harder to warm up an 8 oz. canister with the Moulder Strip, likely due to the increased surface area of the canister. Bob Moulder concurs with this. We both used neoprene cozies for the canisters to help keep the generated heat in, and we used 1/2″ closed cell foam as an insulating base. I’ve been able to get great results with a 4 oz. canister and my Moulder strip down to -5* F. The 8 oz. canister didn’t perform quite as well, but it did work at +5* F.Jan 5, 2021 at 8:25 am #3692225
That’s interesting, I just use 8 ounce canisters. Maybe that explains part of why Moulder strip didn’t work very good with my tall stove, Soto Windmaster.
But I used 8 ounce canister with BRS 3000 and that worked good.Jan 5, 2021 at 8:34 am #3692226
what’s bad about propane is that it evaporates off more at the beginning. When the canister has used half it’s fuel, almost all the propane is gone
So, adding propane to a canister helps it work better in cold weather for the first half of the canister
If you want to use almost all of the canister, you want to have very little n butane.
It is much easier, from a petroleum engineer point of view, to have an equal amount of n butane and isobutane, and then add propane to make it work better at cold temperatures by adding propane, but that only works for the first half of the fuel in the canister
MSR Isopro advertises less than 5% n butane – that’s betterJan 5, 2021 at 8:40 am #3692228
snowpeak gigapower says “85/15 blend of isobutane and propane” so maybe that’s good
Coleman doesn’t mention nbutane or isobutane in the limited amount of time I looked at it. Maybe that’s not so good.Jan 5, 2021 at 1:55 pm #3692287
snowpeak gigapower says “85/15 blend of isobutane and propane”
As you can see, that is a summer or ‘tourist’ mix, not a good snow mix.
I would prefer more propane.
CheersJan 5, 2021 at 6:39 pm #3692325David ThomasBPL Member
@davidinkenaiLocale: North Woods. Far North.
The short height of the BRS-3000T definitely helps a Moulder Strip work well, down to crazy low temperatures. As does the shorter, smaller surface-area 4-ounce / 100-gram canisters versus the 8-ounce / 220-gram ones.
OTOH, I’ve often got a large HX pot when snow camping, so the larger canister and the tripod legs available for them are nice when there’s a larger pot of snow and ice water on the burner.
Or bring 6′ x 6″ of 3-ply door skin plywood like Roger does or a similar stove base of waxed cardboard like I do.Jan 5, 2021 at 7:38 pm #3692331
A solid base is a stable stove. V3 stove, inside the tent. I’m sitting comfortably on a foam sit-upon out of the wind.
Actually, 120 x 120 mm (4.75″) is sufficient – and lighter. I snug it into the snow grass and then stake the stove down.
CheersJan 6, 2021 at 4:42 pm #3692450Edward John MBPL Member
When things get cold I think there are advantages to using an insulated base at least as big as the pot you are using. It does add a few grams but it does stop the warm stove from melting deep into the snow and does reflect some heat back up, which helps keep the gas canister warm if not using a remote stove. A bigger base is also more stable on snow, important when using larger pots.Jan 6, 2021 at 4:52 pm #3692458
A bigger base is also more stable on snow, important when using larger pots.
CheersFeb 20, 2021 at 6:55 am #3700524MikekiMBPL Member
@mikekimLocale: Somewhere East of Montauk
Don’t overlook the CCF base. Moulder and I were out two weekends ago doing an AT section. Overnight low as 6F. Fired up a cold 8 oz canister in the morning with it sitting on the wood table outside the Ten Mile Shelter and it sputtered for a bit until it was noticed that the CCF disk was not in place… Resolved and the snow melting began… a hot breakfast followedFeb 20, 2021 at 3:08 pm #3700587David ThomasBPL Member
@davidinkenaiLocale: North Woods. Far North.
Oh, and if you’ve got a second pot of larger diameter, fill it with snow and use it as a lid for the lower pot – the steam and humid air that would have escaped will benficially pre-melt the next batch of snow for you.Feb 20, 2021 at 5:46 pm #3700620Edward John MBPL Member
Davids post above is why I was so fond of my original SIGG dixies, they were made in such a way that the larger pot in the series was an excellent fit inside the next pot down and saved a lot of fuel. The MSR/Seagull Alpine cookset is not so good in this regard but using the lid upside down works.
You do need a very stable stove. I was using an MSR XGK for winter camping and that was when I first started using plywood and CCF as a stove base, I wouldn’t use this technique on a Pocket Rocket without being ultra careful, remote stoves are better with the stacking technique but it can be done
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