Packing enough fuel

Hi everybody,

I've scoured the internet to no avail, could anyone help me with the following question?

I'm doing an 8 day trip in Northern Yosemite and I'll be using an MSR Pocketrocket lightweight stove. I'm unsure as to how much propane I should be carrying to last the whole trip. I'll probably be using the stove at high heat maximum 40 min/day

If anyone has an idea I'd really appreciate it. thanks!

~Quinn

Actually pretty simple - MSR's own stuff says one of the 227 ml canisters will last 90 minutes on the stove. So, I'd say *IF* your estimate of 40 minutes a day is correct, you need roughly one 227 ml canister for two days, so your 8 day trip would need four canisters.

Now the kicker is - how did you arrive at that 40 minutes figure.

Now me, personally, I take trips using a similar stove (Snow peak) and I figure it out by how much water I will be boiling, and basing it on my experience with fuel consumption in the past - how? I a brand new a 227 ml canister and put it on a postal scale - record the weight. I then take it on the trail in real conditions for a couple of days. Bring it home. Record the weight - do the math. You can quickly arrive at what your *actual* fuel consumption will be and plan it pretty carefully.

That's what I do, too--try it out on the trail, weighing the canister before and after. You can get a fair idea, though, by preparing a couple of backpacking meals on your patio at home, weighing the canister before and after.

My own findings are that with four people, boiling 1 quart of water three times per meal twice daily (once for hot cereal or a one-dish dinner, once for cocoa/tea, once for sanitizing dishes), a large MSR canister (8 oz. isobutane) lasts 2 breakfasts, 2 dinners. It will run out during the second boil for the 5th meal. (I really should get a 2-liter pot so only 2 boils are needed!) When I go out solo, I eat cold breakfasts so boil only 2 cups for dinner (one-dish dinner reconstituted in a freezer bag, plus tea) once a day. If I take one or two non-cook meals, I can go out for 9 to 10 days with one small MSR canister (4.1 oz. isobutane). If I'm going to be fishing, though, I take a large canister for the same period so I can fry the fish.

EDIT: A quart of water takes about 5 minutes to boil. I never turn the burner all the way up--it's more like halfway. This is using the Primus Micron which is comparable to the Pocket Rocket or Snow Peak Gigapower.

I can't understand the "40 minutes at high heat" scenario even if you're doing a lot of cooking from scratch. Normally items being cooked from scratch are brought to a boil but then simmered on as low heat as possible. Check out Sarbar's website (she's a regular contributor here) for lots of recipes, many of which use supermarket ingredients, that require only adding boiling water and sitting 15 minutes in a cozy to keep warm. This saves a lot of fuel, time, and pot-scrubbing. Most of us here use this method or some variation on it.

Please note that the canisters for the Pocket Rocket are isobutane, not propane. The Pocket Rocket is not designed for propane and the results could be more spectacular than you'd want!

I'm sure Quinn means isobutane, not propane. I don't think anyone makes a propane canister that will fit on a Pocket Rocket. I think 40 minutes is probably excessive. I might have run my canister stove that much in winter, but that included melting snow for water and I wasn't running it full blast either.

I'd figure one canister for two days is a safe bet. If you wind up carrying an extra. you may run into someone who needs one.

This site has probably more stove info than most people will ever need, or want.
http://zenstoves.net/StoveChoices.htm

The snowpeak gs100 is in the same fuel efficently leaguge as the pocket rocket. I found that I would get around 40 minute of high heat from the small snow peak canister, and around 80 minutes from the larger canisters from MSR, Primos, etc.

The question is do you really think you will be using the stove for 40 minutes on high / day? My experience is that I could boil 7 1L pots of water or 12 24oz pots using the small snowpeak canister most conditions. Since I only cook dinner, and for dinner boil 24oz... one canister lasts me a long time.

--mark

Wow everybody, thank you so much for all the advice. I really came to the right place! I guess I've totally been schooled and I'm really glad I was.

TomD and OregonMouse, you are of course right that I am using isobutane, not sure how I messed that one up. And to everyone, I'm not sure how I arrived at that 40 min estimation other than I figured ~15 to boil water for oatmeal/coffee breakfast and ~15 for dinner/cocoa and rounded up. This was, not smartly, a blind guess. You're absolutely right that I should test out my stove and fuel and see how long it takes and the weight difference in fuel. I admit that although I've been backpacking for multiple 4-8 day long trips I was never "in charge" of the stove/fuel/kitchen gear so I (stupidly) did not pay attention.

I won't reply to everything but know that I have read your comments thoroughly and I'm taking it all in. All the help you have all given me is invaluable and I really truly appreciate it. Happy backpacking

You can do the same fuel weighing thing by testing at home, with good cold water, and doing a test boil/cook just like you would do for a day in the field. Weigh the canister before and after. You're then pretty close. Of course you probably don't want to cut it to the last gram, leave yourself a margin of error, and do it outside, preferably in windy or not perfect conditions.

Just another note, but many of the isobutane canisters are mixtures of iso and propane.

They all are - essentially there is little difference between most modern blends which are mostly butane, with a little bit of isopro and propane in them to increase cold weather performance.

the trick is that the gases don't actually "mix" - the butane is still butane, and is liquid (read that - no gas comes out) at 4 degrees centigrade - the little bit of isobutane and propane is to give the stove soemthing to burn that will come out at colder temperatures, and hopefully warm up the canister enough that the butane will gasify.

Of course if it's cold enough and you burn off that little but of stuff before the canister warms up enough - it really doesn't work very well so in the cold you may need to warm it up in your hands first, or keep it in your sleeping bag for best performance - practically they do pretty good in my eperience down to about -5 C - after that they get tempermental. So for me, I use them for "three season" trips.

I *have* seen cartridges in europe, with the lindal valve (that worked fine on my snow peak stove) that were *all* butane, no isopro/propane - I guess in ireland they didn't figure on needing any colder weather performance - and I didn't the cartridge worked fine.

Yeah I looked at the bottom of my canister (I'm using MSR) and it says isobutane propane. So I guess that's where I got confused. Thanks phat for the explanation on the non-mixing mixture :-) of butane and propane. I'm basically a 3-seasoner but I'm glad to know about the cold weather/not functioning as well and troubleshooting. Thanks again for all your help and info!

8 days? that's a long trip, for my thought, I always take as many as possible fuel in my backpack, it's not just for me, it also can help others in the group~

If taking a canister stove instead of my alcohol stoves, I would take two small canisters or a single 8 oz canister on such a trip, boiling slightly less than a liter per breakfast/dinner (lunches are generally cold snacks/sandwichs). Most of these stoves will boil a liter of water in about 3-5 minutes. I have a Snowpeak Giga. Got rid of my Pocket Rocket a while ago, as I disliked it immensely - I never got as good economy with it as anyone claimed I would, and the stove would not nest inside my pot with the 4 oz canister as the Giga does. I sometimes wonder if I just had a defective stove. It just would not perform and ran me out of fuel in nothing flat.

You must have drawn a less than perfect PR. I obtained one when they first came out, and it has performed extraordinarily well.

We love our pocket rocket--and get about a week of backpacking out of one fuel canister...and that's for two people. And our pot must be a touch larger, because ours fits just fine w/ a small fuel canister (and folding tripod to boot!)

I agree with phat - do the numbers, @40min per day = 4 cartridges. I can easily use up a cartridge in 2 days bcause I drink hot drinks. Some people are extremely miserly with themselves and their fuel and can make it last 4 time longer.

The question is - what are YOUR fuel needs, and you do not know, The kicker is how cold out it is, the efficiency of your pot/windscreen, and your needs. When it gets colder you need MORE fuel to cook anything and you may feel like lots of warm drinks. Maybe you will carry a bit less clothing because you have fuel. Its a very complex equation and you need to work it out for yourself. In the mean time take extra until you know. Its not really that horrible to carry out 2 unused cartridges, better than learning on the second to last day that you are out of fuel. And of course boiling can sterilse your water eliminating the need for filtration or other weighty/energy consuming method. It also depends on your cooking method. Do you want to boil a cup of water and reconstitute some food powder, or do you cook real food? Generally better eating is energy consuming.
Jim

I dug this up from one of my spread sheets taken from actual usage data:

"It takes 0.3 oz of propane/butane in a near empty cannister to boil 9 oz of water for coffee at around 65 degrees in an easy wind in a high performance stove."

Jim

I use a 2 oz coleman exponent. While on my last trip I took 2 full canisters and never finished the first. Mind you this was for 2 people with one stove and basically boiling water only. simmering takes more. I made a cozy for my only pot out of a wally world sleeping pad , foil, and spray adhesive. C A Cozy will save alot of fuel. Sarbor, and a few others here are the real experts though.

Good post Jim. No better place to use the old adage: YMMV. Your mileage may vary.

I would also add that in some areas, if you DO run out of fuel, you can always cook over a campfire. (personal experience on THAT one, too!) grin.

I do pretty much the same as Lori recommends. I use a Snow Peak Giga and my fuel consumption averages a bit less than an ounce per day. This figure is based on five years of using this stove typically 20 to 30 nights per year.

At breakfast every day I heat 12 oz of water for coffee, 8 oz of water for cocoa and 12 oz of water for tea, not all at the same time. In the evening I will heat 16 oz of water for my meal, another 12 oz for herb tea and, on occasion, another 4 oz for warm soapy water to clean the grease from my eating bowl.

My cooking for evening meals is freezer bag style but rather than re-hydrating in a freezer bag I use a three cup Glad storage bowl with a snap on lid (about 1 oz). On any trip over three days, I save weight using the bowl rather than freezer bags. The minor effort involved in cleanup is worth it to me.

If I think that my fuel supply might be close, I add a CAT stove and a few ounces of ethanol in case my canister goes dry. The CAT stove and alcohol weigh less than does an empty 4 oz. fuel canister.