Fuel Canisters

[ottercreek_hiker]

Of the two sizes of fuel canisters (4oz & 8oz) which one is the best to use and how many will be used on a full thru-hike?

[MuddyWaters]

They both work the same. It really depends on you and what kind of stove you have. With a jetboil, you could use the small ones for about the same time as the large ones with other stoves. With a stove like a pocket rocket, just go for the 8oz. You will probably get about 3 weeks if you only boil water for dinner, and only once per day. Depends on how often you want to plan to replace them, some towns may be hard to find. Often can find them in hiker boxes too. Some have said they never had to buy one, always got them from hiker boxes, but thats not a very good plan.

[peakbagger]

It is mostly a matter of convenience and some slight weight penalty. I would expect that the container holding the fuel would be slightly heavier per unit of fuel in the 4 oz can, but the difference would be minimal. The bigger weight savings is that if you resupply every 4 or 5 days, why carry 10 or 14 days worth of fuel? Of course that implies that cannister are available every 4 or 5 days which is not necessarily the case all along the AT.

I have advocated in the past that hauling a bit of extra fuel will allow someone to take a slightly underrated lighter weight sleeping bag. There is potentially more savings with this gambit offset by the need to carry a nalgen bottle that will hold up to boiling water. If you are colder than the bags rated conditions, you can heat up a bottle with your spare fuel and throw it in the bottom of the sleeping bag. Most of the time you dont have to so you are carry a lighter weight bag.

If you do use a pocket rocket type stove, do consider building a hanging pot shield like i have posted in the past (and have lost the photos) it bumps the efficiency up about 30% and makes it a lot easier to cook in the open with a breeze.

[Coffee]

Of the two sizes of fuel canisters (4oz & 8oz) which one is the best to use and how many will be used on a full thru-hike?

It depends on the availability of canisters at resupply locations. A small 110 gram canister lasts for 8-9 days of use in my Jetboil which I typically use to boil 32-40 ounces of water each day. Next year, I am going to reduce my daily hot water needs to around 24 ounces by switching to granola from oatmeal so I'll only boil water for coffee in the morning (8 ounces) plus 12-16 ounces for dinner. A small canister might last 10-12 days in a Jetboil based on that reduced use.

[ottercreek_hiker]

Ok, I have an MSR Windpro and I plan to do two 40oz boils a day, AM & PM. I was on a 3 day pack trip this past weekend when on the last morning I had a low pressure situation with my 8oz canister but my friend was using the MSR Pocket Rocket with a 4oz canister and had no problem except for the wind. The temps dropped to the upper 30's that night. I was wondering if the small canister was better in a low temp situation. I like the Windpro because I can use a windscreen without worrying about overheating the fuel canister.

[Starchild]

I used a Jetboil for the colder part of my thru. The small canister will boil just over 10 quarts (or l) of water, so 10 is a good baseline number. IIRC the larger one is 250g instead of 100g, so that should do 25. It really does not matter what quantity you heat at a time, it's about 1 cup/minute, so 2 cups = 2 minutes, 3 = 3, and that's the top line, though you can get a bit more water in if you need to.

What does matter is if you cook, simmer instead of rapid heat/boil as that will consume a lot more fuel.

During my thru, I never had any issue finding canisters, though I did have trouble once finding a small one and had to use the larger one. Also most of the time I didn't need to get a canister as they last a very long time with the jetboil. I also got some out of hiker boxes along the way. Another time I could have bought one in one town, but had enough to make it to the next town, I called ahead to insure that they had them, which they did, so calling ahead was helpful.

I would expect more fuel consumption based on the pot/stove set up you have.

[Starchild]

Ok, I have an MSR Windpro and I plan to do two 40oz boils a day, AM & PM. I was on a 3 day pack trip this past weekend when on the last morning I had a low pressure situation with my 8oz canister but my friend was using the MSR Pocket Rocket with a 4oz canister and had no problem except for the wind. The temps dropped to the upper 30's that night. I was wondering if the small canister was better in a low temp situation. I like the Windpro because I can use a windscreen without worrying about overheating the fuel canister.

I've had this with a non-standard Camping Gaz stove/lantern - but it was the same fuel iso-pro/butane mix. This assumes that the canister you are using is partly used. Back when I didn't know any better, I would buy the largest canister so I didn't run out. This was also before LED headlamps so backpacking with a lantern was common.

The problem seemed to be that the mixture of gas would come out unevenly, the 'hotter' fuel (or more pressurized) would burn off more rapidly and leave behind (in the canister) a mixture of more of the 'cooler' burning stuff. In other words the percentage of the fuel mix would change, leaving the flame not as hot, and towards the end this lead to very long boil times. It got to the point that the low canister would be only good really for the lantern.

I think because of the fuel canister size that this problem was amplified and a smaller canister would be a lot less noticeable. Also stove regulators have gotten a lot better and I know that some compensate well for low pressure.

[MuddyWaters]

Ok, I have an MSR Windpro and I plan to do two 40oz boils a day, AM & PM. I was on a 3 day pack trip this past weekend when on the last morning I had a low pressure situation with my 8oz canister but my friend was using the MSR Pocket Rocket with a 4oz canister and had no problem except for the wind. The temps dropped to the upper 30's that night. I was wondering if the small canister was better in a low temp situation. I like the Windpro because I can use a windscreen without worrying about overheating the fuel canister.

Thats a lot of water.

Usually can avoid issues by keeping your cannister in the sleeping bag with you so it stays warm. But extended boiling times, due to big pots/water, or wind, and result in the cannister cooling. Ive never had a problem boiling just 4 cups, which is all we need for 2 people, even on a 25F morning.

As long as you keep it warm, the larger cannister will cool off slower than the smaller and actually work better in cold conditions.

[Nooga]

Its hard to estimate how long a canister will last due to ambient temp, water temp, etc. Down south I carried the smaller size because they were readily available. Once I reached NE, i switched to the larger size. Check out the hiker boxes as there is usually partially full canisters.

[ottercreek_hiker]

That is a lot of water, It should have been 24oz instead of 40oz :confused:
I checked how long it would take my stove to boil 2c of water at home and it took 2.5min. and when I cook my meals I bring water to boil add noodles etc. and cook a couple more min. and then transfer the pot to a cozy for 10 or 15 min. to cut down on fuel usage. I read on another site that a 8oz canister should last about 10-14 days cooking this way.

[Starchild]

That is a lot of water, It should have been 24oz instead of 40oz :confused:
I checked how long it would take my stove to boil 2c of water at home and it took 2.5min..

That is a very good boil time, I didn't know anything but a high efficiency cooking system (Jetboil, Reactor, something with fins on the pot) could come close to the 1 minute per cup 'rapid boil' standard.

[danil411]

I used my Windpro on my thru hike. I purchased large canisters for long legs or when the guidebook indicated I might not be able to purchase any canister for a while. The small canister fits in my cook pot so I prefer it when the situation allows for choice.
I heated about 8 ounces in am and 16 for dinner most days. In good conditions it took 3minutes in am and 5 at night.

Some of the canisters have burn times on them so I used the chrono feature on my Ironman to track fuel usage. I consistently got a little over 1 hour on small canisters.

Dimples

[ottercreek_hiker]

I checked my boil times of 2c water again using my 8oz canister which has about 1/2 to 1/3 of fuel left in it and my times went from 2.5min (full) to 4min. (1/2 to 1/3). At this rate I should get 8-9 days on an 8oz canister. I agree with Starchild as to how a canister looses it ability to produce pressure as the fuel is used. I know that warming the canister will help but I wonder if the smaller 4oz canister with its lower volume would be better in colder temps. I am going to do my tests on a 4oz canister and compare results.

[max patch]

I don't use a canister so what do I know? But common sense tells me a 4 oz canister with 1 ounce of fuel in it will outperform an 8 oz canister with the same 1 ounce in it. The question is common sense correct?

[Kerosene]

I encounter a lot of twenty-something hikers who have switched to 8-oz canisters by Virginia, simply because their appetite has grown so much.

As an aging section hiker out for 7-9 days, I typically try to make do with a 100-110g canister with a SnoPeak LiteMax boiling 2-3 cups of water twice a day for spring or fall hikes.

[aficion]

I'm planning on ten days between resupply. My experience sectioning has been that 8oz is enough for ten days with some left over. No cook breakfast half the time. No cook dinner on occasion. Coffee most days. I carry a 2 quart ti pot which holds the larger canister, stove, lighter, spork, bandana, bar soap, etc. Fits perfectly into rolled foam pad inside pack. Not sure if one 8 oz weighs less than two 4oz though I would guess it does. Definitely costs less. YMMV

[TEXMAN]

The 8 oz is nice because it gives your stove more stability because of the big base it is sitting on....the 4 oz with a jetboil on top can easily be knocked over

[QHShowoman]

When I worked at REI, we tested this.

A 4oz canister gives you approx. 30 mins at full flame.
A 8oz canister gives you close to an hour.

This is with no wind, in the middle of a temp controlled store.

[sliderule]

Ive never had a problem boiling just 4 cups...

Keep practicing. Before you know it, boiling six cups will be like a walk in the park.

[Nooga]

The 8 oz is nice because it gives your stove more stability because of the big base it is sitting on....the 4 oz with a jetboil on top can easily be knocked over

This is a good point. Some 4oz canisters, such as MSR, have a wider base than others such as Snow Peak, although Snow Peak fuel seems to burn better in my stove.

[Coffee]

The Jetboil does come with a base support which some people like to use on the small canisters for stability. I didn't see the need for it and left it at home but I think the weight savings was pretty minimal.

[Starchild]

Yes no issue with stability in the real world with the smallest canister, perhaps on another world, heck YMMV. The smallest one worked without any tipping issue from GA to ME (Excluding CT, MA, VT as I went to esbit then), there was no concern of tipping over either, it is a non issue (and without the stability base)

The canisters are made to fit pots (or pots are meant to fit canisters) either way that is the reason for the sizes we see now as standard.

[TAG]

Back to the original question...to figure out home much/how many canisters you'll need, I think you are going to have to do some testing to find out how much fuel your setup burns. You won't be able to replicate every situation (rain, wind, cold), but you can get a decent idea in the backyard.
one handy trick I picked up (can't remember where) is to put a full canister upside down in water and mark the "water line." Then, do the same when the canister is empty. I now mark all my canisters with the full and empty lines so I can quickly check the fuel level when I'm on the trail.

[RETCW4]

I usually carry two 4 oz. canisters. When one goes empty, then I start looking for resupply.

[Starchild]

I usually carry two 4 oz. canisters. When one goes empty, then I start looking for resupply.

Some would say that means you are carrying way too much, including me.

After a while you get to know the shake test and can go with one with confidence.

[Prime Time]

I start with one 4 oz container, which lasted me between 6 and 10 days, then added a second one when I think I will need it because the first one might run out before I get to my next resupply point. So I almost always had 2, one of which was going empty. This way I always got every last bit of gas out of every container I bought.

[yaduck9]

Ok, I have an MSR Windpro and I plan to do two 40oz boils a day, AM & PM. I was on a 3 day pack trip this past weekend when on the last morning I had a low pressure situation with my 8oz canister but my friend was using the MSR Pocket Rocket with a 4oz canister and had no problem except for the wind. The temps dropped to the upper 30's that night. I was wondering if the small canister was better in a low temp situation. I like the Windpro because I can use a windscreen without worrying about overheating the fuel canister.

an msr windpro has a "generator" that will allow you to invert the canister ( after a few seconds of heating ) so that you will be feeding liquid instead of gas. this avoids the dreaded low temp / almost empty poor performance syndrome.

msr now markets the windpro with this feature. before, it was one of those wink, wink thing to avoid litigation. i would look on the web or contact msr so your up to speed ( that way i avoid litigation ;) )

http://seattlebackpackersmagazine.com/stoves-for-cold-weather-ii/

[ottercreek_hiker]

Thanks for all of the great advice. I got my stove a few months ago and was told by the previous owner that they thought it was a Windpro and when I started to look for repair kits I found out that my stove did not look at all like a Windpro so I sent a pic to MSR and found out that I have a RapidFire stove, which is a spinoff from a Whisperlite to use canister fuel. It has the generator so that the canister can be inverted to overcome the low temp/pressure problem. I tried it out and it does work but the flame control is delayed when turning the heat down. I also made a windscreen and a heat deflector and
that helped my boil times.
24866