Isobutane lasting...

Alright, well everyones stoves say different times, and the cans say different too. So in a nutshell, basically how much will a 8oz can of isobutane last?

How many days can i warm/boil a .75-1L pot of water for breakfast, lunch and dinner? I have esbit for backup, and all else fails a fire, so what kinda time am i looking for this to last?

You can figure this out by testing at home, weighing your fuel canister before and after each boil. A piece of masking tape on the canister will let you keep track. Do this outside on your patio or in your back yard, not indoors (think carbon monoxide as well as more realistic weather conditions). I always allow a little extra as a "fudge factor."

Boiling Sierra water in the summer, I have had the small canister last eight days, just boiling 1.5 cups water in the evenings and maybe one 2 cup Ramen dinner by letting it set a bit before eating so it finishes cooking.

I seem to get about a week out of one, and I drink a lot of coffee.

Howie

It will depend a lot on 1) temperature of the water you start with, 2) wind, 3) air temperature and 4) if you just boil water or plan to cook. I solar pre-heat my water for at least an hour and have a home-made wind screen that is really good. I also cook about 5-10 minutes after the water comes to a boil for dinner and 2 minutes for breakfast. One hot drink and then the meal. I get through a week on one cannister - sometimes I run out the last day or two. I guess that in South Carolina you will not be dealing with lots of cold (unless you mean winter camping). I would say the one cannister should do it. I do not take a backup - just have enough non-cook food to get by if needed. I have also resorted to hydrating instant potatoes in cold water. If you are hungry enough, it works.

I'll get a week to 12 days out of a small (4 oz.) canister, boiling water for oatmeal in the morning and for a freeze-dried entree at night. If I drink only water, and keep the stove out of the wind, I'll hit the 12-day mark; if I fix tea with breakfast or supper, or get careless about wind protection, I'll be down toward 7 days.

alright guys this really helps.

so basically i need a good windscreen and that ads life, and need to get water before and let it warm up.

Everyone that i know is saying to just take soup,trail mix and granola bars, but i'm looking to try FBC and stuff i can do with warm water, instead of boiling, so that'll save gas.

If you're using a canister stove that mounts on top of the canister, be careful with the windscreen. If you fully enclose the canister, you'll end up overheating it - at which point you've got a grenade, not a stove.

Better to simply find a spot that is out of the wind (behind some bushes, a large rock, or log) and use that as a windbreak. I've also tried using one of the MSR-style foil windscreens (like those that come with the Whisperlite) that hooks together to form a circle - except I don't hook it. I leave it in a semi-circle, with one open side. It sort-of works; the flaw is that any good breeze pushes it around and it's not as efficient. I usually use the find-a-windbreak method.

Cool, as I just purchased my first cannister stove, and have been wondering what kind of performance I could expect. I was planning on using my MSR windscreen as well. I still think I'll do the home experiment, as it is something to do while I watch the winter roll in! I'll let you know my outcome

I generally anchor my MSR windscreen with a couple of little mini-stakes I made from some 3/32" aluminum welding rod. They weigh about 0.15 oz and insert through holes I punched in the windward side. In a strong wind, though, I have had them pull out. They also are one more thing to keep track of on a hike. I also have a disc of aluminum flashing that I put between the stove and the canister when I screw them together. It serves to reflect heat away from the canister and toward the stove and has always kept the canister relatively cool. This adds another 0.2 oz to the kitchen weight. A piece of heavy-duty aluminum foil can serve the same purpose. In fact, I often leave these items home and just suffer the wind if I can't find a sheltered spot for cooking.

I'm a little confused by all this windscreen talk.

Both canister stoves I've owned (an old GAZ Turbo 270 and a newer SnowPeak Ti whatchamacallit) offer separately-purchased windscreens that attach directly to the stove, and work quite well. Because of their placement between the canister and flame, they keep the canister safely on the outside of the screen, and also provide heat reflection for increased efficiency.

Those windscreens are designed for canister stoves, keep heat from being relected onto the canister, and do work. My caution was aimed at some misuse I've seen, where people have used a homemade screen or the screen from a white-gas stove to completely enclose the canister and reflect heat downward onto the canister.

I have some flashing that intend to make into a windscreen, but not close it. It'll be almost, but not fully closed. enough to get some heat out.

Ballparky, I budget 1.5 oz/day for mild conditions and "real" cooking. I can eke out more days with less fuel if I'm just boiling and reconstituting, but who likes to eat like that?

Cheers,

I'd suggest "most," not "some." The canister should always be cool enough to touch - leave a large enough gap so you can reach in to touch it without getting burned, and you'll probably be fine.

...and I always scratch a small tick mark in the side of the cannister, just for a rough count of many times it's been fired up.

I find the water temperature makes a huge difference. If I am taking water out of a pond or lake in the heat of the summer, no problem. A mountain spring or water fall is a different matter. It can seem like forever to boil a cup of that really cold water. That is likely the biggest factor in all of this.

Howie

At 1.5 oz a day, that means that a small cannister would only last 2 days?? The net fuel in a small cannister is 3.88 oz?
So from 12 days eating cold meals with the barest of cooking, to a week for more "normal" type eating, ie FBC or one hot instant drink in the morning, and one dehydrated meal at night. To less than a week with some real cooking... wow, it gets a bit confusing.
I am planning a 10 day trip into the Winds next season, (mid August to late Aug) and I will want a hot drink in the morning, I'll want a hot meal (FBC style) in the evening, and a cup of hot tea before bed. So, what do you think I'll need to be happily fed! I also see that there are 3 cannister styles available from 4-18 oz net. So, I'm eagerly awaiting the feedback, and the formulas that you used to go with it. Thanks!
ps, I'll be using a wind screen (prob my old whisperlite screen modified), and I'm very exoperienced with cooking in the backcountry.

2 people, 10 days, FD dinners, a few hot drinks but not every night, a few hot breakfasts but not mostly, no hot lunches,, coleman F1 ultralight stove, AntigravityGear foil windscreen (similar to MSR foil), 1 snow peak canister 8 oz of fuel. That was this last summer.
If you are going solo for 10 days I bet on canister that size (8oz net wt, 13 oz gross) will do fine. If youare 2 people I would bring a big and a little one - you don't want to run short.

Well, I got so bored that I decided to sit inside over the stove and watch water boil from my new Lite Max stove.
The results were very interesting, and I was very pleased with the overall use. Now granted this is far from a true field test, but with the outside temp at or near zero, the water coming out of the sink is alpine cold! I just sat the stove on the stove top, turned the fan on and started boiling liter after liter. I timed each liter to a boil of right at 200 degrees, give or take, and then shut it off, let it cool, weighed the cannister, and started over again with cold water. I wasn't precise by any means, but this gave me a good ball park for the variances in camp. I adjusted the flame to fit the bottom of my Soloist pot, and never really ran the stove wide open.
The results: on each boil, I always had "hot" water within 3 min. (Rising bubbles and steam) True boil, aprox 200-212 degrees was achieved after a low of 7m 25s, and a high of 9m. I boiled 7 full liters plus a partial that reached aprox 130 degrees in 4 1/2 m.
The total burn time of the 3.88 net cartridge (but used a total of 4.1 net oz) was a hair over 60 min. Each boil used right at .5 oz, and it stayed at that level for almost every boil but one, and the last.
The stove functions were very nice, solid feel and adustment throughout the entire range of the valve. Easy on and off with the cartridge. Super stable, as the arms were actually wider than my pot! Thats why I backed off the flame, so as to not melt my handle coatings. I did begin to offset the pot so my handle was more protected, and I could up the flame.
Overall very happy with the cartridge life, and the stove effiecency.
I know this is not a field test, but it does give me a great baseline for working off of. Hope it helps some others as well.

1) take yer stove.

2) take a gram scale

3) take your canister. weigh it -> weight "A"

4) Take the cannister outside, boil your representitive amount of water in as close to field conditions as you can manage.

5) weight the canister again.- > weight "B"

6) subtract B from A = "C" - how much fuel you use to do 4)

7) look at the net weight of the cartridge, how much it holds i.e. 125 grams. 125/C is approximately how many times you can do 4) with one cartridge.

(If you don't trust the net weight you can weigh a full and empty canister)

Idahosteve-
I take one large cannister for a 10-day Wind River trip. I probably cook more than you plan on doing and I only use a very small wind screen that attaches to the prongs. I always use all the fuel. At the end of the trip, if I see I am going to have extra, I either double the hot drinks or wash my face in warm water. There usually are plenty of opportunities to build a fire in the Wind Rivers, so as long as you do not mind cooking on a fire if fuel runs out, a medium cannister may do. I personally think adding a small cannister (one medium + one small) is not very efficient - lots of steel for a little extra fuel.

Phat, you might want to mention that the water temperature needs to be field conditions, too. Tap water is usually too warm. Idahosteve is right that in current conditions (well below freezing outside even where I live) the water approximates what is found in high mountain springs, but it doesn't hurt to check its temperature. I'd want it below 40*F.

I get by with a small canister for 8-9 days, but all I do is boil 2 cups of water once a day. I also take 1-2 no-cook meals for those nights when I'm too tired to fire up the stove. If I think it's going to be cold weather (like my October trip) when I want a cup of tea in the morning, too, I'll bring a large canister for a 8-9 day trip instead.

For the last two family trips with two grandkids, their dad and myself, one large canister has been just right for a three-day, two-night trip. On those trips I boil one quart for freezer-bag rehydration in the evening and for oatmeal in the morning, plus a second quart for cocoa for each of those meals (sometimes reheating the water for a second cup). It's pretty tight, though--last summer the canister ran out just as the last cocoa water started to boil. I take a small canister on those trips for extra (my son gets to carry it!).

Idahosteve, outdoor conditions (wind, et al, plus cold canister) would be a much better test. Not when it's below zero (not worth risking frostbite and canisters don't work well below freezing), but maybe in the upper 30's once it warms up. Here in NW Oregon the dreaded freezing rain that inevitably ends these cold spells is due tomorrow night, with warming by Sunday. Hope is in sight!

Steve
said
"The results: on each boil, I always had "hot" water within 3 min. (Rising bubbles and steam) True boil, aprox 200-212 degrees was achieved after a low of 7m 25s,"

Steve, those are air bubbles coming out of solution. You said yourself that it took 7.5 minutes for a "true boil". Many people are confused by the air bubbles, it seems hot water can't hold as much air as cold. Many have claimed three minute boil times with whimpy home made alcohol stoves. Don't be confused. No offense.
oh yeh, if you drink as much coffee as I do you can go through a can of butane in 2 days.
Jim YMMV

Jim! You're here! So glad to see you still posting!!!!

This is really my fuel sucker. I could get by with just 2 cups of water a day for a hot dinner and a no-cook breakfast if it wasn't for my desire for coffee or tea in the morning, and likely tea in the evening. So I just resign myself to boiling 3 cups in the morning and 3 cups at night.

To say nothing of tea during the day, which was a real pick-me-up on our TLB Forum dayhike!

Thanks for all the feedback. I am a big tea drinker, and I know that I'll be bringing extra fuel for my hot mugs for sure!

Its sure a different aspect coming from the climbing expedition side of things. Fun to incorporate new ideas, methods, and equipment.

Really looking forward to putting stuff to the test, and to trying out new systems.

Like Oregon mentioned...Don't forget that the canister loses efficiency when it gets cold itself...it's not just all about the water temperature. When the canister gets colder you'll notice it starting to spit liquid out, not vaporizing.

sorry i havent been on in a while, all this is great info, thanks guys!

practice, practice,practice,w/stove and food you expect to cook on it in any/all weather conditions you expect to incounter....at home of course, outside...

Interesting info for sure, especially for a guy that has only used a canister stove one time. I've always used a type of MSR whitegas stove. I am going to try two trips this summer with a few homemade alc. stoves I made. I've been experimenting with them this winter and have really enjoyed it.

-Skippy