Stoves and Fuel

“Any comments on how long an 8oz fuel canister lasts? I have the MSR Pocket Rocket and will use for the first time. Email me directly at jiujen@aol.com
Thanks”

“A lot depends on use and conditions.

It will not last long melting snow in freezing conditions. About 3 liters per canister.

Are you just heating water for dehydrated dinners, or are you cooking breakfast and dinner with a percolater for hot coffee as well as food?

If just Dehyd dinner and a hot drink at dinner and breakfast with one or two people using only as much water as you need in moderate conditions you should get several days.

Dehyd, ramen or Lipton noodles and tea or coffee bags are a way of stretching the canister.

Cooking rice or potatoes from scratch, more than 2 people, making lots of hot water frequently are ways of burning the canister out in a day and a half.

Wind protection when cooking is another variable.”

“I don't have much experience with cannisters but yeah. Cooking for 2-3 people, breakie and dinner, around sea level, I had a cannister last about two days. These were realtively breezy conditions.

Altitude, wind and temp will all affect your burn time.”

“I have the pocket rocket, and I had an issue with mine at 7000 feet. It was a little sluggish. Fuel was consumed much faster than I thought it would.”

“"I have the pocket rocket, and I had an issue with mine at 7000 feet. It was a little sluggish. Fuel was consumed much faster than I thought it would."

On the MSR site they said you can place the stove and canister in a shallow pan (pot lid) with an inch or two of water in it to increase performance in a cold conditions. The water helps disperse the cold created in the canister. It really does work well. I found when it runs colder the gas lasts even longer. I’ve stretched a single regular sized canister out to last a whole week. I was cooking breakfast (this includes a whole quart of hot coffee), lunch and then cooked dinner over the fire.”

“Cool, I'll have to try that one. That will come in handy when I do the smokies in March”

“i'll be doing an experiment as soon it gets cold enough.

i'm going to try out my jet boil under various conditions while holding the following conditions as steady as possible:
ambiant temp*
water temp* and amount
initial canister temp*

these are the conditions i want to investigate:
new vs. near empty canister
exposed bare canister
canister inside my home made reflectex cozy
inside cozy with chemical hand warmer under canister
hotwater cozy method - i.e., boil a couple of ounces of water first, then pour the boiling water into the plastic 8 oz. cup that comes with stove, to keep canister warm.

i'll do this and post efficiency results as soon as it gets cold enough to make it worthwile - atleast teens.

comments or suggestions are welcome”

“I think the cozy idea might be dangerous and IMO, the handwarmer thing is a, 'Hey, hold my beer and watch this.' thang.

I'd get in touch (by internet) with the company first.

Doug”

“He!!. 'phone their customer service, it's prolly a 8NN number.”

“huh? you're losing me gremlin”

“DO NOT put anything that will reflect heat around your canister unless your intention is to watch it explode.”

“Most windscreens reflect heat back to the stove...

I think the key is to very, very closely monitor the surface temp of the canister until you are certain that you know how your mod functions. Like, "it feels warm but OK if outside temp is 10*, but it feels too hot above 20*".”

“"Most windscreens reflect heat back to the stove..."


This is why canister stove instructions specifically warn you not to use an enclosed windscreen.
last edited: 12/02/04 10:13:23 AM”

“ok, let me explain.
my cozy is just that, a cozy. it does not go up high enough to reflect any heat around the canister. it just wraps around the bottom of the canister to help slow down the rate the canister cools off from the ground.

also, the hand warmers i'm talking about are those little packets you put in your mittens.
i'm going to try putting one under the canister, inside the cozy in the concave bottom of the canister. the handwarmers do not get nearly hot enough to blow up anything.
last edited: 12/02/04 10:15:38 AM”

“Heard alot about the jetboil but it looks huge. Advantages over a Ti solo cookset and a MSR Pocket Rocket?”

“Alright, it seemed to me that you were talkin' about using a cozy that covered the canister.”

““Heard alot about the jetboil but it looks huge. Advantages over a Ti solo cookset and a MSR Pocket Rocket?”
trailhound57
10:15:54 AM
12/02/04
ignore this user

It's about the same size and weight and is supposed to burn fuel more efficiently. I’ll let someone who actually has one to get into more detail.”

“jetboil is the size of a liter mug. everything [stove, canister] fits inside the mug when packed up.

advantage over the pocketrocket is that it's an integrated system with a heat sink on the bottom of the mug which makes it more efficient.

disadvantage is you can only boil water, so it's not as veratile as the pocket rocket”

“no prob, bison. i hear ya, safety first and all that.”

“sacco, those iron-based handwarmers need lots of oxygen to maintain their heat output. If you bury it inside the cozy under the canister it may not get enough air. Also it may stop working if it gets wet from condensation on the canister. Things to keep in mind as you play around.”

“Obviously, I don't own one. Looks cool but also looks like a good idea that needs a little more development. I'll have to see one on the trail in action before I stick it on my Christmas List.”

“cool tech, i'll find out through experimentation”

“a few notes sacco - the canister does not get cold from contact with the ground - the canister gets cold from the expansion of the liquified fuel into gas (ie the "boiling" of the fuel - having a cozy around the canister is contraproductive IMO

WRT handwarmers - the rechargeable handwarmers are probably a good idea - a fixed max temp (140 deg F approx) is not too hot for the canister and they do not need air (O2) like the iron powder types

using a pan of water is also a good idea but I don't think it really needs to be warmed up/boiling as you describe - also a couple ounces probably is too little - you want enough mass so that the temp change is minimized as the fuel gassifies.

ditto some of the comments about a windscreen but with a jetboil I don't think it is as dangerous as it would be with a pocket rocket type due to the increase efficiency of the heat transfer from the flame to the container. A partial windscreen on the side where the wind is coming from is probably safe. A windscreen that is large diameter is also probably safe - think of a sleeping mat on edge and wrappped around the jetboil with more than a foot of space between the mat and the container.
last edited: 12/02/04 11:23:40 AM”

“HOI, i agree with most of your post but i believe-

the canister does get cold from the boiling of fuel, but also ambient temp. is important.

example: few weeks ago Lthiker and i both had our identical stoves in the cats when it was in the low 20's.
we both warmed up our stoves in our shirts prior to turning them on.
he used his on top of a folded hankerchief on the snowy ground, i used mine on a rock.
wind was not an issue.

his worked much better. mine worked ok for a minute but then got worse quickly. my guess is that initially they worked the same and were the same temp., but then mine lost all of it's heat through conduction into the cold ground. his was insulated a little from the ground and it made a big diff.”

“give your description the first thing that I thought of was that Lthiker had a fresh canister and yours had been used - this is important in the cold because the fuel is a mixture and the more volitile component tends to boil off first - thus a fresh canister in the cold would work better than a partial canister due the partial having proportionally less of the more volitile fuel.”

“agreed HOI.

this is my logic

canisters work better in the cold when you warm them up in your coat first

so once you take the canister out of your coat it's warmer than the environment.

so it will lose it's heat through conduction (whatever it touches) and convection (wind)

if you're in a somewhat sheltered area, then conduction is the bigger heat thief.

a cozy will greatly slow down this conduction, keeping your canister warmer, and more efficient.”

“My own use of my pepsi stove in below freezing temps match what you think, sacco. Lots of people say you can't use them below freezing, but I haven't had a problem when insulating it well from the ground.”

“interesting discussion! I'd be interested in the results. I use a pocket rocket right now with the small canisters. Any way to improve fuel efficiency and increase boil rate would be appreciated.”

“OK I'll grant that insulating the canister from cold ground is a good idea - in fact I had noticed the same thing as techntrek - putting a bit of foil covered closed cell insulation under an alcohol stove improves its performance in the cold and I can see how that would be good for the canister stoves for much the same reason. The part that I still disagree with is insulating the sides of the canister - the heat you put into the canister initially will be gone quickly with the boiling of the fuel. On the other hand if you are using a handwarmer then insulating the canister sides can make good sense.”

“You could always build a small wood fire, set the canister on the bed of coals. That would take care of the bottom and the sides from the radiated heat from coals.”

“Isn't there an old mountaineering trick where you attach a strip of copper to the side of the canister and then fold the end of it into the stove flame? The heat will travel through the copper keeping the canister warm.

*NOTE* I have never tried this and I don’t know if it will over heat the canister causing it to explode.”

“hmm, never heard that one.”

“Using a canister even on the coldest day (10 is about as cold as I've experimented with) is not really an issue if you warm it up(sleeping bag over night, coat etc) and if set it in a pan of water (I usually warm the water in a pan next to the fire) before cooking when extremely cold. Works great. However, most of my cold weather trips consist of a comfortable fire and no cook food.”

“didnt i read something about this the other day?.....oh that was the lava lamp episode...sorry”

““didnt i read something about this the other day?.....oh that was the lava lamp episode...sorry”
2socks
12:25:25 PM
12/02/04
ignore this user

That's probably where I here it. I can never remember my sources.”

“LOL! Read it again. Never did I say that the canister should be in the water as being heated. Actually, I usually rest the canister near the fire just to hear everybody #&%!$.”

“They are having a similar dicusion on the VFTT board. That is where I read the copper thing.

Canister stoves configured as hanging stoves have been traditionally popular in climbing and mountaineering since they are the only stoves I know off that don't require a flat surface and are the safest to use in a tent. Usually the hanging rig has a windscreen and the lack of contact with the ground helps the canister keep pressure. There's also the trick where a small copper tube is taped to the canister so that it sticks up into the flame helping to keep the canister warm- a trick that comes with a series of warnings as it can lead to explosive results.

http://www.viewsfromthetop.com/forums/showthread.php?t=4375”

“ya trailhound, the jetboil system comes with a little 8 oz. plastic cup. i was thinking that it might work great for what you're talking about, except i would just use the jetboil to heat up the water then pour it into the plastic cup, then put my cozy over the cup and canister.”

“that is a very cool idea zac.

if done with a little bit of common sense, it should be completely safe.”

“a jetboil is cool but why bother with one. You get to camp, setup the tent, someone has built a fire. You break out the jetboil, boil water in less than 30 seconds. You eat before anyone else then you sit and sit and sit till bedtime...what is the hurry??? your not going anywhere except to bed.”

“i like it cause of the way the whole system is integrated. it makes for a very neat and tidy setup.”

“sacco - in a prior life were you known as gear slut?”

“One cold morning I wrapped my windscreen too tight around my Campgaz 270 and blew out the top of the canister and melted the bottom plastic parts of the stove. Had to trash it.

On question: How do you boil water to pre-heat the canister so it will burn? Sound like propetual motion to me.”

“HOI, ya i'm def. a gear slut, but never used it as a handle.

BS- when you first take your canister out of your coat or sleeping bag it will be warm and effective.

boiling a couple oz. with a jetboil will prolly take 10-20 seconds.
then you pour that into the cup, set the stove in it and go for real.
the water in the cup will be 212* and cooling rapidly, but should maintain enough warmth to keep the canister working o.k., especially since a warm canister will boil 2 cups in about 2 minutes.”

“BS - you mean catch-22.

Ewker - yup. That's why I'm happy with my pepsi stove. Takes longer, but who cares I'm there for the relaxation and scenery.”

“sacco, I can put my pocket rocket, fuel cannister inside of my cookpot. It is very small when fitted together, probably smaller than the jet boil.
last edited: 12/02/04 2:21:06 PM”

“prolly is ewker”