Stove tests

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Banquo

climber
Amerricka
Topic Author's Original Post - Feb 3, 2016 - 04:54pm PT
I really like my Jetboil stove when I am in the back country except for the Isobutane fuel. As anybody who has ever tried to use isobutane in cold conditions, it sucks as a stove fuel. It isn't even very good in warm conditions if you are going to run your stove for very long since the canister cools down and the fuel supply slows.

At 70 degrees (F) the vapor pressure of butane is 17 psi while Isobutane is 30.7 psi and propane is 110 psi. The vapor pressure goes to zero at 30 degrees for butane, 11 degrees for isobutane and -44 degrees for propane. Butane and isobutane simply won't evaporate to power your stove when the canister gets down in the freezing range. The little canisters use some mix of propane and isobutane but what happens is that in cold weather, the propane burns off first and you end up with a partially used canister that won't run your stove. 20% propane and 80% isobutane is common. They use less propane because the containment pressure is less and they can make the canister thinner and lighter. Isobutane/propane stove fuel is a compromise and I think a poor one.

When I am out in cold weather, I generally use a white gas stove because an isobutane/propane stove is useless for melting snow. White gas stoves are fussy and more trouble to use though.

What I want is a propane stove so I can just turn the thing on in cold weather. (Even a propane stove won't work if it gets really cold but I am going to stay home if it gets that cold)

I bought a propane adapter for canister stoves and tried it out. Here is what I found. The tests were done in my backyard today with air temperature in the mid 50's and overcast. Each test brought to a full rolling boil 16 ounces of tap water from the garage in my Jetboil stove.

Test 1
Jetboil iso-fuel in a nearly empty medium size canister.
Beginning weight of canister 7.2 oz (205 g)
Ending weight of canister 7.0 oz (199 g)
Fuel used 0.2 oz (6 g)
Time to boil 3m 50s

Test 2
Primus propane 1 lb cylinder about 1/2 full.
Beginning weight 1 lb 10.1 oz (740 g)
Ending weight 1 lb 9.8 oz (733 g)
Fuel used 0.3 oz (7g)
Time to boil 2m 42s

Test 3
Full MSR 80/20 Isobutane/propane medium canister
Beginning weight 13.2 oz (375 g)
Ending weight 1 lb 13.0 oz (368 g)
Fuel used 0.2 oz (7 g)
Time to boil 2m 58s

The propane was a notably faster way to boil water than either canister while fuel usage was about the same. The propane pressure was a bit high for the stove and it will nearly blow itself out if I open the valve all the way which is probably an inefficient burn producing a lot of carbon monoxide. I ran it at what appeared to the the highest flow with a clean burn but efficiency might be best if the valve was closed down a bit more however this will also no doubt make it slower. The propane pressure can push out a lot of fuel very quickly and care must be taken starting the stove.

If you try propane in your isobutane/propane canister stove, barely crack open the valve when lighting the stove. Opening the valve normally and clicking the piezo igniter produced a small explosion.

The net/gross weight for the fuel containers are:
1 lb propane cylinder 465/852 g or 55%
Isobutane/propane canister 227/375 g 61%


Happiegrrrl2

Trad climber
Feb 3, 2016 - 05:09pm PT
I guess the thing I would wonder about is the weight of the propane canister compared to Isobutane. For car camping I just don't see any reason to go without a 2 burner stove, but if I am packing in somewhere(which I have never actually done so what good is my opinion) I would probably want the lighter weight can.


As a tangent - I finally bought a decent 2 burner stove. I got eh Camp Chef Everest model and it is F.A.N.T.A.S.T.I.C. For years I had the cheapo Coleman like stoves and suffered the wasted fuel in cold just to boil water, forget heating a real meal. I haven't timed this stove, but am guessing I boil enough water for 2 big coffees in less than 2 minutes. Each burner is 20,000BTUs, compared to anywhere from 6000 to 12,000 for the cheaper stoves. Paid $99 for the unit, but it is usually more.
fear

Ice climber
hartford, ct
Feb 3, 2016 - 05:34pm PT
I've used a hanging isobutane canister rig down to 0 degrees (ambient inside the tent).

Worked great. For years I had a little copper heat exchanger I made out of smashed copper tubing (the thin stuff for like an icemaker) that I ran from the flame down to around the canister. You've got to play with it a bit but it did the trick. To hold the tubing against the canister I had a neoprene sock lined with aluminum foil.



Higher altitudes help. This was used around ~10-13k feet.
Wedberg

Mountain climber
Bishop
Feb 3, 2016 - 05:50pm PT
Interesting tests. Thanks for sharing.

At 70 degrees (F) the vapor pressure of butane is 17 psi while Isobutane is 30.7 psi and propane is 110 psi. The vapor pressure goes to zero at 30 degrees for butane, 11 degrees for isobutane and -44 degrees for propane.
I'm wondering if these psi numbers change at different altitudes.

I use white gas for all winter use and most summer trips. When I use canisters I've had my best luck with the MSR Reactor stove and the MSR fuel you've used. I've used the Reactor as high as 19,500' on Aconcagua and boiled a liter of water in just over 4 minutes. The fuel was the butane/propane mix.

On Himalayan peaks camping at 22000'+ I've used those Coleman propane canisters and the butane/propane mix (70-30). They both worked reasonably well but I'd but the edge to propane, which seems to be consistent with your tests. I could melt snow/ice for water in a reasonable amount of time and heat up simple meals.

Risk

Mountain climber
Olympia, WA
Feb 3, 2016 - 07:10pm PT
Hocking- had that same Bluet stove until someone discovered my cache on the JMT near Clark Point and stole it. In 1986 I was a "trail guard" up there, mostly sitting in a lawn chair, reading or writing poetry, sketching, and sipping hot tea in an awesome spot with an overhang rock for shelter, when necessary. My svea stove still works great. What about the svea stove?
rottingjohnny

Sport climber
Shetville , North of Los Angeles
Feb 3, 2016 - 07:23pm PT
Only stupid Americans use a French Stove...
franky

Trad climber
Black Hills, SD
Feb 3, 2016 - 07:53pm PT
I've never been able to figure out why so many people talk about altitude changing the performance of their stoves. I've always assumed people were just confusing the effects of temperature with altitude.

del cross, are you suggesting that because of the increased gauge pressure, the canister is evacuated quicker resulting in increased evaporative cooling and decreased performance? I suppose that could be an explanation.

Banquo

climber
Amerricka
Topic Author's Reply - Feb 3, 2016 - 08:28pm PT
The pressure inside the canister is a function of temperature. The pressure outside is a function of altitude. The stove works on the gauge pressure or the difference in pressure between inside and outside the canister. With constant temperature, a canister stove should work better at higher altitude so long as there is enough oxygen.

It's kind of a silly test anyways since that stove isn't designed to use propane.

Why is it kind of silly? It works really well I thought.
franky

Trad climber
Black Hills, SD
Feb 3, 2016 - 08:41pm PT
Yeah Banquo, I get that of course. But people talk of decreasing stove performance at altitude, which for the reasons you mentioned has never made sense to me.

Just curious if there was some explanation I'm missing. Like I said, I've always assumed it is simply the user confusing the effects of temperature with altitude.

Not to hijack your thread though, that adapter looks cool, and the weight of a propane canister seems better than added weight and complexity of a white gas stove.
Ghost

climber
A long way from where I started
Feb 3, 2016 - 08:52pm PT
I've got a couple of MSR stoves that are probably older than some of the posters on ST. They'll burn any flammable liquid, their performance is unaffected by temperature, and they're light.

Yes, when the sun is out, and you're sitting around the bivi site in shorts and a T-shirt, some kind of gas-canister setup probably works fine. But when you need real heat...
Banquo

climber
Amerricka
Topic Author's Reply - Feb 3, 2016 - 09:28pm PT
I will admit that my favorite stove is a Svea 123 I got in 1972. It's a noisy little rocket and has never failed me. It's been on at least 4 continents with me. I have a little tiny pump for it that simplifies priming.
BooDawg

Social climber
Butterfly Town
Feb 4, 2016 - 02:29am PT
I have been intrigued by the make it yourself beer can stove that runs on alcohol which is said to be great in the third world where alcohol is readily available. Has anyone tested these in real mountain conditions?
Sierra Ledge Rat

Mountain climber
Old and Broken Down in Appalachia
Feb 4, 2016 - 04:24am PT
I used the old blue on Denali back in the 70s. Other than flare-ups, I don't remember a whole lot of trouble with canisters.

One time we were cooking inside, with the stove in the middle of the tent. It started flaring up something awful. Panic took over and my partner threw the stove to me, to throw outside ('cause I was the unlucky bastard sitting next to the door).

I was in a down jacket and down pants, and I fumbled the pass. POOF! went my down.

Thank goodness for duct tape.
Banquo

climber
Amerricka
Topic Author's Reply - Feb 4, 2016 - 07:16am PT
Those numbers are gauge pressure at sea level.

Thanks for the help with that, I didn't do my numbers research very well. A few years ago I did a better job of it but the info was in a spreadsheet that is now corrupted and full of gibberish. I hate computers.

Reilly

Mountain climber
The Other Monrovia- CA
Feb 4, 2016 - 08:22am PT
Like Ghost my MSR from the 70's still works like a rocket and it still has its original seals!
Wait, I didn't mean to imply that Ghost works like a rocket although maybe his boss would like that.
clifff

Mountain climber
golden, rollin hills of California
Feb 4, 2016 - 10:12am PT
Carbon Monoxide Hazards with Backpacking Stoves

Carbon monoxide (CO) poisoning in tents is a real danger for those that use lanterns or stoves in tents and snow caves. CO is an odorless, tasteless, colorless, nonirritating gas formed by the incomplete combustion of stove fuels and has a way of sneaking up on unsuspecting campers. This poisonous gas can cause minor symptoms such as headache, nausea and fatigue, but can also result in long-term cognitive impairment or death. Between 1990 and 1994, there was an annual reported average of 30 fatal CO poisonings in tents or campers in the USA. And considering the frequency and amount of deaths caused by using stoves in enclosed spaces, it appears that the deadly dangers of using a stove in a tent are not common knowledge.

http://zenstoves.net/COHazard.htm

I bet that over 50% of high altitude climber deaths are due to their physical and mental abilities being compromised by carbon monoxide poisoning. They go out and make poor decisions or lose their balance due to CO poisoning. Cerebral and pulmonary edema are due to low oxygen at the cellular level. Carbon monoxide poisoning greatly impairs the delivery of oxygen to the cells.
MattB

Trad climber
Tucson
Feb 4, 2016 - 10:45am PT

Hey boodawg, alcohol pop-can stoves work amazingly well.. best design I've seen is the "penny stove" .... I've made maybe fifty different ones, some cruder, some more engineered. Jet number, size, orientation, pressure can all be altered.

Definitely could be useful in third world situations..

I've used it in inclement situations, no altitude, but should work well, as the old self-pressurizing alcohol mountaineer stoves work the same.

The beer-can stove is a bit fiddly, dangerous (no on/off valve), burns almost invisibly. Has limited burn time. I would never want to use one in a small tent. Best for a one day jaunt on a cold day.

Good info/thanks banquo... how does white gas MSR boil times compare to the canisters?





Banquo

climber
Amerricka
Topic Author's Reply - Feb 4, 2016 - 11:17am PT
1)
Because the stove isn't designed for propane. It can actually be dangerous; didn't you warn of possible explosion?

2)
If you really want to carry those super heavy propane cylinders into the backcountry you might as well get a real propane stove. There are smaller ones available.

3)
Inverted propane/isobutane canisters and a stove designed for liquid feed are a better choice when it gets cold enough. Or white gas.

1) Probably no more dangerous than many stoves. This is a simple opinion and not verifiable.

2) They aren't really that much heavier. The isobutane/propane canister is 60% fuel while the propane is 55% fuel. Of course if you are on a short trip and don't need a pound of fuel, the propane cylinder isn't reasonable.

3) I have an inverted canister stove, it's probably more dangerous than the propane adapter. For example, if you invert the canister (it's on a hose) before the stove warms up, it can flare up in a fireball. I've had more flare ups with white gas stoves than canister or cylinder stoves.

I would like to do some work on white gas fuel efficiency. For short burns, the fuel used in priming may be significant. Also some fuel is lost each time you take it apart and put it back together.

Jetboil makes an inverted stove but I haven't tried it and I really have enough stoves already. The Jetboil cooker is very efficient so my inverted stove and white gas stoves can't take advantage of that.

The 3 or 4 single burner propane stoves that I have seem to be low BTU providers and take forever to boil water. I have a couple Coleman/Century types, one of which I have modified in an effort to make it burn hotter and improve the wind screen. I also have one of the old Swedish 2-leg ones. They all suck.
Banquo

climber
Amerricka
Topic Author's Reply - Feb 4, 2016 - 08:36pm PT
This discussion got me thinking about white gas stoves so I tried two, my old MSR Whisperlite and my really old SVEA 123.

I tried the MSR with a larger pan with lid which fits nicely into the wind screen and should be about as efficient as it can be. For the test I weighed the bottle with pump in place, attached bottle/pump to stove, primed, warmed up, lit, boiled 16 oz of water, disconnected the bottle/pump and weighed it. This is about worst case scenario for wasted fuel since you lose some priming and more when you unhook the hose.

For the SVEA I weighed the stove, primed, warmed, lit, boiled 16 oz water in the same pan with lid and weighed it again after. No fuel loss disconnecting the hose since there is no hose.

MSR
Beginning weight 10.2 oz (291 g)
Ending weight 9.8 oz (280 g)
Fuel used 0.4 oz (9 g)
Time to boil 4m 2s

SVEA
Beginning weight 14.4 oz (408 g)
Ending weigh 14.1 oz (400 g)
Fuel used 0.3 oz (8 g)
Time to boil 3m 50s

The SVEA was faster and used a little bit less fuel. There was a first run with the MSR but it wasn't running right so I took it apart and cleaned it. The first run with the MSR used 0.7 oz (18 g) of fuel and took 6 m 22 s.

Banquo

climber
Amerricka
Topic Author's Reply - Feb 5, 2016 - 11:07am PT
Frankly, your tests seem sloppy and you're too quick to jump to baseless conclusions. You can't really compare fuel usage when your scale has such poor precision. I mean, you really get no better efficiency using your Jetboil than I do with a pocket rocket and a cheap pot? Either your Jetboil sucks or your measurements are off.

Well I think you're a big pooh pooh head.
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