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Thursday, December 29, 2011

100% Propane for Backpacking? YES!

What's the "holy grail" of canister gas for cold weather backpacking?  100% propane.  Propane is the best.  Plain butane won't vaporize below 31F/-0.5C.  Even isobutane just sits there and looks at you below 11F/-12C.  But propane?  Propane vaporizes all the way down to -44F/-42C.  Sweet!

What's that you say?  Propane is only available in those big heavy steel cylinders that are 16.4oz/465g net weight?  And the total weight is even more than that?  And you're not about to carry that on your back?

Hey, I'm with you.  Don't blame you a bit.  Those big green steel cylinders are just impractical for backpacking.  Too bulky, too heavy, and the stoves that go with them aren't any better.  But what if there were a better way?

Introducing the Bernzomatic Power Cell.
A Bernzomatic Power Cell
Take a close look at that label
A Bernzomatic Power Cell is 100% propane
That's propane baby!

But will it work with backpacking stoves?  Let's have a look.
The connector on a Bernzomatic Power Cell is a standard 7/16 UNEF threaded connector
That's a standard 7/16 UNEF threaded connector, the same one used by backpacking stoves.  Let's try it out.
A Snow Peak GS-100 stove on a Bernzomatic Power Cell
Well, I'll be danged.  Sure enough, it works.  But now you've got an upright type canister stove mounted on a long, slender bottle.  No way is that going to be stable.  We're back to impractical again. What to do?

Well, what if you could separate the burner from the bottle?  You can -- if you have something like a Brunton Stove Stand.
A GS-100 stove connected to a Bernzomatic Power Cell via a Brunton Stove Stand
Well, that's an improvement, but that canister is still a little on the tippy side.  Can't we just lay it down?
A Bernzomatic Power Cell laying on its side.
As a matter of fact, we can.  And, in case you can't see it in the above photo, that stove is on and in use.
 

Warning:  When you lay this canister on its side or turn the canister upside down, you are feeding liquid propane into your stove.  Burning liquid propane can be extremely dangerous.
To play it safe, you should follow the manufacturer's recommendations.  The manufacturer recommends that the canister always be used in the upright position.  See the full warning at the bottom of this post before you try laying the canister on its side or turning the canister upside down.
A close up of the flame of a GS-100 stove running on 100% propane from a Bernzomatic Power Cell
Now, I started with a completely full canister, so by putting the canister on its side, I should be getting liquid feed, the kind of feed you'd want to use in cold weather.  But, just to be sure, I leaned the canister up against the hillside.
A Bernzomatic Power Cell, completely inverted
And how does it work when completely inverted?  Just fine thanks.
A GS-100 stove running on liquid propane from a Bernzomatic Power Cell
The really interesting thing about these tests I ran with 100% propane is that I made absolutely no modifications to the stove or stove stand in any way, shape, or form.  In other words, I was able to run the stove on liquid propane (which is what you get when you invert the canister) without adding any pre-heating device.  I ran my tests in weather that was about 50F/10C air temperature.  In colder weather, a device to conduct heat from the flame to vaporize the fuel before it reaches the burner head may be needed.  At the temperatures I was operating in, the normal properties of propane were sufficient to vaporize the fuel.  I experienced no flaring.  I did allow the stove to warm up before inverting the canister.

There you have it, ladies and gentlemen, practical  propane for backpacking, the holy grail of cold weather canister stoves.  You saw it here first, on Adventures in Stoving.

OK, but now the bad news.  These are hard to find.  They are out there, and they do exist, but they aren't widely available.  But they're very worthwhile if you can find some.  It appears that Bernzomatic may no longer be making these, so once the existing supply is gone, that may be it.  Grab 'em while you can!
UPDATE 12 Jan 2012:  A thoughtful reader wrote Bernzomatic.  Bernzomatic has indeed discontinued the PowerCell (PC8).  The only such canisters available are the ones currently on shelves.  Once those are gone, no more will be available.

WARNINGAny use of a fuel or a stove in a manner not recommended by the manufacturer may be dangerous or even deadly.  You may also void any warranty and/or nullify any legal protections you might otherwise have.  The preceding blog post shows techniques that are inherently dangerous.   Inverting the canister is against the manufacturer's recommendation.  Burning liquid propane can be extremely dangerous.  If you invert (turn upside down) the canister or lay the canister on its side, you will get liquid propane. Screw up here, and you may be cooking a lot more than your dinner, get it?
The author mentions these techniques solely because he believes that they might be of interest, but the author does not warrant in any way that these techniques are safe.  Indeed, these techniques are not safe and are by their very nature dangerous.  Use of these techniques may lead to property damage, great bodily harm, or even death.  The author does not recommend the techniques shown in this blog post.  If you decide to use the dangerous techniques shown in this blog, that is your decision, and you must accept that you have deliberately chosen to engage in a dangerous activity. 

HJ

Technical Appendix
Net weight:      226g/8oz of liquefied propane.
Gross weight:    365g/12.87oz (about 3/4lbs in other words)
Empty weight:    139g/4.90oz
Connector type:  Standard 7/16 UNEF threaded with a female Lindal type valve.
Manfucturer:     Bernzomatic
Stove stand:     142g/5.00oz

9 comments:

  1. WOW, that is cool! It would be ideal for sub-zero adventures when paired with a stove featuring a generator tube. Nice find, Jim! Now everyone else just has to find those fuel cans.

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  2. EXACTLY, Josh. You were absolutely the first person I thought of who would need some of this. You could ditch the hassles of white gas/kerosene if you can find a supply of these. Pretty sweet!

    If you field test these, please remember your ol' buddy, Hikin' Jim, and let me know how it goes. We just don't have the low temps you do for me to give them a REAL test.

    HJ

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  3. I was at the local True Value hardware store this morning and, surprisingly enough, they had some of these propane canisters on the shelf. The bad news was the price. They wanted $8.50 for one 8 oz. can of propane. With the one pound cans selling for around $2.50, these won't be on the market for long. I don't see any reason for someone to buy a propane torch that uses these fuel canisters when they can get a standard propane torch and fuel for much less money. $17.00 a pound might not be out of line for backpacking stove fuel, but I doubt that enough people will buy it to keep it on the market.

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  4. Bill,

    My understanding is that they are ALREADY discontinued. All that's out there is existing stock, and once that's gone, that's it. If you have any interest in winter backpacking gas stove use, buy those canisters now.

    HJ

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  5. Have you tried this inverted with a stove like the MSR WindPro that has a preheat tube for the fuel going around (over) the burner?

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  6. Hi, Mark,

    I think you posted on BPL also, yes? If propane will vaporize with no preheat mechanism at all, then it will definitely vaporize if there is a preheat mechanism. The the preheat mechanism can only make things better. I'll try it if you like, but there's no need to experiment. I know it *will* work great.

    HJ

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  7. How were they doing it w/out a heavy gauge steel canister?

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    Replies
    1. That is a very good question. Smaller gauge cylinders are innately strong; no doubt that's part of it. They also have to have a sturdier bottom and crimp. Interestingly, they also have a different valve crip area than most cylinders (like the 100% butane ones used in the restaurant industry). All that said, I can see some things that are different, but other than those general observations, we don't really know. Inasmuch as these have been discontinued, it's probably not worth pursuing.

      HJ

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