Canister Refiller -- WARNING

I've been seeing a particular canister refilling device on eBay lately as a "MacCoupler Liquefied Gas Refill Adaptor Gas Charging Valve Inflatable converter" [sic].    This particular device is just downright dangerous and in general should be avoided.  I'll explain why I say "in general" in a minute.

A very dangerous canister refiller.  ** AVOID! **

OK, so what's wrong with this refiller?  Well, in case you don't recognize the fittings, this refiller will refill backpacking type gas canisters from a "bulk" propane tank.

A "bulk" type 100% propane tank

Hey, now doesn't that sound like a great idea?  Hey!  I can take cheap gas out of my bulk propane tank (like for a BBQ) and refill my expensive backpacking canister.  Pennies on the dollar!  Sweet!  What could possibly go wrong?

What could go wrong?  A whole lot, and it could be bad, very bad.  First, backpacking canisters do NOT contain 100% propane.   Standard backpacking type canisters in the US are rated at not more than 20% propane (mixed with 80% isobutane) or 30% propane (mixed with 70% butane).  Propane is a very high pressure gas.  Put 100% propane in a canister rated for only 20 to 30 percent propane and what do you get?  Quite possibly a very nasty explosion.

Oh!  I know!  If my canister is only rated for 20 to 30% propane, I'll just fill it up to 20% of capacity and leave the rest empty!  Duh!  Problem solved.

Uh, not exactly.  When combined with butane or isobutane, propane actually forms a blend.  The resultant blend has a lower vapor pressure than 100% propane.  Odd as it sounds, you'll actually have less vapor pressure in a canister with 20% propane and 80% isobutane than a canister 20% full with propane alone.  Besides, what good is a canister you can only fill to 20% of capacity anyway?

Basically, you should never fill a backpacking type canister with 100% propane.

But what if you filled a canister to  80% of capacity with butane first?  If you filled to 80% of capacity with butane first and were exactingly careful about not exceeding the overall rated capacity, then maybe this adapter would be safe.  I'm not saying that it is safe, I'm saying that there's the possibility that the adapter might be safe -- from the perspective of the mix of gasses.  The adapter might still have other problems in terms of materials, design, and construction.  The very fact that someone put a dangerous refiller like this together suggests that they really don't know about gasses.  I have NO confidence that such a person has the ability to build a refiller that is safe in other respects.  I'm certainly not tempted to buy one.

Putting it into perspective
Now, am I just a "Nervous Nellie?"  Maybe this is actually pretty safe, but you know this is modern society, and we have to protect people from themselves, don't we?

I submit to you that I am no Nervous Nellie.  I refill my backpacking canisters all the time (with butane!!).  I use a windscreen with my upright canister gas stove.  I sometimes use my stove inside a tent.  In other words, I do all sorts of things that manufacturers tell us not to do lest doom and disaster overtake us.  I do things like refill, use a windscreen, and cook inside my tent because I've studied the objective dangers and found them reasonable for a person who is careful and has an understanding of how to mitigate the dangers.  But I will NEVER fill a standard backpacking type canister with 100% propane.  It's just too dangerous.  Period.

This refill adapter is:  NOT recommended (in the strongest possible terms).

I thank you for joining me on another Adventure In Stoving.

HJ

100% Propane for Backpacking II

I've described 100% propane as the "Holy Grail" of cold weather backpacking for canister stoves.  Why?  Take a look at the below table of the vaporization points of the gases used for canisters stoves.

Boiling (vaporization) point
n-butane    -0.5C    31F
isobutane    -12C    11F
propane      -42C   -44F

If temperature falls below the values indicated below, you'll have a liquid not a gas.  Ever try to run a gas stove on liquid fuel? Good luck.  Propane has the lowest vaporization point by far.  When other fuels are rendered useless by cold, propane will still be good to go.

So, why don't backpackers all just use 100% propane in cold weather?  Well, two reasons:  1) most stoves designed for 100% propane are big kludgey (by backpacker standards) affairs that were never intended to be carried on one's back and 2) 100% propane has some seriously high vapor pressure.  Those little thin walled backpacking canisters are not going to safely hold something like 100% propane.  You have to carry a heavy duty canister.

Well, we can't do anything about the heavy duty canister side of things (unless you can find a Bernzomatic PowerCell), but what if you could lose the big kludgey car camping stove?  I mean, that's half the battle, right?

How?  With a Kovea LPG (propane) Adapter which I've covered previously.  In this post, I'd like to talk about the practicalities of 100% propane for backpacking.

First, when I say propane, what's typically available that is portable?

A 100% propane cylinder

100% propane canisters typically look like the above (although they're usually green).  Typically such canisters contain 16.4oz/465g of 100% propane.  Bernzomatic brand contains 16.92/479g for some reason.  The connector is the same on 14.1oz/400g propane cylinders commonly used for propane torches.

Let's have a look at the female connector on the tank.

The female connector on a typical propane cylinder 

If you compare that connector to the male connector on a backpacking stove, you'll quickly see that the two aren't compatible.

A male connector on a backpacking stove (top) and a female connector on a propane canister.

How to bridge the gap?  An adapter.

A Kovea LPG (propane) adapter

The adapter threads onto the top of the propane cylinder.

A propane cylinder with a propane adapter.

Our backpacking stove then screws into the adapter.

A Markill Hot Rod backpacking stove in use with a 100% propane cylinder

What's the problem with this set up?  Well, it's just a tad tippy for one.  And a bit of a trick to shield from wind.  THIS SET UP IS DANGEROUS AND IS NOT RECOMMENDED.

A backpacking canister stove atop a 100% propane cylinder.  This configuration is DANGEROUS and is not recommended.

So, let's change it from an "upright" configuration (as shown above) to a "remote" configuration.  First, we'll need a Brunton Stove Stand (or the equivalent).

A Brunton Stove Stand

There.  Well, that's a little better.  But still, that cylinder might fall over.  This set up is unstable.  Not recommended.

A "remote" set up with a backpacking stove and 100% propane.  This is not stable and is not recommended.

Couldn't we just lay the propane cylinder on its side?  I mean, wouldn't that be a lot more stable?

A backpacking stove running with a propane cylinder laying on its side

Indeed we can, and with 100% propane, it works.  Be aware that when you lay a canister on its side, you are sucking liquified propane out of the canister.  I'm running in weather that is about 45F/7C here, which is plenty warm for propane to vaporize before it gets to the burner.  At some point, as the temperature drops, you'll have to shunt heat from the flame to the fuel in order to maintain vaporization.  I really don't know at what temperature you will need to start shunting heat.   I do know that propane vaporizes at -42C/-44F, so as you approach about -37C/-34F, you'll definitely have to start shunting heat to the fuel to maintain vaporization, but I suspect you may have to shunt heat even before that.

So, there you have it, there's how to use 100% propane with backpacking stoves.

Now, even if we eliminate the bulky, heavy car camping stoves, just having to carry that big, heavy duty 100% propane cylinder is pretty heavy.  Why would anyone want to carry it?

Here are a few possible reasons for going to the trouble to carry 100% propane:
1.  Cold weather -- Mechanical Reliability.   Gas stoves typically are more reliable than liquid fueled stoves.  Gas stoves clog less and have no pump to fail.  One might bring propane so that one could continue to use in cold weather the more reliable gas stove.
2.  Bad weather -- Safety.  OK, you're on the mountain.  A storm hits.  What?  You're going to go outside to cook?  Are you nuts?  In a storm?  You tired of life or something?  Yes, I know the instructions on your stove say "never cook indoors."  I'm sure the corporate lawyer who wrote that really feels your pain right now.  Look, you've got to cook up there on that mountain; Mr. Lawyer doesn't.     Cook inside your shelter.  It's the only reasonable alternative.  Gas stoves don't require priming.  BIG advantage if you're tent-bound even for only one meal.
3.  Cold weather -- Functionality.  Propane will work at temperatures way below the temperatures that the gas blend in a typical backpacking canister will work in.  One might bring propane simply because that's the only gas that will work when it gets cold enough.  Some people prefer gas stoves (or hate liquid fueled stoves) that strongly. Gas stoves typically are more fuel efficient and have much better flame control.
4.  Cost.  At least in the US, a standard threaded 450g backpacking canister of gas typically costs $9.00.  A 465g cylinder of propane is $2.56 if you buy a two pack at Wal-Mart.  An adapter and some cheap propane could be really handy for a night before the trip trailhead camp.  You use your backpacking stove, but you run it on cheap propane that first night at the trailhead.  In the morning, you hit the trail with a 100% full backpacking canister, which, depending on the trip, might allow you to carry a smaller canister or not have to take a second canister.

Even if you don't see an immediate application, it's there if you ever need it:  100% Propane for Backpacking.

Now, words of warning:  Propane has higher vapor pressure than the gas blends used in backpacking canisters.  Higher pressure means higher danger.  You could get flame "lift off" where the flame rises up,  away from the burner.  In that situation, the flame may go out while the gas is still flowing.  You've now got a hot stove with no flame but the gas is still coming out.  This could get ugly.  Gas + air + heat = KABOOM!  So, be careful because:

Propane is a highly flammable and potentially explosive gas.

Backpacking stoves are not designed to operate on 100% propane.  Use at your own risk.  Risk includes loss of property, serious bodily injury, and death.

Here are some tips.  These tips might reduce the risk, but no matter how many safety tips you incorporate, working with 100% propane in a backpacking stove is dangerous.  Period.
a) Hook everything up and listen for any sound of escaping gas.  If you hear any gas, STOP.  Correct the leak before proceeding.
b)  Start with the gas turned down low
c) Turn things up slowly
c) NEVER open the valves fully
In this set up, you are the safety device.  The set up has no inherent safety mechanism.  This set up is inherently dangerous, and you are deliberately choosing to do something dangerous if you copy what I have done.
Adapters open up a whole new world in terms of fuel and stove combinations that can be used. Adapters also open up a whole new world of hurt if you exceed the limitations of a particular set up. Just because you can hook up something up doesn't mean it's a good idea. Above all else, be careful.

Thanks for joining me on another Adventure In Stoving.

HJ

The Kovea LPG (Propane) Adapter

I recently picked something up that turns out to be pretty useful:  A Kovea LPG (Propane) Adapter.  This adapter allows one to run a standard threaded canister gas type backpacking stove off of one of those green Coleman 16.4oz/465g cylinders of 100% propane, you know the typical propane canisters that everyone uses for camping stoves and camping lanterns for car camping.

An LPG (propane) adapter made by Kovea

Whoa!  Running a backpacking stove off of 100% propane?  Couldn't that be dangerous?

Well, maybe, and I certainly wouldn't have bought a no-name adapter made in China, but Kovea is a top gas stove manufacturing company with an excellent reputation world wide.  If Kovea makes it, it's quality, and I wanted to give it a look.  Speaking of which, let's take that puppy out of the packaging.

First impression:  This thing is beautiful.  I mean look at it.  Really nice build quality.

A Kovea propane adapter.  This end connects to a typical 16.4oz/465g cylinder of propane of the type that are used for camp stoves and camp lanterns.

A Kovea propane adapter.  This end connects to a typical threaded backpacking stove.

It is made from really solid feeling metal, so it is heavy (105g), but boy is the thing well built.

Now, notice something.  On the side of the adapter there is a little set screw which helps regulate the gas.

There is a set screw on the side of the adapter to help regulate the pressure.

When I tested the adapter, I didn't need to use the set screw.  In other words, it worked just fine out of the box, but it's nice to know that it's there if you need it.  Now, a word of warning:  propane is going to have a higher vapor pressure than the gasses typically used for backpacking.  Yes, the gasses typically used for backpacking include propane, but not 100%.  Usually propane is no more than about 1/3 of the total mix.

Higher vapor pressure could mean higher danger, so pay attention.  If the pressure is too high, you could get flame "lift off" where the flame is blown away from the burner.  In that situation, the flame will frequently die out while the gas is still flowing.

OK, let me get this straight.  I've got a hot stove with the flame out but the gas is still gushing out.  Um, couldn't that be a little dangerous?

Why yes, as a matter of fact it could.  Gas + air + heat = KABOOM!  If you're lucky, all you'll lose is your eyebrows.  If you're unlucky, you'll be finding out for 100% sure whether or not there really is a God, if you know what I mean.  So, warning:

Propane is a highly flammable and potentially explosive gas.  

Backpacking stoves are not designed to operate on 100% propane.  Use at your own risk.  Risk includes loss of property, serious bodily injury, and death.

The first rule, if you've made the decision to accept the risk of using a backpacking stove with 100% propane, is to turn things down low.  Start low, and turn things up slowly.  There's no law that says you have to open the valve completely, so don't.

The adapter comes with some instructions.

The instructions for the "set screw" on the side of the adapter.

Unfortunately, the instructions are written in Korean, which is not a language with which I am conversant.  Still, it's pretty obvious from the pictogram what the set screw does.

Another diagram shows the method of employment, although it will probably be fairly straightforward for anyone who has used both 100% propane camping appliances as well as canister gas backpacking stoves and lanterns.

How to hook up the adapter (shown in orange)

Just in case you're Korean isn't up to speed, here's what the adapter looks like when you hook it up (below).  Note that the propane canister I'm using happens to be blue.  The canister is blue because of the  particular brand of the canister.  Typically canisters are green, but whatever, the adapter hooks up the same.

A Kovea LPG (propane) adapter attached to a propane canister. 

Your backpacking stove then screws into the threads that you can see on the adapter in the photo above. Inside the adapter is the equivalent of a Lindal valve.  In other words, gas doesn't start immediately come shooting out of the adapter when you hook it up.

A Markill Hot Rod backpacking stove in operation on 100% propane.

Really pretty straightforward, but as with any backpacking stove, be freaking careful.  Always listen after hooking everything up before firing up the stove.  If you hear a leak, proceed no further until you've resolved the problem.  Failure to do so could have catastrophic results.

I'll cover the more practical aspects of 100% propane use for backpacking in a separate post.  In this post, I just wanted to showcase the adapter.

Final warning:  Adapters open up a whole new world in terms of fuel and stove combinations that can be used. Adapters  also open up a whole new world of hurt if you exceed the limitations of a particular set up. Just because you can hook up something up doesn't mean it's a good idea. Above all else, be careful.

Thanks for joining me on another Adventure in Stoving,

HJ