Juggling Fuel Canisters

[cmoulder]

My guess is its not 100% effective. Factor in this loss, the energy to make ice and boil water, and the time I could have spent drinking, and it’s a net loser for me.

You only need heat up the donor can with hot water from the kitchen faucet. Room temp for the recipient can is cool enough... no need for ice. This way it will take a couple of cycles heating the donor can to top off the recipient can, and you have to check weight with a good scale (accurate to 1g) but that's about it.

It is 100% effective, and worth it to me to spend 83¢ vs $4.95 for a canister of fuel. Indeed, not at all practical on a thru but totally doable for many other trips.

[meat803]

[QUOTE=Adfischer;2204805]I found the video below which is talking about refilling DOT39 cylinders. That is where the DOT reg I mentioned came from. I'm not sure camp stoves are considered DOT39 so it may apply, but them seem like they are even thinner and less durable than the 1lb mentioned in the video. You are also (hopefully) not refilling from a 20lb propane tank! I'll stick to the manufacturers cartridge, but I think you are wise to only use them a few times after refilling.

The investigators found the 20lb tank was leaking and ignited by a heater. The fire had ZERO to do with the refilled smaller tanks. What a weak example to use that realistically wasn't connected at all. The tank was stored in a confined space with a leaky valve and not turned off. You would think they would come up with a legitimate example or evidence rather than cheap scare tactics. It wouldn't surprise me if some 1lb propane tank lobbyist snuck this law into a larger bill to maximize profits. They do it all the time without legitimate debate.

[Starchild]

There is a version of that valve that will allow you to (presumably) vent the lower can gas while filling liquid from the upper allowing a much faster fill at the cost of a little gas. IDK if it works well but reviews were positive when I looked at it months ago.

[Adfischer]

The investigators found the 20lb tank was leaking and ignited by a heater. The fire had ZERO to do with the refilled smaller tanks. What a weak example to use that realistically wasn't connected at all. The tank was stored in a confined space with a leaky valve and not turned off. You would think they would come up with a legitimate example or evidence rather than cheap scare tactics. It wouldn't surprise me if some 1lb propane tank lobbyist snuck this law into a larger bill to maximize profits. They do it all the time without legitimate debate.

The confined space was definitely a contributor. I don’t believe anyone snuck something in a law. I have seen enough of those brand new 1lb propane cylinders leak after a single use to know they are not reliable and to me refilling is not a good idea. I have been a firefighter for 30 years and have seen some pretty crazy stuff. People doing stuff they thought was safe for years only to have something go wrong just one time. It’s given me a healthy respect for things like highly flammable gases that make me not want to step outside the manufactures specifications.


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[rocketsocks]

Id really like to see someone juggle a lit canister stove, a porcupine and a sopping wet puffy jacket.

[LittleRock]

Eh, I'll stick with my current approach of giving my nearly empty canisters away to LD hikers or dropping them in the hiker box at a hostel on the last day of my trip.

[Maui Rhino]

Thanks for sharing. I might look into doing this.

Back at the start of this century, I spent 3 years living in a homestead with no running water or electricity. I used propane Coleman lanterns for lighting, and kept a fleet of 20 one pound cylinders. Each week, I would refill them from a 20# tank. I always did my refilling outside, and very carefully checked each cylinder after filling them by sight, sound, and soapy water if suspect. Occasionally, a canister would leak after filling, and I would discard those, but I usually was able to refill them 15-20 times without issue. After 20 refills, I replaced them anyway. I did have 3 lanterns fail and start jetting fuel out by the plastic shutoff valve, but not because of any fault of the refilled canisters. YMMV

[TNhiker]

Id really like to see someone juggle a lit canister stove, a porcupine and a sopping wet puffy jacket.

Oh?

a challenge, eh?

[BuckeyeBill]

Very interesting thread. You have the side of this works well for me vs. the side that this is dangerous. The DOT 39 cylinders discussed in the video are made of a slightly thicker metal, as they are capable of holding slightly higher pressures that ISO butane canisters, so you have to wonder if it is dangerous to refill DOT 39 cylinders, how safe is to refill canisters.

There are tools available that allow you to bleed off, then puncture canisters to mark them as empty. Some people use nails or screwdrivers to accomplish the same thing, but I am not sure this is the safest way to do this. You have to wonder that any canister that can be punctured by basically a can opener, is it safe to refill them without exactly knowing the internal pressure of either canister? There are other ways that I can save money while hiking so I can either use the canister until it is completely empty or giving it to someone in need and opening a new canister. I may change my thinking on this if there were a blow off valve that would release at a pressure below the limits of the canister's safety rating.

Jetboil now has a mini scale (weighs 2.5oz.) you can carry with you to determine how much fuel is left in your canister. While it works best with Jetboil canisters, it can be used with other manufacturers canisters.

Of course the standard "This is only my opinion" applies.

[Brutalguyracing]

I do a lot of refilling of my own canisters with leftovers / butane. Beware, the 110g mass of fuel is referenced against a safe volume and the potential expansion of the liquid when the canister heats up due to weather or use. A canister full when cold, may be overfull when hot. When the expanding liquid (not gas) has nowhere to go, it will deform the canister and possibly rupture. Large propane tanks have a gauge with temp on it to help prevent over filling.
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[Adfischer]

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Exactly. Not worth the risk for the little amount of money saved. If you are going to do this, at least cook away from others so you only injure yourself!

[nsherry61]

. . .You have to wonder that any canister that can be punctured by basically a can opener, is it safe to refill them without exactly knowing the internal pressure of either canister? . . .

Two points to think about on this one:
1) You realize we are talking about essentially the same gas most of us carry without concern in our pocket in a fairly easily crushed plastic pressure vessel called a bic lighter, don't you?
2) Unlike pressurized gas canisters for SCUBA diving or welding where the gas is not liquid and pressures are very high, the gas pressure in our little backpacking fuel canisters is essentially independent of how much fuel is in the canister because the fuel is at an equilibrium gas/liquid state with pressure dependent on temperature, not the amount of fuel. If you add more fuel, you would increase the pressure except increased pressure drives the equilibrium to more liquid which reduces pressure, so the pressure is stable at whatever the vapor pressure of the fuel is at a particular temperature. So use the fuel the canisters are designed for, not other fuels with higher vapor pressures. This is basic physics, which if you haven't had or don't remember, may not make sense, but is why these canisters and stoves work in the first place.

Really and truly, filling you car up at the gas station is probably more dangerous than transfering butane between canisters. And cooking with propane, or natural gas for that matter, is significantly more dangerous, but, most of us do both without much thought because we are familiar with the practices.

[rocketsocks]

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holy yield point Batman, watch it, she’s gonna blow!

[FreeGoldRush]

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Exactly. The Darwin Award is earned when someone heats the upper can too much without having any idea how much pressure is present. It's not like these cans are precision manufactured and designed to last a while. Someone will be using a gas stove to heat the boiling water. They'll pour it onto the can that ruptures right next to the open flame. There is a big difference in understanding the science that makes it work and doing the things to make the process safely repeatable.

After all, BASE jumping is perfectly doable and safe until someone overlooks a minor detail.

[FreeGoldRush]

2) Unlike pressurized gas canisters for SCUBA diving or welding where the gas is not liquid and pressures are very high, the gas pressure in our little backpacking fuel canisters is essentially independent of how much fuel is in the canister because the fuel is at an equilibrium gas/liquid state with pressure dependent on temperature, not the amount of

The difference is that my SCUBA tanks are inspected and (used to be) hydrostatically tested every 5 years. It may be high pressure, but the container is 1) Designed for the pressure, 2) Tested to ensure it is safe, and 3) Always used exactly as designed.

You are correct that this refilling process can be entirely safe with the proper equipment. Cheap, disposable fuel canisters do not meet that requirement, in my opinion.

[nsherry61]

. . .After all, BASE jumping is perfectly doable and safe until someone overlooks a minor detail.

A good comparison. Many people love BASE jumping. Some people would never dream of doing it because of the perceived risk. . . kinda like backpacking too.

Although J-walking is probably a better one. You may never J-walk because of the potential risk or just because you always follow the letter of the law. Kudos to you. Most of us choose to j-walk at times because we decide the risk of breaking this rule is small and the reward of saving a few steps or a few seconds of time is worth the small risk.

Life is a risk. Backpacking is a risk. Among the things we do in day to day life and backpacking, I would suggest that reasonable and informed refilling and using of backpacking fuel canisters is NOT one of the riskier things we do. And, being able to adjust the fuel level in a canister for a particular trip may appeal to some people while saving a few dollars or being less wasteful will appeal to others.

Your choice. Please, don't be too self righteous condemning me for mine.

[FreeGoldRush]

so the pressure is stable at whatever the vapor pressure of the fuel is at a particular temperature. So use the fuel the canisters are designed for, not other fuels with higher vapor pressures. This is basic physics, which if you haven't had or don't remember, may not make sense, but is why these canisters and stoves work in the first place.
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This is all correct. And if you pour boiling water onto the fuel canister and it is not properly releasing pressure then the liquid and gas both heat up. The pressure rises. They were not manufactured to be safe at 212 degrees Fahrenheit without an ability to release pressure. One cannot measure the pressure or be confident it is releasing correctly, so how can this possibly be safe?

[FreeGoldRush]

Your choice. Please, don't be too self righteous condemning me for mine.

It was never my intention to indicate that you personally should not do this. The discussion is simply interesting and I have a different opinion. My opinion is that others should not be instructed to do this, but I'm not upset in the least that you disagree.

[nsherry61]

This is all correct. And if you pour boiling water onto the fuel canister and it is not properly releasing pressure then the liquid and gas both heat up. The pressure rises. They were not manufactured to be safe at 212 degrees Fahrenheit without an ability to release pressure. One cannot measure the pressure or be confident it is releasing correctly, so how can this possibly be safe?

I don't know what temperature the canisters are supposed to be safe to. I doubt you do either. Given that, it would be really stupid to place the canister in boiling water. But, a few tablespoons of boiling water on the base is not heating the canister anywhere close to boiling. And, as was noted earlier in the thread by cmoulder, a person far more experience than I am in the reuse of canisters, and the use of canister stoves for that matter, if you are uncomfortable pouring a bit of boiling water onto the base of a canister, hot tap water is plenty to generate the pressure differential needed to drive the fuel flow.

[Adfischer]

...... Please, don't be too self righteous condemning me for mine.

I dont think anyone is condemning you, others just have a different opinion. My opinion is you can do whatever you want with your stove canisters. You think its perfectly safe, I think it is not. We can agree to disagree.

Where I have an issue with what you are doing is if you use your refilled canisters near others. I personally do not want to be near someone that I believe may be creating an unsafe condition and putting me or my kids at risk. It only takes one mistake or one defect in a canister that is exaggerated by a refill to be catastrophic.