soooo you've got a lot of partially filled iso-butane fuel canisters.......

Block

WKR
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That’s pretty cool^^ I usually just keep the iffy ones in the truck for truck camping
 

OutHeavy

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Be careful with this everyone!! Do it outside. I’ve been to some explosions where people were making butane hash oil and butane gas filled the room without warning. It’s very very dangerous with butane, but I realize these aren’t the same thing either.

I could be way off on this, but definitely is worth the precaution of doing this outdoors.


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Way off? What could possibly make you think that? This is exactly the kind of PSA i'm looking for on this forum. :censored:
 

Gearqueer

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Way off? What could possibly make you think that? This is exactly the kind of PSA i'm looking for on this forum. :censored:

Thanks OutHeavy, I probably shouldn’t have minced my words on the PSA, but there are a lot of experts on flammables out there, and I’m not one of them.


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GatorGar247

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Playing with pressurized canisters of highly flammable gases seems like a bad idea all the way around. I'll just carry two canisters and switch them out. Seems pretty easy and not something to risk life or limb over.

I had a friend loose some eyebrows with a canister/stove explode in his face. Very dangerous.

Good luck kids!!
It's really not that dangerous. You can't over pressure the canister from another canister.. the only thing that will happen is the pressure will equalize.. Think about it . It's not like you are hooking it up to a compressor to increase pressure..
 

Brendan

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The fuels are liquid when pressurized, and you're inverting one and letting gravity do the work. Sometimes people are aiding it by putting one in ice water. It is absolutely possible to over-pressurize one.
 

GatorGar247

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The fuels are liquid when pressurized, and you're inverting one and letting gravity do the work. Sometimes people are aiding it by putting one in ice water. It is absolutely possible to over-pressurize one.
Please explain to me how you can over pressure one by filling it from another? If both canisters are rated for the same pressure. You take a half full canister and put it into the freezer dropping the pressure inside to allow it to be filled.. even then you can't get it cold enough to over fill.. the pressure that is being put into the half full one will equalize off the other half full one .. theres only so much room inside..

I could see it if the doner was larger and higher pressure
 
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Brendan

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Please explain to me how you can over pressure one by filling it from another? If both canisters are rated for the same pressure. You take a half full canister and put it into the freezer dropping the pressure inside to allow it to be filled.. even then you can't get it cold enough to over fill.. the pressure that is being put into the half full one will equalize off the other half full one .. theres only so much room inside..

I could see it if the doner was larger and higher pressure
Gravity. Liquid will still tend to flow from the higher canister to the lower. THere are pictures out there of overfilled canisters bulging from the extra pressure, will have to see if I can find them. Differing temperatures help.

Many, many web pages and videos on people doing it and how to do it safely though.


 

Brendan

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some discussion on it in this thread too referencing bulging canisters and potential to rupture:


not saying you can't do it safely, but it is possible to mess it up.
 

GatorGar247

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After doing more research I stand corrected.. you can over pressure a single use fuel canister but it’s not from just putting too much in it.. The blended fuel canisters have propane and iso-butane in them.. the vapor pressure for propane is a lot higher than then iso-butane . When the canisters are used in real cold weather the iso-butane can burn off first leaving more propane. If the refilled canister is filled with more propane it can cause it to buldge or rupture..
 

Brendan

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After doing more research I stand corrected.. you can over pressure a single use fuel canister but it’s not from just putting too much in it.. The blended fuel canisters have propane and iso-butane in them.. the vapor pressure for propane is a lot higher than then iso-butane . When the canisters are used in real cold weather the iso-butane can burn off first leaving more propane. If the refilled canister is filled with more propane it can cause it to buldge or rupture..

It can be from both the vapor pressure difference, and absolute amount when mixing the exact same blend. Easy to show with a gram scale which many people have done. Basically, invert one over the other and gravity is working against the pressure difference because you're dealing with a liquid. Heat/cool the two containers and it helps speed transfer.

If you're going to do it, refill from the exact same mix, and weigh a full container (brand new, exact same type) to the gram so you know how full to go.
 
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I just use them for truck camping or running my little primus lantern. Its not worth the hazard or potential of creating an incorrect mix ratio for the $5 to me.

Seems kind of like shooting a cracked arrow. Might be just fine doing so until one day its not.
 
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The side of the 4oz MSR says 211grams when full. I've been overfilling by 10-15 grams.

Anyways, put a new overfilled can on the reactor and flames started coming out the sides. I'll be sticking back to the 211 grams per can.

Other then that, I've saved a ton by just using 16oz cans to refill my 4oz. Love this product.
 
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