Of course it's possible to refill backpacking type gas canisters. But what are the real risks? What are the practicalities? Is it even worth it?



Please join me as I explore Refilling Gas Canisters

HJ

I would advise against refilling gas cylinders that are intended to be disposable.

When a container is filled, it is most important that it is not completly full, in order to allow room for expansion.
If the container is overfilled, then even a modest increase in temperature may cause it to burst.

There is also the risk of filling a butane container with propane or with a butane/propane mix which has a higher pressure.

The risks may be somwhat reduced by
Only filling on a hot day, in order that subsequent temperature increases are unlikely.
Only partialy filling
Keeping re-filled containers outdoors
Not keeping them long term.

Refilling should be done, if at all, outdoors due to the risk of leakage.

The best advice though, IMO is dont.

AFAIK in some states of the USA it is a federal offence to transport refilled disposable gas canisters.

I wonder why there is no adapter for the 110 g butane canister: a folding three-legged wire frame to replace the backpack canister as a stove support and a flex tube to attach the cheap butane canister directly to the stove?

Not a very good idea. If I really want to save money I will simply build a campfire. I don't do that much any more, but I have cooked many a meal over one.

Somebody filled the canisters in the first place.

How did they do it?

Copy them.

Most likely, it isn't economically feasible to have the same hardware and procedures they used. It certainly isn't feasible for me to pressure-test and recertify them at home.

Adam,

I wonder, did you read my blog post at all?

I specifically addressed overfilling. I specifically addressed the proper mix of gasses. I specifically addressed safe vapor pressure.

If it varies state to state, then it is not a Federal offense. The US Department of Transportation (DOT) regulates interstate commerce. Transportation across state lines is within their jurisdiction, and my understanding is that DOT does prohibit such transport. I so state in my blog post.

HJ

Do you mean something like this: Three Legged Butane Adapter?

I find that it's easier (at least for me) to do the fiddling at home rather than fiddling with an adapter in the field. Also the adapter weighs more (78g) than many stoves (MSR MicroRocket, 73g), so weight wise it doesn't appeal to me. But that equation will be different for different folks.

However, if one were out on a long distance hike, carrying the adapter would mean that one could use either type of fuel, which might be an advantage. I've seen the butane canisters in a lot of grocery stores, stores that I've never seen a BP'ing type canister in.

HJ

Well, it's definitely hiking with the training wheels off. You can do more, but you can also get yourself into a lot more trouble.

I ran everything by an engineer (one who burns hydrocarbons for a living) and a physicist. Clean bill of health. There are dangers, but not inordinate given the type of gas used, the quality of refilling rig used, and the procedures used.

HOWEVER, risk assessment is a very personal thing. If there's any doubt in anyone's mind, then I wouldn't do it. A lot of the time, I post to show what can be done. Most people will never need to use many of the techniques I'm showing.

I'm working on some stuff for extreme cold weather right now (below -35F/-37C). Just going out in that weather is in and of itself risky.

HJ

Why would anyone be willing to play with fire like this (pun intended) to save a few cents? It boggles my mind. If the few cents you might save by refilling something not meant to be refilled are that important to your financial situation, I would recommend using an alcohol or wood burning stove instead of a pressurized gas one.

But if you insist on refilling your cannisters, be sure and yell "Hey y'all, watch this!" before you begin. That is the universally recognized warning phrase that you are about to make your bid for a Darwin Award. Others can clear the area accordingly.