Gear Review: Butane Canister Refill Tool

Update 13/05/13: It has been noted by someone that the company's policy of shipping their adaptors in simple sealed, unpadded envelopes can cause problems - the unpadded envelope may rupture, leading to package loss. I suggest voicing any concerns with shipping to the owner.

An $8 piece of equipment which I highly recommend to any canister stove or lantern user is this butane canister refill tool. I managed to find it from the Camping In Taiwan website/webstore, here.*
The bayonet-to-threaded refill adapter
With butane, there are two standards: the wide and squat EN417 threaded style canisters used in camping applications, and the thin and tall bayonet-style butane canisters often used in home applications. This above tool allows anyone to refill their isobutane/butane blend EN417-threaded canisters with the bayonet type butane cartridges. The benefit of using these bayonet cans to source fuel is obvious: they are cheap, cheap, cheap! But, because they have a bayonet fuel mount, then this adapter is needed. The adapter converts the large nozzle on these butane cartridges into a smaller nozzle - just large enough to fit into an EN417 valve and refill your favourite isobutane cartridge. 

If you are partial to using the small isobutane canisters (like me - I always use the 113g/4oz. cans), so that you aren't carrying the heavy and larger 227 or 450g cans, then using this refilling adapter will save you even more. Lets do some math:

MSR Isobutane (113g): $4.90
Primus Isobutane (450g): $10.00
North 49-branded Bayonet Canister (227g) : $2.99
Generic Bayonet Canister (227g): $1 to $1.50ea (look for these in 4-packs @ your nearest Asian food market)

These work out to (g per $):

MSR: 23.1 g/$
Primus: 45.0 g/$
North 49: 75.9 g/$
Generic: 227.0 to 151.3 g/$

The substantial savings become obvious when comparing like that. Note also how much more you get per dollar when using the larger isobutane canisters compared to the smaller ones. Asian markets carry lots of the bayonet cans at dirt cheap prices, since curved woks won't work on regular electric stove elements, and the butane home ranges are often used instead. But seeing as I don't live near any Asian food markets, I recently have relied on Canadian Tire's North 49-branded bayonet cans as fuel (and sadly, have been paying the mark-up on  price).
The break-even amount I have found is 2 full refills, using my MSR 113g and the North 49 refills. The adapter has already paid for itself a few times over. 


Its just a small piece of machined aluminum and two rubber seals. Weight: 3g. 

Here's how you use it. You'll need a kitchen scale, the adapter(duh), a threaded isobutane canister, a butane refill, access to a freezer and a marker. 

1. Weight a full EN417 isobutane cartridge. If you don't have a full can, you can often find the full weights online. I have recorded this weight on the can's bottom, for future reference:

232g ---> the mass of the butane gas (113g) + canister itself ( 119g)
2. After a few weeks, once your can has been mostly used up, weight it again:

My refill apparatus, with mostly empty MSR cartridge ready to be refilled.
In my case, a fully empty MSR canister would weigh ~119g
3. Now, put the empty can into the freezer, and let it chill. This will help create a pressure difference, and drive the butane into the canister far more quickly.



4. Remove from freezer, and place the adapter into the valve hole.



5. Take the bayonet can and place it into the orifice in the adapter. Press down firmly. If you don't it may leak a bit of butane gas (you'll smell it). Hold it down for a few seconds.


The connector should look like this when ready to go to the next step. 
6. Place the refilled can onto the scale, less the adapter. Aim for a similar weight to that of the full canister. Try not to go over. Under filling by any amount is fine, and overfilling by a few grams shouldn't matter either.

Refilled MSR 113 Cartridge. In reality, the full weight was
to be 232g - it is really easy to over shoot the target.
As in the above picture, I've managed to over fill. By adding these extra 11 grams, I have increase the total fuel by ~10%. Since this refilled can is just pure butane now, instead of the usual isobutane/propane mix, the cold-weather performance should be noticeably less exciting. Butane boils at 0C @ sea level, and so this technique will really only work for spring/summer/fall use. Isobutane boils at -12C, and Propane boils at -42C, and so these fuels should work much better in the cold.

However, this allows us to exploit the higher boiling point - we *can* over fill by some degree with impunity. This can occur without the canister bursting because pure butane won't make as much vapour pressure at room temperature as isobutane/propane will. Slightly overfilling is a good way to cut down weight if you should need more fuel - more fuel for less space and per packaging weight. A way to do this with minimal risk is to let both cans reach room temp, then try at filling a little more. The pressures should equalize to a safe level, and you should still get a little extra fuel added. BUT if something does go wrong, I don't take any responsibility.

* This is not an advertisement for Camping in Taiwan, nor have I had any compensation for this review.

Comments

  1. Great info. Thanks! Ordered mine this week.

    ReplyDelete
    Replies
    1. How do I order one of these ?????

      Delete
    2. My bad --- the hyperlink located at the top of the page (click the word "here" at the end of the first paragraph) expired. Fixed now; clicking that link should bring you to Camping In Tiawan's sales page for the item.

      Delete
  2. No problem. I am always glad when I can help someone along with making an informed decision.

    ReplyDelete
  3. I have Coleman lanterns and Coleman fuel canisters and I have butane stoves and the spray can style fuel canisters. I would like to be able to couple the Colman canisters to the stoves. Anybody know where to get such an adapter ?

    ReplyDelete
    Replies
    1. If by Coleman fuel canisters you mean the bulky propane canisters, then I'd recommend searching for a "propane refill adaptor". Otherwise, there are two ways to go about using the spray-can/bayonet style canisters. Refilling is one way (which I use)and another way is by using a direct can-mount adaptor to convert the spray-can style to En417.

      Some (e.g., Hikin Jim from Adventures in Stoving)recommend avoiding direct-mounts as they can leak easily. I can't advise on that first-hand, though.

      Delete
  4. I thought this was a great review. I ordered 2 adapters, shipping was very quick. Unfortunately they were shipped in a letter envelope with scotch tape around it. The envelope arrived
    empty of course. when I emailed the problem I was told "to bad
    the parts were in a carton and it was stolen by the postman" this even though I sent pictures of the envelope and the baggie where the parts were squeezed out and no carton could fit through the hole. BUYER BEWARE THIS IS A RIP OFF FOR U.S. BUYERS. BAD PACKAGING or worse. I ship 1500 packages a day. This would never be sent by my company this way

    ReplyDelete
  5. Too bad to hear of such an experience. I do remember mine being shipped in an envelope as well, however, and thought it was a bit weird too.

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  6. Nice article. Your idea about overfilling is potentially dangerously wrong though. Overfilling has nothing to do with vapor pressure.

    Let's consider it. A normal gas can should only be filled to 85%. Let's say (just making this up) that at room temperature butane has a vapor pressure of 4atm and isobutate is 6 atm and the cylinder can hold either just fine. Ok now if you fill one of each to 95% what are the pressures? They are exactly the same, 4atm and 6atm. It doesn't change regardless if the can is 85% full or 95% full!

    You might think "Great, then you're right overfilling isn't related to pressure so long as the canister can handle each gas, but then why are you saying this is dangerous". To answer that you must understand the real problem with overfilling. It is not a problem of vapor pressure but of liquid expansion. As the temperature rises the vapor pressure rises (but we know the canister can handle that for reasonable abuse) but ALSO liquid itself expands. This doesn't follow an ideal gas curve and just depends on the liquid. Once there is no more room for gas at all, then watch out!

    I don't know the liquid expansion properties of butane vs isobutane, but just saying "the vapor pressure is lower so it's safe to overfill is NOT RIGHT". You might think it was fine but maybe you never left both in a hot car on a really hot day yet. Overfilling can be dangerous if not done carefully. Make sure you give safe advice.

    -Dan

    ReplyDelete
    Replies
    1. Actually the way I meant to phrase my conclusion is that refilling can be dangerous. The good news though is these canisters are obviously designed to fail by expanding. I'd rather not test it though.

      -Dan

      Delete
  7. Thank you for the info :)

    ReplyDelete
  8. Thanks for your kind review, we really appreciated it.

    On the earlier comment about missing item and packing in a taped sealed enveloped was to save your freight cost. This is not the first time we had this problem with Buyers from USA. Our biggest customers are from Russia and Eastern Europe and we never have this problem, however it always US buyers telling us they received empty package.

    I hope future buyers from USA do understand our part. We are not trying to prove our fact but if you can watch this video, USPS has a problem itself https://www.youtube.com/watch?v=sePdx3TJskU

    ReplyDelete
  9. Thanks for the info. On the same lines, I have found that a needle adaptor for inflating footballs with a bicycle pump works as well, if you cut the needle down to about 4mm, and make a small cut with a hacksaw to let the gas flow through the side of the needle. A couple of small o-rings to seal it all, and away you go.

    ReplyDelete
  10. Is there no adapter for filling the cartridge with bulk gas bottles

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  11. I recently bought one of the adapters from Camping in Taiwan and he is now reinforcing the mailing envelope with tape. Not as good as a padded envelope, but at least there is now a much better chance of making it through the mail without the envelope getting torn and the adapter getting lost.

    ReplyDelete
  12. can you possibly post detailed pic of this adaptor with measurements? i would like to machine a few of these out to hand out as gifts to some backpacker friends. I would rather make them than go through the hassle of maybe not getting them at all.

    ReplyDelete
    Replies
    1. If you do make them, let me know and if they work I will order a few from you. Rather have US made. Don't understand why we have to go foreign to get what should be made hear and better price.
      mogundrum@gmail.com Thanks, Mo

      Delete

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