First of all let me say that this is not a practical solution to a real problem: this is the product of an engineer with a little free time on holiday break. I wanted to try to make a light, low-capacity canister for a Lindal-valve stove for use in moderate temperatures. It seems to work after very limited testing.
I noticed that all of my mixed-gas camping stove canisters have 32-mm-diameter crimped-on tops that look a lot like the ones on the small 35-mm-diameter butane lighter refill canisters with capacities of between 1.4 and 2.1 ounces. After a few attempts (and a little picante sauce spillage) I managed to transfer a Lindal-valve top onto a small butane canister.
The valve tops are attached to both types of canisters by mushrooming the parts inside so that the pressure forces them against the upper canister wall. The installation is not meant to be a reversible process. Here's what I did:
Cut the top off of an empty propane-butane canister by poking a hole in the side and using tin snips.
Squeeze the mushroomed part below the Lindal valve enough that it allows the 32-mm top to push up through the canister top and will drop into the butane canister. Be careful not to crack this boundary or it will leak.
gently pry open the outer lip (visible on an un-violated canister) just enough remove the valve assembly top from the canister. This doesn't take much. Be careful not to scratch or re-shape the area below the lip too much.
Now start with the butane canister. The idea is to sacrifice and remove the original valve top but leave the canister undamaged. The mushrooming under the valve assembly is much less severe on the butane canister since the pressure is lower. I used a pair of needle-nose pliers to rip out the valve and center section of the assembly and then pull the rest piece by piece towards the center until it popped off the canister.
Now put the Lindal top valve assembly on the butane canister. There's a rubber gasket that's designed to make a tight seal when the mushrooming of the lower part of the top pulls it tight to the canister, but there's no way I could find to re-inflate the mushroom. Instead, I removed the gasket to improve the mechanical connection and filled the lip with J-B Weld epoxy. The epoxy accounts for about one third of the total weight.
After letting it cure overnight I put in some butane from a small butane canister using a little electrical tape as a gasket. I have an adaptor on order but couldn't wait. Since the tall, skinny canister is not exactly the best shape for a stove base I poked a hole in the ground and dropped the stove+canister assembly to just above ground level. This method has the additional benefit of drawing some of the cold from the canister as it runs and wants to frost over. I heated some water using first a standard Snow Peak canister and then my butane and couldn't tell much difference in this 50-degree F. test. I'll try it again when we get some cooler weather.
The unit that I made using a 2.1-ounce-capacity butane canister weighs 36 grams empty. Of that, 8 grams are the Lindal-valve top, 10 grams are for the J-B Weld. My 4-ounce Snow Peak mixed-fuel canister weighs 98 grams empty. So, I've saved a whopping 62 grams for quick trips when I only need two ounces of fuel in moderate temperatures. There's still a question of whether the pressure will hold up in real-world conditions. Still, it's a fun ongoing experiment.
I'm planning to take it out on a 2-night trip this weekend with a low temperature predicted between 35 and 50 (it could be about anything this far ahead this time of year) and may post results and a better picture then. In case it's not obvious, the can is mostly buried--necessary for stability and heat transfer from the warmer earth to the cooling can
Edited by 41253 (01/22/1812:15 PM) Edit Reason: It seems that although the Photobucket seemed to work at first now it doesn't. I'm leavivg the imgr link which requires an extra click but no subscription. Suggestions welcome
Well I took it out for a quick 2-night trip this weekend and it worked fine. The temperature never got below the 50s. The ground was soft so it was easy making a hole with a stick for it to rest in. Stability would be an issue with hard ground. The pressure is lower than with mixed gas but there was plenty for the cooking I wanted to do: steak, grits, eggs, tea, ... Two ounces of fuel was just right for the trip and it was nice that the container weight was only about an ounce for a total of about 5 oz including the stove.