I recently bought some adapters off ebay to convert the screw mount adapter of lightweight hiking stoves which run off the squat butane mix cannisters to the butane cartridge gas canisters used by cheap portable stoves. Turns out it is workable, but probably not the most practical.
The idea is that butane cartridges cost around AU$6 for a pack of 4 250g cartridges, while the squat butane mix cannisters cost around AU$10 for a single 220g cannister.
The two applications I had in mind were a lightweight kovea stove, and a small gas mantle lantern. The lantern is more intended for car-camping use, but the stove is a for hiking. Whenever I’m car camping I’ll bring the big cartridge stove along as it’s easier to cook on.
Before getting into the adapters themselves, it is worth noting the differences between the cheap gas cartridges and the more expensive hiking cannisters. The cheap cartridges usually contain 100% butane, while the cannisters usually contain something like 80% butane, 20% propane. The key difference here is the 20% propane in the more expensive squat cannisters. Butane, it seems, boils at -0.5 degrees Celsius. Fine if you live in Queensland (which I do), however if you’re in in a cooler climate (or up a mountain or somewhere it gets to close to zero degrees Celsius) you’ll run into problems. This is the same reason cheap butane cigarette lighters won’t work if it’s too cold. The more expensive squat cannisters address this by containing 20% propane, which happens to have a boiling point of around -42.09 degrees Celsius. Why not just use 100% propane? Well, seems as it has a lower boiling point, the vapour pressures in a container of 100% propane can get much higher than that of butane. This is why butane cartridges are essentially aerosol cans, whereas BBQ gas cylinder are heavy steel. I guess the manufacturers worked out that 20% propane, 80% butane was a sweet spot in terms of boiling point and container weight/cost.
So, the moral of this is that at low temperatures, the cheaper cartridges won’t perform as well/at all compared with the more expensive butane/propane mix cannisters.
I bought two different adapters to trial. The first is a small cylindrical adapter that sits directly on top of a cartridge and couples to the screw mount.
I’ve found this one works really well for the lantern. As the lantern isn’t top heavy there’s no worry of tipping, and the lantern can even be hung from its chain quite nicely. It works well for the stove, but is a little unstable since you’ve got your cooking pot/cup up so high on a cylinder with such a narrow base. The cartridge coupling is a plastic job, with an expanding collar to secure it to the cartridge.
The second adapter has the screw coupling on a wide tripod base, and a hose running off to the cartridge coupling This coupling is a simple pressed steel job, which is functional, but it can be a bit difficult to get on and off. I much prefer the expanding collar design of the smaller adapter. I noticed that using the stove on this (which is the logical option, since it provides a nice stable base) give a bit of an uneven flame. It kind of pulsates in size. In addition, it does not pack down very small unless you unscrew the steel adapter plate – kind of irritating.
So for me, the compact inline converter is a winner for use with the gas lantern, which i’ll use when car camping. As for stoves, if I’m car camping then I’m going to be using a bigger stove which uses the cartridges directly anyway. If i’m hiking, then i don’t want the extra weight and space of a converter, and the gas issue clinches it.
Some background reading on gas mixtures and stoves: