gas stoves

just bought my first tiny little stove. Whats the go on gas canisters? Bought a 190g of butane. Are these canisters all interchangeable?

I have heard that the ideal canister is something like 80% butane and 20% propane which helps with starting.

All canisters of the same type are interchangeable as long as they are the right type for your stove. I can find 2 190g canisters One is long and skinny The other short and stumpy. The short one is designed to puncture when fitted so cannot be removed until empty. The long skinny one is common for the square plastic picnic stoves but not for hiking stoves although you can buy hiking stoves that take them but they are not popular. The more common gas hiking stove takes this canister http://www.livingsimply.co.nz/estore/style/abe%20gm040-002.aspx The stove that take these canisters tend to be smaller for the same output. In gas mixtures the cheap canisters are butane which is ok above freezing point but you are better buying canisters with a mix of 80%isobutane and 20%propane. They will work in 75% of the weather conditions you might find yourself hiking in in NZ. Below -10C or so you need either a liquid fuel stove or a gas stove that either preheats the gas or can burn it in a liquid feed arrangement.

if the canister fits your stove (if the attachment is the right one) then its interchangeable. There are different mixes of propane/butane but they all work. The ambient temperature makes a big difference in how well the gas vapourises and hence the pressure in the canister hence how fast the stove will heat your pot. Keeping the cylinder somewhere around 20 deg is good. Don't ever let it over-heat. Using a wind shield is a good idea - especially outside - oven tray liners can be cut up if you don't have an old msr style one lying around.

Thank. as a ball park figure, how many days use to empty?

Depends on several factors - output of your stove, how many meals per day you're using it for, ambient temperature, whether you're out in the wind or not, whether you're melting snow for water.... One 230g canister will usually last me 4-5 days below the snow line - that's breakfast, lunch and dinner and a couple of hot drinks. I always carry an additional means of starting a fire in case something stops working (something you should have in your emergency kit anyway)....dehy meals aren't very nice made with cold water :-)

second everything that hutchk wrote; the main factors you can control - get an efficient billy / pot, use a wind/heat shield, don't waste a gram of gas - put the pot on before you light, click off when it boils. Gas stoves used to be considered convenient but low powered inefficient and expensive to run - its a learnt skill but they can be great. With two people and a 230g cannister we get 3-5 days - so again much the same as hutchk.

- when you really need to melt snow - double your fuel figures.

20 years ago gas stoves were laughed at but then it was pretty much only Gaz piercable cartridges and pure butane. Slightest hint of cold weather and it was all over. Nowdays isobutane mixes and the resealable cartridges have made them a practical option in all but the worst of conditions in NZ. Liquid stoves are still king as they work in all conditions but they are more expensive to buy and take more maintenance and can be harder to use. Most dont like simmering as well.

I use a Jetboil & budget on 7g per boil-up. If you've got kitchen scales, weigh the cylinder, cook something, or run it for 10min, and weigh again. Maybe work it out per minute of burn time ?. Keep in mind it'll usually take longer when things are done outdoors. ps - keep an eye out for Rebel Sport or even Warehouse sales.