I take a Primus EtaExpress stove with me when camping, and am slowing accumulating a collection of canisters with only around ~20% gas in them.
With this little gas, they don't have enough pressure to be useful in anything except ideal conditions (hot, windless, and you have all the time in the world) but I'm reluctant to dispose of them.
Is there a good way of constructively using up the remaining gas - and what's the right way to recycle the canisters when they are properly empty?