This is the proof-of-concept demo for my mini flame effect.
I thought it’d be a good idea to start with one of those little portable butane stoves. They’re cheap ($10-$15), they have a neat mechanism to lock the fuel canister in, they’ve got a built-in regulator and piezo sparker and they’re pretty easy to disassemble.
Firstly, you take the case off. Undoing the obvious screws (and pulling off the knob and the bit of plastic on the canister lock lever) should let you get the whole canister holder/regulator assembly detached from the black “shell” which you can discard (there might be a couple of metal tabs you have to bend to get the fascia behind the knob out too).
Models from different manufacturers are subtly different, but the copper pipe coming out of the regulator on the one I got was 3/16” diameter. So I went to a big hardware store and got myself a 3/16” compression fitting to 1/8” female pipe elbow piece. (Graham from the DSC recommended Orchard Supply Hardware who had a wall of these gas plumbing fittings I never knew existed and staff who knew what they were talking about; I suspect you’d have less luck with something like Home Depot or Bunnings).
I cut off the small brass fitting which originally went into the burner with a little pipe cutter and mated the compression fitting to that copper pipe (make sure you get the order of these things right; it’s convenient to take the regulator assembly off the canister cage to cut the pipe, but you have to put it back on before you add the external fittings).
Graham had brought a 1/8” solenoid for me to test with (they’re USD$45 RRP, about half that on eBay but in any case I didn’t have one) which we mated to the other end of the 6” by 1/8” pipe I’d screwed into the elbow joint. He also had a little Benz-o-matic to use as a pilot light. Now, the solenoid he had was a 110V one (they’re also available in 12V and 24V DC) so yes, that is me sticking leads into a live mains extension cord to activate the solenoid.
As you can see, it worked and we got a nice little “poof”. A bit too little, so for the next iteration I think I’m going to go with 1/4” pipe for the accumulator, and therefore maybe even a 1/4” (this time 12VDC) solenoid. Apparently Asco “red hat” valves are recommended and they’re heaps cheaper on eBay than retail. Among other pearls of wisdom were to use PTFE tape to seal the joints, solenoids must be rated for “light oil” (otherwise the membranes inside will degrade on contact with the butane) and propane is always 150 PSI before it hits a regulator. Also, flare fittings are better than compression fittings—and that all these things are available from a hardware store in the first place!
There are still a couple of open questions (how to do the pilot, how to mount it) but these are relatively straightforward. My ultimate aim is to post something on Instructables with a total project cost of less than $50 and hook one up to the Safety Bike for Burning Man 2011. Big thank you to Graham from the DSC for teaching me all this stuff and being so patient!
