So, I grabbed a 6 pack, my Dremel and headed to the shop. I have run three of these empty so far, it has worked flawless so I figured it would be safe to share.
Tools- 1/8" drill bit, pliers, small chunk of wire and butane.
First, you need to pull the brass valve from the canister, a pair of pliers works just fine, careful not to damage the O-ring. A simple tug and it should slide right out
Now you can see the check valve when you look inside, it prevents you from refilling the canister. Use the 1/8" drill bit and drill it out carefully, there is a layer of plastic, then a thin layer of aluminum. You have to drill pretty deep, lots of stuff in there, about 3/4". Once done you can see in to the canister, shake out the drilling debris.
Now the valve gets pressed back in, easy as pie! You could add super glue at this stage, but I don't think it is nessasary.
Now it is ready to be filled, the brass valve is very similar to the valve on a car/bike tire, there is a small nipple in there that needs to be depressed to allow fluid to pass through it. My technique is a bit primitive, but worked like a charm! I cut a small tidbit of wire and dropped it in to the brass valve, once the butane is applied the pressure opens the valve and allows the transfer of fluid.
I filled 7 in about 5 minutes, the fluid exchange takes about 4 seconds to go from empty to full. Seven refills did not noticeably affect my big butane can. I use Ronson butane, I like the good stuff because I have had clogging issues in the past with off brand butane with other projects. I am going to retrofit a filling nozzle to avoid the chunk of wire, but it sure worked well.
Just like that it is over, an inexpensive way to enjoy the Thermacell for pennies. We run ours almost daily, between my work, picnics, the pool and camping every weekend they see a bit of abuse.
I hope this helps someone!
