Thanks to inspiration in the form of a recent post on DIYGK, I decided to drag this out of mothballs, and finish it. I started it about 3 years ago for a go kart project- now it's going on MII.
Heineken Mini Keg, for thirsty consumers. The can is thin stainless steel and features a small can of co2 inside. I lost my original pics, I'll include a stock photo at the bottom.
I began by removing the plastic tap handle and spout, and bleeding off the remaining co2. I drilled a small hole in the top, then used aviation snips to cut a 2" hole to correspond with the marine style filler I got at Princess Auto.
Inside was a small co2 cartridge, in a plastic bracket. The cartridge came out easily with some screwdriver work, but the bracket was glued to the bottom of the tank. Suspecting hot glue, I flipped the can upside down, and applied a little heat with my propane plumbing torch... *PLOP*- dropped right out.
Now- again, the steel is pretty thin- I drilled holes for the fuel outlet and vent, and ran a tap into them for the sole purpose of giving the brass fittings a "bite". I mixed up some 2-part epoxy, applied it to the fittings liberally (NOT a political remark) and wrenched the fittings in snugly.
FWIW, I used this fitting method on a small s/s water bottle that I use as a test tank, running engines on the bench. 5 years later, the fitting shws no sign of loosening or leaking.
I piloted screw holes, and applied RTV silicone to the back of the filler. After a few minutes to skin up, I screwed it on.
Due to the tanks potentially fragile nature, I will be modifying a commercial fire extinguisher bracket for mounting, and mounting it in a manner and location so as to protect it from impacts.
A note on the vent fitting... You COULD just drill a small hole in the top of the tank or the cap somewhere, but I'm a big believer in remote vents. Cuts down on fuel spills when thrashing around. So, with the vent fitting there, I will run a length of 1/4" fuel hose to a suitable location, and probably top it with a fuel filter to keep the crap out.