Rockenstein,
First off, my purchase of the brass fire extinguisher did not work out simply because it is too small. The description of it's diameter from the seller was way off, so this particular one is out. It has chemicals in it, so it now lives in the glove box of my truck. Back to the drawing board.
A couple of days ago I was looking at a Coleman fuel tank which looked about the size I'm looking for to fit between the upper tubes of my Worksman paperboy and 50 Schwinn straight bar. I took it to the plumbing department and discovered that a 3/4" copper male fitting for plumbing screws right in there, so I bought the male fitting, an elbow and a female fitting for the top of the filler tube. Today I've been fitting things together and it is ready to be soldered. The copper pieces are simple enough, but I have a question regarding the possibility of soldering copper to aluminum... is it even possible? I kind of doubt it. If it is, I'd like to solder the male fitting into the end of the fuel tank to be sure it can not leak ever. Short of that, what would be best to use as a sealant on the threads? Any ideas? I also have to join the vent and the fuel line tap and shutoff valve. The aluminum tank is thin and it seems to me that tapping it is a kind of waste of effort. No doubt I can "tap" the fairly soft aluminum with the threads of the shutoff valve, but again, what would be good to use as a sealant and a way of making the connection solid. Would JB weld work if soldering is out? I've been taking pictures, but will hold off posting until I know this will work. SB