Re: no more cops sneaking up on me...
it's for aluminum only, and it works with mapp gas better than propane. i just use a regular yellow mapp bernzomatic torch.
i've been wanting to make an aluminum gas tank with it for awhile, but one of the problems is, after you weld up one side, the heat transfer will melt it when you try the other side. i'm sure there's a way to sheild it, but i haven't worked it out yet.
it's more like brazing then soldering. it doesn't "flow" like solder into joints as well, either, and if you're using 2 different thicknesses of aluminum, it can be a real pain.
it's a real trial and error method. for me, more errors than successes.
i have no idea what it's made out of.