as long as you have the right equipment to weld aluminum, it should work fine. I have seen a pipe which split down the center joint, a good thick-bead weld around the pipe kept it together nicely, so a stinger should not be a big problem. the thing with alu is, it oxidizes before you know it, so as long as you clean the joint really well, and know how to weld alu, the welded joint with actually be stronger than it was from the factory. as far as other methods, I just can't think of anything better than a weld. I guess you could drill out the hole in the pipe to the size of the stinger, and then tap threads onto both parts and just screw them together. High temperature metal epoxy / resin on the threads would keep it tight, but the whole thing would crack and rip the threads if it got bashed. good luck!