I have recently uploaded a video to YouTube to show DIYers how they can make an aluminium petrol tank and weld it with gas, if they do some practising. I am self-taught and worked for myself doing this back in the seventies but it is really a spin-off hobby from making my own parts for my drag-racing bikes. I am an electrician by trade but am retired from work now but still race. I am an OAP of 71 now, but thought that the video might help others to have a go. Hope it helps. Cheers, Pete:-
http://youtu.be/rw5lYMmxSB0