Soldering Fuel Tanks

I don't know if this is of any help or not. Roughfly 30 years ago I had a chat with a mechanic who served in the RAF. He said that the way that they handled gas tanks was to clean the site of the puncture etc up and put some flux on it then heat the end of a bar of solder and jam it into the puncture. Given the present discussion I don't know if this would work or not.