Gas tank help

Believe it or not, plain old bondo, body filler, whatever you want to call it works.
Years ago, I put a gash in my gas tank backing over a rock in the dark. I was in the middle of nowhere. I called my buddy, who picked me up, and I stayed at his house. (I was going to a party there.) A guy at the party told me about this trick. The next day, he gave me sandpaper (to clean the metal around the repair) and bondo. Let it set up, put gas in and drove it for a week, til I got another tank. The repair was solid and I was tempted to leave it!