gas tank dent removal using only ice

my gas tank has a minor dent, from me being hit by a car a while back, (moron cagers) and the tank isnt wrinkled or anything, a buddy of mine suggested that I could removed the dent by simply taking the tank off of the bike, filling it with water, leaving the filler cap open and throwing it in the freezer, so that the ice will expand and pop the dent out.

anyone ever tried, or even heard of this, or have another method that doesnt involved me repainting the tank?

sounds crazy! If the dent is small the ice might bypass it. I have also thought throught the science of it and you will have to keep an eye on it every hour because that ice can also split the seams of the tank if not carefull

what about dry ice?

www.google.com/search?hl=en&q=dry+ice+dent&btnG=Google+Search

I thought you was joking Red till I saw your link

but with dry ice you have to heat the tank up, and id rather not char the paint.

I wouldn't try filling the tank with water and freezing it, even with the cap removed. The tank would probably split at the seams.
As far as the dry ice method, you don't have to heat it up that much. Letting it sit in the hot sun will heat it up enough for that. I did it to my wife's Miata with some Hail dents. The idea is to let the metal heat up, then place dry ice in a circle around each dent. The metal surrounding the dent will contract, pulling the dent out. It works somewhat good. It didn't remove all of the Miata's dents, but most of them came out.
One time, I had a small dent in the side of my XS650's gas tank, and I got it out by smoothing round the end of a piece of rebar, then bending it to where I could reach the dent from the inside of the tank. I used the tank opening as a fulcrum to pry and work the dent out. If you try it, be sure to use a rag in the tank opening to cushion the rebar. Of course, it does matter where in the tank the dent is, and what kind of dent it is.