I stripped almost my whole truck plus an extra bed, door, and fenders with 3" bristle disks. They leave a better finish and don't gum up when removing the original baked finish. They will remove metal and they will alter the metal surface but it's nowhere near as dramatic as a grinding or abrasive disc.
http://www.3m.com/product/informatio...stle-Disc.html
Seems like local swap meets are filled with Chinese imitations for all the 3M stuff. The quality's not good but the price is cheap enough so you can buy more.