Tom, no special metals. I match the gauge of the metal, but that's it. Only plain untreated steel though.
Firstpantera, yes..I can't disagree. Didn't mean to imply I had a preference with the wheels. I should probably have flipped it over so no brand showed. I find the 3M last longer, however Harbor Freight carries these Chicago ones in a really thin width, so the cut line is narrow and clean. I do like that aspect. Haven't found the 3M in such a narrow thickness. But again...I'm a big 3M fan when it comes to abrasives.
Banzai, One word of caution with sand blasting, it can warp your panels. I had my body panels chemically stripped first, then lightly blasted with plastic media. The rest of it was only media blasted. I would remove the windshield and the side glass. I only left mine in because I ran out of time to get them out before my scheduled date/time at the media blaster.