Found a tool box for $50, how to prep before painting?

Can I just sand it with 200 grit and put some Rustoleum primer then flat black it? Or should I wet sand it after 200 grit with like 1000 or something? Then clean with what? Acetone? Not a painter here but it's a chrome diamond plate tool box from better built.

Neighbor tried to paint his but used a scotch brite pad and cleaned it with dish soap before hand. His box looks like ass now after just 6 months. I searched and found a few people who have done this but all really old threads and never any after the fact pictures. I'm always up for suggestions! Thanks TW

 

heres my box that use to be polished and all i did was wash it soap and water, scuff it with scotch bright til it was dull, wiped it with rubbing alcohol and hit it with 3 coats of satin black. i dont know if thats the right way to do it but its holding up pretty good. ive had it for 1 yr and never touched it up. no peeling so far

 

Humm didn't work out so well for the dude next door though.

 

Probably because he didn't clean off the dish soap. You need to get all oils, soap residue and wax off things before you paint. A scotch bright pad would work fine and would be easier than using sand paper. Scotch brite it til it's dull in color, hit it with some primer (you can wet sand at that point if you really want but if it's diamond plate you're wasting your time) then color and clear coat. Allow all coats to dry properly before applying the next coat and you'll be good to go.

Also, 1,000 grit is overkill for Rustoleum. You use 1,000 grit for automotive paint because the scratches left by a rougher textured sand paper show through the finish coat. Rustoleum is thicker and hides those minor imperfections much better.