I used cold galvanize paint on things I don't want to rust, but don't care the finish. I painted angle irons on a 20' antique windmill out in our yard 10 years ago, looks like I painted it yesterday, comes in gallon cans or spray cans. On the RumRunner I used many quart cans of Krylon Rustoleum and disposable foam brushes.
same paint, no overspray.
2001 GMC 6500 Topkick, 22' box, dropped frame, designed to fit into a 9' garage door. 3126 CAT 6spd Man Lo-Pro 19.5's w/ 3.07 rear axle ratio