What I recommend to folks wanting to paint my sliders is either get the least expensive paint they can find and then plan on touching it up from time to time, or go for a really good coating (I use POR-15 with good results, proper prep is critical). But at $45/qt. for POR-15, I could buy ~18 cans of spray enamel at the local hardware store and keep the parts touched up as needed. I once used the Rustoleum hammered finish paint on my sliders and after one trip over sandy/gravel roads, all the front and down facing surfaces were sandblasted to bare steel. I found that that paint cures too hard that is is brittle and chips off. Cheap paint tends to cure softer and not chip as bad. Also heard of folks using bed liner on sliders and having it pull off in long strips if they actually slid the sliders over rocks.