Whoa, fellas! Didn't mean to start a fuss here.
The paint I used on the underside of my platform dumper was a rattle can John Deere yellow and green. It was just what I had laying around when I needed to spray something on the bare metal. I forget who the brand was.
But it seems that the most important step is the prep. Most especially the primer.
For nearly 20 years now, I've had excellent results (for quick work) with the NAPA/Permatex "Rust Treatment" primer that "destroys rust on contact." The item number is 765-1671. It's awesome stuff and everything I've primed with it is still good. I even use it on clean, sand blasted metal.
If you do good prep work, I think you could brush on latex paint and have good results.
But that's just me. And I am NOT a knowledgeable expert or a professional (by any stretch of a Crank-addicted imagination). I've just done two trucks and a car and I know what has worked for me.
If you don't care what it looks like, but just want something to stand up to years of use, I say POR it or use the NAPA rust primer and your favorite rattle can paint -- good and thick.
If you DO care what it looks like, don't ask me!
John
