Thanks to all for the input.
I did check with Rustoleum and they recommended rusty metal primer and then a rustoleum automotive finish. I asked about using the Ospho as well and they nixed that idea.
I plan on driving this truck and where I live this means plenty of gravel roads.
My original thought was to use POR15 because I had read that it was tough.
I still have not decided which way to go but I appreciate everyone's food for thought. Thanks again!
