I bought a gallon of the Herculiner brand at Lowe's and just rolled it on. I think I went out and bought a new foam roller because I didn't like the way the supplied roller was applying it and the new roller worked perfectly. I actually primed and then spray lined the fenders first and then did the Herculiner. They should be pretty much indestructible to anything now, let alone rust.
It looks nice, I Had the entire bottom of mine wirebrushed and then replaced a few of the body mounts and had the entire bottom coated with POR. You can’t scratched the stuff with s screw driver. It’s awsome.