Instead of POR15 I used "Chassis Saver".

I did mine over a year ago, it still looks good.

Word of warning, don't get the stuff on your skin.

 

Yeah, I've heard it is tough to get off.

 

You guys ever try....don't laugh, lets have a real discussion. The old timers would coat the roof on their steel buildings with Foundation coating [tar]. It comes in a bucket & is very sticky. It hardens up like a brick & If you've ever tried, it is very hard to get off of metal. I use it all of the time on my foundations. Wonder how it would work if someone were to mix about 10% Kerosene with it & coat there frame? Or even shoot it inside the rockers/fenders? I spilled some in my old chevy truck & It was still stuck to the bed when I sold it, like concrete.

 

Hey looking good , anyway I had a jeep one time I stripped the whole interior and roof tared the whole inside. Bought like a 5 gallon bucket for under 30 bucks. It took a loong time to dry but if you put it in a heated garage it might speed up the process.

 

Eastwoodco also has that chassis black stuff you could try. Id imagine a good epoxy primer would work too.
I have tried POR and used the whole process and it does just peel off after awhile. Maybe I goofed on the prep.
The only thing that seems to repel rust for me is zinc primer.
Ill try buying some of this stuff for the summer when I re-do the underside.
I wish I had a lift for this stuff. =(