Yep, The POR -15 for black is good. Top coat with Rustoleum. I did the plywood bottom and top with that on my panel. The clear marine varnish was brushed on 8 coats. One a day.
~ BD. "You won't find me in an old folks home" Pioneer Florida Cracker 1958 Apache Stepside 1958 Apache 1/2 ton Panel 1959 Apache 1/2 ton Panel