No matter what varnish product you use, you're going to have to plan on sanding and refinishing it on a regular basis. I used a wide range of product on sailboat brightwork over a course of years, and the best that I got out of any was about a year and a half. The sun and weather just breaks the coating down, no matter what additive you have in the mix. Ironically, it is often the most expensice coating that fails first! The Helmsman UV resistand coating began to crack and peel after 10 months. Sikkens, who are supposedly one of the top finishes, shows wear and tear after a year. Varnish is just not a good finish for a truck bed. That's why they used the black paint! A working truck for the working man.
