The Stovebolt Site Forums The Shop Area Making a Stovebolt Bed Mar-K Bed Wood Kit

3 coats of POR (all six sides)
followed by
3 coats of semi-gloss black exterior house paint (all six sides)

You can use cheap rollers (throw away after each coat)
Follow the POR instructions for the amount of time between coats.
Mar-K Tips & Tricks

We did this on 18' flatbed boards several years ago - has held up well (outdoors half the year).

I'll be doing this on the '54 pickup that I am restoring.