Mine were originally coated with gel coat, the same color as the hull. Large flakes and pieces had chipped of so I wanted to refinish them. The three pieces are cast aluminum. After a little research, I found out the most often recommended coating for aluminum in a marine environment is epoxy. I grinded and sanded most of the old coating off, but much still had a tenacious grip on the aluminum and I could not remove it. (I figured if a grinding wheel on a Dremmel tool wouldn't remove it, then it was OK to coat over.) I gave each piece a coat of clear epoxy and then sanded it smooth. Then I applied a second coat of epoxy with fairing compound mixed in and gave them a good sanding to smooth and even-off the surfaces. I coated, sanded and painted all sides and edges, inside and out. Over the sanded, faired epoxy, I brushed on five coats of Easypoxy one-part urethane paint, sanding lightly between coats. They now have a thick coating and a smooth, even, mirror-like finish. I figure if they get scratched, I can touch them up with the Easypoxy or sand and repaint. The epoxy base coats should last a very long time. My work received a couple of appreciated compliments at the boat yard.