Step 1
Clean your surface well and then mix and apply marine or fiberglass polyester resin as per the manufacturer's instructions. Shape the resin close to the final shape you desire.
Step 2
Cure the resin for a minimum of six hours at room temperature. Feel the surface of the resin. If it feels smooth and slick to the touch, then it is properly cured -- if it feels tacky or sticky, then allow it more time to cure.
Step 3
Sand the surface of the cured resin with 120-grit sandpaper. Do not sand heavily. Sand to remove any fibers or other imperfections. Shape as you sand.
Step 4
Sand with 180-grit paper for the final sanding to smooth the surface of your resin until it is virtually as smooth as glass. Wipe the sanding resin down with a tack cloth and then paint if desired.