This may show my inexperience towards boat building, but here goes. I have been restoring an Old Towne row boat that was once my mom's. The wood plank floor has been replaced and fiber glassed. I know, not a good idea., but the boat will be kept out of water and I needed a way to make it water tight. Now I need to West System the inside floor to also prevent water from coming in the boat. Question - Can you paint a polyurethane primer over the West System?