The black plastic is a continuous insert into a white, hard plastic rub rail holder . You will keep your black plastic insert. Pull out a section of the black plastic to expose the damaged area of the rub rail holder. You will need to expose an area that includes at least two screws, so that you can firmly attach each end of the new section. Measure the damaged length to extend an inch beyond the nearest screw at each end of the damaged section.<img src="http://forums.sbo.sailboatowners.com/attachment.php?attachmentid=87805"/> I am sorry for the delay. Just launched today and it was difficult to say the least. Good thing I have a 'back up' motor. now at dock. Here is a pic of the side. Looks like I new to replace top and bottom of the black plastic?
When I did a repair like this I decided to just cut the rigid white rail straight rather than at 45 degrees. It just seemed way too awkward of a spot to accurately miter the joint, but a more skilled hand than I might not think so. One tip, slide a piece of Masonite or cardboard behind the rub rail as a protection against cutting the gelcoat. I did mine with a hacksaw, used 3M 5200 to seal everything up and to bridge the millimeter or so between the new and old rigid rail. It turned out better than I had thought it would. You can also make the rail more malleable by putting it in a black plastic bag out in the sun for an hour or so.Once you get the new section, you will cut the ends at 45 degrees. You will lay this section over the current rub rail and draw where you need to cut the old one at 45 degree angles. Cut the old section out and fit in the new section. Screw in the new section. Refit the black insert. That should do it. Thanks, Andrew