I replaced my entire rub rails when rot developed in the originals, which were mahogany, not teak or artificial material. I never considered partial replacement. Rails are through-bolted and I'm not clear whether partial would be easier that total or not.
I found some wonderful solid PVC material at Hamilton Marine in Searsport, Maine. They have an amazing selection and one virtually matched the profile of my original. I assume that you have the grey artificial material I have seen which may be exactly what I found at Hamilton. Mine is white; other colors were available. Hamilton was great to work with; material was reasonably priced and shipped. I had my yard do removal and installation which was quite extensive and expensive. The result is far superior to my originals. If you are capable of doing it yourself the cost would be minimal but the effort quite high.
Fred & Linda Rachwitz
NS 30 U #445
Concerto
Harbor Springs, Michigan USA
