I recently acquired a 15’ Old Town Trapper. It has a clear fiberglass finish from the factory . It’s in pretty decent shape . First question , it has a few deep gouges into the cloth on bottom. Would it be okay to sand the bottom and apply a fresh coat of resin , applying extra coats where the scratches are ? Second , I want to refinish the gunwales , rub rail and the keel. On other boats (gunwales) I have always used tung oil . Should I sand these parts, to remove old varnish or use a stripper ? Thank you for any help. New to all wood boats .