I'm building a glass kayak from deck and hull molds i built last year. I'm looking for a material to finish the exterior deck and hull seam. The two parts, deck and hull I joined using an H shaped vinyl moulding available at home depot. With the parts joined, the seam is tacked in place and the interior seam glass taped and epoxied. i'm looking for a material the same or similar to what commercial builders use on the exterior seam. I've seen some boats with a heavy grade tape? or gasketing material that is form fitting at the bow and stern. Any help or suggestions about alternatives would be appreciated.