I've applied Eternabond tape on several coaches, and have never added anything to the edges.I sealed seams on a flat roof at our house that's been there for ~9 years with no leaks or problems at all. The trick to Eternabond or any similar produict including Dicor, is to get the surface prepped properly. On our present coach, I have covered the front and rear cap seals with Eternabond. It has been on there for 4 years and ~40,000 miles with no lifting, peeling, or degradation.
Jim and Lynda, (Sophie, Jake, attack trained killer Shi-Tzus :-))
2003 Fleetwood Expedition 38N 2005 Saturn Vue