The best thing I have seen for attaching the deck to the hull is silicon and screws or rivets if you think you will ever need to take it apart again. If you use 5200 there will be fiberglass damage when you take it apart. The 5200 is very rubbery when cured, cutting it or breaking it is almost impossible. If you use the 5200 to attach it it will be there forever, that could be good, or bad.