I have access to an epoxy product that we use at the boat shop to join our hull and decks together. This stuff has about a 20 miniute work time. To give you an idea of how strong the bond is, once a hull and deck have been bonded and the epoxy is cured, the fiberglass substrates will give way before the epoxy joint will de-bond! I can get them in the 50ml size for around $15 USD but you need a special "gun" as well for $35. But all told this stuff is easy to work with and is tougher than Hades. It states on the side;
"A structural adhesive suitable for bonding plastics,conposites metals and dissimilar substrates ."
Sounds like every thing a model submarine builder has to use in a model at one time or another!
Let me know if any of you are interested.