A Really Good Epoxy
SailboatsToGo recommends G/Flex Epoxy from West Marine: West System G/flex 655 Epoxy Kits Thickened (two 4.5oz. Aluminum Tubes Of Adhesive (one Resin; Hardener) . Uses include gluing foam sponsons to canoes (plastic or metal), gluing the rub rail onto a Snark, and you will find others. This epoxy is unusually good at bonding a wide range of materials, including many that other glues cannot stick to. And the bond that it makes is very strong, yet compatible with materials that flex. Disclaimer: Because your results will depend on many factors we cannot control we disclaim any responsibility for glue performance.