For a little Aluminum boat, skip the epoxy. You'll just be adding weight, expense and labor to the job. If you keep the boat dry while storing, (that's when boats rot) you'll be fine for many years using a good indoor outdoor waterproof glue. Don't trowel it out too thick, but cover the entire top surface. the glue has to be able to evaporate in order to bond. If you do go the epoxy route or fiberglass resin route, you'll need a solvent based glue, not a water based glue.