I have been using a powdered marine resin glue for building kayaks for years with great results. Yes you have to mix it (with water) but if you use a graduated syringe and a measuring spoon it takes about the same time as it does to mix up a batch of epoxy - faster actually - because you don't have to be mixing multiple little batches as has to be done with epoxy.

Good pot life, wets well, good tack and reasonable price. If there is something better I would like to hear about it.