I'm really a fan of the polyurethane adhesives now available, like "Pro-Bond" and "Gorilla Glue". They work on balsa, ply, plastics, even aluminum. Firewalls, landing gear blocks, and wing-mounting blocks are fine. I think the stuff is better than epoxy. They are not toxic.(but don't get them on your hands anyway...your fingertips will be black for several days before it wears off). They expand as they harden, so they fill gaps. They are sandable...probably better than aliphatics. Fuelproof, waterproof. The only down side is you have to glue stuff, clamp it in place, then leave it for a coupla' hours.

I built my last four planes using almost nothing but PU glues, and they are light, strong, and not brittle. I built a Wonder with it, and dumb-thumbed it into the ground at full-throttle. It broke a lot of wood, but not the glue joints. My Senior Telemaster has been flying (on floats) for over a year without a problem.