RE: vectorflight extra300 or edge540
I used polyurethane glue on mine for all the joints- stab, wing joiner etc
make sure to add tailplane braces and fill in around the wing bolt blind nut plate. I am considering beefing up the area where the wing bolts pass through the wing with some 1/16 ply - after a few hundred flights, the area is starting to look a little weak.