The similer glue I mentioned previously is the Gorilla glue. I use it for Fuse box construction.  Doublers.  But not where I want all the strength I can get.  I use epoxy to join the wing halves to each other  and the verticle stabilizer to the fuse.  And the firewall.  I have never had a joint seperate.  See if you can find a syringe to shot the glue into tight spaces.  I get mine at my LHS.  I have also had Walmart give them to me for free.  But they were not hobby syringes and were too small.