Sheeting foam cores
In the olden days I used sourgum contact cement with really good results. It was cheap to get and lasted for ever on the shelf. Now I can not find it any more so I have used 3M-77(old), epoxy, alphetic resin powder you mix mith water, latex contact cement.
For the cost the latex wins hands down. It holds like crazy, does not soften in the heat, does not get brittle in the cold, does not eat foam, semi flexable so it bends a little instead of breaking. I picked up a quart for $8.00 at an apoulstery store. It does have a smell of amonia, but it goes away after ten minutes.
Gorillia glue works very well. Do not get ANY of it on the balsa. It does not sand woth beans. This also goes for the alphetic resin glue. It cures so hard it is not easy to sand. THe only problem I had with the OLD formula of 3M-77 was on real hot days the skins could begin lifting.
My opinion.
Dru.