I've recently discovery the Loctite Sumo glue. It is inexpensive and very strong. I believe it is better on foam (BluCore / Depron) than CA or epoxy. It is lighter and absorbs shock much better. It does foam up some so you have to use it right so it doesn't foam out all over the place. On bulkheads I actually put on a little more than needed and when it foams out the sides it creates an even stronger structure as it makes a reinforcement on both sides of the bulkhead. Sets up in a few minutes but takes a few hours to reach full strength. You have plenty of time to properly position pieces. I think I got a bottle at Lowe's Hardware store. (If not Lowe's it was Home Depot but pretty sure it was Lowe's.) Best glue for foam I have found so far. Unlike CA you can also trim it with a razor and sand it. Very similar to Gorilla glue but dries faster and does not foam as crazy like Gorilla glue. I've often seen on a hard landing or crash where the joint glued with CA fails. This stuff on a foamy airplane will not come apart at the seams as the seams will be stronger than the rest of the structure!

Wing on my airplane smacked a power line yesterday and my Sumo glued airplane held up pretty well. Despite the cable cutting through the depron up to the CF rod in the wing, none of the Sumo joints failed.

The photo shows a bulkhead where I intentionally did not clean off excess glue and let it expand around the joint. But you can make very clean joints with no glue showing if you put the right amount down and wipe the excess off a couple minutes after it sets.