I would make sure that you use plenty of glue next time. Put the glue on both halves, all surfaces. It should be dripping out of the wing joint after you push it together. Then just wipe up the excess with paper towels and alcohol. It should be SLOPPY with epoxy.

There is also a device they sell that will put little tiny holes in the balsa surfaces so the epoxy sinks into the wood. Some people sand it to get the shiney surface off the wood too.

Then of course you can glass it.

What kind of epoxy did you use?

Joe

P.S. I've read a lot of the threads on this ARF and the wings collapsing is not an issue. But there is always the possibility of a bad wing.