Well, you can't say "Never" use CA to glue two wing halves together.

For the most part, 30-minute epoxy is the method of choice, but there ARE some wings out there that are designed to be held together with CA.

I know I built one many years ago that was designed like that, but I'll be darned if I can remember which one it was (Memory is the second thing to go... I forgot what the first was)

So unless the MFG specifically designates the use of CA, go with 30-minute epoxy