RE: Need Help!!! Great Planes Cap 21 Giant Scale (88" wingspan)
You can make it a 2-piece wing. I was going to do the same exact thing with a Lanier Giant Stinger kit. Not planning on buiding the kit for awhile--so it's on hold. But, it can be done. Just costs money.
I contacted one of the foam wing cutters, and asked him if he'd take my cores and cut socket holes in them so that I could install a phenolic and an aluminum tube. He said it was no problem as long as I had the cores and construction on the wings had not been started yet. About $35 + shipping both ways.
What you do is install the phenolics and put a piece of lite ply at the bottom of the socket to keep the tube from digging into the foam when the wing is assembled. Drill a hole in the back of the wings and install a brass tube and use a 5/16" dowel about 3" or 4" long for an alignment pin.
Put a dowel in the LE of each panel and a hole in the back of each wing for a mounting bolt.
You now have a 2-piece wing. It still attaches to the fuse with dowels in the front and bolts in the back--your just using a tube for the center section and a dowel in the root, at the rear for alignment purposes. Take the bolts out and pull the wing off the fuse. Slide the wings apart and go home. When you want to fly--just slide them together and bolt it in the fuse.
Crude MS Paint image attached: