If the wing is skinned (a solid layer of balsa all the way around), then definetly fiberglass it. Usually I peel the covering back about 2 inches on both sides of the wing joint. Do this on the top and bottom of the wing. Then you will need to buy some fiberglass sheet. A sq. yd is about 5 bucks at you LHS, and you will have plenty left over. There are different weaves though, some are very tight and are like silk, and others are very spaced out. You want some that is fairly spaced out, dont get the really fine kind. This way the epoxy will be able to mix in. Then just get some 30 minute epoxy, put a small thin coating on the wing, then place the fiberglass over it(cut it to fit), then take a paintbrush and paint the epoxy into the fiberglass, this is why you want the fiberglass that has the looser weave. Make sure it's stuck down well, and let it dry. Do it to the top and bottom and you shouldn't have to worry about your wing ever again. If you used plenty of epoxy in the first place you are probably fine, but adding the fiberglass gives you added confidence, and it may end up holding it together after you put it through a full throttle blender. Good luck

Alex