I had a Great Planes 27% Cap232 and the same problem. I hope I get this all understandable. The wing was a pins in front bolt on in back like most wings are now days. So, I had a bolt and a pin on each side. I took the joiner and figured out which side it fit tighter in. Then went through the normal procedures of testing fit and alignment like you would if you are normally gluing it. Then, I got out the wax paper and tape and epoxy. I prepared the wing so when I glued the joiner into the side that was a loose fit, it wouldn't stick to the other side that was the tight fit. Then I slid the wing together and taped it and aligned it like normal. Then I mounted it on the plane like you would to fly, and used more wax paper and tape to keep things separate. The next day I took the wing off and removed all the tape and wax paper and the wing came apart in two pieces thanks to wax paper. So I had a wing half with a joiner sticking out and one half without. Test fitted again and it fit perfect and aligned perfect. Flew the heck out of it for about 9 months with no problems before a disgruntled club member decided it was time I got shot down.

hope that works any questions pm me..worked great on a 3D plane I think a cub can handle it especially with struts.