Take all 3 joiners , line them up so all the edges line up... if you have one upside down they will NOT all line up. Once you have the the orientation right mix up some 5min or even 30min epoxy spread a nice thin layer over both sides of the center piece of the joiner and join all three layers together using clamps to hold them in place until the epoxy dries. now stand it up on a flat surface(table)... ends touching the table do you see a gap in the middle? that would show Aihedral and tell you it's up side down... if it wants to balance in the middle with the ends off the table thats showing Dihedral and the way you want it to glue into your wing. Now take your wing panel... put that epoxy down right NOW! slip in the joiner and then slip on the other wing panel, lay the wing flat bottom down on your table... do you see a gap in the middle with the wing tip's touching the table? again thats Aihedral and you don't want that when you have it right you should be able to hold one wing panel flat on the table and have the other wing tip about 1 to 2 inches above the table depending on how much Dihedral is built in the wing... you MUST have some! now your ready to join the wing.

I've used several brands of 30min epoxy over the years... they ALL did the same thing just pick up what ever your Local hobby shop has... the most important thing is you get 30min and mix it properly... just follow the directions.

John