I happen to have both wings (arf and rtf). The ARF wing has a ply jointer because the ARF wing is glued together with 30 minute epoxy. For ease of assembly, the RTF wing has a metal rod and two small metal straps that join the halves. the RTF one held for me, until I did a couple simultanious hard loops and the wing began to split and come off the airframe [X(] When I landed, the holes where the straps screw it were stripped out, so I moved both straps up slightly and retapped holes. Then, I glued the RTF wing together, and haven't had a problem since.