After priming the ribs and skin I realized I hadn't prepared the W-423 join plate for the right wing. I scuffed the part with scotchbrite, then dimpled the screw holes. I used the dimples as a guide to cleco on a nutplate and then match drill the holes for the mounting rivets. Repeated this for all screw holes then dimpled all the rivet holes. I re-bent the W-423 to match the wing shape as all the dimpling tended to straighten out the part. Finished by washing the part in Dawn dish soap and warm water.