Lateral balance is important when you are trimming your model for straight and level flight. If you need to laterally balance your foam plane after a wing repair, here is an easy trick. Place the centerline of the repaired wing on a vertical support and place finishing nails (6d to 8d “penny”) on the lighter wingtip until the wing balances level. Then just push the headless nails into the wing tip and add a dab of foam filler to fill the hole. A little paint touchup and you will be ready to fly!