Sounds like a good time to break down and start buying the rest of the RC hobby stuff - a roll of Monokote, covering iron, and some practice balsa to learn how to apply covering. Aftetr you have learned how to apply the Monokote the your practice balsa, learn how to put apply a Monokote patch to the already covered practice balsa (you have to learn how to control the heat on the covering iron), then go fix that wing. Packing tape is a good temp fix, but at least with Monokote (or Ultrakote, or whatever brand you get) your learning a new skill that will help if you ever decide to buy a kit instead of an ARF. Plus, you'll also learn how to repair those pesky hanger dings that all of us get.