Wing Sheeting

Sheeting Foam Core Wings

Sheeting foam core wings is easy, follow these steps
and learn the enjoyment of building what you fly!

The wings being built are for our KI-46 Dinah III.

1. Prep the wing cores for sheeting. Trim the last 1/4” of each wing panel at the trailing edge. This applies to the wing panels only, do not cut the wing saddles. Aligine the leading edge of the wing panels flush with the front of its saddle.

2. Measure from the trailing edge of the saddle forward 1/4” and mark at each end. Once the panels are marked, use a straight edge and a #11 exacto knife and trim the last 1/4” of material off each wing panel. Remove the wing panels from there saddle when cutting them as to not cut the saddles.

3. Using a sanding block with 220-280 grit sandpaper, lightly sand the foam cores of any irregularities or cutting wire lines. Dust the cores of any “fuzz”.

4. You can make the servo and wire channel cutouts before sheeting the wing or after. If you wish to make them first mark the motor wire and servo wire channels into the wing according to the plan included in the instruction book. Note that there is no critical location for the wire channels or servos.

5. You can use a basswood block with sand paper glued to it so that you can sand the channels into the wings or use a Dremel with a router bit attached. I prefer to cut the aileron servo wells out after the wings are sheeted.

6. Fully sheet the wing cores with the eight 1/16 x 3 x 36 inch planking sheets provided. To square the sheets use a metal straight edge and a sharp #11 exacto knife.

7. Arrange the sheets in two groups of four sheets. Butt the sheets up against each other and use masking tape to hold the sheets together. Tape the sheet along the entire butt joint.

8. Trace the outline of the wing saddle blanks onto the planking sheets making them slightly larger then the saddle, approximately 1/16” all the way around and cut out. “NOTE” the planking sheets will carry 1/4” past the trailing edge of the wing cores themselves making up for the 1/4” of trailing edge material we trimmed off in step 1.

9. After cutting the sheets out, measure from the trailing edge forward 1/4” at each end and mark. Use a straight edge to draw a line along the entire trailing edge connecting the marks. This will be your reference line for lining up the cores properly when sheeting and assure that you have exactly 1/4” of sheeting that carries past the end of the wing cores. “NOTE” make sure you draw the lines on the un-taped side of the sheeting.

10. Using masking tape, tape the top and bottom wing sheets together at the trailing edge leaving a 3/32” gap between the trailing edges so that the sheets do not kink when folded on top of one another. “NOTE” make sure that you have the 1/4” marked lines to the inside so that you know where to place the wing cores.

11. Before mixing up your resin do a dry run with the cores in place to make sure you have everything set correctly.

12. To glue the sheets to the wing cores use a slow cure epoxy that has a 60 minute or longer curing time. Two good systems to use would be Ez Lam or West System. Mix up enough epoxy to cover all four wing sheeting panels.

13. Use a small squeegee to spread a thin coat of epoxy over all four planking sheets. Remember that the purpose of the resin is simply to adhere the sheeting to the wing - just use a thim cote. Place the bottom side of the wing cores down onto the planking sheets.

14. In a separate cup mix up some epoxy with micro balloons to make a paste like consistency. Use a small brush and apply the paste mix along the trailing edge of the wing where the cores stop at the 1/4” marked lines. This will fill any gap between the cores and the trailing edge of the planking sheets as well as provide strength to the trailing edge.

15. Now fold over the top sheets making sure that the wing cores stay lined up and place them back into their saddle. Place the wings in their saddles on a flat surface and put a flat board on top of the saddle and place at least 50 lbs of weight on top of the board evenly distributed and allow to dry for 24 hours. Make sure you use a flat surface and a flat board when sheeting the wings as to prevent warps or twist in the wings.

16. After the wings have dried for 24 hours, remove the wings from their saddles and sand any overlap of the planking sheets flush with the cores. You now have two nice foam core sheeted wings that simply need finishing out.

17. For the Dinah we need to cut the motormount slots into the wing at this time. For kits such as our MIG-15 or Heinkel this step is not used.

18. Measure and cut the slots open at the leading edge of each wing for the motor mounts. Use a #11 Exacto knife or use a band saw if you have one.

19. Locate the leading edge stock and cut to length. Use white glue or 30 minute epoxy to glue the leading edge stock in place. Be sure to center the leading edge stock both at the root and tip and use masking tape to hold the stock in place while drying. Once dry, sand the ends flush and the leading edge to shape as shown on the plans.

20. Attach the balsa block tip blocks. Use white glue or 30 minute epoxy to glue the tip blocks in place. Be sure to center the tip blocks. Once dry, use a sanding block to sand the tip blocks to match the airfoil shape of the wings and then sand the edges of the tip block round.

21. Using a sanding block, sand the trailing edges top and bottom to an even taper leaving a trailing edge thickness of just over 1/32”.

22. Mark the aileron outlines according to the instructions.

23. Use a straight edge and a very sharp #11 exacto knife to cut the ailerons out.

24. Cap the face of each aileron. First remove 1/8” of material from the leading edge of each aileron. Before capping the aileron leading edges use a sanding block to bevel the face of each aileron to an even taper. After beveled glue the 1/16 x 3/8” stock in place using epoxy or white glue.

25. Use the 1/16 x 3/8” material to cap the aileron openings of the wings. Glue the stock in place using white glue or 30 minute epoxy. Once dry, sand any overlap flush with the wing and aileron.

26. With the wing sanded out you can now cut out the servo wells and make the wiring channels if you have not done so already. Use a sharp #11 blade to cut open the servo wells.

27. If the wire channels were not made before sheeting the wing do so now. Use a 12" long 1/4" drill bit and carefully drill the channel by twisting the drill by hand from the root end to the servo well. A referance line drawn on the wing can help you guide the drill bit - just take your time and be carefull not to drill through the wing sheeting by accident.

28. Before gluing the wing halves together you will need to cut an exit hole for the wire leads for the motors. Cut a 3/8” hole through the bottom sheeting in line with the servo channels as shown on the plans.

29. At this point your wing is almost finished. It is now ready for joining and a few final details. We hope this simple how-to assists you in your projects. The best way to find out how easy it is to sheet your own wings is to just do it! It really is no big deal. By learning these basic modeling skills you open yourself up to an even wider range of projects and even more enjoyment of the hobby.