Start with a balsa plank. Make two profile templates from 1/16 plywood, and glue one to each end of the base. Rough out the shape with a razor plane, and finish forming with a bar sander. If the base is made from two planks bonded together, make sure that the glue in the joint doesn't extend to the finished surface. The mold should be about 1.25"-1.50" longer in chord and span than the finished dimensions of the wing panel.

The curved portion of the template is made in the shape of the BOTTOM of the airfoil. Extend the template from the L.E. and T.E. by straight line tangents.

Making a Wing Panel

Cut the foam blank slightly smaller than the the mold, and bevel the edges. Place the blank on the mold, and cover with a piece of plastic wrap. Tack down the corners of the plastic with bits of masking tape.

Note: it is much easier to tape the foam down without a plastic cover sheet, but this damages the surface of the finished wing when the tape is removed.

Tape the work piece to the mold with packing tape, starting at the center and working outwards. Work carefully to get everything to lie flat, with no cordwise wrinkles. Overlap the ends of each tape strip on the bottom of the mold. It is essential that they do not let go when heated. Overlap each wrap as you work outward, so that the foam is secured with a double layer of tape.

Bake at about 175 F for about 15 minutes, and cool for an hour. Experiment to find the optimum for your oven. More is not better in this case, use just enough heat to form the curve. There is no springback.

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