The root ribs are cut from 1.5mm ply and glued to the foam wing cores. Also included are a 5mm bolt for mounting to the fuselage and two locator lugs made from leftover carbon-fibre rods.
The wings are now ready for sheeting with 1.5mm balsa. First the sheets need to be glued together along their edges. They are taped together, flipped over and yellow glue applied along the joins, then weighted down while they dry.
Gluing the sheets to the foam wings can be tricky, as it’s very important to get a consistent bond. But with the right tools it’s actually very easy.
Yellow glue is spread with scrap balsa like butter to cover every bit of foam. The balsa is laid in place hard up against the leading edge, and now for the tricky part. The wing is inserted into a giant vacuum bag from Bunnings, and the air sucked out and left to dry overnight. Clever eh? Perfect results every time.
Do that with the other three sides, trim the edges, and the wings are now super strong and light.