The top and bottom spars are of 1/8in spruce, 1/2in wide for the inboard section then tapering to 1/4in at the tip. With a sharp knife, I just about managed to cut the tapering pieces from a sheet of 3mm spruce, then spliced them onto the straight inboard sections.Spar building continues with the fitting of the 1/32 ply outer sections of the front and rear spar facings.
The plan shows the wing joiner boxes supported in ply formers fitted inside the spar. Instead I cut sets of balsa wedges. The first pair, shown below left, set the forward sweep angle. This assembly is then fitted between two more wedges to set the dihedral angle. The spruce insert is just a stopper to make sure that the joiner blade doesn't go too far into the wing.
Finally, the rear facings can be glued on and, to my relief, I had two appropriately handed spars, and could begin to fit a few riblets. The spar was heavily weighed down to keep it vertical and a length of aluminium angle used as a dummy leading edge.
Once all the riblets had been fitted, the aluminium angle was removed and the balsa false leading edge fitted.
