Hi

I am currently building a Sig Something Extra Kit and have a problem I think. The wing should be mounted to the fuselage with an aluminium tube through the fuselage but I have a small gap (about 1 mm) between the left wing and the fuselage. Upon closer inspection it seems as if the left wing's inner plywood piece is a bit warped. The leading and trailing end touches the fuselage and in the middle there is a 1 mm gap.

What is the best way to correct this? (should I ad a sheet of balsa and try to sand the inner edge absolutely true (I dont have any large sanding tools though and I am a bit concerned that the wing will end up with incorrect angle to the fuselage)

Will the plane hold if I leave the gap?

/Johan