Removed tanks from wings, thought I might paint wing and tank as one, but talking to another builder, it would be better (no paint cracking due to expansion/contraction) to paint tank only. So removed again, another sanding with 600, fixed one small dent in one tank, taped up and one coat of primer (had already primed a while ago), but couple of chips needed rubbing out and figured the paint will bond to a recently primed part better.
