James.

Skip the micro balloons for filler on the spars, use milled glass fibre.
you may needt o file out some of the glue fillets on the fuse formers to getthe spars flush to them. I had to but it did not take long,

I can send you some, Just PM me your snail mail address.

Too cold to paint here this past week. So I made a cowl out of balsa for my Hobby Shack Joss Stick. I hope the Saito 180 will pull that tank around. To think they put a single servowith torque rods in that big sheeted foam wing. I cut the pocket open for dual servos. I know I should have bored a hole thru the foam and mounted the servo midwing.

bob