I finished the sanding of the doubler last night. It turned out OK and wasn't nearly as difficult as I expected.

I moved on to the next step which is to glue on some sheeting on the bottom and top of the leading edge of the wing. At that time I realized that I forgot to sand the bottom portion of the leading edge. Oh joy! More sanding to do!

The instructions state that I should do my best to prevent warping of the wing as I glue the sheeting on. Does anyone have any recommendations on the best ways to prevent warping? It doesn't look like I'll be able to tack the wing down to the plans very easily. Thanks in advance!