Prep sand the back of the spar and install the foam pieces in the hollows. The plans don't say much about the contour, or how far to go, so I contoured the foam so the forward face follows the wing kink and the top is flat, tapering to nothing just past the cowling flange. Clamped with hot glue blocks and mixing sticks, only resulting in minor burns.
Using the metal firewall pieces as a template, mark the fibrefrax and cut it out with a box cutter. This stuff is VERY fragile. I note in research Glassairs have 1/2" of this stuff behind the metal. Hmmmmmm.
