Foam excations done on the flaps now, it's time to bring out the flap hardware, FL1, FL3 and FL7 plates. Since these components are to be bonded to resin and flox, they must be ScotchBrite scuffed to key the surface.

Now a quandry - how to protect the metal from corrosion? My HWV buddies maintain that anodizing after scuffing is best. The local consensus in the shop (Bob, Russell, and Jim Thursby) all concur that post-facto self-etching primer is perfectly adequate. If anyone outside the Europa HQ knows more about building this A/C than these guys, I'd like to know. Therefore, despite some misgivings I go with phosphoric primer.
Here a flap is dry micro'd, slurry'd and the hinge slot is cut in the now projecting flange. I used a dremel cutoff wheel with two nervous hands holding on!
I'm checking the alignment of the FL bracket against the jig.
This side is now all glassed in (or closed out!). Russell is checking my slot cutting accuracy in the tip side of this flap.
To place the center hinge FL2, I had to cut the skin of the flap over a brown streak which was in fact a thin wedge of urethane between the styrofoam cores. Using a variety of implements including picks, shovels, files, and drill bits, I excavated the urethane all the way to the glass on the other side of the flap. A word of warning here - use compressed air to blow out the urethane chips. I got quite a bit in my eyes and nose by blowing the chips away with my mouth!