Brief Description: Filler Box Pilot Drill and Upper Firewall Bow
Fitted/aligned and pilot Drilled the filler box assembly (box, box end, and doubler). It looks pretty good...I was worried about drilling the stainless steel parts, but it turns out it was a piece of cake, it just takes a little longer than aluminum. I did have one #40 drill bit catch in the metal and break, but it didn't mar the hole and drill bits are cheap, so no problem.
I also fitted the bow to the upper firewall and clamped in place. I made a spacer to fit under the firewall out of 3/4" oak plywood, to provide the proper 3/4" offset and align the bow. I clamped and weighted (with my cleco cans) it to make sure it was flat against the spacer. I got the bow aligned properly, but the pre-drilled holes miss the flutes, so I'm going to have to bend the flutes out some to make flats for the rivets to grip. I also had to bend the firewall flange to the required 77 degrees at the top (from the factory it was 90 all around) to make the filler box fit properly against the lower mating flange.
