Countersink the Firewall spacers and angles - 2 hours

Not a huge day on the build, but a big airplane day. I had a flight booked and the weather was perfect, so I flew a 1.6 and a 1.0 under the hood (working on my night rating), that ended up eating away most of my mid-day.

I was dreading countersinking the firewall parts. I've never enjoyed this process as I could never easily work out the best countersink depth for mating a dimpled piece in a countersunk piece. Getting a rivet flush with the material was the easiest cause you just work up to flush. But its never really clear how far past flush you go for nesting pieces. I ended up countersinking a little past flush so there was a very small ring around the rivet. When cleco'ing a small piece of dimpled material to it a very small gap was still present. I believe when I rivet this gap will disappear, or a very least be nearly gone.

Unfortunately I made one small oops. I had accidentally countersunk the topmost #30 hole in the F-601N-L stiffener. That one particular hole shouldn't be countersunk as it rests on top of the F-601L-1 stiffener. Oh well, I will have to put in a small order after Christmas to Van's and rivet it later.