5.4 hrs
Today was spent on final prep of the left wing spars. All the #40 holes on the main spar are countersunk. The compressor would kick on after about 15 holes, I would continue till the next rib attach point and then give the countersink bit and compressor a break by working on the rear spar.

Deburred all the #40 holes on the rear spar during these breaks. When the main spar was completely done, so was the rear spar. Then dimpled the rear spar, and then used the deburring bit to slightly ream out the dimples for a better skin/spar fit.

Lastly, primed all of the countersink cuts on both spars.

It doesn't sound like that much work when typed up like this, but it took quite a bit of time.

Tomorrow the rivet count goes up!