Countersinking the longerons^3h

Today I countersinked both longerons and continued deburring the parts.

Not much to say here, a lot of holes to countersink. I used my electric drill at low speed (450 RPM), which worked nicely. Before counter-sinking I brushed some Boelube on the longerons, which helped.

Then I took apart the central part, for the last time. I found that a couple of holes on the F-715 rib flanges were elongated. I think it would have been better to drill these holes once the front bottom skin is clecoed since it helps to position the F-704 halves. I will upsize the holes to NAS1242AD4 or maybe even AN470AD5 rivets. There is enough edge distance for that. Since these holes use universal rivets, I can drill them once everything is put together.