Spent time prepping the wing skeleton for the upper skin. Deburred the lower holes for the ribs (only did uppers yesterday).
L-angles were cut yesterday so today I checked the fit of each - they can't be too long otherwise they'll hang up on the ribs during riveting. Had to adjust most of them.
Drilled pilot holes in one end of each L-angle after marking the centerline with a Sharpie marker (to see the centerline when looking thru the pilot holes in the skin.
Cleco'd each angle with one cleco. Turned wing over so topside was up. Reached underneath to hold each L-angle while I drilled the second hole for each angle (using the Sharpie line for reference).
Went back and drilled all pilot holes thru the angles based on spacing on the upper skin. Cleco'd every other hole. Once all drilled, went over all the un-cleco'd holes with a #30 bit to final-size the holes in prep for A4 rivets.
Removed the remaining #40 cleco's and drilled all remaining holes.