Matched HS-609PP bars inside HS-603PP spar channels. Sanded bar edges. Deburred holes in spar channels. Dimpled flanges. Final-drilled all holes. Deburred again. I used a hand deburring tool for a while, then switched to cordless screwdriver with a deburring bit in the chuck.
In my inexperience, I overlooked several small milling marks that were left on the faces of the bars. These were not noticed until after assembly, but I think they'll be OK.
The Sioux lightweight drill is fantastic and highly recommended.
A sheet of sacrifical MDF on the table top is very useful.
