I formed these channels a couple months ago and already attached them to the fuselage sides with clecos. Yesterday, I finally drilled all the rest of the holes. The 3/4″ and 1″ holes were drilled with wood-drilling forstner bits from Harbor Freight in my drill press. I really like these bits for this sized hole in aluminum sheet metal even though it probably isn’t the perfect tool for the job (it should only need to remove the outer edge of the hole, but it starts shaving some extra metal inside the hole before it breaks completely through the sheet).
Notice the two templates below the channel. I made these a couple months ago and finally used them to save time laying out all the holes on each channel. They came in really handy, but I started getting worried that the holes might have been positioned wrong and I might end up in a measure once, cut 6 mistakes conundrum. I double-checked and they are fine.
I haven’t mentioned them yet, but I have made some of the rear fuselage formers. My dad helped with this one.