Luis & Fab's RV-7A Construction Log

This weekend was spent priming the main wing ribs. I was already planning on spending all day Saturday and all day Sunday washing, re-washing, and priming ribs. However, Fabiola volunteered to help, and we finished much quicker. I didn’t have a place to prime all 28 ribs at a time, so I did most of them on Saturday and then few left over on Sunday.

I used the AFS (now Steward Systems) water-based primer. We first washed with Dawn detergent, then used their acid-based detergent/etch. Even though we have a sink in the garage, Fabiola suggested using the bathtub for the washing 🙂 (“There is A/C in the bathroom, there is no A/C in the garage!!”).

 

After washing, we moved the ribs to the garage and hung them from the wing jigs. Then it was just on to actually spraying the primer!

The move came at a good time, since we were done match drilling the wings and even had the leading edge riveted. Since last April, I did manage to debur and dimple all of the main ribs.

The last thing to do before priming and riveting them to the spar is to drill a hole for the electrical conduit that will carry power to the lights, autopilot (!), etc.

These holes are not pre-punched, but Van’s has a document showing three recommended locations for the conduit. I elected to go with a hole near the bottom, next to the largest lightening hole. I made a cardboard template to make sure all of the ribs had their holes in the same location. I used the template to drill a #30 hole in the ‘Right’ ribs (some of these go in the right wing and some in the left..confusing!).

For the ‘Left’ ribs, I just clecoed a ‘Right’ rib on top of it and drilled through the first hole. Simple.

Finally, I used a unibit in the drill press to enlarge the hole to 3/4″, as specified in the Van’s drawing.