Final rear spar work before priming

The areas on the rear spar where the aileron brackets will be mounted have been know to develop cracks on older RV-7 kits, so the newest kits include blank doubler plates that need to be match drilled and riveted to the spars to keep things strong. Probably a good thing.

I did my best to center each plate with its corresponding rivet holes, clamped each plate flush with the spar, then match drilled each one.

The hole where the aileron pushrod goes through the spar of course needs to be cut into the doubler plate to match, lest I try to fly an airplane with no ailerons. I started by tracing the cutout onto the doubler with a sharpie then drilling a #30 hole into the plate as close to the center of the cutout as I could. My plan was to use the step drill to gradually enlarge the hole then use the dremel to finish it off.

At this point the unibit was too big to keep going with it, so I switched to using a dremel tool with a cutoff wheel to remove most of the rest of the material.

It looks messy as heck, but trust me, it gets better!

To finish each cutout I switched the cutoff wheel for a sanding bit to file and smooth the cutout to its final size. The results speak for themselves:

Clean!