I found some posts regarding countersinking several holes where the wing root fairing attaches to the wing. The plans are a little vague, but the consensus online (and endorsed by Vans) is to countersink several holes in the top skin and the fuel tank attach point. The tricky part is that the quick builders have already put the nutplates on, so the countersink pilot is too wide to fit into the threaded nutplates. The trick is to use a different size (#30) which fits inside the threaded nutplate and cuts just the same.
I tried this on a couple of holes. The single-fluted cutter does a nice job.
It seems like dimpling all of these holes would have been better, but that’s not an option with the Quickbuild. I’m hoping all these knife-edges won’t crack over time.
