Smoothing edges in notches has been a tedious activity. I just haven't been satisfied with getting into those radii with a small file, sandpaper, etc. And having many years experience finding cracks in places just like that on F15's, I am not about to let those edges go unfinished.
Finally, the easy way for the radii: The side of a drill bit. Chuck it in the drill, spin it in the little radius for 2 seconds and it's done! The bit I use is just small enough to fit into the radius at the bottom of the cutout. I tried a reamer, but for a radius at the corner, the reamer wanted to skip out of the notch and skitter across the surface. Can be a problem with a bit also, but less so. Does not leave the polished surface you get with a Scotchbrite wheel, but it does convert those marks that lie across the edge to harmless marks going along the edge.
Now, let's find an easy way to do the edges of those notches!
Finally, the easy way for the radii: The side of a drill bit. Chuck it in the drill, spin it in the little radius for 2 seconds and it's done! The bit I use is just small enough to fit into the radius at the bottom of the cutout. I tried a reamer, but for a radius at the corner, the reamer wanted to skip out of the notch and skitter across the surface. Can be a problem with a bit also, but less so. Does not leave the polished surface you get with a Scotchbrite wheel, but it does convert those marks that lie across the edge to harmless marks going along the edge.
Now, let's find an easy way to do the edges of those notches!