Route notches for back braces—The ends of braces go under the kerfing for extra strength. On the soundboard side, kerfing pieces are glued over the braces after the soundboard is in place. This isn't practical on the back, because you'd have to reach through the soundhole to do it.

I carefully align the back on the ribs, clamp it in place, and mark the location of each brace. Using a laminate trimmer with this extra-long base, I route pockets for each brace. When carving the back braces, I made sure that each end was precisely 1/8-inch thick. This way, I only need one router setting for all the notches.