1. Sanded the transitions on the new shim patches on the inside of the skirt. 2. Drilled all the skirt holes up to their final sizes. 3. Began countersinking the holes, using a combination of a 100-degree PermaGrit countersink bit (for most of the holes) and an 82-degree 3-flute steel bit (for the 6-40 screws that will attach the canopy bubble). These holes are quite tedious to countersink, because of the toughness of the carbon fiber. I feel like the bits are getting duller rapidly--even the normally-indestructible PermaGit bits.