I completed the work on the tip ribs today. I started by filing the slots in the ribs. Next, I used a sanding block to knock the burrs off the outside of the rib and then I used scotchbrite to finish the outside. I used some 220 grit sandpaper around a long drill bit to clean up the inside edges of the slot and the same sandpaper to clean up the burrs on the inside of the rib. I finished up the slots using scotchbrite.