I’ve done lots of harpies, both serrated and straight. The straights are easy, the serrated ones require my top secret, seemingly never to be released 🙁 , serrated attachment. The inside curve of the harpies is easy enough with the diamond stones, even easier with the more narrow waterstones. Another advantage of the waterstones for inside curves is that the corners and sides of the stones can be used to get inside the tight spots.
