The SEM Weld feather edges fairly well, but not fine enough for a invisible repair. We used fine polyester finishing glaze, a body repair product, for the final surface finish. It mixes like Bondo (which it basically is, only finer) and is spread in a very thin layer. Extend the glaze past the area previously sanded. The glaze fills any pinholes, gives an invisible feather edge, and fills the relatively rough #80 grit sanding scratches from the previous step.The glaze should only be used as a surface finish, since it isn't structural like the repair compound. #220 grit sandpaper works well to cut back the glaze, with a final sanding using #320. After sanding, it should be so thin you can see through it.