I really wasn't sure if it was going to work when I started. On the driver side panel I started with 80 grit and then 220 grit...just the driver side alone was 3 hours of sanding and even then it wasn't exactly where I would normally like it but when I redo them I'll use a sander and finish with a finer grit sandpaper. It won't take near as long now that all the rot is gone