jcwit
member
I have sharpened C-2 and C-3 carbide router bits easily with 200-400 grit 'auto'/wet-dry' sandpaper.
I used carbide saw blades and router bits and carbide end mills and I'd sure like to see the sharpening done with wet or dry sandpaper on any of these. Sorry, I just can't fathom it. Not calling you a lier but just can't believe it either.