I thinned one of my white steel honyaki gyuto. I used Norton Blaze Ceramic 50 grit, Blaze Ceramic 120 grit, Ceramic Norax X65, Norax Piramid x45, and finally Norax Pirmaid X30.
I then moved onto a hand-sanding, starting with 180 grit 3M automotive paper. I discovered that under all these grits above, the initial scratches done by Blaze Ceramic 50 are still here and there on the blade.
After some more sanding, some scratches were still difficult to remove. I wrapped a sand paper around a wooden block and applied a good amount of pressure. but I felt that I need to drop way below 180grit to make a difference. Didn't have a a lower grit paper on hand, so had to just keep sanding with 180. Very lengthy and inefficient process, as it turned out.
Norton Blaze is quite popular line of belts, so how do you guys deal with this issue (deep scratches) before moving onto a hand rubbed finish? Is there a better way to remove the deep scratches? I heard people use a disc sander for that, but I haven't tried it myself.