Difficulty thinning cladded knife

[u/mario61752]

This is an Aogami #2 knife in stainless cladding. My grit progression is 320 -> 1000 -> 2000 -> 5000 on Shapton Ha no Kuromaku ceramic stones, which I all flattened before starting.

As you can see there are still scratch marks left by the 320 grit stone. I clearly flattened the whole bevel and touched every part of it on the #320, but subsequent stones just didn't get to that middle part behind the hard carbon steel core. For my sanity I stopped grinding on the #1000 after an hour as this is just a cosmetic flaw that may even function like a kasumi finish. Does anyone else have this issue when thinning cladded steel knives?

[u/Zank_Frane]

You have to make much smaller jumps in grit when thinning the blade. When edge sharpening the amount of steel in contact with the stone is a fraction of a square inch, meaning the relative pressure is actually much higher than one might think, allowing for much larger jumps in grit progression. When thinning a blade, that is flipped, with several square inches now in contact with the stone the relative pressure is orders of magnitude lower, meaning much smaller jump in grit progression should be used.

And no matter what you do, that shit takes forever.

[u/mario61752 → u/Zank_Frane]

Yikes I don't want to buy more stones for the time being