Cheap stainless santoku, the tip and middle raise a burr in a couple of minutes but the last 3cm toward the heel gives me nothing no matter how long I grind. I can feel the stone contacting there. Marker test shows the ink coming off the shoulder but not right at the edge in that section. Am I doing something wrong or is the geometry off from the factory?
Also check that your 1000 hasn't dished in the middle. If it's low in the centre, the heel section rides on a curve and never gets flat contact. Pencil grid, 40 or 60 grit flattening plate, thirty seconds, and half the mystery problems go away.
Second this, and flatten more often than feels reasonable. A soaking stone can dish visibly in one long session on a hard knife.
Forty minutes on a 1000 without a burr means the stone is glazed, dished, or you're not on the apex. Rub it with a nagura or a bit of coarse stone until it feels grabby again before you assume it's technique.
One more thing to rule out: on a lot of santoku the heel has a slight ricasso or an unsharpened choil area. If that's the case you may be trying to sharpen a section that was never meant to have an edge.
@whetstone_wu · 7mo ago · 3 replies
Marker coming off the shoulder and not the edge means you aren't reaching the apex there, which is almost always a thicker bevel near the heel from the factory grind. You have two options: raise your angle a couple of degrees just for that section until you get a burr, then blend it back, or commit to thinning the shoulder on a coarse stone. On a cheap santoku I'd do the first one, it takes ten minutes instead of an hour.
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@kraut_corner · 7mo ago
Raised it maybe 3 degrees for that stretch and had a burr in four minutes. Slightly annoyed it was that simple.
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@whetstone_wu · 7mo ago
It usually is. Nobody grinds a 30 pound knife to a consistent bevel down the whole length.
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