kennbr34 wrote: ↑Tue Mar 21, 2023 11:31 pm
vandelay wrote: ↑Tue Mar 21, 2023 5:00 pm
Maybe 5 minutes for a chipped blade on a DMT x-coarse stone. Those really chew through steel.
How? I've got a lot of very coarse hones--an Atoma 140, a Shapton 120 and a Baronyx Knife Co "Manticore" that's a 60 grit SiC stone--but none of them will repair or reprofile a very blunt blade in less than an hour or two. I've heard similar time estimates before but can never understand how it's possible unless you're all using super fast strokes and tons of pressure or something, but even when I have tried that it doesn't seem to speed things up at all.
It depends on more than the grit. I have a 120 grit flattening stone from my old sharpening set. It sounds aggressive but the grit isn't very exposed so it barely takes steel off. The DMT x-coarse stone is incredibly aggressive (it's visibly coarse), so it's able to just grind away steel really quickly. The downside is that it's so aggressive that you need to grind on a higher grit for the edge to actually cut anything (it also microchips higher carbide steels).
I've sharpened a number of kitchen knives for family. They're usually 1.4116 or 440A, totally blunt and have sizeable chips. I just do rapid short strokes and it grinds the steel away fast enough to get it back to a rough apex in a few minutes. I don't time it so maybe 5 minutes is an exaggeration.
I use a similar technique to what's shown in this video (except I'm much worse at it):
https://youtu.be/QIo9p4W_QJ8
kennbr34 wrote: ↑Tue Mar 21, 2023 11:31 pm
I'm also not really sure why people are suggesting soft knives are any harder to grind? I have just heard it's harder to deburr them.
Yeah, in terms of just removing metal, I remember it being easier on really low carbide steels back when I used an aluminum oxide stone. With diamonds, they all feel about the same. When trying to get a good apex, you can run into burr formation and microchipping, but that's only a real problem once you've got a rough apex.
Burr formation can be really annoying on some low carbide steels though. I remember cleaning up a chip in a 1095 knife and getting a visible burr that was at least 0.5mm long.