JNATs and powdered steel gyuto, any success?

[leeskeeee]

So I’ve had success with JNATs on my wide bevels from aogami to ginsan. I would like to use JNATs on my gyutos too but all my gyutos are powder steel Hap 40 and ZDP. For gyuto, I set the bevel with 1k chosera then to 3k chosera then to JNAT. I’ve tried aiiwatani, hideriyama, binsui, Tsushima, and shoubudani with not much luck. Not much feedback from the stone and the edge feels “rolled” like it would if one over polished. I’ve tried with pressure, light pressure, slurry, no slurry. I’ve given up until recently I wanted to give it another try. I have a very soft and fast maruoyama shiro suita on its way I’m excited to try with it.

Has anyone had any success with powder steel and JNATs? Any tips would be appreciated or do those steel and rocks just not go together?

 

[refcast]

I've had Sg2 by Ryusen and hap40 by 2 makers (gihei and a tosa maker)

Yeah jnats tend not to do well. I've had similar experiences. A diamond slurry and rough surface help a bit though.

Belgian blue works great though

 

[leeskeeee]

I've had Sg2 by Ryusen and hap40 by 2 makers (gihei and a tosa maker)

Yeah jnats tend not to do well. I've had similar experiences. A diamond slurry and rough surface help a bit though.

Belgian blue works great though

For your hap40, do you still sharpen with natural stones or just synthetics?

 

[nakiriknaifuwaifu]

I've had Sg2 by Ryusen and hap40 by 2 makers (gihei and a tosa maker)

Yeah jnats tend not to do well. I've had similar experiences. A diamond slurry and rough surface help a bit though.

Belgian blue works great though

the abraisive in belgian blue are nice chubby garnets, so they will cut hard steel
i've finished my R2 takamura on aoto before, they work - but nakayama with m390 is very not good

 

[refcast]

Hap40 I've only cared to use synthetics. I have tried jnats on it, but they never got a hair grabbing edge, but they felt great in produce anyhow. It doesn't like to sharpen them so I don't care too much, and can make edges i like in synthetics, as long as the stone is fast cutting enough. It's been awhile and I haven't had a hap40 for a bit, I've sold them off in kitchen knives.

 

[SwampDonkey]

Coticule works pretty well with slurry on SG2 and S30V. By "well" I don't necessarily mean "fast" but I've been happy with the edge using it as a finisher. Not Jnat but the closest I've got for you

 

[Steve56]

For the hard, eear resistant steels like those mentioned, it depends on the stone. For example, I can put two almost identical looking and performing (on normal steels) kiita next to each other, one will cut powder steels and the other won’t. In addition to the usual steels, I have knives made of SLD, R2, and HAP 40. So far, the Yoshikane SLD has been the most finicky. It just burnishes on some stones. Not to worry though, a Shapton Glass HR will cut them like butter, since it’s what they were designed to do.

Good hunting, just try as many stones as you can.

 

[MSicardCutlery]

Find a source that lists the carbide volumes and types in the steel. Anything with MC type carbides will be less than ideal for sharpening on natural stones, though it can be done with varying degrees of success. Carbide volume and types are a more relevant detail than whether the steel is made by a PM process or conventionally. The reason is that some steels have carbides harder than conventional abrasives, that are a significant impediment to sharpening.

 

[Dull_Apex]

I successfully touched up my SG2 Kobayashi knife on my Yaginoshima suita (4/5 hardness) but the swarf looked like it contained a fair bit more stone slurry compared to a normal sharpening.
The next time that I used the stone was for a white paper steel knife and it seemed like the aggressiveness had been worn away when it would normally last longer before a refresh.