New (to me) steels

[gman]

I've collected 6 blue super knives over the last 4 years, and have been pretty satisfied taking them up to 8k, but I'm now branching out to other materials and looking for input on whether I will need to do anything differently.

I bought my wife a Kurosaki 180mm gyuto in R2 stainless. I'm probably overly excited about this knife, but after a very slow adoption from using steak knives and other abominations, she had finally settled on using my 150mm petty has her primary knife, and is now comfortable enough with it to graduate to something a little bigger. Is there any point taking R2 past 3k?

The other new knife on the way is a Kitaoka 165mm deba in white #2. This is my first single bevel. I originally wanted a deba capable of dealing with lobster shells, but decided that was a dumb idea and will keep using a cleaver for that. This knife will be used only for fish, from trout on the small end to coho salmon on the large end. I understand that I should sharpen it less acutely at the heel, and put on a microbevel, but what grit should I be using?

Thanks in advance!

 

[Paraffin]

I have three knives in main rotation as a home cook, all in Blue #1, and one other in Aogomi Super that I use occasionally. My wife uses a Kurosaki 180mm nakiri in R2, so that would be equivalent to your wife's R2 gyuto. Here's some feedback based on those similarities.

First, I use a progression of 2k and then 6k on those carbon knives (Gesshin soakers). Nothing higher grit, because I like a little "tooth" for home kitchen use. So that's one difference between us, but may not too significant.

When it comes to my wife's Kurosaki nakiri in R2, I basically treat it the same way I do the carbon knives. It just takes longer because it's more difficult to get (and detect) a decent burr along the edge, compared to the carbon knives. I start sharpening on the 2k stone, I do 90% of the bevel set and de-burring there. Then finish on the 6k just for final burr removal and a tiny effort at a micro-bevel, not trying to get a polished 6k edge.

Now, if it was something specialized like a carbon single-bevel usuba or yanigaba, I'd probably be going to 8k. I'm pretty firmly in double-bevel knife land though, where a toothy 2k edge with a light 6k finish works for me. And especially for stainless steels, even the fancy stuff like R2 or HAP40, I'm happy with that approach. Anything more on stainless is just too much work.

 

[Benuser]

I have better results with AS when started on a medium-coarse stone. Must have to do with tungsten carbides, I guess.
Otherwise, I'm with Paraffin: above 2k only for deburring or for fun.

 

[inferno]

I happen to have 3 knives in r2. All kurosakis. You can take them up to whatever grit you want. even 30k. It will get shinier but not necessarily that much sharper past a certain point. I think at around 4k all SS and powder is at their max. I took one to 8k, it felt very sharp but not anywhere near blue 2 at 8k. All SS and powder lose this ultra sharpness very very quickly too so its very short lived in my experience. Basically its usually not worth the hazzle to take them above 3k or so. maybe 4k. And at 3-4k things start to get really sharp i think. Really no need to go above this.

With that being said I took an skd11 santoku to 12k a couple of days ago. Just for fun. Its now so sharp it actually scared me when i felt the edge with my fingers. Is it worth it?? Not really. But doable.

Also what edge one guy gets off a 2k stone doesn't necessarily mean that the next guy with different stones get the same edge, could be better or worse. Sharpening is a skill you learn and become better at.

 

[galvaude]

FWIW the Takamura brothers sharpen their R2 knives up to 3000, the progression seems something like 500-1000-3000, finish straight off the stones

 

[galvaude]

Just to add, I sharpen most good stainless knives on the Shapton Glass 500 and use it like I would use a 1000 grit stone. I then finish on the Shapton Pro 2000. This is my favorite progression for most good quality steel, I even like it for carbon.

 

[gman]

thanks all, very useful!

 

[LucasFur]

FWIW the Takamura brothers sharpen their R2 knives up to 3000, the progression seems something like 500-1000-3000, finish straight off the stones

I would disagree with you and suggest that Takamura wraps up their sharpening on chromium oxide.

For the OP ... as far as i can tell R2 and Blue super are on par in many respects in use. Both will benefit equally from going to a higher grit. Admittedly my goldilocks grit for my knives is in the 3-4k range.

 

[galvaude]

I would disagree with you and suggest that Takamura wraps up their sharpening on chromium oxide.

For the OP ... as far as i can tell R2 and Blue super are on par in many respects in use. Both will benefit equally from going to a higher grit. Admittedly my goldilocks grit for my knives is in the 3-4k range.

I could be wrong but everytime I saw one of the two brothers sharpen they were sharpening the knives up to a Shapton Glass 3000 and then they proceeded to deburr on coarse fabric (swipes). Could very well be different at their shop for production knife but it is the sharpening progression they recommend.

 

[LucasFur]

Could very well be different at their shop for production knife

I could be wrong also ... let me elaborate --- this is from one friend visiting the shop he saw them finish on one of those spinning jigs that was loaded with green paste. (which was interpreted as chromium oxide)
This was a Uchigumo line that might have just been getting the final buff before going in the box. But from use and owning 3 takamura's i can say their box edge is quite sharp, and very very thin. It always micro-chips right from the box. I interpret it to show how fine the edge can be.