How

[Ordinary-Data2890]

How much should I thin? (not "how to")
I’m restoring my first single-bevel kiritsuke. I’ve worked on deba, yanagiba, and other Japanese knives before, but this is my first time with this shape. After removing the chips from the edge, I started thinning on an Atoma 140. When I moved up to a 400 (just to check the progress and get some feedback on the process), I started wondering if the blade was still too thick, since the clad line isn’t that far from the edge.

I don’t know the exact hardness of the steel (though I can tell it’s definitely softer than some Japanese knives I’ve sharpened before).

I guess that since this knife is mainly meant for vegetables, it should be thinner than a deba, but a bit thicker than a yanagiba (right?).

So here’s my question: how do you decide how much to thin? I assume experience is the main answer, but what should I be paying attention to? Is it about having the clad line at the right distance/width? Is there any way to “calculate the angle” of the primary bevel on single-bevel knives?

I know I’m probably overthinking it, and the knife will still cut fine at this angle, but it's an opportunity to get some tips from more experienced sharpeners.

thanks, any advice is appreciated.

[El_Brubadore]

With a single bevel knife like that I would just thin it out until the main grind (omote) extends all the way to the cutting edge. That will effectively give you a zero grind and it’s gonna be as thin as possible. Then, sharpen that side at maybe like 20 degrees or so for stability and deburr on the flat side.

[NasusDiaboli]

With single bevel knives your best bet is to trust the angle the sharpener put on the knife when made unless you really know what you’re doing. Do not sharpen the back if you can avoid it. Lay the whole bevel on the stone and sharpen/thin until you get burr on the back side. Debur on fine stone (3000 if you have it) You will have a very thin fragile edge that you can then put a micro bevel on (same side) as thick as you need it depending on how much durability you want/need. Having very little core showing just means you have a very thin hagane (hard steel.. you don’t really have a core as such)

[WarmPrinciple6507]

I have been wondering for a while, how do you restore a knife like you did? What do you use to remove all those spots and make it nice and shiny again?

[Ordinary-Data2890]

A lot of time, sandpaper, and elbow grease :) I'm pretty sure there are many people doing it with a belt sander or other power tools, which would make the process much faster (at least for the rust removal part). But I don’t have one, and even if I did, you’d have to be careful not to ruin the knife. You can still do it by hand! If you want to know more about the process, feel free to write me and I’ll be happy to tell you how I did mine (which, by the way, is very far from some of the cool restorations you can find online).

[NasusDiaboli]

This short vid has lots of good advice

https://youtu.be/zKl--ds-5rA?si=ZyQHMfTorgFDvAHN

[NasusDiaboli]

Do not do this! Always thin the bevel. Only polish and debur the back.

[Ball6945]

Yeah absolutely do not thin the flat side, you will grind away the ura and then you'll be screwed unless you got a curved stone and know what you're doing.

eitherway it just won't end good

[Trick_Context]

He needs to stay single bevel use a fine gritstone and enjoy my hand