Polishing Noob...

[HumbleHomeCook]

So I'm just taking a couple baby steps into this to see if I like it. I don't even know most of the Japanese terms so bare with me.

Here's my Wat Pro that I played with on a small shoubudani.



Clearly the shine at the shinogi and edge reveal the bevels are concave (same on both sides). Is this where you either flatten them, use sandpaper or finger stones or powder?

I assume this also means losing the bead blasted finish yeah?

 

[cotedupy]

So I'm just taking a couple baby steps into this to see if I like it. I don't even know most of the Japanese terms so bare with me.

Here's my Wat Pro that I played with on a small shoubudani.



Clearly the shine at the shinogi and edge reveal the bevels are concave (same on both sides). Is this where you either flatten them, use sandpaper or finger stones or powder?

I assume this also means losing the bead blasted finish yeah?

Basically - 'yes' to all of those q.s. You've got exactly the right thinking already!

One thing I'd say is: If you want it looking really nice then I would flatten it completely to a zero bevel and then go from there. IME bead blasted 'kasumi' finishes tend to hide some quite deep grind marks that sandpaper and finger stones are probably going to struggle with.

 

[HumbleHomeCook]

Basically - 'yes' to all of those q.s. You've got exactly the right thinking already!

One thing I'd say is: If you want it looking really nice then I would flatten it completely to a zero bevel and then go from there. IME bead blasted 'kasumi' finishes tend to hide some quite deep grind marks that sandpaper and finger stones are probably going to struggle with.

Thanks buddy. I knew you were going to tell me it was going to be work.

Is there no real performance set back by flattening the concave bevels? I know it will happen over time as I thin anyway but thought I'd ask.

 

[M1k3]

Is there no real performance set back by flattening the concave bevels? I know it will happen over time as I thin anyway but thought I'd ask.

Depends.
If you make the bevels super flat, you'll increase stiction. But make polishing much easier.

If you keep the same overall angle between the cutting edge and the shinogi, it'll be thicker directly behind the edge, compared to a hollow grind.

If you convex it, raising the shinogi and keeping behind the edge thin, then you should have an amazing cutter again. But polishing will require a little extra work.

 

[user 16756]

fwiw it's really hard to make completely flat bevels when shaping by hand, at least IME.

also IME, convex wide bevels are almost always an improvement on the hollow originals.

 

[tostadas]

I have not found a strong correlation between convexity and stickiness. I've had highly convex knives that stick like glue, and also had dead flat blades shed food like nothing. I feel like the blade finish has a much greater influence on the amount of stiction you experience.

That being said, if it were my own knife to polish, I'd raise the bevel until you can get the blade road even (unless you do this on sandpaper+atoma, it will likely end up being at least slightly convex regardless) , then go to town with your favorite rocks.

 

[HumbleHomeCook]

I have not found a strong correlation between convexity and stickiness. I've had highly convex knives that stick like glue, and also had dead flat blades shed food like nothing. I feel like the blade finish has a much greater influence on the amount of stiction you experience.

That being said, if it were my own knife to polish, I'd raise the bevel until you can get the blade road even (unless you do this on sandpaper+atoma, it will likely end up being at least slightly convex regardless) , then go to town with your favorite rocks.

When you say "raise the bevels" you mean raise the shinogi?

 

[tostadas]

When you say "raise the bevels" you mean raise the shinogi?

Yes

 

[cotedupy]

Thanks buddy. I knew you were going to tell me it was going to be work.

Is there no real performance set back by flattening the concave bevels? I know it will happen over time as I thin anyway but thought I'd ask.

I've never noticed any no. In fact, like others have said - it should be an improvement.

I've flattened the wide bevels on quite a lot of knives and extremely easy to do, takes a little while, but not difficult. You don't really even need to think that much about what you're doing, because you'll naturally get a touch of convexity into it anyway, at a level that seems pretty perfect for kitchen knives (imo).

---

There is of course one other option if you wanted to be really kooky. I've never actually tried it cos of the effort involved, but it will work... you could polish a concave bevel and maintain the grind if you convexed the surface of your stones.

 

[HumbleHomeCook]

So, the question I've now encountered is, is edge bevel polishing more than just aesthetic? I mean that Wat Pro is slicing like a demon with just the little bit I did. Could be my imagination because I freshened the edge too.

 

[M1k3]

Makes the food taste better. The more expensive the stone, the better the food will taste

 

[M1k3]

Honestly, unless you're making an improvement on the geometry, no it won't affect performance.

 

[tostadas]

So, the question I've now encountered is, is edge bevel polishing more than just aesthetic? I mean that Wat Pro is slicing like a demon with just the little bit I did. Could be my imagination because I freshened the edge too.

Polishing only the edge bevel doesn't do much. If you polish the whole blade, depending on the final finish, it can affect the food release. I've seen significant improvement before and after on a number of my blades. It takes some experimenting with different stones to see what you like.

Also, depending on the existing finish, the overall impact will vary. For example, if the knife has a coarse king 800 finish, then polishing it up higher will allow for less drag (you can feel the difference when you dry with a damp towel). If on the other hand the knife has a finish where everything sticks to it, a hazier kasumi could help break some of that stiction.

 

[HumbleHomeCook]

So when I look at work like this from @milangravier(which is awesome):



How are the three different finishes maintained? More specifically, how is the hazy middle portion and the rather distinct yet still wavy line between it and the polished edge maintained?

I get the upper forged section and I get the edge polish section. It's the middle that boggles my mind. Especially maintaining the waviness and not just ending up with a straight line.

Hope that makes sense.

 

[M1k3]

So when I look at work like this from @milangravier(which is awesome):



How are the three different finishes maintained? More specifically, how is the hazy middle portion and the rather distinct yet still wavy line between it and the polished edge maintained?

I get the upper forged section and I get the edge polish section. It's the middle that boggles my mind. Especially maintaining the waviness and not just ending up with a straight line.

Hope that makes sense.

Different thickness in the knife. Thicker = higher shinogi. Thinner = lower shinogi.

 

[HumbleHomeCook]

Different thickness in the knife. Thicker = higher shinogi. Thinner = lower shinogi.

But in this case, isn't the shinogi the dark line beneath the "nashiji" finish? What I'm talking about is that middle section that is so often sand blasted on common knives.

 

[ethompson]

That’s not a finish from a different stone, it’s just very defined carbon migration IMO. Pulling out that might detail to show the carbon migration vividly is a labor of love

 

[HumbleHomeCook]

I mean this part:

 

[M1k3]

I mean this part:

View attachment 232580

Soft iron. Different results compared to the hardened steel. Usually maintained with the same stone, I believe.

 

[HumbleHomeCook]

@M1k3 Okay that makes sense. I ask because when playing with a knife with a sandblasted finish, I tend to start to form a straight line between the hazy blasted finish and the polished area. I reckon apples and oranges then huh? The blasted finish being a surface finish of it's own and not actually integral to the metal.

 

[stringer]

@M1k3 Okay that makes sense. I ask because when playing with a knife with a sandblasted finish, I tend to start to form a straight line between the hazy blasted finish and the polished area. I reckon apples and oranges then huh? The blasted finish being a surface finish of it's own and not actually integral to the metal.

Yeah different kind of beast. He hand forged the cladding and then he has a really complex grind that is differential on all three planes. And then hand polished and blended on hand picked heirloom jnats.

 

[stringer]

Yeah different kind of beast. He hand forged the cladding and then he has a really complex grind that is differential on all three planes. And then hand polished and blended on hand picked heirloom jnats.

Very handsy

 

[HumbleHomeCook]

Yeah different kind of beast. He hand forged the cladding and then he has a really complex grind that is differential on all three planes. And then hand polished and blended on hand picked heirloom jnats.

Yep. As soon as @M1k3 pointed it out, I had a forehead slap moment. Totally get it.

Also, did I mention that @milangravier's and @DanielC's stone work is absolutely gorgeous?

 

[PostLimón]

For what it's worth, Milan did a live showing how he approaches prepping a blade for polishing and how the stones bring out different finishes in the hardened steel vs the soft iron. It's a long video, but worth a watch!

 

[mockit]

Milan.... so hot right now . Deservedly so, I might add. Interesting to see your journey HHC! Is the Wat Pro considered a wide bevel? It doesn't seem that wide, but the height of the nakiri may be skewing my perspective. The polish job looks great. Is the discoloration at the heel from an uneven shinogi or a high spot? Got to get me some wrought iron to play with .

 

[riba]

I am not into polishing myself (rather admire somebody else's work ) but I've been grinding my Wat pro just little bits over time.
One stubborn low spot left on this side.


(Needed a touch up after ARM)

 

[naader]

Is there no real performance set back by flattening the concave bevels? I know it will happen over time as I thin anyway but thought I'd ask.

not enough to notice on a bevel that short lol. plus a bit of convexity at the edge goes a long way.

You gotta flatten that thing on stones if you wana enjoy jnats with it.

 

[naader]

I am not into polishing myself (rather admire somebody else's work ) but I've been grinding my Wat pro just little bits over time.
One stubborn low spot left on this side.


(Needed a touch up after ARM)

didnt see this before my last post. Pretty good!

 

[riba]

I don't notice any difference