Show your work! Uchigumori and co...

[tostadas]

also - checking for thinness BTE while you thin... press the edge / BTE area against your nail and see how flexy it is. A common mistake is to overthin and end up with a foil edge. Then when you sharpen the edge crumbles and that can affect the profile (or it even starts crumbling while you thin).

To add to this. If it's nail flexing while you're still on your coarsest stone, the edge isn't gonna hold up. Check the thickness regularly and allow for some buffer as you move up the grits.

 

[NickMinton]

To add to this. If it's nail flexing while you're still on your coarsest stone, the edge isn't gonna hold up. Check the thickness regularly and allow for some buffer as you move up the grits.

So what’s the best move if you’re on an Atoma 140 or 400 and there’s still a significant low spot but you’re getting to the point where the edge might become flexible / weak? Abandon the idea of polishing that blade?

 

[Ok__mode_6953]

So what’s the best move if you’re on an Atoma 140 or 400 and there’s still a significant low spot but you’re getting to the point where the edge might become flexible / weak? Abandon the idea of polishing that blade?

Finger stones?

 

[Choppin]

So what’s the best move if you’re on an Atoma 140 or 400 and there’s still a significant low spot but you’re getting to the point where the edge might become flexible / weak? Abandon the idea of polishing that blade?

mmm good question… it depends, but I’d consider pushing the shinogi up over that spot (put pressure just below the shinogi when thinning). Then hopefully you’ll keep the edge as is and be able to create a flat surface from about the middle of the bevels up to the new shinogi. Hope that makes sense. A side effect is that you’ll create some convexity and end up with a bevel that’s not entirely flat. But it should be free of low spots at least.

For instance, on the Ikenami I’m thinning I have a low spot here (the red circle, my stone masked it but it’s there). I’m doing a sort of hamaguri bevel so convexity is welcome. I’ll push the shinogi up to the red line more or less, it should look good in the end, and then just polish the area close to the edge with my next stone.



If the low spot is close to the edge, then honestly I’d use muddy stones or fingerstones… IMO better to live with a less than perfect finish that an altered profile.

 

[Heckel7302]

If it’s hollow ground and already thin BTE, you’ve got to concentrate all your effort up at the shinogi. Take out the hollow from the top side.

I usually run into getting too thin near the tip, usually at the curviest part of the profile a coulple cm from the tip. I have to always be sure to concentrate on my angles and concentrate more effort near shinogi.

Getting to edge crumple stage isn’t the end of the world though. Just mean a slightly shorter knife.

 

[ethompson]

I’d recommend sacrificing some height at this point. Shave off 2mm sharpening at 45-70° and you’ll have a thicker edge you can work with.

@tostadas had a good point - you don’t want to hit nailflex on the coarse stone. I usually target hitting that early on at 800 grit. By the time I’m done with 1500 grit then the edge is flexing nicely without being weak.

 

[NickMinton]

If it’s hollow ground and already thin BTE, you’ve got to concentrate all your effort up at the shinogi. Take out the hollow from the top side.

I usually run into getting too thin near the tip, usually at the curviest part of the profile a coulple cm from the tip. I have to always be sure to concentrate on my angles and concentrate more effort near shinogi.

Getting to edge crumple stage isn’t the end of the world though. Just mean a slightly shorter knife.

Ok cool, that makes sense. Thanks!

 

[NickMinton]

Thanks everyone for the pointers for a guy relatively early in his polishing journey!

 

[NickMinton]

I’d recommend sacrificing some height at this point. Shave off 2mm sharpening at 45-70° and you’ll have a thicker edge you can work with.

@tostadas had a good point - you don’t want to hit nailflex on the coarse stone. I usually target hitting that early on at 800 grit. By the time I’m done with 1500 grit then the edge is flexing nicely without being weak.

Thankfully the heel height is high (56mm) so I may go that route

 

[deltaplex]

So what’s the best move if you’re on an Atoma 140 or 400 and there’s still a significant low spot but you’re getting to the point where the edge might become flexible / weak? Abandon the idea of polishing that blade?

A good amount of this can be avoided by charting out the current bevel geometry and then laying out the intended changes before starting in on altering it. With that, you have a reference that you can check your progress against, and make adjustments to as you go along, so you aren't trying to figure out how to deal with a low spot after you have removed a bunch of material. It also really helps you figure out what is or is not possible on any given knife, and how difficult it should be to accomplish.

To echo what @ethompson said: as you remove material from the bevel, you're altering the structural properties of the blade. The metal is going to respond to these different structural forces, so it's in your best interest to remove it as evenly as you can from both sides (or whatever is appropriate for the construction), and check the state of the blade as you make progress, not only against what your plan is, but also for any additional movement; you cannot over-check.

There are plenty of times I've had an overgrind close to the edge that isn't worth trying to work out, for a number of reasons, and in those cases you can even the finish out using flexible abrasives, little bits of stone, polishing compounds, and etchants.

I'm well behind on my knife work queue, but I do have one close to the front where I'm planning to layout the WIP from assessment through finishing that will at least show how I approach this kind of work; as always feel free to ask in threads or DM about anything you've got questions on.

 

[tostadas]

So what’s the best move if you’re on an Atoma 140 or 400 and there’s still a significant low spot but you’re getting to the point where the edge might become flexible / weak? Abandon the idea of polishing that blade?

If it’s hollow ground and already thin BTE, you’ve got to concentrate all your effort up at the shinogi. Take out the hollow from the top side.

I usually run into getting too thin near the tip, usually at the curviest part of the profile a coulple cm from the tip. I have to always be sure to concentrate on my angles and concentrate more effort near shinogi.

Getting to edge crumple stage isn’t the end of the world though. Just mean a slightly shorter knife.

I’d recommend sacrificing some height at this point. Shave off 2mm sharpening at 45-70° and you’ll have a thicker edge you can work with.

@tostadas had a good point - you don’t want to hit nailflex on the coarse stone. I usually target hitting that early on at 800 grit. By the time I’m done with 1500 grit then the edge is flexing nicely without being weak.

You need to think about it also in the other directions besides just up and down. The local "low spot" is often a result of higher spots above and below. But also you should look to the left and right of the spot for higger spots.

So you don't necessarily always need to make the decision to take from the edge side or the shinogi side. It may be just a matter of being more thorough of distributing your thinning along the entire length of the blade. Remember, to remove a "low spot" is to remove all the surrounding"higher spots" around it.

 

[DanielC]

 

[ethompson]

Soft and fine stones are such a pleasure to polish on. Crazy glossy kasumi off a Takaoyama

 

[MowgFace]

Thankfully the heel height is high (56mm) so I may go that route

This is what I had to do with a Goko. Same issue. Overground close to the edge. I shaved off ~2mm and thickened up the edge. I have plenty of room now to thin as I please.

 

[ethompson]

Macros of the crazy grain on this Hinoura santoku

 

[Pie]

Big shout out to my iyoto for making me feel better about my polishing skills

 

[Ok__mode_6953]

What is harder, adding convexity, or getting it on camera?

Still one or two more steps of refinement to go before I’m happy, but this Jiro project is almost done thanks to some tutelage from @cotedupy on the rotary whetstone.

 

[EricEricEric]

What did you think of the wheel?

 

[KasumiJLA]

What is harder, adding convexity, or getting it on camera?

Still one or two more steps of refinement to go before I’m happy, but this Jiro project is almost done thanks to some tutelage from @cotedupy on the rotary whetstone.

I would say both! Haha

Nice work indeed if it is not easy to see with naked eyes. That means the job is well done and it blends in beautifully

 

[Ok__mode_6953]

What did you think of the wheel?

Not as terrifying as expected with a moderate speed and a 400 grit stone installed.

It’s much easier to build convexity in than with a bench stone imo - you only have to focus on maintaining the angle you want and the stone does the work, you can gently move the angle back and forth to blend everything together.

It took about 45 minutes (bearing in mind I’m still new to this and check my work very frequently) on the wheel to do what probably would have taken me easily >6 hours on a bench stone at home.

I would say both! Haha

Nice work indeed if it is not easy to see with naked eyes. That means the job is well done and it blends in beautifully

Thank you kindly my good man, although I’ll need to see how well it cuts before we can call it a success

 

[Choppin]

Ikenami, getting there. I kinda like the wavy shinogi

Most of the convexity is gone. Debado 180 then SG220. Small low spot near the tip that I might live with as I want a more robust tip on this one.

 

[EricEricEric]

You could also consider making it an ultra wide bevel like you see with hado knives

 

[rob]

Here is a quick and dirty job i applied to an old Shun i found at the local thrift store.
Came up OK for a first attempt.

 

[deltaplex]

What is harder, adding convexity, or getting it on camera?

Still one or two more steps of refinement to go before I’m happy, but this Jiro project is almost done thanks to some tutelage from @cotedupy on the rotary whetstone.

It doesn't seem that hard to meeee...

 

[DanielC]

Bought a Venev from @Byphy And had to try it out over the weekend on a knife kicking around the shop, and just kept going. Pretty nice. I do enjoy the 100 grit quite a lot.

 

[Ok__mode_6953]

Well, here it is the ‘finished’ product

After all that work, it turns out none of my Jnats wanted to play nice with the cladding - slurry, no slurry, working the slurry for ages, Atoma, nagura, differing levels of pressure, you name it - scratchy cladding.

The cladding did actually look good with the Morihei 4k, but in my infinite wisdom I didn’t take any pictures.

Happy with the geometry though.



I am now quite happy not taking on any more projects requiring major thinning for the next few months at least!

 

[DanielC]

Well, here it is the ‘finished’ product

After all that work, it turns out none of my Jnats wanted to play nice with the cladding - slurry, no slurry, working the slurry for ages, Atoma, nagura, differing levels of pressure, you name it - scratchy cladding.

The cladding did actually look good with the Morihei 4k, but in my infinite wisdom I didn’t take any pictures.

Happy with the geometry though.



I am now quite happy not taking on any more projects requiring major thinning for the next few months at least!

It can be quite difficult to get such a wide bevel to play nice. I've done it that wide a few times. When in doubt, scratch it all up with a Debado 180 again.

 

[Byphy]

Bought a Venev from @Byphy And had to try it out over the weekend on a knife kicking around the shop, and just kept going. Pretty nice. I do enjoy the 100 grit quite a lot.

View attachment 272833 View attachment 272834

Glad you're liking it, I know you'll maximize its potential!

 

[KasumiJLA]

Here is a quick and dirty job i applied to an old Shun i found at the local thrift store.

I should go to my thrift shop more often

 

[rob]

I should go to my thrift shop more often

or mine!