"Fixing" an asymmetric choil

[esoo]

So I have the Tanaka/Yohei that is up for sale (or I could possibly return) as the choil is 70/30 right biased. I held the knife again and I'd much rather keep it as it is a gorgeous piece, so how hard is it to balance out a choil? Shoe-shine it with sandpaper? Dremel it?

I know it'll likely never be a good as having been ground the right way in the first place, but if the chances are good that I could get it the point that it is good for a lefty, I may just decide to keep it.

 

[esoo]

OK, so I've decided after holding the knife in my hands a few more times that I'm going to keep it and work on the choil.

I've ordered a bit better sandpaper to work on the choil, and that will arrive soon.

Next step for this thread will be get some pics in here to document the starting state.

 

[tostadas]

Choil is not too difficult to do. Just find something round to wrap the sandpaper around (wooden dowel, cork, marker, etc) and smooth out the areas that bother you. Id also tape up the parts of the knife that you want to avoid inadvertently scratching in the process. I recommend 120-220-400-800 sandpaper at the least. You can always do more depending on the final level of polish you like.

 

[Delat]

Are you simply looking to improve comfort when holding the knife, or change the whole grind to lefty?

 

[esoo]

Are you simply looking to improve comfort when holding the knife, or change the whole grind to lefty?

Improving the comfort. I know I can't change the grind to a lefty.

As far as I can tell, this knife is actually ground biased for a lefty (with the exclusion of the choil). Using a business card resting on the right face, it is quite flat while on the left side you can see the convexity. I'll try and get a pic of that later, but I only have so many hands to hold things.

Here is a choil shot I just took. You can see the hard edge of the choil as the silver line slightly offset to right in pic. That is what needs to be reduced to help with the comfort.

There is also some optical illusion going on with that shot. Due to the way the choil is ground, there is more "exposed" steel on what is the right face than the left face, which makes things look a bit funky.

 

[Delat]

When I rounded the choil on one of my knives I just wrapped sandpaper around either a pen or fat sharpie, depending on how large a diameter I needed. Then it went pretty fast - just some rubbing against the hard edges at varying angles.

I think I started with 320 or 400 grit and went to 600; it went super fast but that particular knife has very soft cladding compared to some of my other clad knives.

 

[Nemo]

You can improve the comfort a lot by removing a little bit of metal (champfering the "sharp" right angle).

You can improve the comfort a little more by removing a lot more metal (almost making a shallow "groove" for your finger).

Option 1 is usually fine.

 

[zizirex]

Ask Bryan or Chuckie to polish the choil for lefties

 

[esoo]

Ask Bryan or Chuckie to polish the choil for lefties

Who?

 

[zizirex]

Who?

Bryan or Chucky from Tosho.

if you want nicely polished, Dremel is the only way to finish.

But to take away metal on early stage, sandpaper is a safer bet

 

[esoo]

Bryan or Chucky from Tosho.

if you want nicely polished, Dremel is the only way to finish.

But to take away metal on early stage, sandpaper is a safer bet

Ah. Only know Tyler, Joey, Josh by name there.

And interestingly they didn't offer it as an option when I talked to them about the choil.

 

[zizirex]

Ah. Only know Tyler, Joey, Josh by name there.

And interestingly they didn't offer it as an option when I talked to them about the choil.

Tyler is Chucky.
Well, it's a service that's not common but they are pros and I think they could help you either as a service or as a bit of advice.

 

[myguidingmoonlight]

Tyler is Chucky.
Well, it's a service that's not common but they are pros and I think they could help you either as a service or as a bit of advice.

I asked them about refinishing services once for a gyuto they just said they can only do services available on their website.

I have a couple gyuto that needs choil and surface refinishing, thought of Jon from JKI but their service is on hold right now.

 

[esoo]

So I did a little work yesterday.

Blade taped up to protect everything except the choil:

100u paper wrapped around copper tube - this seem to nicely fit into the curve:

And after about 20 minutes and a few strips of paper, this was the result:

Compared to the previous choil shot, you can see that the choil has widened. I did better up the edge of the blade (where I did just use some paper and shoe-shine it). Seems good enough for now, but I'll likely comeback and work on it some more.

As for paper - I used this paper 3M Aluminum Oxide Films for Sharpening - Lee Valley Tools in the 100u format. It was a bit of a pain - it feels like it is plastic backed, and used dry the abrasive came off of it so incredibly quickly it was ridiculous. The 30u and 9u are the same plastic backed, but the 3u is paper backed. I'll use the stuff as that is what I bought, but I won't buy it again.