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Sharpening help needed.

Mon May 14, 2012 2:27 pm

Hi. I have a 7" Ken Onion Santoku by Shun and I'm wanting to grind the belly to be more flat. The spot is about 3" long and about 3mm deep or so. Would it be better for me to grind the belly flat and then resharpen the edge, or grind the belly with the 50/50 bevel? Or, is there a way to do it that I'm not thinking of? Basically I'm wanting to make the knife more flat as that better suits what I'm using it for. Any help is appreciated.

Philip S.

Re: Sharpening help needed.

Mon May 14, 2012 3:12 pm

Well, it appears the Ken Onion Santoku actually already has a fairly flat profile to begin with, so yes, you could grind this knife to have a flat profile again without too much fuss. The edge needs to placed flat against a grinder (like a 4 x 36), or diamond plate, and the edge needs to be ground flat. Where to start grinding it flat and how much is to be determined by the user, but basically you can get your diamond stones out and just go ahead, place it straight down onto the stone (oh that's scary the first time you do it) and saw back and forth the get the flat spot larger, or you can rock slightly with the motion to blend the profile if you don't want a dead-flat spot.... like I said, it's up to the user where and how flat it ends up, use your common sense.

Once the desired blade profile has been achieved, you have to make sure the edge has been knocked off of most of the knife.. just trust me on this. Even though you are maybe only working on 50% of the blade, you still want to knock the entire edge off before resetting the bevel and thinning, it takes so many problems out of the equation. Wreck the whole edge after you achieved your profile, then you can thin it out a bit. After thinning, or if you don't need to thin, simply start a new bevel and sharpen it back up.

Problems you will run into are if you take too much height from a particular spot, it will cause the knife to get thicker on one spot and thinner in other, causing you to hit the edge earlier in some spots than other... causing waves in the profile if you aren't careful.

On this Ken Onion, you can probably flatten it with a 220 diamond plate (or coarser) and you won't be taking off too much metal, so just be sure to start a new edge from scratch after you flatten the edge. If you are uncomfortable with this I could also fix it for you, just PM me. :)

Re: Sharpening help needed.

Mon May 14, 2012 10:36 pm

Here's a perfect example of how to remove belly from a knife with too much belly in it. As Shaun mentions, just remove the edge, set the belly and put a new edge on it. Trying to keep the same angle during the process will cause you pain, making it very hard to get things flat.


Re: Sharpening help needed.

Mon May 14, 2012 11:42 pm

Seems I'm late to the party :-)

Excellent advice already. I grind the edge flat against a belt sander, then reestablish an edge.
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