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Thread: Wide Bevel Sharpening

  1. #1

    Wide Bevel Sharpening

    I've often been asked why wide bevel sharpening is so expensive. I think this will help to show why.
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  2. #2
    The shiny sections are from a flat diamond plate. The dark sections on the bevel show how the bevel is hollow ground with deep grooves remaining from the water wheel used during production.

    In my experience I've seen this same thing on many other makers' knives. The cheaper the price the worse the issue seems to be although some maker's get good money regardless so we can't use price point as an indication of an issue or not.

    Is this a problem? No not really. It's only a problem to the person who wants to thin the edge AND have it look decent afterwards.

  3. #3
    Senior Member chefcomesback's Avatar
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    Wide Bevel Sharpening

    Dave , in that case would you try to thin the blade the to get rid of those high and low spots ? Or worry about the bevel and then polish it to make it look even?


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  4. #4
    Quote Originally Posted by chefcomesback View Post
    Dave , in that case would you try to thin the blade the to get rid of those high and low spots ? Or worry about the bevel and then polish it to make it look even?

    We have the choice of either just sharpening at the little edge bevel or hitting the whole larger wide bevel on the stones. If we chose to hit the wide bevel to thin and/or make for flatter bevels or whatever we then have to decide to either leave the mess from the maker or keep on trucking with a flatten/thin of the bevel or maybe spread the work out and do the big work over several sharpening sessions. In my case I'm usually working on a customer's knife so once I go to the wide bevel I'm committed to seeing it through to the end. The difference between hitting just the edge bevel vs doing the whole wide bevel is usually many hours of work.

  5. #5
    Here's the opposite side of the knife. It shows the bevel as flattened out. This side was in the same condition as the picture above shows. Stones used to fix the bevel were the ATOMA 140 diamond plate and the Beston 500x.
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  6. #6
    And that knife was probably pretty thin to begin with...yikes, I bet it screams now.
    once in a while you get shown the light, in the strangest of places if you look at it right

  7. #7
    Dave,

    When you flatten the bevels are you not altering the intended geometry of the knife? How does the knife cut before and after with that hollow removed? I'm still trying to wrap my head around kitchen knife geometry and so I am a bit confused.

    Thanks,

    Pete
    Twitter: @PeterDaEater

  8. #8
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    Good question. Also I wonder whether the geometry magic happens higher up the blade?

  9. #9
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    Pete, I think it's tempting to claim that one might lose some food release, but under almost all circumstances the variation in geometry is subtle and shallow enough (unless there is an intentional compound grind which is usually much deeper) that it likely has no real effect on food. Near-edge convexity, bevel polish, and the primary shinogi are much stronger influences on sticking, in my opinion. Raising the shinogi too much can affect things by reducing its angle (allowing food to slide over more easily) and increasing surface area that contacts the food directly. Otherwise, I doubt flattening (and some convexing if applicable) are in any way harmful to the cutting ability of the knife.

    Further, knife geometry can be wildly inconsistent even from the same maker, such as the Carter shown. This is usually not extremely nuanced stuff.

    Rami, most knives like this operate on relatively simple geometry, unless we talk about convexing near the edge. There are some knives that implement a hollow (accidentally or intentionally) on the hira (flat, above the shinogi) but most don't.

    The Carter that Dave posted is pretty crazy. I've got two and their bevels aren't anywhere near as horrific. My Toshihiro actually was quite nice to flatten and thin; even from 800-grit, there were almost no wobbles or high/low spots. Though I like my Zakuri knives a lot...some of them have been quite a bear to achieve a nice flat even bevel on.

    Carter:


    Toshihiro (bottom knife):


    Zakuri fresh (top knife):


    Zakuri cleaned:



    For the trouble that some of these cause...once the bevel has been flattened and thinned appropriately, they are some of the nicest knives out there. It's a shame more makers don't invest more time and effort in getting a consistent bevel (though it can be argued that it's not necessary as long as long as the edge itself is not affected).

  10. #10
    Pete, I'm in agreement with Robert (XooMG) on this. That is that the knives are a lot better once the blade road (wide bevel) has been flattened out. They sure are easier to maintain and they look better too.

    The food separation seems to happen up higher on the blade anyway so removing the hollow doesn't appear to be a negative on that factor and IMO stiction isn't a problem so long as the surface is made smooth vs rough (course).

    This is all general in nature though, each knife can be specific in it's needs.

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