Results 1 to 10 of 10

Thread: How to Flatten Hollow Japanese Chisel Backs?

  1. #1
    Join Date
    Feb 2011
    Location
    Carlsbad, CA
    Posts
    1,638

    How to Flatten Hollow Japanese Chisel Backs?

    Some of the very best edge tools in my shop are Japanese chisels and plane blades made with the slight hollowing on the back of the blade. These tools are a joy for me to work with as a take a fantastic edge and are often the "tools of last resort" in difficult jobs.

    My challenge is once I've sharpened the bevel back to the point where the cutting-edge begins to intersect with the hollow on the back of the chisel, I'm not sure how I'm supposed to "pound out" (?) the soft steel on top of the blade so that the hollow is "moved backward" and the back of the blade at the cutting edge is again flat? To date I tried setting the blade on anvil and using a small hammer (and sometimes a punch with a large hammer) to get the desired result. Obviously, I'm super nervous about inadvertently striking in cracking the hardened steel on the bottom of the blade that forms the cutting edge. I very much appreciate any advice and suggestions?

    I apologize I don't know the correct Japanese words to describe various elements above.

    Thanks, Mike

  2. #2
    Join Date
    Aug 2019
    Location
    Pittsburgh, PA
    Posts
    104
    Hi there, I don't know much about Japanese chisels, I don't own one either. I'd suggest you ask the dealer that sold you the chisels, or call one of the stores that specializes in them.



    You may need to change your sharpening method to keep moving the hollow.
    Last edited by Jim Becker; 03-26-2020 at 4:24 PM. Reason: removed direct link to another forum. Not permitted by TOS

  3. #3
    Join Date
    Jan 2007
    Location
    On the edge of Pisgah National Forest
    Posts
    147
    I've just recently begun looking into Japanese Chisels and this guy seems to have a lot of knowledge. Check his blogs. https://covingtonandsons.com/

  4. #4
    Join Date
    Dec 2010
    Location
    South Coastal Massachusetts
    Posts
    5,634

  5. #5
    Join Date
    Jun 2008
    Location
    So Cal
    Posts
    2,596
    Donít pound them out mike Flatten the back some more.
    As long as thereís a little bit of flat your good to go.
    Some of mine have barely a 1/32 and cut just fine.
    Good Luck
    Aj

  6. #6
    Join Date
    Apr 2013
    Location
    Stone Mountain, GA
    Posts
    583
    The tapping out is more for plane irons than chisels. Most chisels have the hard steel layer wrapped up the sides and that makes it too rigid for tapping out to have much effect.

    On the widest chisels you can move the center portion a little bit. But for the most part you regain the hollow by simply removing material from the back.

    As Andrew says, you only need a very small landing behind the edge.

  7. #7
    Join Date
    Feb 2004
    Location
    Perth, Australia
    Posts
    7,230
    Usually it is enough to do a few strokes on the back with a medium- and then the polishing stones. This done each time the bevel is honed.

    Regards from Perth

    Derek

  8. #8
    Join Date
    May 2017
    Location
    Germany
    Posts
    438
    Mike, I asked several people the same question, since some of the Japanese chisels don't have much flat area on the back before the hollow starts. The answer was always similar in they didn't care because they will not likely outlive the chisel before the flat touches the hollow.

  9. #9
    Join Date
    Feb 2004
    Location
    Perth, Australia
    Posts
    7,230
    Exactly Mike. Most of my blade backs have about 1- 2mm before the hollow. That’s plenty.

    Regards from Perth

    Derek

  10. #10
    Join Date
    Feb 2011
    Location
    Carlsbad, CA
    Posts
    1,638
    Thanks very much guys- I really appreciate the advice! Some how the geometry of intersecting back and hollow escapes me but this much better solution than swinging a hammer at my prized edge tools!

    Once again the generosity of SMC community save me from my own ignorance - startling common occurrence!

    Cheers, Mike

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •