Picking up bad sharpening habits. Halp!

Discussion in 'Sharpening Station' started by DisconnectedAG, Nov 23, 2019.

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  1. Nov 23, 2019 #1

    DisconnectedAG

    DisconnectedAG

    DisconnectedAG

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    Hi folks,

    So I recently realised I've picked up a very bad habit of introducing a flat spot near the tip of knives I sharpen, esp my smaller knives. Annoyingly, I have taken conscious care to try to do the tip, but clearly I have not managed my pressures and angles correctly.

    My sharpening skills I would describe as average. I can get all my knives shaving sharp, do the grape and tomato tests, cut kitchen roll etc. I haven't done a lot of polishing yet, so in that area I'm very much a noob.

    I've taken a picture shrew it's more visible on my petty.

    Any tips that you guys can give me? I haven't come across this particular pitfall in videos or on the forums before.

    It's a learning journey for sure, so now that I know I'm doing it I'll pay more attention, but any advice appreciated.
     

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  2. Nov 23, 2019 #2

    nutmeg

    nutmeg

    nutmeg

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    This won't happen if you sharpen with strokes that are parallel to the axis of the edge.
     
  3. Nov 23, 2019 #3

    idemhj

    idemhj

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    Use sharpie and check out this picture (from Jon) as a reference. Seems like your problem is over-rotation and/or not lifting up enough. Oh, and BTW don’t worry too much, I did the exact same thing :rolleyes:
    upload_2019-11-23_13-30-13.jpeg
     
  4. Nov 23, 2019 #4

    Benuser

    Benuser

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    With the coarsest stone, I stay perpendicular to the edge, which makes me turning the blade when reaching the belly and tip. For the tip, lift the blade as well to reach the very edge. Check with a marker and a loupe.
     
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  5. Nov 23, 2019 #5

    DisconnectedAG

    DisconnectedAG

    DisconnectedAG

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    Good points. It's sharpie time. I have a gem loupe, so that can be used as well.

    Thanks for the tips. It's the rotation that I think I haven't gotten right.
     
  6. Nov 23, 2019 #6

    Michi

    Michi

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    Just say “no” to sharpening ;)
     
  7. Nov 24, 2019 #7

    ian

    ian

    ian

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    What does rotation mean here?
     
  8. Nov 24, 2019 #8

    big D

    big D

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    IE: Handle in hand, spine towards you, edge on stone. While entering the curve of the blade from the flat with edge leading strokes, starting to lift with your hand, one rotates (starts pulling the handle towards your body allowing the tip to move forward at a faster rate). If you sharpen with edge towards you, again edge leading, then when entering the curve and starting to lift your handle, rotate (twist) so the handle moves away from your body. (Allow the tip to come to you at a faster rate}
    Basically, if you have the blade 90 degrees to the stone while doing the flat, rotating{twisting) holds the same angle to the stone as you follow through the curve. (again not edge angle). Keep twisting all the way through while you increasingly lift.
    Picture knife square to stone 90 deg. Now think of the curve consisting of a multitude series of small flat spots. Take a center spot and draw a line square to that spot. It is a different angle than your primary edge. Therefore by twisting(rotating) you are keeping the edge square to the stone at all times, when of course you are rotating at the correct speed/timing.
    Hope I was able to describe this clear enough.
    D.
    cleared up a few things I think--- edited
     
    Last edited: Nov 24, 2019
  9. Nov 24, 2019 #9

    ian

    ian

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    thanks, that makes sense.
     
  10. Nov 24, 2019 #10

    Xenif

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    Damn how come no one showed this to me a year ago!
     
  11. Nov 24, 2019 #11

    big D

    big D

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    Your welcome.
     
  12. Nov 25, 2019 #12

    bahamaroot

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    This highlights the importance of making sure you have an even burr along the entire edge when sharpening. It shows that you are removing an even amount of steel across the entire edge and not more in some areas than others.
     
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  13. Nov 25, 2019 #13

    Benuser

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    And, if I may add, the use of a loupe with the marker trick, to verify whether the ink has really gone.
     
  14. Nov 25, 2019 #14

    DisconnectedAG

    DisconnectedAG

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    I agree, but I always thought I have a decent burr consistency and have achieved good cutting performance along the whole length of the blade. Clearly you are right, as the facts point to me not having removed enough metal at the tip, but just feeling for a burr isn't enough in this particular case.

    I've found a solution though. I'm just going to blame it on the VG10. That way I don't have to improve my technique. Sounds like a perfect way of doing it.
     
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  15. Nov 28, 2019 #15

    ITKKF

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    This video from Jon@JKI illustrates a tip sharpening technique. Worked well for me. Good Luck!
     
  16. Dec 6, 2019 #16

    Keith Sinclair

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    There are diff. Techniques for tips. What ever works. Knives like Santoku with little sweep at the tip to knives with a lot of sweep. You adjust your tech. some with diff. knives.

    On DB knives use Dave Martell's thinning a little behind edge at low angle say 3 degree than finish with higher bevel. I teach an even bevel & steady spine heel to tip. When get to curve of blade two fingers sweeping blade length of the stone. The spine angle stays the same. You lift your handle hand to continue contact with the stone. Do not lift the spine to make contact at the tip, that will give you uneven bevel at the tip. Same goes for thinning & final bevels. Main thing is you are making contact during your sweeps all the way to the tip.

    Your flat spot at tip comes from moving blade up & down stone same all the way to the tip. Because there is less steel in the tip it flattens out & you can even get bird beak tips over time. Simply a little tip sharpening with even bevels you can maintain good knife geometry over the years when steel is worn off the knife you still have a nice even blade.
     
  17. Dec 6, 2019 #17

    Benuser

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    Little warning in addition: some blades get thicker at the tip. E.g. Robert Herder's. Use a marker, and a loupe (8-10x).
     
  18. Dec 6, 2019 #18

    kayman67

    kayman67

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    Well, getting to feel the bevel along the length of the blade is really important, but also understanding that the contact area has a huge impact on pressure and some points have a great less contact, increasing the pressure even if by hand you apply the same all-over. Combine these two in an unfortunate manner and you get some nasty spots fast.
     
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