Difficulty sharpening a petty!

Discussion in 'Sharpening Station' started by dafox, Feb 15, 2020.

Help Support Kitchen Knife Forums by donating:

  1. Feb 15, 2020 #1

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    Aargh!
    This is the most frustrated I've been sharpening a knife.
    It's a Fujiwara Kanefusa FKM 120mm petty, aus8.
    I started sharpening it at an angle about like I usually do with my other knives but I wasnt able to raise a burr, used a Shapton pro 1K. Then i switched to a Sp320 and increased the angle, did raise a burr that way. I sharpened it about 70/30. Then I used the same angles and ratio using a Sp1k, got it pretty sharp but it snagged and tore the paper pretty badly during a cutting test. I went back and started with the 320 again and followed it with the 1k again and got it better. Did it a 3rd time with both stones and was even more diligent with controlled deburing strokes on both stones. Passes the paper cutting test better but it still snags and tears if you dont cut just right. I get my other knives screaming sharp with the same techniques. I've always had difficulty sharpening petties. What's up?
     
  2. Feb 15, 2020 #2

    panda

    panda

    panda

    O.G. Supporting Member

    Joined:
    Dec 3, 2012
    Messages:
    7,146
    Location:
    south florida
    crap heat treat, you gotta deburr the crap out of it
     
  3. Feb 15, 2020 #3

    kayman67

    kayman67

    kayman67

    Senior Member

    Joined:
    Aug 3, 2019
    Messages:
    634
    Location:
    EU
    Try stropping between stones (not on fine leather) and try a mixed technique with edge leading on one side and edge trailing on the other (always finish with first), keeping in mind what side you are most comfortable with for edge leading.

    How old is this knife? Maybe the edge got damaged and you will need to remove some more material.
     
  4. Feb 15, 2020 #4

    vicv

    vicv

    vicv

    Senior Member

    Joined:
    Jan 13, 2013
    Messages:
    440
    Yes it sounds like a deburring issue you have to keep at it. Also I wouldn't recommend raising a spine when you're having an issue raising a burr. I know it can be frustrating but you have to keep at it at the low angle otherwise you're going to get a very thick knife. I don't imagine it's a bad heat treat I trust stainless knife heat treat by Japanese makers a lot more than I do a carbon knife. I would try three or four Edge leading passes with the spine twice as high off the stone as you sharpen. With not even the weight of the knife on. That should grind the Burr off without thickening the edge
     
    ITKKF likes this.
  5. Feb 15, 2020 #5

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    Its new.
    I dont have any problem with the other knives that I have in this model, I also sharpened a 180 the same day, no problem.
     
  6. Feb 15, 2020 #6

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    Thanks, I think you're right, its a deburring issue. I did end up sharpening it at my usual angle, just kept at it and focused on deburring better. It's still not as good as my other knives in this model, my 180 gyuto is easy to sharpen, I like the Shapton pro 1k edge on it, I use it for chicken butchery. I've never tried edge leading strokes, maybe it time...
     
  7. Feb 15, 2020 #7

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    Any other tricks to sharpening petties?
     
  8. Feb 15, 2020 #8

    vicv

    vicv

    vicv

    Senior Member

    Joined:
    Jan 13, 2013
    Messages:
    440
    Just a couple extremely light passes at the end. I will very often follow that with a couple of edge trailing strokes at my sharpening angle
     
  9. Feb 15, 2020 #9

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    Thanks, my usual sharpening regimen includes ending on very light stropping strokes.
     
  10. Feb 15, 2020 #10

    captaincaed

    captaincaed

    captaincaed

    Senior Member

    Joined:
    Aug 29, 2017
    Messages:
    839
    Location:
    Pacific Northwest
    M1k3 likes this.
  11. Feb 15, 2020 #11

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
  12. Feb 15, 2020 #12

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    That was great thanks, just what I was looking for. I didnt read this before, I thought it was too nerdy, but, I needed that!
     
  13. Feb 15, 2020 #13

    captaincaed

    captaincaed

    captaincaed

    Senior Member

    Joined:
    Aug 29, 2017
    Messages:
    839
    Location:
    Pacific Northwest
    I'm glad! It was pretty nerdy. I was having a day...
     
  14. Feb 16, 2020 #14

    Benuser

    Benuser

    Benuser

    Supporting Member

    Joined:
    May 3, 2011
    Messages:
    6,094
    Stay as long as needed with the coarsest stone. Deburr by edge leading with the lightest touch. Only go to the next stone when you can't reduce the burr any further and it only flips. Rough split leather may help to clean up one side after which you deburr the other one, and vice versa.
     
    ITKKF, Carl Kotte, M1k3 and 1 other person like this.
  15. Feb 16, 2020 #15

    VICTOR J CREAZZI

    VICTOR J CREAZZI

    VICTOR J CREAZZI

    Well-Known Member

    Joined:
    Dec 16, 2019
    Messages:
    68
    Location:
    Denver area
    @dafox , I'd like to sharpen that petty when we meet up.
     
    M1k3 likes this.
  16. Feb 16, 2020 #16

    dafox

    dafox

    dafox

    Senior Member

    Joined:
    May 27, 2017
    Messages:
    980
    Location:
    Colorado
    That would be great!
     
  17. Feb 16, 2020 #17

    MowgFace

    MowgFace

    MowgFace

    Well-Known Member

    Joined:
    Mar 27, 2013
    Messages:
    286
    I have the most trouble with my shorter knives. They tend to have a more continuous curve so it’s constantly shifting angles of contact. I have to go super slow.
     
    ITKKF and Kristoffer like this.
  18. Feb 16, 2020 #18

    Benuser

    Benuser

    Benuser

    Supporting Member

    Joined:
    May 3, 2011
    Messages:
    6,094
    You will love this one. [​IMG]
    Robert Herder's Yatagan. The only way I've found is in keeping the scratch pattern rigorously oblique to the edge.
     
  19. Feb 16, 2020 #19

    Benuser

    Benuser

    Benuser

    Supporting Member

    Joined:
    May 3, 2011
    Messages:
    6,094
    [​IMG]
    Herder's Hechtsäbel.
    Same idea.
     
  20. Feb 16, 2020 #20

    andrewlefilms

    andrewlefilms

    andrewlefilms

    Well-Known Member

    Joined:
    Feb 17, 2019
    Messages:
    59
    Location:
    Florida
    I agree with deburring between stones. I also prefer cheap stainless petties for cutting lemons and the sort and I find that along with light stropping on a course stone, it also helps to pull the knife through a soft wood to deburr, and then stropping again before moving on to another stone
     
    kayman67 likes this.
  21. Feb 16, 2020 #21

    Benuser

    Benuser

    Benuser

    Supporting Member

    Joined:
    May 3, 2011
    Messages:
    6,094
    Getting used to edge leading 'stropping' on stones has helped me a lot.
     
    VICTOR J CREAZZI likes this.
  22. Feb 17, 2020 #22

    kayman67

    kayman67

    kayman67

    Senior Member

    Joined:
    Aug 3, 2019
    Messages:
    634
    Location:
    EU
    Usually, I refresh mine with in hand sharpening. But I'm well aware this is not for everyone and since you guys mostly sharpen kitchen knives, somewhere that's not in the field on the go, I image this skill saw little to no development. This gives a much better feel and allows for changes that easily follow the bevel and the geometry.
     
    Benuser and VICTOR J CREAZZI like this.
  23. Feb 17, 2020 #23

    MowgFace

    MowgFace

    MowgFace

    Well-Known Member

    Joined:
    Mar 27, 2013
    Messages:
    286
    Yeesh. Bane of my existence.
     
    Benuser likes this.
  24. Feb 17, 2020 #24

    bahamaroot

    bahamaroot

    bahamaroot

    Senior Member

    Joined:
    Jan 14, 2013
    Messages:
    1,625
    You should be able to cut paper cleanly off the 320. If you don't have a sharp edge off that stone don't go to you're 1k. I think you're just not getting all the burr but otherwise doing fine. It's the steel not you.
     
    MowgFace and Benuser like this.

Draft saved Draft deleted

Share This Page

Group Builder