Can't get Leek as sharp as Sodbuster!

Discussion in 'Maintenance, Tinkering & Embellishment' started by woodsman313, May 29, 2020.

  1. woodsman313

    woodsman313

    15
    Mar 24, 2018
    I'm not very experienced when it comes to sharpening, so I may be missing something obvious, but...

    I have a Kershaw Leek and a Case Sodbuster Jr.

    I've sharpened both on a two-sided japanese whetstone, moving first from 1000 grit to 6000 grit. I think I'm doing the same thing with both knives, but I just can't seem to get the Leek as sharp as Sodbuster. My testing method is paper slicing, of course.

    What gives? Thx all!
     
  2. wade7575

    wade7575

    944
    Apr 3, 2013
    Are you making sure that you are forming a burr,also how steady are hands you need to try and keep the same angle when sharpening as much as possible.

    What brand of stones are you using.
     
  3. Ajack60

    Ajack60 Platinum Member Platinum Member

    Apr 21, 2013
    I would guess that the leek will take more time. Carbon vs stainless
     
    115Italian likes this.
  4. Twindog

    Twindog Gold Member Gold Member

    Apr 6, 2004
    As Wade said, you have to raise a burr on both side of the edge, from heel to tip, then remove that burr without creating a new one.

    Your Leek may have a wider angle than the Sodbuster, so on the Leek you're just grinding on the shoulders of the edge bevel, but not reaching the apex. When you reach the apex, a burr will form.

    Have you tried looking at the edge with a good loupe to see what's happening? The scratch pattern will tell you a lot. But if the scratch pattern is difficult to see, you can paint the edge with a Sharpie and then make a pass with the stone, you'll see where the stone is making contact with the edge.

    Also, if you're using a 1,000-grit stone for sharpening, it may take a while to reach the apex. If you're closer to the apex with your Sodbuster, the Leek will take a lot longer to get sharp.
     
  5. Eli Chaps

    Eli Chaps Gold Member Gold Member Basic Member

    Apr 20, 2018
    Sodbusters come in both carbon and stainless.

    Get a marker, and mark the bevel so you can see what is happening. This will show you where you're hitting. Raise a burr on one side. Raise a burr on the other side, De-burr.

    1000 grit is pretty fine for initial sharpening.
     
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  6. Jason B.

    Jason B. KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Jun 13, 2007
    Personally, I think your testing methods is not accounting for blade geometry. The likely thinner profile of the sodbuster even when duller would probably still slice better than many other sharper knives including a leek. The leek tends to have a decent hollow grind but the shoulder is sometimes a bit thicker and with such little blade height, well... that only makes slicing performance decrease. And no matter how sharp you make an edge there is only so much you can do against a knife with superior geometry.
     
    Airborne 1 and Eli Chaps like this.
  7. 115Italian

    115Italian

    Nov 13, 2015
    What are the blade steels? What was the condition of the edge before sharpening?
     
  8. The steel type for the Leek hasn't been mentioned yet - it's important and would be good to know.

    As Jason mentioned, the grind geometry near the edge might be an issue too, with the Leek possibly being thicker and/or the edge angle itself wider from the factory. I have several Leeks in various steels (440A, S30V, ZDP-189) and all of them wanted for some edge-thinning from the get-go. The Sod Busters from Case tend to run thinner near the edge in the smaller '37-pattern 'Jr.' form (high, thin hollow grind). The large '38-pattern soddie from Case is a flat grind and relatively thick-bladed as compared to the Jr. soddie.
     
    Last edited: May 30, 2020
  9. woodsman313

    woodsman313

    15
    Mar 24, 2018
    Thanks, everyone! The Leek is in 14C28N stainless steel, and the Sodbuster Jr is in Case's "Chrome Vanadium" carbon steel.

    This morning, paying close attention to the elements of sharpening mentioned by various commenters, I was able to get both the Sodbuster Jr and the Leek very sharp, though I still think the Sodbuster Jr has a very slight advantage in the paper-cutting task. That could well be down to blade geometry, as Twindog, Jason and David suggest.

    I love the slim profile of the Leek in the pocket, the smooth brushed stainless handles, the elegant lines of the design, the fine tip for ultra-detail work, and the fun assisted deployment.

    But the Sodbuster Jr has that thin blade you see on traditional folders that not even the sliciest of modern folders can seem to match, though the Leek comes very close!
     
    Eli Chaps likes this.
  10. For paper-slicing tests at least, even the (possibly) thicker blade of the Leek can be made to eventually slice like the Soddie. Going more acute at the edge for sharpening will get it closer, especially at or below 30° inclusive. The more acute sharpening angle will make the edge bevels look wider on the Leek (again, assuming it is thicker) than they will on the Sod Buster Jr. at the same sharpening angle. But for slicing paper, an edge angle in the sub-30° inclusive ballpark will make a big difference. I 'test' my own edges the same way, slicing paper. And I do what's needed for the edge on each knife, to get it in the same 'zone' in terms of how effortless that paper-slicing becomes. On the thicker blades, that always means their bevels will get noticeably wider in appearance; but I don' t worry about that. The real beauty is in the cutting anyway. Adding a little bit of convex to the shoulders of bevels on thicker blades will also reduce the friction & drag that makes cutting a little more difficult when the shoulders are otherwise very crisp & angular. So that's another way to make a thicker blade slice more like a thinner one.

    Thicker blades will still not cut as well in other materials, like heavy cardboard or in food items that tend to squeeze or pinch the blade during the cut. But again, there ways to cheat it a bit, by convexing the bevel shoulders and also polishing them, which makes them even slicker.
     

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