Stropping with compounds vs sharpening

Discussion in 'Maintenance, Tinkering & Embellishment' started by CoryS, Jul 7, 2020.

  1. CoryS

    CoryS

    22
    Apr 23, 2020
    I did a search and found a thread discussing this, but I'm still a little confused on the difference.

    If I finish a knife on a 3 micron stone, and then strop it with 3 micron paste, is it doing anything other than removing a bur and maybe a bit of convexing? How about if I finish on a 1.8 micron stone and strop on 3 micron paste, did I regress my edge polish?
     
  2. Bill3152

    Bill3152

    301
    Nov 27, 2018
    Stropping removes the bur which by some accounts is always there after the stone. After using super low micron pastes I find a 3 micron is definitely good enough for me.
     
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  3. CoryS

    CoryS

    22
    Apr 23, 2020

    I know of the things it does is remove a bur, but it does do more than that, for example 3 micron Diamond compound shines my edge up nice vs right off the stone.

    So I'm still confused on when you get into the ultra high grits of stones, what the difference are when compared to using a compound.
     
  4. Diemaker

    Diemaker KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    607
    Apr 28, 2017
    Stropping is just sharpening with a different bond, especially if you are using an aggressive abrasive like diamond. Don't get too hung up on the grit rating of any stone, the bond and other things have a huge effect on how they work. Going to a leather, or wood, for the "bond" changes the nature of the "stone" in interesting ways. A good microscope is essential, IMO, when exploring them. Have fun. So far I don't like going below 1 micron on my strops, so far.
     
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  5. CoryS

    CoryS

    22
    Apr 23, 2020
    That's what I thought, but had heard conflicting opinions and wanted to get a straight answer, thank you!
     
  6. David Martin

    David Martin Moderator Moderator Gold Member

    Apr 7, 2008
    Stropping refines your blade. If you want this then go ahead. But some want a more coarse edge and don't strop. DM
     
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  7. Diemaker

    Diemaker KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    607
    Apr 28, 2017
    IME there comes a time to change bonds when the grits get too fine for a ridged one, that is how I view strops. When the finer stones start getting random scratches then you know it's time to change bonds. As for a straight answer, that is a hard one as it changes with the variables, which are nearly infinite, and as we learn more.

    I know this hasn't come up here but I there are also tapes, which I think go between stones and strops, if used. Either way I do think tapes are worth playing with some, at least to figure out how you like them.
     
    Last edited: Jul 7, 2020
  8. Craig James

    Craig James

    162
    Oct 30, 2018
    Personally I have found that stropping helps me improve the keenness of my edge, more so than I am capable of doing purely on the stone.

    If I finish on a polishing stone, say 6000 then bare leather does fine. On 800 then I typically turn to a 3 micron diamond loaded strop. On both I take minimal passes and obviously here all I am doing is removing burr remnants.

    the scientist in me suggests that being able to do the above on a hard substrate (stone) is the optimal solution for a better apex. Alas my skill does not allow that
     
  9. Bill3152

    Bill3152

    301
    Nov 27, 2018
    Some people like to whittle hair , mirror polish their bevels etc. That's all good if that's what you want. I think most people get to a stage where the finish is determined by how you use it. For me 325 to venez 1200 for my edcs works perfectly. For my kitchen it's 325 one and done. But you will figure out what you like eventually and then do that.
     
  10. CoryS

    CoryS

    22
    Apr 23, 2020
    could you link what you’re referring to? I can’t picture that.
     
  11. CoryS

    CoryS

    22
    Apr 23, 2020
    I guess my question is more about the extreme grits. Like 12-24k grit stone vs a compound strop. Do they become the same thing at some point?
     
    Last edited: Jul 7, 2020
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  12. hughd

    hughd

    443
    Feb 18, 2014
    CoryS likes this.
  13. Zeunerite

    Zeunerite

    27
    Dec 24, 2019
    As long as the stropping base is softer than stone then a 1 micron compound strop will produce shallower scratches than a 1 micron stone because less pressure can be applied by the strop.
     
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  14. Diemaker

    Diemaker KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    607
    Apr 28, 2017
    Just my opinion based on using EP tapes and how I think they fit in with stones and strops, all looking through a microscope. The firmness of the "bond" seems to fit in between stones and strops as well. Even the EP 6k tape leaves tiny scratches under the microscope, that a strop would then be the best tool to polish them out with, IMO. Tapes are interesting but I don't use them, I like to go from my finest stone, a 4k Matrix, straight to a strop. I am still learning about strops so my opinions on them will probably change.
     
  15. ToddS

    ToddS Basic Member Basic Member

    379
    Jan 15, 2015
    The main difference between a stone and a strop is that the stone can/will abrade the entire bevel, while the strop primarily affects only the last few microns near the apex. That's not to say that the strop doesn't also polish the bevel, it just does it very slowly. The film/tape is also typically slow, but will "micro-finish" the bevel towards a mirror fairly efficiently in that 3 micron range, much more so than a strop.

    The critical point is that you can produce a keen, refined apex by simply micro-convexing those last few microns with a strop and the finish on the rest of the bevel is of no consequence. Alternatively, you can try to refine the entire bevel to a polish and hope that the apex also ends up being keen and refined in the process - but there is no guarantee that this will happen.

    In my experience, the adhesive backed film/tape is a bit "squishy." Particularly the diamond version seems to produce foil-burrs fairly easily. I found that the plain film simply stuck to glass with water works a lot better.
     
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  16. HeavyHanded

    HeavyHanded

    Jun 4, 2010
    All abrasive bonds fall on a gradient of mobility and deflection into their backing. Depending on the surface, stropping on leather falls at the outside end of the "deflection" range. You almost have to spec out what exactly you mean by "stropping"
     
  17. Diemaker

    Diemaker KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    607
    Apr 28, 2017
    The last ceramic knife I sharpened I couldn't avoid microchipping with my Matrix stones, which was a first. Sure I have had problems with it before but I have never been unable to get around it with a different technique. It is a Kyocera nakiri black ceramic which is different from the white. After some thought, I suspected the apex couldn't stand up to the localized pressure since it isn't supported so I tried diamond loaded leather strops, using water as the carrier to keep the leather firm and slick, to try to reduce the pressure on the apex. Wow, no microchips and the bevel looked pretty flat as I was worried it would be too convexed. I ended up loading 3 strops with 10, 5, and 1-micron diamond which worked out perfectly to sharpen this knife. The blade now has about a 3-4 degree bevel with a .03" wide 18 degree "micro" bevel. I am quite curious as to how well this will work with Maxamet? I am afraid it would be too aggressive for nearly all the steels out there, as Todd said that apex can disappear fast, as in just a few strokes.
     
  18. Jason B.

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

    Jun 13, 2007
    My 0.02,

    Sharpening is sharpening but stropping is an enhancement to sharpening and is not the same as sharpening. IMO, they are separate and you should view them as such.
     
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  19. Diemaker

    Diemaker KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    607
    Apr 28, 2017
    But as you add abrasives to the strops then it seems to me you start to blurr that line.
     
  20. Jason B.

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

    Jun 13, 2007
    Like I said, just my opinion but loaded strops are included in that opinion. As @HeavyHanded mentioned, the backing becomes of greater importance. If you have a soft backing like leather then IMO, you are always at the disadvantage of the backing and the rounding/convexing it causes. If the backing is iron plate or glass then we get closer to sharpening but it will never be the same as a bonded abrasive stone. It will always be an alternate method to stone sharpening and IMO, will never be able to perform at the levels a bonded stone can and this instantly puts you the sharpener at a disadvantage.
     

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