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Chemical Sharpening

Discussion in 'Maintenance, Tinkering & Embellishment' started by Hairy Clipper, Jun 12, 2019.

  1. FortyTwoBlades

    FortyTwoBlades Baryonyx walkeri Dealer / Materials Provider

    Mar 8, 2008
    Emphasis on myth. If they have any chemical effect it may bring out the appearance of a hamon in the blade being worked, but it sure isn't improving the edge left by such a stone.
    Hairy Clipper and DeadboxHero like this.
  2. DeadboxHero

    DeadboxHero Triple B Handmade, Custom Knives Knifemaker / Craftsman / Service Provider

    Mar 22, 2014
    Exactly what Benjamin said, it works abrasively not chemically, popular for helping bring out the contrast between soft and hard steel on bi-metal blades with a "kasumi" or also can polish a "hamon" which is a transition line between hard and soft steel on a mono steel blade with a differential HT using clay at the spine.
    Hairy Clipper and FortyTwoBlades like this.
  3. Hairy Clipper

    Hairy Clipper Basic Member Basic Member

    Feb 28, 2009
    Mine was a 1935 Chevrolet Master DeLuxe 4 door sedan with suicide doors front and back with an AM radio that had the antenna under the running boards. The wheels were not wire spoked they were something new called artillery wheels it also had knee joint suspension.


    Blades: Hamon??? I had to look that up! More continuing education for an old dog.
    Last edited: Jun 13, 2019
    Natlek likes this.
  4. tiguy7

    tiguy7 Gold Member Gold Member

    Jun 25, 2008
    Hydrogen embrittlement can be prevented by baking the parts after they have been exposed to the Hydrogen. I think 1/2hr at 350F does the trick.When acid sharpening files (with HCl), the teeth were not as sharp or uniform as the original, but the alternative was chucking the file.
    FortyTwoBlades and Hairy Clipper like this.
  5. drail


    Feb 23, 2008
    Files are not that expensive. When they're trashed - replace them. NOTHING cuts like a new file. I cannot see how acid could possibly "sharpen" an edge.
    Hairy Clipper likes this.
  6. mycough


    May 20, 2007
    Marcineks post explains why this works so well on fish hooks.
    After mechanically refining the point it is chemically refined and sharpened BECAUSE it is the thinnest part of the hook.
    All i know is if I get too close to one it ends up stuck in a finger or thumb.
    Actually I know one other thing... They go through the bony mouth roof of a small mouth bass pretty darn well.
    I need coffee, have a great day guys.

    Hairy Clipper likes this.
  7. ToddS

    ToddS Basic Member Basic Member

    Jan 15, 2015
    Normally, etching is "isotropic" meaning it removes metal in all direction uniformly - so if you etch away 5 microns, your "sharpest" feature would have a 5 micron radius.

    What you need for sharpening is "anisotropic" etching - in principle this can be achieved with electric fields. It's a common technique for making sharp tips.
    Hairy Clipper likes this.
  8. HeavyHanded


    Jun 4, 2010
    I wonder if this couldn't be used specifically for burr removal, or use a layer of chemical on top of the abrasive surface in an assistance role.
    Hairy Clipper likes this.
  9. ToddS

    ToddS Basic Member Basic Member

    Jan 15, 2015
    That's called CMP - Chemical Mechanical Polishing.

    Mud/slurry accomplishes this mechanically. The rolling grit particles soften the steel and knock off the weak steel at the apex.
    Hairy Clipper likes this.
  10. HeavyHanded


    Jun 4, 2010
    Well, my waterstones are a whole lot easier than wetting my stones with acid, so that's nice to hear!
    Hairy Clipper and mycough like this.
  11. Wowbagger


    Sep 20, 2015
    I was going to mention this.
    I have seen it where chrome plating has been done to welded parts.
    The parts failed at the welds (right through the weld rather than around the edge of the bead . . . which happens when the parent metal is thin and the weld puddles too thick and bulbous). The effected parts had to be recalled. The welds were good but the bead metal had been effected.

    I was on the receiving end of the parts (not on the fabrication end).
    Hairy Clipper likes this.
  12. Allan DeGroot

    Allan DeGroot

    Jun 15, 2019
    The main Reason HCl works so well on clogged files is because Hydrochloric acid vigorously attacks Brass (More specifically the Zinc that is alloyed with the copper) and aluminum as well as converts Ferric Oxide (Rust) into Ferric (II) Chloride (Responsible for that virulent yellow color of the acid bath after putting any rusty steel into it.)

    But it doesn't actually make the file sharp again, it just removes the foreign material that is "clogging" the file.
    And as someone said above it is preferable to the alternative, Chucking it and buying a new file.

    BTW "Hydrogen Embrittlement", several racing sanctioning bodies (CART USAC & NASCAR) have very specific rules about baking suspension components between steps in the plating process to reduce the threat!
    Last edited: Jun 18, 2019
    Hairy Clipper likes this.

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