Knife sharpening.

Discussion in 'Cooking Knife Reviews' started by IoannisII, Feb 7, 2018.

  1. IoannisII

    IoannisII

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    Hello everyone.I am a home cook and I have come across a problem and I need your help.Do you have any ways of sharpening knives that you can recommend that doesn't involve stones?(I am afraid I will ruin a bunch of knives before I learn how to use the water stones)
    Thank you.
     
  2. millionsknives

    millionsknives

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    It's a lot easier to ruin knives on other methods. What kind of knives?
     
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  3. IoannisII

    IoannisII

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    Stainless steel chef knives mostly and a filleting knife.
     
  4. rick alan

    rick alan

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    It's not the knife-type to consider, are talking about ordinary German stainless, or something like it?
     
  5. IoannisII

    IoannisII

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    They are ordinary German knives.
     
  6. rick alan

    rick alan

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    You'd have to make a completely conscious effort to ruin any knife on a stone, and with Germans that would also be a considerable effort given how thick they are at the edge, along with the general abrasion resistance of stainless. A King 300 paired with either the 800 or 1200 grits will set you back about $50, and that is all you really need. Unless you have the annoying and useless dumb ass full bolster, then a bench grinder comes in handy for removal.

    Recent posts tell where the sharpening tutorials all are. It's nothing more than rubbing steel on stone.

    If you still want to go another route then it would be an electric, ranging $100-150.
     
  7. IoannisII

    IoannisII

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    I actually worry that I will ruin the geometry If I happen to use the wrong angle or I will fill the blade with scratches and these two things wouldn't make me very happy.
     
  8. benuser

    benuser

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    Sharpening a knife is not about restoring an edge. It's restoring a configuration that has moved to a slightly thicker part of the blade. To give an idea: the very edge is perhaps a few micrometres thick. Above the edge, expect some 0.2mm, at 5mm from there, 0,5mm.
    With stone sharpening you start by thinning behind the we edge. With a ceramic or diamond rod, you only abrade steel from the very edge. After a few sharpenings the area behind the edge has become thicker and starts to cause more resistance when cutting.
    [​IMG]
     
  9. rick alan

    rick alan

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    And that is why you need a 300 grit stone, and electrics are a bad choice. Right out of the packaging your knives could have used considerable thinning.

    Ruin the geometry of an ordinary German knife? You really could only make it better.
     
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  10. rick alan

    rick alan

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    And don't worry about scratches, it's not as if you have a mirror polished honyaki there.
     
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  11. benuser

    benuser

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    The figures I gave were those of good, thin knives. An average German stainless shows the double of that. So, there is quite a way to go.
    Scratches will occur but with coarse ScotchBrite you can restore at least an even finish.

    [​IMG]

    Simple daily use of your tool will cause scratches as well. As for scratches by sharpening, make sure your stone is flat.
    Make a piece of wood or cork with an inclination of a few degrees and use it as a reference for a minimal angle.
     
  12. sgsvirgil

    sgsvirgil

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    If you are intent on doing the sharpening yourself, there really isn't any way to avoid learning some sort of method be it with stones, or some electrical device (which I would not recommend) or some sort of mechanical device like a hand sharpener. I would strongly encourage investing the time in learning how to use water stones. Its really not that hard at all and you can practice your technique on crappy knives until you are confident enough to use it on your good knives. It is time and money very well spent. Trust me. You can find hundreds of videos on YouTube that deal with how to use whetstones to sharpen your knives.

    But, the question I have is do the blades really need to be sharpened or simply "restored?" Sharpening removes metal from the blade and a good knife under moderate to heavy use in a commercial kitchen may only need to be sharpened once every 3 months or so. Knives used by home cooks have a lighter work load and therefore, may only need to be sharpened every 6 months or less. This is not a steadfast rule, however. When a knife needs to be sharpened is a combination of the user's preference and the status of the blade itself. I've heard of some chefs using a whetstone on their knives daily to keep an insanely sharp edge.

    However, a common mistake is confusing the need to sharpen a knife with the need to simply restore the edge. This is where a good honing rod comes in. When a knife edge dulls, its because the sharp edge itself has curled, usually from coming in repeated contact with the cutting board. A few well angled swipes with a honing rod will restore the edge of the blade very nicely. Its good practice to get in the habit of using the honing rod each time before and after the knife is used. That way you will always have a sharp edge when you go to use the knife.

    You should inspect the edge of your blades by very carefully feeling the edge with your finger. If you feel nicks and burrs, the blade needs to be sharpened. If it feels smooth, but dull, try a few swipes at a 15' degree angle on a honing rod and recheck the edge. If the sharpness seems to be returning, give it a few more swipes and recheck. Rinse and repeat until it seems like the edge is not getting any sharper. If the sharpness does not fully return, adjust the angle and try again. If you can't restore the edge regardless of how many times you swipe the knife on the honing rod, the knife most likely needs to be sharpened. A honing rod will only do so much.

    If you are not motivated to learn how to sharpen your knives at home, you should have no problems finding a professional sharpener in your area to do the job for you for a few dollars per knife. Higher end blades tend to cost more. Just make sure the person you hire to sharpen your knives is experienced and reputable.
     
  13. benuser

    benuser

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    Traditional steel rods reset edges that are out of true, who are slightly folded, as it happens with soft steel. Harder steel won't fold, it breaks, or chips as it is called here.
    Grooves in a steel rod create a wire edge that will cut for a few strokes.
    Both are to be avoided with good knives.
    A ceramic rod will abrade a bit of the fatigued steel that caused the edge to fail. So far so good. But it will create a burr as well, and it takes quite some experience to get rid of that burr on a rod. When not used very carefully the rod will eventually change the edge's geometry.
    I see a ceramic rod as an emergency solution in a professional environment. Better refresh the edge on the last stone used for sharpening. Just strop and deburr.
    Have tried different ceramic rods with soft carbons like Sabs and slightly harder Sheffields. It works, but not for long. You start with an edge fresh from the stones and work on a crappy poly board -- the worst there is. After say 3/4 of an hour you notice serious performance loss and use the rod. Next stop will be after fifteen minutes.
    Why? You have rebuilt an edge out of fatigued steel, steel that has failed.
    At this stage, having probably gone too far, stropping and deburring on a medium-fine stone will completely restore the edge and its retention. Still better, do it on your finest stone -- meaning the last one used for sharpening -- as soon as you detect the slightest performance loss.
     
    Last edited: Feb 11, 2018
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  14. benuser

    benuser

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    As for finding a good professional sharpener: they are rare, very rare. With the price of a few dollars per knife people are prepared to pay for it, expect some powered equipment to be used, with unnecessary loss of material and overheating.
    Sharpeners working on stones will charge some $3 per inch of blade length for normal sharpening, besides thinning or large repairs, plus shipping.
    Better learn it yourself. It isn't beyond your possibilities. Before WW2 almost every man sharpened his own razor. Even if the technique is slightly different, it gives an idea.
     
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