How do you maintain serrated edges??

Discussion in 'Maintenance, Tinkering & Embellishment' started by Houlahound, Jul 4, 2019.

  1. Houlahound


    Aug 2, 2017
    I prefer serrations for edc/utility work from cutting rope to food prep. I have been looking for sharpening equipment and tutorials for serrated knives but doesn't seem to be a lot of info.

    How do you maintain a serrated edge?

    Note most of my kitchen knives are serrated and cut steak, vegetables, bread etc. They are all cheap knives but last a long time in the kitchen.
  2. Skywalker31


    Feb 29, 2012
    I only really use serrated edges for kitchen knives. 4 swipes on the edge of a sharpmaker triangle rod, down and up, on the side of the knife the serrations are ground on. Then one swipe of the same on the unground side. Repeat as necessary until sharp.

    Read that one from someone on Spyderco's forum (EvilD, maybe?) and it's been working well for my VG10 kitchen cutlery.
    4mer_FMF, GasMan1, McFeeli and 2 others like this.
  3. palonej

    palonej Platinum Member Platinum Member

    Aug 5, 2015
    I carry a Pac Salt serrated for work, HVAC, and this is exactly how I maintain mine......and that bitch is stupid sharp.
    4mer_FMF likes this.
  4. GIRLYmann


    Nov 7, 2005
    Close fine serrations can be sharpened by
    running it across an abrasive rod ....
    If you're on the cheap a fine grid diamond coated rattail file would suffice.
  5. McFeeli


    Feb 13, 2017
    I sharpened my Tasman Salt similar to @Skywalker31 ’s method recently. I expected it to be much harder, serrated hawkbill equals my worst sharpening nightmare, haha. Thank god for that handy little Sharpmaker. I only drew it down, but a few swipes on the ground side, one on the flat. Spyderco’s serrations are purpose made for the Sharpmaker, so you may have a tougher time using a different variation.
    kwselke likes this.
  6. Alberta Ed

    Alberta Ed

    Jun 29, 1999
    There are hones designed to sharpen serrations or wood carving gouges from a number of sources, Spyderco for one. I think DMT offers some, too.
  7. Twindog

    Twindog Gold Member Gold Member

    Apr 6, 2004
    Ideally, the diameter of your sharpening rod perfectly matches the diameter of the serration scallops. Then you just match the angle of the chisel grind and sharpen each serration until you establish a burr on the flat side of the blade. Then you remove the burr on the flat side of the edge with a gentle stroke at a very shallow, even flat angle.

    But serrations come in all different sizes, often different sizes on the same edge. So your sharpening rod is not likely to fit all of the serrations.

    You can use a tapered rod -- using only the tapered portion of the rod that matches the diameter of the serration -- but then you have to use very short strokes to keep the rod diameter at least roughly matching the serrations. You can use a V shaped rod, but then you have to carefully sharpen the profile of each serration, which takes a lot of time. You use the same technique with a round stone that is smaller than the diameter of the serrations.

    Most of the cutting is done around the tips of the serrations, but most people concentrate their sharpening in the bowl of the serration, which reduces cutting performance.
    kreisler likes this.
  8. The method demo'd in the video posted by GIRLYmann earlier actually works quite well, IF the serrations aren't allowed to get too dull in the first place. Use the narrow edge of the hone for the scalloped side, as demo'd in the video; then use the broader or flat side of the hone for the back, unscalloped side, at a very low angle to clean up the burr and refine further. In drawing a serrated blade across the hone, a light touch is EVERYTHING, else more damage than good will result, with very heavy burring and/or bending of the points of the serrations. Also need to pay close attention to the held angle, so it doesn't get too steep and do the same sort of damage.

    I tested the above method yesterday, using the edge of a triangular Sharpmaker rod (medium) on the small scallops of a Victorinox paring knife, and also on a Wusthof tomato knife with larger/wider serrations. Worked great in both cases.

    If serrations are really dull, then one-at-a-time, scallop-by-scallop regrinding to a full apex is the way to go, using a coarser rod or hone edge ideally sized to match the width of the serrations. The narrow, rounded edge of some brands of oval diamond kitchen 'steels' works well for something like this, BTW.
    Last edited: Jul 6, 2019
  9. Twindog

    Twindog Gold Member Gold Member

    Apr 6, 2004
    I watched that video, but it's difficult to see what's happening. The chatter made by the stone makes me think that the high points between serrations are being worn down and the full edges of the serrations are not being reached. After a while, I'd guess that the cutting power of the serrations would be lessened.

    Do you see anything like that happening?
    kreisler likes this.
  10. HeavyHanded


    Jun 4, 2010
    I use a tapered rod if they're really dull.

    For touchups, I fold over a piece of cardstock a few times and apply compound to the edges. This allows the sheets of cardstock to separate around the highpoints and focus on the scallop - reduces rounding the tips. This is also how I finish off a tapered rod sharpening.
    Ace Rimmer likes this.
  11. razor-edge-knives

    razor-edge-knives Moderator Moderator Knifemaker / Craftsman / Service Provider

    Apr 3, 2011
    A paper wheel with compound is probably the best/quickest method. That will last for a while before your edge needs to be completely reground. For regrinding serrated edges I use a radius'd wheel under coolant and it works amazingly well
  12. Bigfattyt

    Bigfattyt Gold Member Gold Member

    Jun 23, 2007
    I've used a triangle on one side, round and flat combo Smith Ceramic sharpener with fantastic results.

    I just got a Spuderco sharpmaker this weekend. But have not used it on serrations yet.

    Cold Steel serrations are a different beast, but still respond very well to sharpening the scallops individually with a triangle l, and then a few passes on the back at a 0 angle (matching the factory angle on the back sides of the points on the flat side of the rod.

    Works great.
  13. This is why I stressed pressure and held angle are important. That 'chatter' made when drawing the serrations across the edge of the hone is something one has to get accustomed to. It's kind of unnerving at first, but it's also some unignorable feedback that'll make you pay attention. You can feel if it's too hard, or if the angle is too steep, and then make adjustments until the feel becomes sort of a smooth buzzing effect, kind of like the feel of a zipper. You can sort of intuitively feel the edge of the hone gliding around the tips & through the scallops of the serrations, instead of hammering through them. If the tips of the serrations are getting severely burred, or worse, being bent, curled or rolled over, that's the cue that pressure's too hard or the angle is too steep. That was my 'learning curve' in figuring out how to use a ceramic rod to sharpen serrations. For a while, I was really beating up the tips on them, so they were getting curled (very fine-pointed serrations) or heavily burred. That makes them snag, but not cut, so cutting effectively gets stopped in it's tracks.

    It's also important that the edge of the hone, or the cross-section of it, is at least as narrow as the scallops themselves or narrower. Seems obvious; but otherwise the only thing being touched will be the tips of serrations, which doesn't really do much for cutting, as most of that cutting efficiency comes from the scallops between the tips.
  14. SOLEIL

    SOLEIL Gold Member Gold Member

    Mar 20, 2006
    check out Lansky dog bone. they are made for cold steel and spyderco serrations, very easy to use.
  15. Mr.Wizard


    Feb 28, 2015
  16. kreisler


    May 11, 2012
    i can and did sharpen serrated edges (and scythes which are basically a giant serration) with the Sharpmaker or its triangle rods (manually, freehand). it worked.

    no regrets but I'll never do it again.
    Twindog likes this.
  17. bgentry


    Aug 3, 2009
    This method is nearly exactly how Spyderco tells you to use the SharpMaker to sharpen serrated blades. Also essentially the same as using the 701 (M or F) sharpeners, which are shaped very similarly to the stone in the video.

    At one time I carried a serrated Delica and I used it quite a lot and sharpened it like a sharpening obsessed person that would make long posts on a knife sharpening forum. :) . It was nearly always phonebook paper slicing sharp. After a while I noticed that it didn't have the "bite" like it first did when doing a pressure cut. When I first got the Delica, the points were extremely sharp and cut into things like plastic blister packs most impressively. After a year or so of sharpening it all the time, the points were rounding off. Not totally dull and round, but no longer impressively pointy either. The scallops would still slice phonebook paper.

    I gradually figured out that I had "ruined" the profile of these serrations with this method of mostly only sharpening the scallops and using the "chatter method", which encourages rounded off points. Later after reading posts from Jason B, I realized that there were many ways to approach this, including Jason's way which is roughly:

    1. Grind the flat back side (not the scallops) at a very shallow angle (5 to 8 degrees as an estimate; nearly flat) until you detect a burr being formed in all of the scallops.
    2. Remove the burr on the scalloped side using a sharpmaker, Spyderco 701, tapered rod, or something else appropriate.
    3. Maybe a few more strokes on the flat side if #2 has flipped the burr to the flat side.

    This seems to keep the points sharper for longer. I've restored at least one rather abused serrated knife this way and it worked well.

    Individual grinding of the scallops is probably even better at keeping the points pointy, but requires a ton of attention to detail and probably a jig or fixture (or maybe just a clamp and a tabletop) in order to do it well.

    Mr.Wizard and Twindog like this.
  18. The thing about rounded 'points' on serrations is, they'll still slice just as cleanly if they're also fully apexed in cross-section, just like any cutting edge. Cross-sectional geometry is what does the cutting; it really doesn't matter if the tips of the serrations are round or needle-pointy along their longitudinal (fore/aft) dimension. Consider the factory serrated edges from Kershaw, which are essentially inverted as compared to most 'pointed-tip' serrations, leaving 'scalloped' tips distinctly & deliberately rounded in profile, but still wicked-sharp in cross-section. They still cut like a laser, if kept fully apexed like any other cutting edge.

    I've never worried about maintaining a needle-pointy tip on serrations, as it's not necessary for good cutting. They're structurally weaker, being acutely thin in 2 dimensions instead of in cross-section only. In fact, I've grown to dislike acutely pointed tips on serrations, because they're too vulnerable to damage (bending, curling, flattening, breaking off) by impact with very hard materials or cutting in tough materials; any damage there will effectively halt and/or snag clean cutting. A curled tip on a previously pointy serration becomes a snagging anchor in tough materials. A fully apexed and 'rounder' tip (longitudinally) will actually be more durable and will slice better than the pointed tips will. To keep it cutting well, just make sure it's fully apexed in cross-section, like any other cutting edge.
    Last edited: Jul 9, 2019
  19. bgentry


    Aug 3, 2009
    I disagree. Try cutting open a blister pack with a serrated blade with rounded points. Now try it with one with nice sharp points. Initiating the cut is far easier with pointy serrations. Because they penetrate into the material, breaking it open and offering an edge surface for the scallops to slice.

    This is material dependant of course. Tougher materials will show the biggest difference. It's amazing how tough plastic is when trying to pressure cut it.

  20. The thin & acutely-sharpened tip of a traditional stockman's sheepsfoot blade is my favorite go-to for blister packs. The tip initiates the cut and the very thinly-ground straight edge does the rest with ease, after the tip dives in. Works much better than trying to cut this sort of plastic with any serrated blade, whatever it's points may look like. Very thin primary grind and an acutely sharp apex is what makes it work well. Most modern or tactical blades, both serrated and not, are usually overly thick and aren't well-suited to it by comparison. At one time, I used to use a combo-blade Spyderco for stuff like this and I never liked it for the task. Not so much about what the tips of the serrations were doing, but more about the thickness of the grind behind the edge causing binding in the plastic after the cut was started. Blister packs pinch a thick blade pretty firmly; a thinner grind handles it better than anything else. And a thin hollow grind is even better.

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