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SHUN knives Chipping while sharpening

I have some Shun Classic kinves and I have tried sharpening them with an 800/4000 King wet stone. I find that I am getting small chips in the knife edge. I believe I have the proper angle and I only am sharpening about 10 strokes a side. can someone help enlighten me?

Fudd

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    1. I have that particular stone and have sharpened shun knives before. That said, I can only take a guess at your problem:

      I imagine you are sharpening shun classics, or one of their lines that uses vg10 anyway. It tends to be a little chippy-er than some other steels. Have you done a lot of hand sharpening up to this point?

      If I had to guess, I would say the most likely problem is you're not quite keeping the knife's edge flat against the stone as you sharpen. That is, you're pointing the tip down or up while sharpening so that only one part of the edge is in contact with the stone (applying lateral pressure on that tiny part of the edge), which in turn punches out a tiny chip.

      If this is the case, here are a few suggestions that should help:
      1 - Use less pressure while sharpening. Practice more before applying much downward pressure.
      2 - Flatten your stones and grind down the corner bevels.
      http://www.youtube.com/watch?v=Mcmcg5...
      http://www.youtube.com/watch?v=bNKuLh...
      This could be creating a problem if you have pretty good form or exacerbating a problem if your're a little wobbly. If you don't have a stone fixer or a DMT plate, you can also use cheap drywall screen on any flat plate.
      3 - Try using your 'off-hand' to keep the knife's edge flat against the stone (if you don't already do this).
      Here is a pretty well controlled sharpening motion that you should be able to emulate -
      http://www.youtube.com/watch?v=GB3jkR...
      http://www.youtube.com/watch?v=SKeSRD...
      The author of those videos contributes here every once in a while, btw.

      If you don't think I've described your basic problem, then I might need some more information to help you out. A lot of things can cause a Shun to chip - I'm just guessing at the most likely reason they'd chip DURING sharpening.

      2 Replies
      1. re: cowboyardee

        I am fairly new to hand sharpening. And yes it is the VG 10 steel. The small chips are occurring sometimes in the curve and sometimes in the middle of the blade.
        Your suggestion may be the case... Maybe I am unconsciously applying uneven pressure.
        Let me watch the videos you suggested.. Most of what I have learned about sharpening has been off youtube. I have also heard that I might be making the blade to thin. Thank you. I will let you know..

        1. re: cowboyardee

          "Use less pressure while sharpening. Practice more before applying much downward pressure. "

          excellent point.

        2. do you have any pictures showing what you are talking about? That would be very helpful in figuring out whats going on here.

          11 Replies
          1. re: JBroida

            I will post some pictures on tonight .. My 6 inch chef is the worse so I won't touch the others till I get this right.

            1. re: Fudd2010

              cool... if you can, please take pics of the whole blade on both sides and then closeups of the problem areas on both sides please

              1. re: JBroida

                JB I will try to get them up tomorrow. Cell phone won't zoom in close enough to get a clear picture.

                1. re: Fudd2010

                  no worries... dont rush on my accord. Just trying to help if i can.

                  1. re: JBroida

                    Sorry for the delay .. the pictures are not great. My cell phone can only focus so close.

                     
                     
                     
                    1. re: Fudd2010

                      hmmm... still tough to tell from the pics (no offense... i know its tough to take good photos with a cell phone).

                      I have a feeling other people are on the right track with this. Try this... make sure that your hand touching the blade (not the one holding the handle) always stays over the center line of the stone (i.e. not off of the sides or over the edges). Also, use less pressure... somewhere around 500-700 grams for the bulk of your work). Relax your handle holding hand too. When this is too tense, you tend to sharpen at angles where the handle is either higher or lower than the stone, causing the edges of the stones to dig into your knife. If you had to guess, about what angle would you say you sharpen at?

                      1. re: JBroida

                        I Feel that my angle is about 15 degrees.. but maybe it is less so I am getting a thinner edge.. I am going to try to integrate your suggestions plus the videos cowboyardee suggested.. thank you all. I will let you know how it goes.

                        1. re: Fudd2010

                          15 should be totally fine. Anyways, keep us posted on how things go.

                          Also, i dont know if this will be much help and i know someone already posted a couple of them here, but i recently put together a playlist on yourube with all of our sharpening videos in one place... maybe you will find some of them helpful:
                          https://www.youtube.com/playlist?list...

                          1. re: Fudd2010

                            Unlike the (many) folks with more experience here at Chowhound, I find it difficult to eyeball the sharpening angle. So I made a little wooden wedge (like a thin doorstop) with an angle of 16 deg. You may not want to go to that much trouble, but you could still use a protractor to cut out a little cardboard wedge. Just stick it between the blade and the stone to get an idea of the proper angle. Be sure to take it out before you start sharpening. Works for me!

                            PS. I bought some of those clip-on plastic angle guides, but found that the angle was unpredictable (it would vary depending on the edge-to-spine height of the blade) and was generally too low (12 degrees or so) for cooking knives.

                        2. re: Fudd2010

                          A few dumb questions it just occured to me to ask:

                          Your stone doesn't have little chips or divots or crumbling spots at its edges, does it?

                          Also, you're not giving the knife some swipes with a ribbed steel immediately before or after sharpening, right? Do you do anything other than use those two stones while sharpening - deburring, steeling, stropping, etc? If so, what exactly?

                          Finally, while you're sharpening, have you ever felt, seen, or heard it chip? Or do you just notice the chips afterwards? If it's afterwards, do you notice while sharpeing, immediately after sharpening, or while cutting with the knife later in the day?

                          1. re: cowboyardee

                            "Also, you're not giving the knife some swipes with a ribbed steel immediately before or after sharpening, right?"

                            Excellent question.

              2. I meant to reply earlier but couldn't. I have had chipped knife edge while sharpening, but that has to do with DMT diamond stone. I have never had my knife edge chipped while I am sharpening on a Japanese waterstone before. It is entirely possible to put an angle too low and chip the knife edge while cutting, but I have not had one chip while on a stone.

                2 Replies
                1. re: Chemicalkinetics

                  Well I could have used to tight an angle but rather feel I made the edge to thin and or didn't apply even pressure like cowboyardee was suggesting

                  1. re: Fudd2010

                    Just speculating but could the chips have come from board work and you just became aware of them as you started inspecting them prior to sharpening. If so just keep sharpening and follow the advice given in this tread.

                2. I see a lot of chipping on Shuns that come in. I sharpen them out but will watch and see if other chips develop in the process.

                  Jim

                  1. In addition to the advice already given…
                    1) Make sure your stones are clean, free of leftover debris or weird defects, and properly moistened.
                    2) Try using the magic marker trick to help narrow down what’s going on. Mark the bevel of the knife with a sharpie, make a few passes on the stone and check the markings. If you’re only removing the marks near the edge -you’re too high. If you’re only getting the shoulder- you’re too low. If you get the shoulders AND the edge - you’ve matched the existing angle. Also, make sure the markings along the length of the edge are wearing away somewhat evenly. You may not be adjusting correctly for the edge curvature and causing the chips at the belly curve.
                    3) The edge maybe crumbling from fatigue or ill heat treatment; like a burnt piece of toast, you’ll need to remove the burnt parts before creating a fresh edge.

                    1. We have had the same issue with the Shun Classic Chefs knife and believe it is defective material after sharpening corectly, using on proper surface and food stuffs this continues to happen...went to carbon steel. It is the sharpest knife I have ever used at home or resturant. It is very heavy and must dry constantly but love it.