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Oct 17, 2011 03:49 AM

Sharpening help

Hey all,

Just a quick question for the sharpening gurus here.

I've just started to develop an interest in Jap knives, and freehand sharpening. I've read Chad Ward's book, and a lot of stuff online. I've bought a few knives, but I'm first practising on some old blunt ones: My housemate's old Victorinox chef's, and a very blunt Kasumi paring (my Mum does not know how to look after knives). Both stainless steel.

I'm using Naniwa superstones - 400, 1000 and 5000. Then stropping with chromium oxide.

I'm sure my technique is pretty poor, but I'm being slow and patient, and trying to minimise wobble. I aimed for 20 deg on the Victorinox and 12 deg on the Kasumi.

The issue? I don't seem to be raising a burr, and the knives are getting sharper, but really not super sharp. Why am I not raising a burr? Is it the metal? Do I need to start with a coarser stone? Not enough pressure? Or is it just from choosing the wrong angle to start with?

I'd appreciate any advice!

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    1. "Why am I not raising a burr?"

      Many possible reasons....one reason is that these knives are extremely dull that you have not yet able to get the two sides of the edge met.

      "Is it the metal? "

      Metal matters, but these knives you mentioned should able to raise a burr

      "Do I need to start with a coarser stone? "

      A burr is easier to form with a coarser stone, but a 400 grit stone should be coarse enough.

      "Not enough pressure? "

      That is a possibility, but I cannot be sure how much pressure you are using. You may be doing it too light and removing metal very slow, and therefore will take a long time to form a burr. Or you may be applying enough pressure and further pressure will be unnecessary and potentially harmful.

      "Or is it just from choosing the wrong angle to start with?"

      20 degree for the Victorinox should be fine.

      1. As mentioned the chances are you are not pressing hard enough yet or you have not taken enough strokes. Use a firm pressure but only what you can control the angle with. It takes a while to bring back a very dull blade. But once you get a sharper edge you can reduce the pressure.

        1. Depending on how dull they are you may have to work a while to raise a burr on the 400 grit stone.

          More than likely you are sharpening at a flatter angle than the current edge is set at. Have you done the Sharpie trick to see if you are grinding at the edge? My brother brought over a very abused Henkel chef knife. I started him out and let him go at it on a 220 grit stone. It took a while but he finally got a burr but we were first trying to level the edge since it had a significant dip from poor sharpening

          1. "Why am I not raising a burr?"
            That's a tough question to answer. In part because we don't know whether you're not raising one or just not feeling one that is there.

            The most likely cause of your problem: you are switching sides repeatedly while sharpening. Don't do that yet. When you switch sides of the knife, you both flip the burr and abrade some of it away. In other words, the burr is there but will never get huge, and if you've never felt a burr before, you want a big, obvious one to start with. Don't worry about keeping the bevels symmetrical - you can even out the bevels later. Just work one side of the knife until you have a burr you can easily detect. Later on, once you can reliably detect a burr, then you can work with a smaller one.

            Second most likely problem: you're not feeling for it correctly. After sharpening one side for a while, hold the knife with the edge angled down. Place your other hand on the knife with your finger pads resting against the edge of the blade, on the opposite side to the one you sharpened - it should be almost as though your off-hand were a sharpening stone and your knife was resting its bevel on it about to be sharpened. Now pull your fingers away from the spine and edge, like you were stropping the blade with the pads of your fingers. You should feel a little ridge - that's a burr. If you did the same with the other side, it would feel smooth - no burr. Once you can feel one, take a close look - you might even be able to see it, especially with a magnifying glass.

            Third most likely problem: You are just not getting your bevels to meet. Too impatient. Keep in mind that if your knife was super dull to start with, it can take a long time to make your bevels meet and form a burr, even for an experienced sharpener - and that goes triple for someone who isn't consistently holding an angle yet.
            Third most likely problem, part 2 - your angle is too acute and that's part of the reason it's taking forever
            Third most likely reason part 3 - your stone is too fine and that's why it's taking forever. But as Chem pointed out, 400 is certainly coarse enough.

            Now, since your knives have been getting sharper, I suspect your problem isn't really that your bevels aren't meeting (though its likely they are not meeting consistently for the length of the blade yet). It's probably that you're creating a burr but not good at detecting it yet and also likely not making it big enough to be easy to detect. Victorinox knives don't form as huge a burr as some others, but it should do well enough. I haven't sharpened any Kasumi that I remember, but those look like they should work just fine for learning to sharpen.

            Lastly, I would suggest avoiding using a lot of pressure right now. For beginners, that tends to mess up your ability to hold an angle and as such is counterproductive. Just use enough pressure that the sharpening motion feels natural and smooth and consistent to you, if that makes sense. The stone will do the rest. There are a lot of acceptable ways to hold and knife and apply pressure while sharpening, but I recommend taking a look at this video by Jbrioda (posts here sometimes) - he has a nice, controlled, technically sound, and reproducible method.