Sharpening a round knife
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- This topic has 8 replies, 3 voices, and was last updated 09/24/2018 at 8:59 am by tcmeyer.
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09/21/2018 at 4:37 pm #47701
Hey everyone. I’m starting to dabble in leather work (means more sharp stuff!). I will be in investing in a very good round knife. I’ve seen the video that Clay did on it from 6 or 7 years ago.
Most round knife makers use a convex edge. The particular maker that I will be going with uses steel that keeps the edge very well and just hones his knives on a 10-12oz leather strop using Brownell’s 555 black compound, maybe followed the green compound.
With that said, has anyone tackled such a knife recently with the latest iterations of the WEPS with success and not reprofiling the edge? If I can clamp it on my 130 between projects and strop away with the diamond emulsions without having to invest in more stuff and time learning to get the angle right 👍
Thanks!
William
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09/21/2018 at 5:22 pm #47703William I personally have never done a blade like this. If I were to attempt it, I would think I could do it in two steps. I’d clamp it between the handle and the curved wing, on the back side of the vice. I’d orientate it to give me full access to the about 2/3 thirds of the blade from in front to behind the handle and off the back edge. I’d work that side first then flip it end for end, reclamp it the same way, again between the handle and the curved wing and repeat it on the other wing. I’d blend the two portions together to even out the applied edge.
Since I’ve never seen or handled the knife and don’t know the dimensions, as I’m looking at it and it appears in your picture, I think it should be able to be clamped as I see it.
Marc
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09/21/2018 at 5:48 pm #47704William I personally have never done a blade like this. If I were to attempt it, I would think I could do it in two steps. I’d clamp it between the handle and the curved wing, on the back side of the vice. I’d orientate it to give me full access to the about 2/3 thirds of the blade from in front to behind the handle and off the back edge. I’d work that side first then flip it end for end, reclamp it the same way, again between the handle and the curved wing and repeat it on the other wing. I’d blend the two portions together to even out the applied edge. Since I’ve never seen or handled the knife and don’t know the dimensions, as I’m looking at it and it appears in your picture, I think it should be able to be clamped as I see it.
Hi Marc,
Thank you! Round knives tend to be smallish in stature. This particular model is 4.25” from tip to tip and overall length of 5.75”. The steel is about 1/16” . Mostly used for nice, straight push cuts and handling curved cuts. For slicing through thicker leather, most makers are using convex edges.
William
09/22/2018 at 1:54 am #47706It looks a lot like an ulu, but I think it might be intended as a skiving knife. In any case, they’re really nice knives to work with. As an ulu, eskimos use them for skinning seals and whales. Traditional skinning knives usually have sweeping, rounded blades.
I’d use the approach as Marc described it, but if I understand him correctly, I’d orient it somewhat differently. Assuming that the blade has an arc of about 160 degrees, and assuming that the center of the blade is zero degrees, I’d rotate the blade about 40 degrees, clamping it with the handle well off to one side. Try to put the mid-point of the area you intend to sharpen at the very top. Sharpen that half of the blade, overlapping the center zone so you can blend the bevels as you sharpen the other half when you’ve flipped the knife in the clamp.
Geometrically, I think mounting the blade higher would be an advantage in reducing any angle change, so the LAA might be an option you’ll want to consider.
The idea is to minimize the rotation of the stone from one end of the sharpening stroke to the other. You want to keep the tangent points at the start and end of the area being sharpened as far from vertical as is possible. Is that confusing? Say so and I will try to make a diagram.
My skinners have a somewhat larger radius (about 4 or 5 inches, compared to <3″ for yours ) and I orient them with the mid-point of the belly at the very top for sharpening. I’m sure there’s some change in the bevel angles at the ends, but not so much that it’s noticeable. The tighter radius of your knife might not be so friendly to my method. I don’t have a photo of the knife in a vise, but here’s one of the knives to give you an idea of what I’m describing.
09/23/2018 at 1:30 pm #47712It looks a lot like an ulu, but I think it might be intended as a skiving knife. In any case, they’re really nice knives to work with. As an ulu, eskimos use them for skinning seals and whales. Traditional skinning knives usually have sweeping, rounded blades. I’d use the approach as Marc described it, but if I understand him correctly, I’d orient it somewhat differently. Assuming that the blade has an arc of about 160 degrees, and assuming that the center of the blade is zero degrees, I’d rotate the blade about 40 degrees, clamping it with the handle well off to one side. Try to put the mid-point of the area you intend to sharpen at the very top. Sharpen that half of the blade, overlapping the center zone so you can blend the bevels as you sharpen the other half when you’ve flipped the knife in the clamp. Geometrically, I think mounting the blade higher would be an advantage in reducing any angle change, so the LAA might be an option you’ll want to consider. The idea is to minimize the rotation of the stone from one end of the sharpening stroke to the other. You want to keep the tangent points at the start and end of the area being sharpened as far from vertical as is possible. Is that confusing? Say so and I will try to make a diagram. My skinners have a somewhat larger radius (about 4 or 5 inches, compared to <3″ for yours ) and I orient them with the mid-point of the belly at the very top for sharpening. I’m sure there’s some change in the bevel angles at the ends, but not so much that it’s noticeable. The tighter radius of your knife might not be so friendly to my method. I don’t have a photo of the knife in a vise, but here’s one of the knives to give you an idea of what I’m describing. SGAHPWILLIAMZUK
Thank you Tom! I think what I may do is get a cheaper round knife or score one off eBay to practice on. This way, when this one comes into fruition a long while from now (on a wait list), I will know what I’m doing with it.
And that’s a beauty of a skinner knife you have. Nice!
William
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09/23/2018 at 2:14 pm #47713You might purchase an inexpensive wheel pizza cutter to practice with. This one’s close to your perspective knife’s diameter. If all you’re looking to do is learn the WE stone technique to sharpen a round blade this may be an inexpensive way to do that. You may want to remove the handle, or not.
Marc
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09/23/2018 at 8:05 pm #47714Marc,
Ya know, that might not be a bad idea! 4” blade which is reasonably close. I could maybe glue it to keep from spinning so I could concentrate on the “half moon” portion of the blade. Work on it in halves and blending per the suggestions from you and Tom
William
09/23/2018 at 8:46 pm #47715Maybe just clamp it on the round steel blade and rotate the handle in front of or behind the vice, depending on how you choose to position the round disc in the vice jaws. Maybe you can draw a line with a sharpie marking the circular blade similarly to how the leather knife is shaped. This may make it easier to mimmick how you clamp the leather knife in the vice jaws. It’ll also make it easier giving you refernce points when moving the blade in the vice as you make available all the portions of the circular steel that relate to the real knife as you practice the sharpening process.
Marc
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09/24/2018 at 8:59 am #47720Thank you Tom! I think what I may do is get a cheaper round knife or score one off eBay to practice on. This way, when this one comes into fruition a long while from now (on a wait list), I will know what I’m doing with it.
And that’s a beauty of a skinner knife you have. Nice! William
Always happy to show off my amateurish handiwork! Thanks!
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