Convex Grind Sharpening

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Jul 4, 2002
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I have been admiring the Bark River knives but am hesitant to purchase because they are convex grinds. Can anyone tell me how one sharpens a convex grind? I have been using a Sharpmaker on all my knives but am unsure this tool would be appropriate for a convex groung knife.
 
Cut a mouse pad into two or three strips and glue different grits of sandpaper on it. Sharpen as you would a regular edge on a benchstone, the flexible mouse pad will accommodate to the convex shape.

By the way, there are already lots of threads on this subject out there. Here are a few of them:

http://www.bladeforums.com/forums/showthread.php?t=401547

http://www.bladeforums.com/forums/showthread.php?t=387802

http://www.bladeforums.com/forums/showthread.php?t=245309

http://www.bladeforums.com/forums/showthread.php?t=229605

http://www.bladeforums.com/forums/showthread.php?t=222896

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Also, please note that we have a forum dedicated to sharpening and maintaining knives here.
 
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The wider the range of grits you use, the better the result will be. It will work with the abovementioned two or three different grits if you don't let the blade get really dull before sharpening it or expect an extremely sharp edge. Don't forget to strop the edge afterwards with a leather belt and, ideally, some stropping compound.
Convex edges are great for all kinds of work knives, so don't let the unusual sharpening procedure turn you away from them.
 
Willieboy said:
I have been using a Sharpmaker on all my knives but am unsure this tool would be appropriate for a convex groung knife.

That is how Fallkniven sharpens their convex ground blades, small v-bevels applied to the very edge, lots of people do it that way, including the ABS guys who forge convex blades, Fowler for example. You can maintain the entire convex profile if you want on a Sharpmaker as well, but that is usually not the most efficient method to sharpen a blade.

-Cliff
 
I just could not seem to get one of my convexed SAKs hair-popping on the mouse pad the other day, so I took it to the sharpmaker for around 5 passes per side and it was as sharp as I could ever expect from a knife. I have a feeling that using a steel would have produced the same result and I just had a micro bur or rolled edge.
 
Give Bark River a call. They are wonderful people to work with and they will be more than happy to get you started. They have a site on the "Knifeforum" with lots of sharpening advice.

All I have ever had to do to sharpen my Bark Rivers is to strop them on the back of a notepad, but severely dulled knives might need more. The Bark River people can get you started. According to them, sharpening a convex blade is easier than maintaining the constant sharpening angle required by a "normal" blade.

Go ahead and get a Bark River. For the price, you can't go wrong.
 
Menocu said:
I just could not seem to get one of my convexed SAKs hair-popping on the mouse pad the other day, so I took it to the sharpmaker for around 5 passes per side and it was as sharp as I could ever expect from a knife.


Edge trailing tends to promote burr formation, often not a problem on steels usually used for convex knives were are 52100 or similar, very fine grained. Other steels, especially stainless can require edge-into honing to remove any problematic burrs.

-Cliff
 
Cliff Stamp said:
Other steels, especially stainless can require edge-into honing to remove any problematic burrs.

I maintain the convex edge on my Vic. Tinker (Rostfrei/Inox steel!) using edge-into honing on a ceramic hone (Spyderco Double-Stuff). The magic of having stretchable and compressible tendons, ligaments, muscle, fat, and skin over them handbones is that if you're holding the knife, hone, or both with your hands, you're going to end up with a convexed edge. You need unforgiving surfaces holding both the abrasive and the blade to get a flat edge.
 
Yes, when I take a knife which I have recently recut with waterstones to diamond stones I notice a huge difference, the actual stability of my honing being possibly a detriment because it means the diamonds can't be used without extensive reprofiling even at the same angle. I naturally on waterstones go from 3 to 6 or 10 to 12 just by the give and feel of the stone, but on diamonds it tends to want one of the other. That is what you get for sharpening about 1000 knives a year again and again, too much muscle memory.
 
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