How do I sharpen hollow & convex blades...

F

fordf250

Joined
May 6, 2007
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114
The flat, sabre and chisel ground including the compound bevel I can do. What tool do I need to sharpen the convex & concave rounds without flattening them into one of the above?

I'm sure the answer in right in front of me, but I guess I just can't see it... thanks for helping
 
Thanks for the link to convex sharpening. It seems like a no brainer once you see how it's done. I knew it must be there right in front of me!

I'm not as sure about the solution for sharpening a hollow grind. I can see how a sharpmaker would be a good tool to maintain/sharpen the cutting edge, but if I were to use an Edge Pro to sharpen the blade cutting edge I'm not sure I can do that. I would also be afraid of taking out the "hollow" and getting a flat grind for my efforts. I can only imagine how difficult it would be to re-profile a hollow blade. That MUST use a different tool?

I was kind of sheepish about asking this question. I figured I must be the only person in the knife world to not know the answer. I suspect by the very limited number of replies that many knife people don't know the answer either? Hummmmmmm...

Thanks for you help...
 
A hollow ground knife is only hollow behing the edge, so you would sharpen it like you would a flat ground blade. Hollow grinds are easier to sharpen since you aren't hitting as much steel behind the edge. They will also dull faster and are a little weaker than flat grinds because of this.
 
If you think sharpening a hollow grind is a problem, consider the Chris Reeve hollow grind -- with a convex secondary bevel! :)

One of the classic problems with a hollow grind occurs when you do sharpen it and sharpen it and sharpen it over the years, until you find yourself sharpening into thicker and thicker territory, and now your blade's edge is not so thin as it was.

The answer is the back bevel. For example, if you sharpen the secondary bevel at 30 degrees (inclusive) you would follow this by sharpening again at 25 degrees. This will not hit the cutting edge, it will hit the shoulders of the 30 deg. bevel, thinning it behind the edge, thinning the blade itself to slip through material more easily.
 
to put on a hollow grind,edge bevel, blade main grind, or both, use a round wheel. The larger the wheel the shallower the hollow produced. Sandpaper on anything with a curve will work also.
 
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