Drawbacks to convex edges?

[dbooksta]

Realizing that I am unlikely to ever develop adequate skill at hand-sharpening, I bought a Work Sharp and spent an hour putting a polished convex edge on a bunch of my EDC knives. So far I'm so happy with these edges I'm wondering why these aren't the norm?

The only drawback I can think of is that it would be very tricky to resharpen these on a flat stone. Is that the only reason factory knives are finished with a flat edge?

 

[HeavyHanded]

Its much easier on powered equipment to turn out consistent V bevel than convex. It takes a bit of extra effort to guarantee any sort of reliability in terms of angle at the apex, thickness behind the edge.

Its easier to do them on a flat stone than you might think, though getting the cosmetics nice is a bit more challenging.

 

[FortyTwoBlades]

Lay the convex on the stone with the edge apex tilted up off the stone. Then lift the spine until you see the edge contact the stone's surface. Sharpen at that angle like you normally would.

 

[David Martin]

Its much easier on powered equipment to turn out consistent V bevel than convex. It takes a bit of extra effort to guarantee any sort of reliability in terms of angle at the apex, thickness behind the edge.

Its easier to do them on a flat stone than you might think, though getting the cosmetics nice is a bit more challenging.

I agree. It can be done on a flat stone with experience. DM

 

[Obsessed with Edges]

A back & forth 'scrubbing' motion on a flat stone is going to introduce some convex on it's own, whether one is aiming for that or not. It's a product of the natural and inevitable variation in held angle, when done freehand. That's how I've deliberately convexed some of mine. Just let it happen, when shaping the bevels.

For the refining/finishing work at the apex itself, the angle can be more tightly controlled with edge-leading passes only, and with a fingertip or two on the blade, directly over & slightly behind the portion being worked. Start with the guiding instructions mentioned by FortyTwoBlades above, and go from there. This can also be done with a scrubbing stroke, after getting the feel for it and learning to control it. But starting out, careful edge-leading passes are the safer way to go, to keep the apex crisp.

Don't worry too much about cosmetics right now. Focus on keeping the apex crisp & sharp, and the cosmetics will come with more practice.


David