Convex edge on a full flat grind

[FortyTwoBlades]

That is correct , but in any case after many sharpening I will have MORE usable knife then FFG

Only because the region behind the edge itself is also being worked, which can also be done with a FFG as I described above. It's very easy--in fact, it's arguably much easier with an FFG knife to maintain the overall geometry, so long as you're willing to work the flats of your blade.

 

[cbwx34]

I would like to see someone to do that Here I speak like user /minimal sharpening tool / not knifemaker .

Watch any Murray Carter (CarterCutlery on YT) sharpening video....

 

[maximus83]

Watch any Murray Carter (CarterCutlery on YT) sharpening video....

Was thinking same thing. Here's one by Carter I've seen on sharpening convex edges.

 

[samuraistuart]

Thanks, sounds cool. Have not heard anyone describe in this much detail.

Do you see a noticeable improvement in slicing task performance with that approach, due to the thinner geometry behind the edge? Do you recommend your customers who are manually maintaining these to just maintain the 15 dps edge (so this is essentially a micro-bevel on your convexed edge)? If that's the case, then I assume at some point after a lot of sharpenings, the end user has to either send the knife back to you, or learn how to thin and maintain that convexed shoulder area.

I don't notice a big change in performance. But most all my knives are hunter/kitchen knives cutting softer, non abrasive stuff that is easy to cut through anyway. There is a bigger change (although still very slight....to me anyway) when cutting stuff like cardboard and the like, that is harder to cut into because there isn't as much give in the material (I hope that makes sense). Basically I am just knocking off an edge shoulder (rounding it and blending with the rest of the blade bevel), but yet another edge shoulder is created when I sharpen, it's just smaller now (thinner edge). Correct, I recommend a ceramic rod to maintain edges for my customers who aren't into that much sharpening, like the Sharpmaker or round butcher's ceramic "steel" for kitchen knives. The edge is not convex itself, so I don't have to bother with showing someone how to maintain a convex edge (mousepad/sandpaper, or rolling motion on stones, etc). Why do I do it? Simply to have a thin edge geometry (thinner than if I didn't do that). "Maintaining the convex shoulder area" is the same as if it weren't convexed, thin as desired/needed.

 

[me2]

For the knife used add an example on page 1, full flat grind with a convex edge just means the blade is full flat ground, then the final edge is applied with a slack belt on a belt grinder. No real advantage, and potentially some disadvantages.

 

[FortyTwoBlades]

For the knife used add an example on page 1, full flat grind with a convex edge just means the blade is full flat ground, then the final edge is applied with a slack belt on a belt grinder. No real advantage, and potentially some disadvantages.

Potentially disadvantages if the steel was burned, but that's less of a convex issue and more of a power sharpening issue that's easily avoided with minimal experience. As far as advantage, the convex will still be thinner at the shoulder than a "V" edge of equal angle.