Converting Convex Edges to V Edges

[Szilard]

Is this a totally sound practice? Assuming I'm going to keep the inclusive angles the same, and therefore have approximately the same amount of material behind my edge, should the cutting be approximately the same? If a maker chooses to have a convex edge will I somehow weaken the blade by making it a V or does that amount to rumor?

It seems like it'd be a fairly easy enough job.

 

[bpeezer]

Think of a convex edge like a continuous microbevel. It slightly improves edge retention at a minimal cost to "sharpness". If you go out and chop with a convex edge and then with a V edge you'll see why people like a convex. The V has more of a tendency to get stuck in the material you're cutting, especially with wood.

To actually answer your question, it shouldn't be hard to do. However, if you want a flawless V you might want an angle controlling system.

 

[palmerdl]

You won't have the same amount of material behind the edge. Draw a picture and you'll see. If you are going to freehand sharpen, you are going to end up with a convex edge anyway. Why not just stay with the convex? Very simple to maintain.

You won't weaken the blade by converting to a 'V' bevel, just the edge.

 

[Jason B.]

Depends on how its shaped and what the primary grind is.

The old draw it out does not work, a convex edge has a steeper apex angle but the grind itself is thin and thinner than a "v" edge.

The whole point of sharpening convex is to thin and smooth everything behind the apex while leaving the apex at a more obtuse angle. So if you sharpen at the apex angle then you will create a obtuse bevel that does not cut nearly as well. If you sharpen the bevel then you will need to grind out the curve until the shoulder and apex are on a even plane.

 

[Szilard]

I have a Wicked Edge so all of my edges are V edges, and they are fairly "perfect" minus perhaps the very small degree of play from having the strops on the guided rods. I guess I should suck it up and learn how to take care of convex edges. Wicked Edge produces a document that you can see here :

http://www.wickededgeusa.com/files/Creating a Convex Edge.pdf

It seems like a ridiculous amount of work to maintain with multiple angle resets as opposed to simply running the stone flat against the bevel. Looking at the angles provided here - it seems to back up that it is just as strong. A 20/20 degree V edge would have a thinner bevel with just as much material behind it as a 20/20 original bevel on the convex, which would an ascending 21/21 and 22/22 curve towards the apex. What knifenut says makes perfect sense - thinner cutting geometry with a more obtuse apex.

The last sentence is "strop at the original angle to maintain it". Is it really that simple?

 

[bpeezer]

The last sentence is "strop at the original angle to maintain it". Is it really that simple?

For a while, yes it can really be that simple. Stropping can only go so far, but it goes a heck of a lot farther than not doing anything

 

[Twindog]

You can convert a convex edge to a V edge. The only real issue is what kind of V edge you want to create -- acute, obtuse, with or without a microbevel. The best angle will depend on your blade geometry, blade steel and how you use your knife.

Convex edges can be thick or thin, acute or obtuse, as can V edges. One is not necessarily better than the other. However, the V edge is in most cases going to have a more acute edge angle. If you have a Wicked Edge, I'd stick with a V edge. It will be a perfect edge, and you'll know the exact angle of that edge. If the edge proves too thin, you can add a microbevel or make the angle more obtuse.