Thread: Convexed bevel, Good thing?

Micrographs of a convex edge.

Here is an interesting video by Dave Weaver, Dave is an SRP member but has not posted in a while. This video is part of a series on the “Unicorn edge” and buffing an edge with a buffer, posted on the Sawmill Creek forum,

While this technique will not work on a razor, it is interesting what his micrographs show of the edge taken of chisels at a side profile.

As Dave says, the technique is not new, I was first taught it by famed carver W.P. Wilcox in the early 80’s for sharpening carving chisels. W.P could not be bothered with sharpening on stones, except to remove chips and often said. “We don’t get paid to sharpen tools; we get paid to cut wood.”

And off a leather wheeled buffer they cut wood like butter.

What is new is Dave’s new look at the technique and experimentation with edge sharpness, longevity, and dramatic micrographs of the bevel side profile.

So, how does it apply to razors? Buffing and the result of buffing is exactly what we do by stropping. The strop works exactly the same way, except that it removes microns or fraction of microns, rather than thousands by buffing.

It has long been contended that stropping convexes a bevel or if done incorrectly rounds an edge. My contention has always been that convexing a bevel is a good thing and makes a stronger edge.

The best example is a Scandi grind vs a bevel grind on a knife. A Scandi grind is a convexed bevel on steroids. No question that a Scandi is a stronger edge than a bevel edge, and possibly sharper, or at least subject to less resistance. Think boat hull design.

Dave also touches on how a buffed convex edge is stronger and cuts cleaner than a Micro bevel. And the video also makes an argument that bevel angle is not as critical as once thought, that bevel shape may trump bevel angle, Dave’s convex bevels are much steeper than the honed bevel angle yet perform much better.

So, yes Dave’s cutting wood and we are cutting hair, two different kettles of fish… or are they?

What are your thoughts?

(Micrographs video Unicorn Edge)

(Dave’s first Unicorn Edge,)