Freehand sharpen convex bevel?

[froglips]

Ok, all you way backers out there, got a sharpening question for ya.

This fellow did a fine write up on sharpening irons and chisels with a convex bevel. As in, the opposite of a bench grinder bevel.

http://www.owdman.co.uk/howto/howto.htm

I grabbed my high end Sears/Craftsman $5 learning chisel. This chisel has seen most of my "I wonder if" tests including the dreadful cement block and slate tile experiments of '06.

It was in passable shape before, but still had some issues in pairing end grain. In all my efforts to free hand this sucker, I usually ended up with numerous facets and loads of time wasted.

I don't care for the bench grinder approach, which I know helps free handing. Nor am I looking at honing guides or micro-bevels. All too "fancy pants" for my interests.

So, back at the ranch, no pulling of legs or cracking of jokes, in about 3 minutes on waterstones of 1000, 8000 and honing, I put the convex bevel on.

It now cuts end grain like I always read it should. So far, the chisel edge doesn't crumble like it used to. Being of the highest quality steel, I just assumed it would never hold up.

So, anyone out there tried this little bit of heresy? Any thoughts as to drawbacks of a convex bevel?

Jim

 

[Dragon]

Well, I ain't got no fancy sharpening stuff myself. All I have are some files and a couple of Arkansas stones. Been using them for years on my knives and chisels and it works for me. Now, as far as convex or concave or whatever bevels, I try to hold an "eyeball" 30 degree or so angle on knife blades and whatever angle the chisel had when I bought it. So far so good. I'm still managing to cut wood fairly decently and from time to time my fingers or the occasional steak or tomato when the need arises. You may find this amusing,:wsmile: archaic,:roll: or downright appalling, buy many times I've been known to whip out the pocket knife in a restaurant because what they provided wouldn't cut air. :eusa_doh:

 

[Mike Davis]

The concave edge is easier to sharpen and hone because only the outer edges of the concave need to be reduced by hand. Less material needs to be removed so less time and effort are required.

The flat grind is a little harder to maintain due to the precise angle that must be held by hand. Sharpening devices that hold the angle help, but still more time and effort are needed to remove the flat plane of material.

Convex edges are stronger and can be as sharp as the concave if the back edge is removed enough to allow a good angle at the outer edge. Convex sharpening is easier to maintain by hand because the angle is less critical. A slack belt grinder and some sandpaper placed on a mousepad or piece of thick soft leather forms the convex easily. You can also get the correct geometry by rocking the tool as you stroke the stone with it. But this takes a little more of a learning curve.

 

[CarvedTones]

Interesting. I have done that before but not on purpose. The only drawback that I can think of is there is no bevel to ride. I sometimes use a flat ground chisel to clean up an edge after sawing by riding the flat bevel, not trying to take anything below the surface. If the bevel isn't dead flat, it will either do a sloppy job because the cutting edge isn't right at the surface or it will dig in.

 

[Jerome B]

I like the idea of doing more with less. Besides I am not up to the dramatics of sharpening wars. Pretty lazy.

I'm going to try it. I think that he has a seriously good point about not going over 30 degrees. after that I think that one would have the face of the plane blade hitting the wood before the edge of the blade does. Thus preventing cutting action.