Thread: To Lap a New Hone...

Originally Posted by holli4pirating

This makes no sense to me. If you lap the entire surface of the stone, the edges will be at the same height as the middle. "High corners" means that the hone has not been properly lapped.

Check your flattened stone by running your finger/thumb from the middle of the stone out and over the edge and you'll feel the high edges. When you sharpen a knife on a stone that hasn't been rounded on the edges the stone will only show black streaks on these high edges - nothing in the middle. This means that you are only providing 1/4" of stone surface to the knife when you should be providing the near full width of the stone. This isn't something that's easily seen or apparent when razor honing since razors don't bridge across the width of the stone the same way that knife does, however, on thin width stones (sometimes used) and in certain techniques the edges of the stones are coming into play more than others. I can't tell you how many times I've seen people proclaim their dislike of a stone that they had high edges on only to fall in love with the stone later on when the edges were rounded for them. The reason for this is that they are using more surface area of the stone after the edges have been rounded. The question is then often asked about why they don't notice this on other stones that they lap the same way and love? My answer is that some stones cut faster than others and the small amount of contact area presented by some stones doesn't matter where it matters very much on others.

Correct me if I'm wrong here - after you lap a hone, the top surface is flat. On a flat surface, all points lie in the same plane. Therefore, the sides of the hone are at the same height as the middle of the hone.

I don't know what you mean by "bridge," but I have hones that are narrower than a razor and hones that are wider than a razor, and I've never had any issues with a razor only contacting the edges of a hone on any lapped hone. I cannot imagine why a knife with a straight or smiling edge would act any different than a razor with a straigth or smiling edge, but I don't hone knives, so I'll take your word that there is a difference. Knives may indeed need rounded edges, but razors do not. The only reason, based on my experience, to round the edges of a hone is so that you don't accidentally dig the edge of your razor into a sharp edge and damage the edge.

Originally Posted by holli4pirating

The only reason, based on my experience, to round the edges of a hone is so that you don't accidentally dig the edge of your razor into a sharp edge and damage the edge.

Early on Randy told me to round the edges so that if there was a minuet chip in the edge of the hone it wouldn't catch the edge of the razor and chip it. I do that as soon as I get any hone. Funny thing is I have bought or traded hones from knowledgeable honers who didn't round their edges or flatten those hones. I didn't know what to make of that but I would rather be safe than sorry so I flatten and round no matter what rock it is.

Originally Posted by holli4pirating

Correct me if I'm wrong here - after you lap a hone, the top surface is flat. On a flat surface, all points lie in the same plane. Therefore, the sides of the hone are at the same height as the middle of the hone.

I don't know what you mean by "bridge," but I have hones that are narrower than a razor and hones that are wider than a razor, and I've never had any issues with a razor only contacting the edges of a hone on any lapped hone. I cannot imagine why a knife with a straight or smiling edge would act any different than a razor with a straigth or smiling edge, but I don't hone knives, so I'll take your word that there is a difference. Knives may indeed need rounded edges, but razors do not. The only reason, based on my experience, to round the edges of a hone is so that you don't accidentally dig the edge of your razor into a sharp edge and damage the edge.

Absolutely true - the surface will be dead flat but those edges won't. I don;t have a reason but I do have theories which mean nothing. All I know is it's a fact.

BTW, no one has to agree with me on this, I could care less. I'm simply offering up some insight gained from an immeasurable amount of stone work. If I'm coming across as a "know-it-all" then I apologize, I just wanted to help where I can see a problem.

Dave