What side is dull?

[Jville]

If you try to shave arm hair and on side shave and the other doesn’t what side is dull. Meaning if (for example) you take knife in right hand and try to shave up your arm with right side of the blade face down towards your arm and left side is face up and it doesn’t shave, which side needs sharpening or debuting etc.

 

[jedy617]

 

[McMan]

This question sounds like a riddle.

In theory, the edge is an apex--a point--an edge can't have "sides", so there can't be a sharp side or a dull side.

I suppose one edge bevel could be more refined than the other. I forget who, but there was (at least) one sharpener who finished each edge bevel at different grits. I also forget what the logic was.

If there are burrs still hanging on, I'm going to guess and say that, if it shaves, the "up" side not the "arm" side has the burr. I think the burr would interfere more with cutting if dragging against the arm ("down") than dragging against nothing ("up"). But this is just a guess, and there are probably many other variables that could enter in. For example, what if it's a foil edge and flip-flops, so the shaving is really more like stropping?... Then, the side won't matter, what will matter is first-vs-second stroke, since the first stroke would flip (or drag) the burr. So, the second stroke would either be worse (or better) than the first, regardless of the side.

Again--just spitballin here... so put this in the "best guess" bin.

 

[Jville]

This question sounds like a riddle.

In theory, the edge is an apex--a point--an edge can't have "sides", so there can't be a sharp side or a dull side.

I suppose one edge bevel could be more refined than the other. I forget who, but there was (at least) one sharpener who finished each edge bevel at different grits. I also forget what the logic was.

If there are burrs still hanging on, I'm going to guess and say that, if it shaces, the "up" side not the "arm" side has the burr. I think the burr would interfere more with cutting if dragging against the arm ("down") than dragging against nothing ("up"). But this is just a guess, and there are many other variable that could enter in. For example, what if it's a foil edge and flip-flops, so the shaving is really more like stropping?... Then, the side won't matter, what will matter is first-vs-second stroke, since the first stroke would flip (or drag) the burr. So, the second stroke would either be worse (or better) than the first irrespective of the side.

Again--just spitballin here... so put this in the "best guess" bin.

Ok that makes sense. Thanks for getting the conversation going maybe some others will chime in. I’ve always wondered why one side sometimes can shave and not the other.

 

[Redwax]

That sounds like a burr. Logically, at least to me, if you had a clean apex then it wouldn't matter which way you held the knife.

If it were me, I would either go back and do some more deburring on the stone or loaded strop. A loupe or some form of magnification would be helpful here.

 

[refcast]

Sometimes this is an issue with kamisori, which are single bevel razors. One side will shave differently than the other. Or with chisel, kanna, kiridashi.

For razors though, both sides should shave . . . At least on my kamisori. But I use mine mainly with the ura away from skin. If I use ura toward skin, shave is closer but the razor wants to move deeper into the skin.

 

[Gavva]

I forget who, but there was (at least) one sharpener who finished each edge bevel at different grits. I also forget what the logic was.

Shibata is one of the more popular proponents of differential grit sharpening.

 

[Benuser]

That sounds like a burr. Logically, at least to me, if you had a clean apex then it wouldn't matter which way you held the knife.

If it were me, I would either go back and do some more deburring on the stone or loaded strop. A loupe or some form of magnification would be helpful here.

A rudimentary way of feeling where a fat burr is, is in determining which side feels sharper. There is the burr.

 

[mengwong]

But I use mine mainly with the ura away from skin. If I use ura toward skin, shave is closer but the razor wants to move deeper into the skin.

It puts the ura on its skin or else it gets the hone again!

 

[Jville]

Thanks peeps, makes sense it’s a burr, or wire edge rather than one side not being sharpened enough. Even though I’ve thought this before and dealt with it usually with stropping, I was never totally sure that’s what it was.