Thread: Why hone with light pressure?

Of course I'm referring to after the bevel has been set.

I guess it's a silly question, but it's something I keep thinking about. Is it to conserve metal? Is it so the edge you create is "softer".

It's probably pretty obvious.

The lightest pressure possible will give the sharpest edge. It's ok to use a little (very little) pressure at first, especially on the coarser hones. Once you get to 4k and above, the results of using less pressure becomes quite noticeable. I always end my strokes on each grit with as super-light a pressure as possible, especially the last 5 to 20 laps(depending on the hone).

Less blade flex? Smaller striations/teeth on the edge? Less "micro-burring"? The technical reasons why are beyond me... it just always seems to work out that way.

The flexibility of a full and ultra thin extra hollow blades still amaze me. Whether or not it's happening as I imagine it, it's easy for me to visualize unwelcome upward deflection of the edge when pressure is applied to those types of blades. A great argument for as little pressure as possible.

What about wedges though? I'd like to get experienced honemeisters to hopefully weigh in here. Do others feel that little to no pressure is also crucial with wedges that have a much flatter grind? If so, why would that be? Do knifemakers who hone true flat grind or very lightly hollow ground blades go only "weight of the blade" when they want to get their knives scary sharp?

Chris L

I remember how surprised I was when I read post where people talked about feeling full hollows flexing when they shaved with them. Then when I finally got to shaving and I felt it myself it was a trip. I suppose even the very edge of a 1/4 hollow or a wedge is very thin and delicate. Less then the thickness of a piece of tracing paper.

There are probably a few reasons, one being spine wear, which I have seen when using too much pressure, but the predominate, documented, reason is because of upward edge flex as the blade gets sharper.

I can also tell you, pretty emphatically, that it works. And I add that because there are a lot of things I don't know about straight shaving (like exactly why something works). I just know through trial and error (years of it) that light pressure does in fact work.

Light pressure is one of the main things that seems to help get a blade sharp and has the least documented support for doing it. I find that interesting as well. It is documented, but not as much as I would expect it to be .

I have always suspected that the tinsel strength of steel would make it fracture when being honed instead of flexing which would make it duller. I think overhoning is a form of fracturing of the metal. I'm not sure how anyone, historically, could really know that the edge was tipping upward when being honed.

I will tell you that whenever I'm trying to really impress someone with the quality of an edge I have honed I often think of it as sculpting the edge as lightly as possible to produce the thinnest possible edge without fracturing it.

If you really want to take honing to a wicked science spend a few years trying to learn how to hone an edge using about half the weight of the blade. That is, to actually relieve the weight of the blade off the hone, while stroking. The results are pretty darn neat.

If you want to demonstrate how this works to yourself try this:

Take a wooden shim, and "sharpen" it with some sandpaper just like you would if it were a plane iron. Raise it about thirty degrees to the paper and you will really see you light pressure removes a tiny even layer of wood while heavy pressure catches the wood and causes it to tear and chip right on the edge.

THis is how I think of what I am doing and why I wlways try for the lightest smoothest honing stroke I can get. I want the metal to shave off that edge evenly and smoothly as I slide it along I don't want any tearing of that finely grained edge.

Originally Posted by AFDavis11

There are probably a few reasons, one being spine wear, which I have seen when using too much pressure, but the predominate, documented, reason is because of upward edge flex as the blade gets sharper.

I can also tell you, pretty emphatically, that it works. And I add that because there are a lot of things I don't know about straight shaving (like exactly why something works). I just know through trial and error (years of it) that light pressure does in fact work.

Light pressure is one of the main things that seems to help get a blade sharp and has the least documented support for doing it. I find that interesting as well. It is documented, but not as much as I would expect it to be .

I have always suspected that the tinsel strength of steel would make it fracture when being honed instead of flexing which would make it duller. I think overhoning is a form of fracturing of the metal. I'm not sure how anyone, historically, could really know that the edge was tipping upward when being honed.

I will tell you that whenever I'm trying to really impress someone with the quality of an edge I have honed I often think of it as sculpting the edge as lightly as possible to produce the thinnest possible edge without fracturing it.

If you really want to take honing to a wicked science spend a few years trying to learn how to hone an edge using about half the weight of the blade. That is, to actually relieve the weight of the blade off the hone, while stroking. The results are pretty darn neat.

A huge +1 on this post. In my honing experience, sharpness is directly related to pressure. The lower the pressure the sharper the razor will be. I think the forces that impact the very edge can be enormous in relation with how thin and fragile the steel is at that part of the blade. Keeping a hone well lubricated and pressure as low as possible (while maintaining an even stroke) seems to allow for the best results. On my DMT1200 I have witnessed this countless times. I always aim for a positive HHT, before I finish honing on the DMT. It really make all the difference to minimize the pressure as soon as the edge starts passing the TNT. Soon thereafter it 'll pass the HHT.

For me, speed helps. I usually start on a hone with doing slow and precise X-strokes, watching the wave run up the edge. After a while, I feel that my "muscle memory" has locked on to the motions and then I start to speed it up a little, adding a sort of a soaring idea to the the blade. I realize that it's not the common way to do it, but it really makes a difference in my end results. I also pay a lot of attention to turning over the razor as smooth as possible. I start lifting the edge near the end of the stroke and I'm already commencing a new stroke before the edge touches down again.

I'm not saying this is the only way to get a keen edge. I merely want to illustrate how much pressure management relates to good honing results.

Best regards,
Bart.

I think that the when the edge is honed to the optimum level of sharpness that that hone can give, the blade edge vacuum sucks down onto the hone of its own accord. This suction is the optimum pressure.

When you really know your hones, you can feel the suction and at that point you should stop as the hone is adding no further value to the edge. In fact it may well be reducing the fin that you have worked so hard to create.

How do I know this? Well I have no scientific answer. Its a bit like knowing when the sugar has dissolved when you stir your coffee cup with a spoon. You just feel it.

It is the best way to finish but to do it throughout the process I cannot understand. why? because my razors are very sharp and I don't need to spend hours and hours getting there.

Thanks everyone. Everyone has some really good input. I've gotten some good ideas that I want to try.