Strop effect

[PolsBirthday]

Here's sort of an odd question....we all know that strop helps edge your blade, but what exactly does rubbing a slab of metal on leather do? I've heard in several places that a strop will remove no metal whatsoever, so what are the scientific facts? Does it align the bonded molecules perpendicular to your blades edge? Or organize the free electrons found in certain metals?

anybody know the deal?

 

[Pierce]

If you look at cooking where your slicing and dicing...

You sharpen the blade on a stone, but once you do that you rub the blade on a steel.

The point of the steel is to serate the blade or "set the bite" onto the blade. This bite then allows you to cut into what your trying to slice so you dont have to use downward pressure (if you do your tomato is going to be flat rather than nice and round) only a forward motion with the shape of the blade should slice the item.

Now obviously on a straight your not cutting into skin so rubbing it on a steel would be a bad idea.

On any sharpening process your going to create a "burr", by using the strop your going to polish/smooth that "burr" so it doesnt cut/dig into your skin.

That is what I understand so far.

Pierce

 

[scottish steve]

As I understand it, it smoothes and re-aligns the edge which has become slightly kinked and stressed by the action of cutting hairs. As to a pasted strop, I think that might remove miniscule bits of metal, but I'm not 100% on that.

 

[Chimensch]

Another explanation I have heard is that stropping cleans off the micro-oxidation that builds up when it is not being used.

 

[mdunn]

ive heard both the straighten the fin, and remove oxidation theory. Probably its a combo of both

 

[scottish steve]

It definitely works tho!

 

[mparker762]

The oxidation is much softer than the underlying steel, so a leather strop with a lot of draw may be able to remove some of it. A linen strop is definitely abrasive (though only slightly); I once stropped a dull razor back to shaving sharp condition by giving it a huge number of laps on unpasted linen. But aside from that the leather definitely does *something* to the edge since the razor is much sharper after stropping on leather. Exactly what it does we don't really know, since nobody has looked at unstropped and stropped razors at the resolutions needed (3000x or so with a scanning electron microscope).

If you put an abrasive paste on leather (or linen) then it will remove metal at a rate that depends on the type of abrasive used. There are some extremely fine abrasive pastes out there that are much finer than any hone - you can get 0.5, 0.3, 0.25, 0.1 micron and even 0.05 micron abrasives for only a few dollars, since these are now produced for industrial purposes.

 

[English]

Not only does it work, but the finer the surface on the strop, the smoother the shave. Much like the grit on a hone or finishing paste the sharper the edge.

In the world of strops, you have smooth finishes and rough finishes and you have leather from different animals. The leather from the horse is generally finer than the cow and a special piece of leather from the hind quarters of the horse called "Shell" leather is generally considered the finest.

Generally speaking though, most modern strops that are discussed on the shaving forums are very high quality and do a really good job.

After you have honed a razor to a level of sharpness that is acceptable to your beard and skin, you will find that stropping on a smooth leather strop will refine the smoothness of that edge, removing any scratchy feeling. It makes a significant difference to the comfort of a shave.

Barbers would always strop their razors between customers to smooth the edge for the incoming customer.

One barber told me that he always used his linen strop to clean any rust off the edge first thing in the morning. He said it kept the leather strop clean. But today, there are many modern theories about what the linen will do. Some add a fine grit paste to the surface of the linen(or cotton or canvas) which will actually re sharpen the edge. They call this touching up the blade.

But a leather stropping is the final adjustment to a razors edge before the blade meets the whiskers on your face. I think of it as a refresh process that polishes and cleans the blade so that the soap will easily fall off the metal and it straightens up and smoothes the razors edge so that the blade glides smoothly on the face.

Technically, I think that the process aligns a very thin edge and removes oxidation. But more importantly, it works and is the most significant aspect of the maintenance of a razor to ensure comfortable shaving.

 

[huracan]

Check this out, mparker links to an article about razor blades that also discusses the effects of stropping on straight razors and how the edges compare under magnification. The article itself is almost 80 years old, but it deals directly with PolsBirthday's questions.

In one word: "friction"

{link}

 

[Light Beard]

I read it just aligns the burr on the edge that strayed right and left during use?

 

[Thebigspendur]

Also consider that jewelers and watchmakers use a lap wheel with a large very heavy leather to final polish all kinds of metals and it works very effectively.

Your not doing anything drastic and in the case of a strop the very edge of the blade is micro thin so it doesn't take much to work. Most here will tell you if you do a bunch of passes on a linen strop you will bring back an edge that is just starting to deteriorate.

 

[PolsBirthday]

Check this out, mparker links to an article about razor blades that also discusses the effects of stropping on straight razors and how the edges compare under magnification. The article itself is almost 80 years old, but it deals directly with PolsBirthday's questions.

In one word: "friction"

{link}

Brilliant find!

 

[Thebigspendur]

Also, remember the Grand Canyon was formed by running water (well mostly anyway).

 

[TomFox]

Also, remember the Grand Canyon was formed by running water (well mostly anyway).

Running water carrying lots of sediment.
I guess you could say the Colorado river was kind off like a pasted strop.....

Echh. That was cheezy. Can't believe I said that.