Verification of Strop Theory

[Chicken Enchilada]

Now for a serious post regarding stropping. I've been reading up about strops lately. The conclusions that I have come to (as for as researching goes), is that if you want to go a really long time without having to use a stone you need a strop with a horsehide leather component, and a linen component.

The linen component actually removes metal, acting like a superfine grit hone. The horsehide component has very little draw, and realigns the edge. Combined, these two components work well at maintaining a razor. Presumably this is the ultimate stropping set up, and with it I can go a really long time without needing to use a barbers hone(or whatever).

I want to verify these conclusions I have come to. Please enlighten me. Also, what is the difference between cotton, and true linen?

I'll probably ask more later, but for now I have to go.

Happy shaving,
Justin

 

[professorchaos]

Essentially true. There are those who will disagree with me, but I don't believe the linen/cotton component removes metal. Sure, it removes rust and dirt, which accounts for the discoloration you will see over time. But remove metal? Without the addition of some abrasive, it simply doesn't add up.

 

[leighton]

Thats what our resident master of strops has to say on the subject.

Cloth just feels less abrasive. Is it true on the microscopic level? I don't know. But it certainly is cheaper.

 

[richmondesi]

To the other point. I don't think I would rely only on my horsehide/linen for maintenance. I'd have at least a coticule or other similar stone for touchups.

I mean MParker says he took a dull razor and made it shave ready with linen after 1400 passes... I don't think I'll ever test that personally

 

[ambrose]

Ive done some experimenting with strops and the razors edge under loupes.

I have found that cotton/linen does indeed remove a small amount of metal. Now Im sure its just either the wired edge from a good honing session or the micro corrosion that naturally happens to the edge. Either way its good things. Now I found that the latigo dose more to an edge than horsehide alone with similar amounts of laps. After stropping an edge on latigo the edge was more polished and straightened also very even a major difference from freshly honed. After stropping an edge on horsehide it was similar but not nearly as much as what the latigo had done but it was very very polished much more than the latigo.

I used similar amount of laps and retouched the edge before every stropping session.

Like Ive said before latigo alone is great, horsehide alone is ok, one after the other is just fantastic.

If I could only own one strop it would be my custom TM red latigo 24 long x 2.5 wide barbers end cotton strap. The only thing is what the fun in just one strop. I have 4 and will add at least 2 more in the very near future.

YMMV

 

[Seraphim]

Now for a serious post regarding stropping. I've been reading up about strops lately. The conclusions that I have come to (as for as researching goes), is that if you want to go a really long time without having to use a stone you need a strop with a horsehide leather component, and a linen component.

The linen component actually removes metal, acting like a superfine grit hone. The horsehide component has very little draw, and realigns the edge. Combined, these two components work well at maintaining a razor. Presumably this is the ultimate stropping set up, and with it I can go a really long time without needing to use a barbers hone(or whatever).

I want to verify these conclusions I have come to. Please enlighten me. Also, what is the difference between cotton, and true linen?

I'll probably ask more later, but for now I have to go.

Happy shaving,
Justin

The only true conclusion you can possibly come to is that there is no firm conclusion to be drawn!

Horsehide?

Or Latigo?

I have personally found a great deal of functional effect difference between the two I have tried. Although I recently got a vintage horshide that behaves more like latigo than the previous horsehide shell strop I had previously had did, which was like glass to strop on, and never seemed to impart much, if any improvement to an edge.

And then cloth components:

Linen?

Canvas?

Untreated?

Or with very lightly abrasive chalk white paste?

Again, my personal experience showed me little if any effect of using untreated canvas. But after reading a vintage barber's manual on the subject (in Classic Shaving's "how & why" section), it discussed treating the cloth component. So that is what I did-I went out and got some Dovo white paste, and loaded it up, and smoothed it out. After that it was a marked change in effectiveness of the canvas component.

You can get a more in-depth review of my results here. White paste is NOT the same as ChromOx, or any of the other pastes. It serves a different purpose. It fills in the weave, as well as providing a slight amount of abrasive quality. You can use it daily.


So, I submit, that there is no hard-and-fast conclusion that can be made. You are just going to have to buy a bunch of stuff and try it out, just like the rest of us poor slobs!

 

[Kees]

Essentially true. There are those who will disagree with me, but I don't believe the linen/cotton component removes metal. Sure, it removes rust and dirt, which accounts for the discoloration you will see over time. But remove metal? Without the addition of some abrasive, it simply doesn't add up.

So does this mean that stainless steel razors need little if any stropping at all?? Removal of dirt should take 2 or 3 roundtrips at the most.

I still do not believe stropping does not remove metal. If it wouldn't stropping would be pointless unless you believe in the realignment theory.

 

[professorchaos]

So does this mean that stainless steel razors need little if any stropping at all?? Removal of dirt should take 2 or 3 roundtrips at the most.

I still do not believe stropping does not remove metal. If it wouldn't stropping would be pointless unless you believe in the realignment theory.

Not exactly...given that the cloth component isn't wholly smooth, more than a few laps are required to hit all parts of an edge. What's more, not every uses the cloth component. Those who don't clearly don't consider it necessary.

Abrading relies on the difference in hardness between the material being abraded and the material doing the abrading, with the abrasive being the harder of the two. Of course this is not an absolute requirement. Anyone who has walked up very old, well traveled stone stairs will witness that (comparatively soft) shoes have removed (comparatively hard) stone.

What I am saying is that the cloth component may remove metal from a razor, but the razor, being the harder of the two, surely must remove cloth at a faster rate. Achieving an appreciable difference in an edge using the cloth must come from a mechanism other than abrasion.

Perhaps I am just splitting hairs and defining abrasion too narrowly. Of course, if anyone can show me cold, hard facts to the contrary, I am receptive. Anecdotal evidence we can agree upon - stropping improves a razors edge. I remain skeptical about how it does so.

 

[Seraphim]

Not exactly...given that the cloth component isn't wholly smooth, more than a few laps are required to hit all parts of an edge. What's more, not every uses the cloth component. Those who don't clearly don't consider it necessary.

Abrading relies on the difference in hardness between the material being abraded and the material doing the abrading, with the abrasive being the harder of the two. Of course this is not an absolute requirement. Anyone who has walked up very old, well traveled stone stairs will witness that (comparatively soft) shoes have removed (comparatively hard) stone.

What I am saying is that the cloth component may remove metal from a razor, but the razor, being the harder of the two, surely must remove cloth at a faster rate. So achieving an appreciable difference in an edge using the cloth must come from a mechanism other than abrasion.

Perhaps I am just splitting hairs and defining abrasion too narrowly. Of course, if anyone can show me cold, hard facts to the contrary, my mind is open. Until then, I remain skeptical.

I put for this theory: it is not the soft shoes that did the abrading of the hard stone steps, but rather the also very hard dirt and sand that was on those stairs and on the bottoms of the shoes that did the abrading.

Same thing with the Grand Canyon. It wasn't water alone that caused the erosion, but rather the water carrying along sediment, which is actually the slurry that caused the erosion of the hard stone.

There is a modern technology that is used for cutting metal Abrasive Water Jet cutting. It uses a stream of water in which is suspended a suitible cutting medium (garnet, etc.). Obviously it is not the water that is doing the cutting. Same thing with the stairs & the Grand Canyon, it is not the shoes, nor the water in those cases either.

That is why I pasted my canvas. It needs more "oomph" than the steel does, and I feel that the cloth alone cannot provide that.

 

[Chimensch]

I bought my Illinois strop new in 1980 and, today, you can see the linen loaded with swarf, just like a hone. Tomorrow I'll put a picture.

 

[professorchaos]

I bought my Illinois strop new in 1980 and, today, you can see the linen loaded with swarf, just like a hone. Tomorrow I'll put a picture.

That is an observation, not a fact. To be convinced, I need more than a picture. So the linen has turned dark over 30 years. It needn't be swarf doing it. It could have been caused by other processes than removing metal from the razor. The question remains: is it from metal being abraded or rust and dirt being removed? If it is in fact swarf, would it not clog the linen over time and lessen its' effectiveness? Yet I presume you think the linen remains effective since you continue to use it.

A great debate ensues! What we need is a strop, a razor, a stropping machine, a metal detector and a very precise scale. Is there a scientist among us?

 

[leighton]

So does this mean that stainless steel razors need little if any stropping at all?? Removal of dirt should take 2 or 3 roundtrips at the most.

I still do not believe stropping does not remove metal. If it wouldn't stropping would be pointless unless you believe in the realignment theory.

The problem with your theory is this: SS is not stainless. It just rusts less quickly.

 

[mparker762]

Perhaps I am just splitting hairs and defining abrasion too narrowly. Of course, if anyone can show me cold, hard facts to the contrary, I am receptive. Anecdotal evidence we can agree upon - stropping improves a razors edge. I remain skeptical about how it does so.

It is possible for a softer material to abrade a harder one. Iron Oxide, graphite, and paper are all softer than our razor steel yet all are popular tools for sharpening razors.

I'm sure you've seen the photos from that old popular mechics article where you can clearly see that metal has been removed by the strop. Maybe it works by abrasion, maybe it's surface flow of the steel, or maybe all the strop removes is the softer oxidization and not the hard steel and the rusting process itself is what really keeps the razor sharp. Or maybe the microscopic bits of rust coming off on the strop are what sharpens the razor (iron oxide is a well-known abrasive after all). One thing I've noticed is that over time (months of use) the edge of a razor that is regularly stropped on a hanging linen strop becomes ovalled the same as one that is stropped on pastes. Again, the mechanism by which this happens is unknown to me, but *something* is happening to remove metal from the edge. Maybe the edge rusts a bit more quickly, maybe the metal is gradually drawn off the edge, maybe the linen directly removes the metal, or whatever.

There was a guy on SRP a few months ago with access to a SEM that I was trying to get to look at these issues, but the rest of the guys kept wanting him to look at coticule edges vs diamond edges etc, and I think he got overwhelmed and left. Short of an SEM though I really dunno.

 

[Seraphim]

It is possible for a softer material to abrade a harder one. Iron Oxide, graphite, and paper are all softer than our razor steel yet all are popular tools for sharpening razors.

I'm sure you've seen the photos from that old popular mechics article where you can clearly see that metal has been removed by the strop. Maybe it works by abrasion, maybe it's surface flow of the steel, or maybe all the strop removes is the softer oxidization and not the hard steel and the rusting process itself is what really keeps the razor sharp. Or maybe the microscopic bits of rust coming off on the strop are what sharpens the razor (iron oxide is a well-known abrasive after all), and since razors rust black that would look like swarf on the strop. One thing I've noticed is that over time (months of use) the edge of a razor that is regularly stropped on a hanging linen strop becomes ovalled the same as one that is stropped on pastes. Again, the mechanism by which this happens is unknown to me, but *something* is happening to remove metal from the edge. Maybe the edge rusts a bit more quickly, maybe the metal is gradually drawn off the edge, maybe the linen directly removes the metal, or whatever.

There was a guy on SRP a few months ago with access to a SEM that I was trying to get to look at these issues, but the rest of the guys kept wanting him to look at coticule edges vs diamond edges etc, and I think he got overwhelmed and left. Short of an SEM though I really dunno.

Isn't Iron oxide simply oxidized iron? Therefor, of a similar hardness as steel (another form of iron)???

I have never heard of graphite being used as a sharpening agent, can you tell me more?

And if by paper you are refering to newspaper, it is the carbon in the newsprint that is causing the abrasion, not the paper, right?

 

[leighton]

Isn't Iron oxide simply oxidized iron? Therefor, of a similar hardness as steel (another form of iron)???

I have never heard of graphite being used as a sharpening agent, can you tell me more?

And if by paper you are refering to newspaper, it is the carbon in the newsprint that is causing the abrasion, not the paper, right?

On that logic, and I'm playing devil's advocate here...

Steel is "hard" because it has been heated to a certain degree and then quickly cooled, thereby creating a crystalline structure.

Iron is a component of steel, but what makes steel steel is the carbon. The carbon enables the martenistic(?) formations that makes steel hard. If you remove the carbon from the iron, your left with a lump of very soft iron. Iron is not all that hard IIRC.

Anyway, food for thought. I have no idea. I just know stropping works.

 

[mparker762]

Isn't Iron oxide simply oxidized iron? Therefor, of a similar hardness as steel (another form of iron)???

I have never heard of graphite being used as a sharpening agent, can you tell me more?

And if by paper you are refering to newspaper, it is the carbon in the newsprint that is causing the abrasion, not the paper, right?

Iron oxide is much less hard than the 60HRC-65HRC steel in our razors. I can't find what it runs on the HRC scale, but the various flavors of iron oxide (there are several besides the common red stuff and razors tend to rust black which indicates to me that they're rusting to one of the other variants) tend to run from 2-4 on the Mohs scale. Iron oxide is the abrasive in Dovo Red paste, and it's a reasonably fast cutter though slower than diamond.

Graphite is the abrasive used in the Dovo Black paste, several other members here have had success with simple lead pencils as well. It's a pretty slow cutter, about like 0.3 micron aluminum oxide.

Nobody really knows what the abrasive is in newspaper. If it's the carbon black then that's really seriously soft stuff yet it still abrades the steel. It may also be the paper fibers themselves, possibly the oil that is used as the carrier dries and stiffens the wood fibers making them more abrasive - this is also consistent with the observation that heavily-printed sections of the paper seem to work faster. Whatever is doing the work, it seems to hone about like 0.1 micron diamond, though at this point a SEM would really really be handy, 'cause I think this is getting at the extreme limit of what the steel can handle. You wanna get feather sharp, this is the stuff to do it with, and you still need a light hand on the newsstrop.

To the OP - I'm afraid you'll just have to experiment a bit and find out what works for you. There isn't really any established theory in this area yet, just lots of WAGs.

 

[Seraphim]

You guys are right. Iron rates about a 4 on the Mohs scale, razor steel is about 7.5.

 

[northpaw]

Re: does a linen/canvas strop remove metal

Why not strop with it a bunch, then put a bit of it into a glass of water and scrape the surface with a fingernail or whatever. Afterwards, take a magnet and move it around the outside of the glass - from the bottom to the sides - and see if you're dragging around any particles.

Disclaimer: I don't have a fabric-based strop, nor have I used or even seen one, and I have no idea if any of the above might hurt it.

 

[mparker762]

Re: does a linen/canvas strop remove metal

Why not strop with it a bunch, then put a bit of it into a glass of water and scrape the surface with a fingernail or whatever. Afterwards, take a magnet and move it around the outside of the glass - from the bottom to the sides - and see if you're dragging around any particles.

Disclaimer: I don't have a fabric-based strop, nor have I used or even seen one, and I have no idea if any of the above might hurt it.

I'm not sure if this would work. With steel particles of the scale we're discussing (nanometers) the molecular attractions between the steel and fibers, or steel and water, might well be stronger than the pull of the magnet or the scraping of the fingernails. Things get wierd at that level.

 

[leighton]

Adding to what mparker said, I don't think any of us are arguing that micro-oxidation isn't being removed. So, you could get a false positive from that test.