Thread: Verhoeven Paper Question

Originally Posted by Bart

All sources I ever read, including your link, always advice to dress the leather with an abrasive compound.
...

In the book's link, Butz says that he sometimes uses "a little polishing compound". The implication being that he more often does not. That's a long way from "always advice to dress the leather with an abrasive compound.". In the Butz book, anyway.

Verhoeven conducted the leather experiments on flat hones and flat leather strops...

It's interesting that Verhoeven is actually using a Butz strop (named and designed for the expert in my link), but gets results opposite to what Butz gets. Verhoeven is a researcher, not an expert craftsman in any field or craft that requires practical application of sharpening (that I know of). Butz is an expert on sharpening curved and straight cutting surfaces. When it comes to an opinion on sharpening, I'll go with an expert on sharpening the tools in question. Especially so since I am certain that Butz gets better results from a Butz strop than Verhoeven or his assistant did.

I do remove small burrs from my chipcarving tools all the time. When they are large, I use a hone. When they are small, I use plain leather; since I don't like a pasted strop around or in my tool roll-ups. Obviously, I always try to place the smallest burrs possible on my woodworking tools.

...
I advocate the use of the word "fin" for that strip. Stropping on clean leather is friction and it aligns and straightens out the fin of an edge. Stropping on paste is an entirely different thing.
...

That friction is precisely why you have an abrasive action...

Originally Posted by Bart

Hi, Kees,
I was talking about benchstrops for honing chisels and such, in response to Stickiy's post about sharpening tools for woodcarving. Most sources advocate dressing the strop with some kind of abrasive compound, often CrO or diamond paste. Neatsfoot oil is used for nourishing leather. I don't really see the connection.

Best regards,
Bart.

Neatsfoot oil changes the friction coefficient of the strop. Increased friction = increased abrasive action (between 2 objects in contact and possessing relative motion). Friction and abrasion go hand-in-hand. The abrasive action of a strop is the entire reason that we rub steel against it.

A strop and a razor, each, obviously possess innate friction qualities; even at rest. So in engineering terms: whenever you rub one against the other... you will have an abrasive action. It is unavoidable.

If one moves their hand fast enough it will catch on fire due to the abrasive action (i.e. friction) between their skin and the air.

abrasion: removal of material by friction with another.
friction: a force applied from rubbing one material against another.
significant: with effective relevance

That said:
Friction is a force. That force may pull chunks out of something, or it may not, in which case the energy of that force is released into heat.
There's always a ratio between those two. Grating cheese is causing much abrasion and little heat. Rubbing a wooden stick over a file is causing much abrasion and little heat. Rubbing that same wooden stick over another piece of wood is causing little abrasion and much heat. Do it fast enough and you can start a fire.

Theoretically, you can abrade steel with a stream of water. But has that any effective relevance for our honing practice at home?

From an engineering viewpoint (since you seem so keen on dismissing science as a valid source of truth), there's abrasion and there's burnishing. The former relies on removal of material. The latter relies on plastic deformation of the surface (plastic flow). Any decent textbook about finishing metal surfaces will provide that information. Polishing is combination of both and the finer the polishing medium the more the principles of burnishing enter the mix.

There is little doubt in my mind that a clean leather strop relies heavily on burnishing. Verhoeven found no significant abrasion in clean leather (but of course that makes him a moron according to you, doesn't it), hence that leaves me with burnishing. Burnishing=plastic deformation=(re)aligning the tip of the edge instead of abrading it.

I won't deny that you can knock a small fold-over bur off the edge of your tools. Or maybe the strop just grabs the bur and aligns it in the right direction where it actually becomes the tip of the edge. Who's to tell? But on a razor there is no fold-over bur to break off. There is just the edge, and after carefully considering all the variables I say a clean leather strop (re)aligns the edge, with the aid of friction (which is no synonym for abrasion, as you incorrectly suggested).

Originally Posted by Bart

abrasion: removal of material by friction with another.
friction: a force applied from rubbing one material against another.

I just said in my last post, "That friction is precisely why you have an abrasive action...". It seems that we are in complete agreement about that, then.

significant: with effective relevance

I get enough relevant friction to remove burrs on plain leather all the time.

That said:
Friction is a force....

Precisely...

From an engineering viewpoint (since you seem so keen on dismissing science as a valid source of truth),...

I like the Engineering viewpoint because I am a real-life Engineer (in two different disciplines). Due to long established habit, I always look at most things like an Engineer would; because I am one... I eagerly await you establishing that my statement "friction is precisely why you have an abrasive action" is in error. This will be very difficult in view of your own definitions above.

... there's abrasion and there's burnishing. The former relies on removal of material. The latter relies on plastic deformation of the surface (plastic flow). Any decent textbook about finishing metal surfaces will provide that information. Polishing is combination of both and the finer the polishing medium the more the principles of burnishing enter the mix.

Burnishing, polishing, and grinding are all an abrasive action. And all are due to friction. If you look at a burnishing tool after using it, you will see particles from the burnished workpiece on the tool, and/or around the workpiece. Those particles are removed from the workpiece, through abrasive action...

There is little doubt in my mind that a clean leather strop relies heavily on burnishing.

You make my very point. Burnishing is an abrasive action. REF: Vibratory tumbling machine vessel for burnishing obviously, as one simple example, uses abrasives.

Verhoeven found no significant abrasion in clean leather (but of course that makes him a moron according to you, doesn't it), hence that leaves me with burnishing. Burnishing=plastic deformation=(re)aligning the tip of the edge instead of abrading it.

I am amazed that you would call Verhoeven a moron... Verhoeven is a researcher. I am simply saying that Butz has qualifications in practical application that Verhoeven himself acknowledges. This is why Verhoeven selected/used a Butz strop. If myself, Butz, and others can remove a burr with a plain strop, then the action is noticeably significant. If it wasn't, we wouldn't be doing it.

I won't deny that you can knock a small fold-over bur off the edge of your tools. Or maybe the strop just grabs the bur and aligns it in the right direction where it actually becomes the tip of the edge. Who's to tell? But on a razor there is no fold-over bur to break off. There is just the edge, and after carefully considering all the variables I say a clean leather strop (re)aligns the edge, with the aid of friction (which is no synonym for abrasion, as you incorrectly suggested).

Rest assured, the burrs are removed by abrasive action. Strop or hone. It is abrasive action due to friction. Without friction there is no abrasion. With friction, you will have abrasion. They go hand-in-hand as I previously state.

Of course, Verhoeven's paper has only general application to straight razors. I can however state that his sharpening efforts and results regarding removing a burr on plain leather: Are simply wrong. Butz does it. I do it. Many woodcarvers do it. So can anyone else who uses small burrs.

Once you do it yourself you'll see the error in Verhoeven's report. It's easier to do with a German chipcarving tool than a knife, but either will work. The real secret is to make the smallest burr possible.

Bart & Sticky,Marquis of Queensbury rules, no biting, no kicking, no gouging, no rabbit punches. No hitting below the belt. If I tell you to break I want you to break clean. In case of a knock down go to a neutral corner. Now shake hands and come out fighting.

Originally Posted by mparker762

...
I've never really seen the leather act like an abrasive - it can improve an edge a bit after it comes off the hone or linen, but you hit its limit really fast, within 30 laps or so. I've tried doing hundreds of laps on the leather to see if it will improve further and haven't seen it.

I agree that canvas/linen is more abrasive than plain leather, by far. I always find more metal particles on vintage canvas than I do on vintage leather. I have picked up razor splinters from both, however (much more often from the canvas/linen).

Originally Posted by JimmyHAD

Bart & Sticky,Marquis of Queensbury rules, no biting, no kicking, no gouging, no rabbit punches. No hitting below the belt. If I tell you to break I want you to break clean. In case of a knock down go to a neutral corner. Now shake hands and come out fighting.

Good point. Thanks for reminding me, Jimmy. It's been a long time since I tutored Engineering classes (theory or math).

Originally Posted by Sticky

I just said in my last post, "That friction is precisely why you have an abrasive action...". It seems that we are in complete agreement about that, then.
We are not in agreement at all. Abrasion relies on friction to remove metal. My hand must move to write. But does that mean every time my hand moves, I am writing? Same thing for friction. Plastic flow can also be caused by friction. That is the core of our disagreement. I say a clean leather strop causes the surface of the razors edge to deform at the smallest level. It does not (significantly) remove metal, it aligns it.
You, on the other hand have made a nice syllogism. Abrasion is caused by friction, a strop causes friction, hence a strop abrades. My car drives on gasoline, gasoline is a fluid, hence my car will drive on fluid. That's really the only argument you've been repeating, and now you try to twist my words in that fallacy.
I don't like that.

I like the Engineering viewpoint because I am a real-life Engineer (in two different disciplines). Due to long established habit, I always look at most things like an Engineer would; because I am one...

In Europe, and I suspect in the US as well, the engineering courses focus heavily on scientific methods and research. If you google for surface finishing of steel, you 'll find an abundant amount of research articles about surface engineering. There are quite a few exiting things going on in that field.

I eagerly await you establishing that my statement "friction is precisely why you have an abrasive action" is in error. This will be very difficult in view of your own definitions above.
Here's a quote from a basic article about surface finishing:
"The task of the finishing medium is to control and reduce surface roughness through either abrasive action or by plastic deformation of the surface." (http://www.jh-vac.com/image/pdf/poli...%20English.pdf)
Here's another:
"Buffing is a smoothing operation which is accomplished more by plastic flow of the metal than by abrading."
http://www.public.asu.edu/~smurshed/...operations.pdf

If you look at a burnishing tool after using it, you will see particles from the burnished workpiece on the tool, and/or around the workpiece. Those particles are removed from the workpiece, through abrasive action...

Actually, If I look at my strop that has seen a lot of use in the past 2 years, I can't see any evidence of steel debris. However, if I look at my CrO pasted loom strop, that has seen very little use, there's plenty of black discoloration. I also checked at magnification (40X). The CrO strop shows black hazy high spots, with no discernable particles at that magnification, which is to be expected for debris abraded by 0.5 micron particles. The clean leather strop shows nothing of that kind.

You make my very point. Burnishing is an abrasive action. REF: Vibratory tumbling machine vessel for burnishing obviously, as one simple example, uses abrasives.

I am amazed that you would call Verhoeven a moron...
Another twisting of my words, that only serves to get on my nerve.
It was you that called his research a joke: "I couldn't help but giggle when I read that a plain leather strop couldn't remove a burr.
This will come as a big (and humorous) surprise", you wrote a few posts ago. You also stated that he "needs a better technique, a much smaller burr, or maybe some different leather", while he actually used the same brand as yours (and some others as well), and he actually conducted extra experiments before he was prepared to change his orginal mindset (something all people with a scientific training must be always prepared for).

If myself, Butz, and others can remove a burr with a plain strop, then the action is noticeably significant. If it wasn't, we wouldn't be doing it.
Breaking off a small bur, can even be done by cutting a piece of paper, and there's always the possibility that your clean strop aligns the bur in "edge direction". I am certainly not advocating that stropping is futile. Only that, in main principle, it is not abrasive, but aligning.

Rest assured, the burrs are removed by abrasive action. Strop or hone. It is abrasive action due to friction. Without friction there is no abrasion. With friction, you will have abrasion. They go hand-in-hand as I previously state.
Well you are wrong, 2 engineering degrees and tutoring classes doesn't change that one bit.

Once you do it yourself you'll see the error in Verhoeven's report. It's easier to do with a German chipcarving tool than a knife, but either will work. The real secret is to make the smallest burr possible. I have no problems making my woodworking tools sharp. Mostly I use a Tormek machine that has a leather buffing wheel loaded with diamond compound.

If you want to argue, please use real arguments instead of circular reasoning, authority arguments and arguments that exchange correlation for causation. I'm not here for the sports of discussion. I'm only interested in the science of sharpness and hope to learn more through constructive discussion with others.

If Verhoeven was wrong, I'll be in good company being wrong with him. But you 'll have to convince me first.
How comes that more stropping than my regular 60 laps doesn't make my edges sharper and sharper? How comes that a razor that lacks a hint of keenness off the hone can't be brought in line with a double or a triple stropping session on clean leather? If it were abrassive, there's no reason why it shouldn't. But if it were just aligning the edge that's there, making it a bit more effective without any real honing action, it all makes sense. At least, to me it does.

Bart.

Originally Posted by Bart

We are not in agreement at all. Abrasion relies on friction to remove metal. My hand must move to write. But does that mean every time my hand moves, I am writing?Only if you have a pen in hand and it is burnishing the paper beneath it... Same thing for friction. Plastic flow can also be caused by friction. That is the core of our disagreement. Yes it is. Plastic flow can be caused by abrasive action due to friction (and/or weight). The innate friction (of 2 objects in contact) at rest will cause little to no plastic flow at all unless the weight of one object is significant when compared to the other objects compressability. But add relative contact movement and you will have abrasive action, regardless of weight. Objects in contact and moving increase their friction coefficients dramatically. Burnishing is also an abrasive action. Whenever you have 2 objects in contact and possessing relative movement, you will have abrasive action.I say a clean leather strop causes the surface of the razors edge to deform at the smallest level. It does not (significantly) remove metal, it aligns it. It removes metal, and if you can "notice" a burr being removed by the leather: then it is "noticeably significant". Many of us have picked up razor splinters from rubbing our hands over a plain vintage strop. All who have done it can testify that the splinter was removed from a razor in a very "noticeably significant" way.
You, on the other hand have made a nice syllogism. Abrasion is caused by friction, a strop causes friction, hence a strop abrades. My car drives on gasoline, gasoline is a fluid, hence my car will drive on fluid. That's really the only argument you've been repeating, and now you try to twist my words in that fallacy.
I don't like that.

Abrasive action is due to friction, especially if the objects are in motion.

If Verhoeven was wrong, I'll be in good company being wrong with him. But you 'll have to convince me first. I'm perfectly happy with you believing Verhoeven. I'm just saying that Butz is an authority on sharpening, while Verhoeven is not. If we all believed the same things, forums would be very boring indeed.

abrasion : 1 a: a wearing, grinding, or rubbing away by friction

Here's how I see abrasion: anytime you rub 2 friction surfaces together, you have abrasion of at least one surface. Whether you see it or not decides whether or not it is significant (to you), but it doesn't negate it in the slightest.To Verhoeven and crew he didn't see it. He was also careful to say "no significant abrasion"; because as an Engineer he is well aware that it was still there.

To Butz, myself, and all the others who regularly remove burrs on plain leather, it is noticeably significant. Obviously we don't rub burrs on plain leather if they remain in place.

Verhoeven's statement is at odds with a worldwide recognized expert authority on sharpening curved and straight edges.

It simplest terms, you like Verhoevens report on knives and apply it to razors. I like this report on razor edges and apply it to razors. The report that I like says a strop has abrasive qualities. So we can agree to each defend the report that we like best. You with the knife report, myself with the razor report.

Originally Posted by Sticky

It simplest terms, you like Verhoevens report on knives and apply it to razors. I like this report on razor edges and apply it to razors. The report that I like says a strop has abrasive qualities. So we can agree to each defend the report that we like best. You with the knife report, myself with the razor report.

But that report didn't say which side of the strop was abrasive. The two reports are consistent if the linen side of the strop is the abrasive side.

Too bad he wasn't more specific. It's probably too late to ask Mr. Martin now. Even if he meant plain leather, his conclusions still wouldn't settle the issue of "how abrasive is leather?".

Originally Posted by JimmyHAD

Bart & Sticky,Marquis of Queensbury rules

Courtesy of Wkipedia:

To be a fair stand-up boxing match in a 24-foot (7.3 m) ring, or as near that size as practicable.
No wrestling or hugging allowed.
The rounds to be of three minutes' duration, and one minute's time between rounds.
If either man falls through weakness or otherwise, he must get up unassisted, 10 seconds to be allowed him to do so, the other man meanwhile to return to his corner, and when the fallen man is on his legs the round is to be resumed and continued until the three minutes have expired. If one man fails to come to the scratch in the 10 seconds allowed, it shall be in the power of the referee to give his award in favour of the other man.
A man hanging on the ropes in a helpless state, with his toes off the ground, shall be considered down.
No seconds or any other person to be allowed in the ring during the rounds.
Should the contest be stopped by any unavoidable interference, the referee to name the time and place as soon as possible for finishing the contest; so that the match must be won and lost, unless the backers of both men agree to draw the stakes.
The gloves to be fair-sized boxing gloves of the best quality and new.
Should a glove burst, or come off, it must be replaced to the referee's satisfaction.
A man on one knee is considered down and if struck is entitled to the stakes.
No shoes or boots with springs allowed.
The contest in all other respects to be governed by revised rules of the London Prize Ring.