When are the strops working best?

[Phil Pasteur]

It also takes tolerance of failure…
Perfection is an almost unatainable goal…
Just keep after it and you might get to…
“It makes me happy because it makes them happy”
The customer… even if that is you!

Even though I can still see them damn SCRATCHES under specific …non-natural conditions.. after all of the work, just pisses me off… Most folks I deal with think I am some kind of sharpening god…
WRONG! But then I am never completely happy with anything I do! It is a persoanlity flaw called being a perfectionist.

(250 lumens Parallel to the blade.. and less than 5% visible scratches, true bathroom mirror reflectivity, my harsh standard, <10 % succcess rate, no visible scratches 0%)

But ya just have to keep trying… that is what makes it fun !!
:woohoo:

[Johpe]

Just wanted to post a short update.

After going the whole route to stropping on more knives it seems that the strops just needed breaking in. Now (after about 7-8 stropped knives) I have a totally different feel to them. And there is a noticeable difference to the edge both visually and in sharpness after using the strops.

I’ve tried both with and without alcohol on them, and there is a definite difference in feel while stropping but the end result seems to be more or less the same either way (at least for me).

[Mark76]

Thanks for your excellent posts, Phil.

I know Curtis also asked this question, but what would be a better term for “stiction”. I also used it (until you mailed me 🙂 ). As Curtis said, mainly because it sounds like like “stickiness” and English is not my first language. (I learn a lot of new terms here on this forum, not only about sharpening, but also about, e.g., engineering 🙂 .) You used the term “sliding friction”, although in a slightly different context. Would that, or stickiness, be a better term?

About the scratches remaining visible. You wrote they remained visible even after a 0.025 micron compound. That makes me think you used diamond sprays. I found a quite remarkable difference between the Wicked Edge pastes and some other sprays/pastes. I reported on this on my blog and you can see photographs there that show it. Only the Wicked Edge pastes provide so much stiction/stickiness/static friction. That seems to make it much easier to create mirror edges (although they may still show tiny scratches under a microscope).

What I’m also interested in is what actually happens with these pastes. You wrote me that it is unlike that leather with a compound can actually result in metal being moves/smeared out IIRC (I don’t have the mail anymore.) Is this really true? The Wicked Edge pastes do work, so there must be something going on. I wonder what.

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Phil Pasteur]

Thanks for your excellent posts, Phil.

Why you are quite welcome!

I know Curtis also asked this question, but what would be a better term for “stiction”. I also used it (until you mailed me 🙂 ). As Curtis said, mainly because it sounds like like “stickiness” and English is not my first language. (I learn a lot of new terms here on this forum, not only about sharpening, but also about, e.g., engineering 🙂 .) You used the term “sliding friction”, although in a slightly different context. Would that, or stickiness, be a better term?

I see where everyone is coming from on this. Stiction sounds like it says what we want to ecpress here. I may never have thought about it at all, but I have built and modified several Dobsonian typ telescopes in the past. Part of the process is getting the action to work smoothly and consistently. You need to move the telescope at high magnification in small increments to track objects as the Earth turns. The hardest thing to do is to eliminate stiction. That increase in force that it takes to get the scope moving. It is easy to see that, if overcoming stiction takes too muc force, and after that the coefficient of sliding friction is much less (it always is, by definition)it adds the problem of overshooting a target. Bascically it makes tracking an object at high magnification a real pain.

So maybe we need to understand the process better. When people have their base lifted off of the table, is this just when beginning a stroke prior to the strop actually moving, or is it when the strop is somewhere in mid stroke… That is, actually in motion??

If it is before motion has begun, it is the result of static friction, which is often shortened to “stiction”. If the strop is in motion, it is being caused by sliding friction. It would seem that spraying with alcohol, for instance, increases both static friction and increases the coefficient of sliding friction.

I know it goes against the grain these days when everything is shortened as much as possible. Perhaps the product of the world of texting, perhaps simply because we are all somewhat linguistically lazy, BUT, why not just refer to what we experience by the accepted names. If we did this, there would be no confusion about where in the process we saw the a specific effect.

BTW, there is a component to both types of friction which is important. This is the force normal to the object to be moved. In other words, how hard are we pushing the strops against the steel. I found when using alcohol on the strops I tended to have to push harder to get the strops to slide (increased both static and sliding friction) as a result I was pushing against the blade harder, which increased bot kinds of friction… I can well see that this process could lead to lifting the base. I can also see where it would lead to greater convexing of the edge due to the pressure causing greater defelction of the leather. But that is for another discussion.

About the scratches remaining visible. You wrote they remained visible even after a 0.025 micron compound. That makes me think you used diamond sprays. I found a quite remarkable difference between the Wicked Edge pastes and some other sprays/pastes. I reported on this on my blog and you can see photographs there that show it. Only the Wicked Edge pastes provide so much stiction/stickiness/static friction. That seems to make it much easier to create mirror edges (although they may still show tiny scratches under a microscope).

I was not aware that WEPS made any pastes at the 0.025 micron level. Currently I have no WEPS paste. I use DMT paste for..IIRC 10/7/6/3 micron, then diamond and CBN sprays abelow that. (1, 0.5, 0.25, 0.1, 0.05, 0.025). I Usually have a mirror edge for all practical purposed before even using the strops. After the Chosera progression through 10K and finishing with the 12K Superstones. As Tom has mentioned many times, this whole idea of “uncovering” or revealing scratches from previous grits when using finer and finer grits, is maddening. Your only choice is to drop back several grits and work up again. More often than not, after 3 + hours, I just call it good. Chances are, really, no one would ever see these but me. BTW, the scratches on the bevel don’t affect the sharpeness at all…
🙂

What I’m also interested in is what actually happens with these pastes. You wrote me that it is unlike that leather with a compound can actually result in metal being moves/smeared out IIRC (I don’t have the mail anymore.) Is this really true? The Wicked Edge pastes do work, so there must be something going on. I wonder what.

I am not sure what the mystery is or why it is hard to understand. The pastes have abrasives in them, they are abrading the steel (ever notice the gray or black stains the strops get?). When you get to a fine enough abrasive size, we call this polishing. Polishing consists of both scratch removal, and the rounding and smoothing of the peaks and valleys of other scratches (by abrasive action). The finer the abrasive, the more polishing effect we get. The more polishing we get, both the more edge refinement is possible and the more reflective the bevel becomes.

So yes they work, but they work just the same as any other abrasive works, by abrading.

Think about it, with all of the photos we have seen, even the John D. Verhoeven SEM photos, with the possible exception of some exceedingly tiny, questionable areas in a couple of Clay’s photos, all we have seen are scratches. This goes on until the resolution of the device in use is exceeded. Clay has photos that show an almost featurelessly smooth surface at 520X. At 800X, more pictures of scratches. I have looked at all of your pictures. I have taken numerous pictures at 400X and a bit higher myself, screwed around with lighting and lenses until I was burnt out. I see nothing but scratches made by abrasives.

So I ask again, why is it so hard to think that our abrasives are abrading. That is what they were designed to do. The finer ones abrade to the level we call a polish. I am not sure why we are looking for effects such as burnishing to account for the results. :S 😉

Edit:

Mark, I know that you have said that you have tried different pastes and found that you like the way the WEPS pastes work better than others. I am not sure how I would even start to explain that. The DMt pastes are a bit sticky causing higher friction when first applied. Friction is increased when I tried alcohol with them. In any case, as with stones, different kinds of abrasive and different substrates, or in the case of pastes, different carriers, result in different results. I will say that I like the WEPS pastes better. Unfortuantely I bought a whole bunch of the DMT stuff. Wehn I need more, I will buy the WEPS pastes.
I am sure that Clay did his homework when chosing his pastes. It is not a surprise to me that they work well. It would be a huge surprise to me if they worked through any means other than abrading the steel.

[John Batinovich]

This thread is apropos to my situation, which is not even a month of owning the pro pack 1. I’ve also experienced the excess paste on the strop thing, but I did not know to try scraping off the excess and letting them dry. My experience so far with the WE strops is less than impressive. I get much better results sharpening to 1000 grit then stropping with my portable Stropman strop. Pretty dramatic difference, actually.

Working with the WE strops often results in an edge that is less sharp than it was after the 1000 grit stones. I’m working with some very light pressure also. I’ll try to incoporate the info in this thread and see if it helps.

As an aside, I’ve no interest at this point in obtaining mirror edges, just razor sharp ones. All of this has been a big learning experience, but I can pretty consistently get really sharp edges right now. I’m just not satisfied. I want edges where the bevels are perfectly even (an ongoing bugaboo of mine) and impressively sharp. It’s funny though, I’ve been hounding the guys I work with to give me their knives so I can get more practice, and they always seem really happy with the edges even though I’m not completely satisfied. Go figure.

One thing I’m very happy about is having this website as a resource. All the experienced people here are really helpful.

Thanks for the info!

[Mark76]

Thanks again Phil. First, to clear up a misunderstanding, Wicked Edge doesn’t make any 0.025 micron diamond pastes. The only stropping compounds with particles of that size I know are the polycrystalline and monocrystalline diamonds sprays by Ken Schwartz. That is why I thought you had use at least one of those.

I am not sure what the mystery is or why it is hard to understand. The pastes have abrasives in them, they are abrading the steel (ever notice the gray or black stains the strops get?).

The mystery I don’t understand is the following. The Wicked Edge diamond pastes don’t produce scratches of the size they are listed for. You can see the pictures of the results of the 14 micron paste http://moleculepolishing.wordpress.com/2012/03/29/wicked-edge-14-micron-diamond-paste/%5Dhere%5B/url%5D">here[/url]). But the Wicked Edge pastes don’t.

The only way I (and others) were able to explain this was stiction/stickiness/sliding friction.

And why I like the Wicked Edge pastes? Because they work 🙂 . The 3M paste I tested also worked well. The Dovo paste was much, much less effective (to the point where I’d say it doesn’t work – at least not as expected).

Molecule Polishing: my blog about sharpening with the Wicked Edge

[Phil Pasteur]

A good start to understanding the reasons that the pastes work the way that thye do would be to understand what exactly is in them. As we have talked, usually any abrasive is listed as an average size. The range of sizes in the material and distribution and limits of those deviations from the average is also important in understanding the results. I have not seen that published for the WEPS pastes. The concentration of the abrasives is likewise important.

One explanation for what you describe would be that the distribution runs on the small side, or maybe the concentration is low or both …and potentially the carrier has some polishing ability of its own.

You mention…scratches are scratches per grit (or words to that effect)… we know that is not always true. On a macro level, for instance scratches from a 5K Shapton stone are much more prominent than those from the 5K Chosera, even though the grit sizes are pretty darn close. Even on the microscopic level there are differences easily detected. The polishing component of the Chosera actually looks like it removes, or at least softens some of the scratches… at least to me.

In any case, without knowing what is in the pastes, exactly, any assignment of causes for any percieved difference in their functionality, is pure conjecture. In particular, those that don’t make any physical sense, should be examined more closely, IMHO.

Phil

[wickededge]

This is a fascinating conversation and I hope to be able to contribute more to it soon. I’ve got some plain carrier paste in house now without any abrasive that I will be testing. We’re also tinkering with the concentrations of the diamond pastes to see what kind of results we’ll get. I’ve been lacking the time lately to perform any real controlled tests, but am hoping for more time soon. Once we move into our new space, we’ll have a better R&D facility and performing these experiments will be a little easier.

-Clay

[Mark76]

I’ve got some plain carrier paste in house now without any abrasive that I will be testing. We’re also tinkering with the concentrations of the diamond pastes to see what kind of results we’ll get. I’ve been lacking the time lately to perform any real controlled tests, but am hoping for more time soon.

Awesome! Really looking forward.

Molecule Polishing: my blog about sharpening with the Wicked Edge

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