Welcome, Guest
Username: Password: Remember me
Stropping Discussions

TOPIC: A theory of how the WE diamond pastes work

Re: A theory of how the WE diamond pastes work 1 year 11 months ago #6607

  • PhilipPasteur
  • PhilipPasteur's Avatar
  • OFFLINE
  • Platinum Boarder
  • Phil
  • Posts: 944
  • Thank you received: 233
  • Karma: 66
One other thought about an experiment. If we want to look at simply burnishing as a property of stropping itself, why not try some Kangaroo or Nanocloth with no abrasive. If we are talking local pressure with the strop, would you not still see it with materials that have minimal (nonocloth supposedly almost none) abrasive properties of there own.

Not sure how to duplicate the stiction... perhaps just the right amount of water or alcohol.

In any case, this might be a sort of "control" scenario. It may help to isolate whether any burnishing that may be happening is due to the strops or the abrasives, or maybe the combination.

Phil
Phil

MAX 2001-2013
Hoping there is that bridge!
I miss you Buddy!
The administrator has disabled public write access.

Re: A theory of how the WE diamond pastes work 1 year 11 months ago #6608

  • wickededge
  • wickededge's Avatar
  • OFFLINE
  • Administrator
  • Posts: 1802
  • Thank you received: 649
  • Karma: 92
Hey Phil,

Thank you for all your thoughts. I really appreciate your balanced skepticism and I agree that the idea that leather can burnish the metal defies intuition. Still, I've seen some effect that looks like burnishing so often that I haven't been able to come up with a more competitive theory. At the moment, I'm speculating that the 'stiction' is able to apply enough pressure locally that it can move some small amounts of metal around. It is remarkable how much drag I'm able to create with the strops; so much so that they will actually lift up my granite base. I will try some blank strops, that's definitely on the list though in the past, when using water, I haven't been able to duplicate the 'stiction'. I might do better with alcohol, that seems to work very well. I've also got some plain paste on order from our supplier so I can experiment with the effect without the abrasives in the equation. Eventually, I'll get the project with Sandia Labs and their SEM done and we might have a more definitive answer.
--Clay Allison
The administrator has disabled public write access.

Re: A theory of how the WE diamond pastes work 1 year 11 months ago #6614

  • PhilipPasteur
  • PhilipPasteur's Avatar
  • OFFLINE
  • Platinum Boarder
  • Phil
  • Posts: 944
  • Thank you received: 233
  • Karma: 66
I was thinking that.. at one time, I could do the calcs. Find actual yeild strenght numbers and look at what kind of pressures might be applied through the leather. This would give us a good idea if it is even physically possible to burnish with the entire contact area. Of course the local pressures at the top of the scratch peaks may be impossible to calculate without some serious programing... which is beyond the time I have to actually do. I am at a loss as to how various levels of stiction could be calculated though. Time to go back to the books. I have some vintage 1968 Materials properties texts...:unsure: I was once even pretty good with the Calculus... once.

I also wonder, after reading what you said, if I, with my technique, would ever see the effect. As I mentioned before, I have looked for the amount of compound on the leather with alomost zero moisture content (relative humidity here often in the single digits...but almost always quite under 40% that give me the lowest amount of friction, hence stiction I guess ...using very very light strokes... with the calculated intent of simply letting the abrasive do its work. Perhaps this might also be why I can see very little convexing of the shoulders of the edge at 400X as well.

If I was lifting my 16 pound marble base when stropping ... I would figure out how to stop it from happening...
:)

Thanks Curtis for the links... I have a sick server that I am working on tonight...maybe I can get something done on this tomorrow...

Phil
Phil

MAX 2001-2013
Hoping there is that bridge!
I miss you Buddy!
Last Edit: 1 year 11 months ago by PhilipPasteur.
The administrator has disabled public write access.

Re: A theory of how the WE diamond pastes work 1 year 11 months ago #6618

  • FredHermann
  • FredHermann's Avatar
  • OFFLINE
  • Gold Boarder
  • Posts: 208
  • Thank you received: 41
  • Karma: 18
So after my head was done pounding reading this, following all the associated links, and marveling at the pretty pictures...one thing stands out.

Clay, how much pressure are you using when stropping? I *have* to assume you use equal pressure thru the process, but how much? I saw mention of lifting the base edge when stropping, which implies lots of pressure....
“On one otherwise normal Tuesday evening I had the chance to live the American dream. I was able to throw my incompetent jack*ss of a boss from a fourteenth-story window.”

Owen Pitt – Monster Hunter International
The administrator has disabled public write access.

Re: A theory of how the WE diamond pastes work 1 year 11 months ago #6620

  • PhilipPasteur
  • PhilipPasteur's Avatar
  • OFFLINE
  • Platinum Boarder
  • Phil
  • Posts: 944
  • Thank you received: 233
  • Karma: 66
I guess I was trying to hint at the same question. Considering the repeated advice given all over this forum to use very light strokes when stropping...indeed with all of the stones, I wonder how many are lifting their bases when stropping... and if not, if anyone would be seeing similar results to what Clay has seen... whether these results are the result of true burnishing or not..
??

Phil
Phil

MAX 2001-2013
Hoping there is that bridge!
I miss you Buddy!
The administrator has disabled public write access.

Re: A theory of how the WE diamond pastes work 1 year 11 months ago #6622

  • mark76
  • mark76's Avatar
  • OFFLINE
  • Administrator
  • Posts: 1282
  • Thank you received: 420
  • Karma: 87
PhilipPasteur wrote:
I guess I was trying to hint at the same question. Considering the repeated advice given all over this forum to use very light strokes when stropping...indeed with all of the stones, I wonder how many are lifting their bases when stropping... and if not, if anyone would be seeing similar results to what Clay has seen... whether these results are the result of true burnishing or not..

Just a brief quote from Clay:
wickededge wrote:
I removed the sample and cleaned it well, the completed 5 strokes per side with firm pressure using .75um CBN on cow leather.

I don't know whether you've read the posts on my blog regarding stropping, but in some experiments I did over 500 stropping movements per side. That is a lot :cheer: , and in order to see effect more quickly I used quite a bit of pressure.

My pictures are not nearly as good as Clay's, but my conclusion was definitely that burnishing occurs, and that the WE pastes excel at doing this. That's why I started this threat ;) . You can read all of my posts on stropping here .

That is not to say that the common knowledge that you have to strop lightly is a myth. I don't know exactly where the idea of stropping originated, but it has been widely used in the straight razor world for over a 100 years. If you use too much pressure on a straight razor, with an edge that usually has an acute angle and is very thin, you simply destroy the edge. Also, if you strop just to remove a burr (which is not necessary when you're using a WEPS), you don't need much pressure. And if you're stropping free-hand, a mistake is made easily if you use pressure, so you'd better be safe than sorry.

Even with a WEPS, if you use a lot of pressure with a leather strop and don't adjust the angle, you will round the edge. So setting back the angle (with leather I do 1 or 2 degrees) is necessary if you use a little force.
Last Edit: 1 year 11 months ago by mark76.
The administrator has disabled public write access.
Time to create page: 0.139 seconds