Is stropping really an effective practice?

TheOne45 said:
The only shortcoming I see is with so called toothy edges. After each refreshing on a strop you loose some of those teeth till you end up with a very refined push cutting edge.

If I may add...
here and there I see a statement that you can round the edge if you strop too much and you loose the sharpness.
I must say I couldn't do that so I wonder if I misunderstood the word "round".
Do this mean radius on the apex (dull edge) or convexing the edge?
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Yes, correct- I like fine edges, so I have no toothyness to loose.

Blues said:
If one is not careful with their stropping, they may blunt the edge which they had properly apexed on the stone. (Rounding the very edge.)

But stropping with abrasives can also be used to convex the bevel as well.
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Blues is right on both counts.

Stropping will invariably slowly convex the edge over time. This is usually rectified by a stone sharpening once there's some blunting that strops aren't going to expediently correct.
 
Blues said:
If one is not careful with their stropping, they may blunt the edge which they had properly apexed on the stone. (Rounding the very edge.)

But stropping with abrasives can also be used to convex the bevel as well.
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I suppose so,
If stropping freehand it's not so simple to maintain the same angle and same pressure each stroke. I would say it also depend on the strop... thickness and softness of the leather and size of the fibers.
For my sharpening system I made strops with very thin leather (1 milimeter) and this leather has very short fibers. After tests I discovered I need to increase the angle for 1.5 (sometimes 2) degrees. If not the strop has no effect and does not remove the burr if I apply normal pressure on guiding rod.
When I strop freehand I just go with a feeling. It's hard to say but I think I can't hold the angle better then +-1 or 2 degrees.

Most people don't know the strop will convex the edge no matter how carefull they are and they try to strop at sharpening angle. In best case it will convex only a few microns of the edge. Of course, you can't see this with our magnifying glasses (only with SEM) so most think there is no convexing.

And I agree,
you can convex the bevel. I did this with my Bahco 2446. First I reprofiled the factory scandi grind to even it and make it true scandi and then stropped to get a convex edge. I did it with felt wheel and industrial polishing compound but I could do the same with a strop. But it would take much more time.
 
I actually convex my edge on stones using a rocking motion and a loose wrist. Problem is when stropping those convex edges it's difficult to feel out the correct angle, whereas with a V edge it's more straight forward. To make matters worse, I've been edc'ing a lot of really hard D2, and for the life of me I can't get the burr off of it using a strop loaded with my usual white gold compound... instead I have to do it with fine diamond stones and adding a microbevel, which ruins my pristine convex geometry.
 
SwissHeritageCo said:
I actually convex my edge on stones using a rocking motion and a loose wrist.
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I never tried that yet.

SwissHeritageCo said:
To make matters worse, I've been edc'ing a lot of really hard D2, and for the life of me I can't get the burr off of it using a strop loaded with my usual white gold compound... instead I have to do it with fine diamond stones and adding a microbevel, which ruins my pristine convex geometry.
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I only use diamond strops for my two D2 folders. I never tried to strop them on my strops loaded with ordinary polishing compound so I cant say much. I only use those 'ordinary' strops for kitchen knives.
I can only say I took one of those knives in our lab and it measures 61HRc. It's not the hardest K110 steel but it sharpens so nicely and the burr is not a problem to remove. I can't say this for my fathers Mikov pocket knife. Almost impossible to remove a burr with a strop. It's like rubber.

To add,
I tried the microbevel on my Opinel 10 and it worked just fine, no complaints. It fascinated me how easy it was to make it and how it removed all burr. But I somehow couldn't hold on this micro bevel thing. I don't know why. There is something I find fascinating about strops but I can't put my finger on it.
 
TheOne45 said:
I never tried that yet.


I only use diamond strops for my two D2 folders. I never tried to strop them on my strops loaded with ordinary polishing compound so I cant say much. I only use those 'ordinary' strops for kitchen knives.
I can only say I took one of those knives in our lab and it measures 61HRc. It's not the hardest K110 steel but it sharpens so nicely and the burr is not a problem to remove. I can't say this for my fathers Mikov pocket knife. Almost impossible to remove a burr with a strop. It's like rubber.

To add,
I tried the microbevel on my Opinel 10 and it worked just fine, no complaints. It fascinated me how easy it was to make it and how it removed all burr. But I somehow couldn't hold on this micro bevel thing. I don't know why. There is something I find fascinating about strops but I can't put my finger on it.
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Makes sense. 62.5 hrc on this one, but I know a lot to do with it is not raising too large of a burr to begin with so I've bee raising the smallest burr possible. Even so my traditional compound just wont cut. I've been avoiding diamond compounds for no good reason, guess it's time to try them out.

But yeah you can put a beautifully blended convex edge on by just using a loose wrist and a rocking motion. Feels surprisingly natural and efficient.
 
SwissHeritageCo said:
I actually convex my edge on stones using a rocking motion and a loose wrist. Problem is when stropping those convex edges it's difficult to feel out the correct angle, whereas with a V edge it's more straight forward. To make matters worse, I've been edc'ing a lot of really hard D2, and for the life of me I can't get the burr off of it using a strop loaded with my usual white gold compound... instead I have to do it with fine diamond stones and adding a microbevel, which ruins my pristine convex geometry.
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Try stropping with diamonds.
 
SwissHeritageCo said:
Even so my traditional compound just wont cut. I've been avoiding diamond compounds for no good reason, guess it's time to try them out.
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You will find some diamond compounds also don't cut so good.
I haven't tried Gunny juice, Stroppy stuf and other popular compounds among knife users. I only use diamond compounds we use in our company for polishing mostly carbide hardness tooling. Some of them cut good and some of them not so good. I also have a set of Badak diamond compounds. Despite the price and origin they work surprisingly good.
 
J. Doyle said:
I need to try this.

The diamond paste I got years ago on ebay doesn't seem to cut that well.
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I think you'll be pleased, John. Don's a great guy. I have the 1 micron emulsion and a few of his strops on hand.

I have some oil based diamond paste I bought on eBay or Amazon, I forget, and it pales in comparison and is messy.
 
Guy McVer said:
Before I forget, I also want to point out that this also applies to sharpening on stones or ceramics or diamond plates. The edge can be full of particles from the sharpening process. A simple wipe clean will remove them. I have experienced this from lots of testing with cutting materials. The use of a strop is not required.

Burr removal after sharpening is another matter, of course. But a ceramic hone can usually do the work of a strop, and without the convexing.

Diamond paste applied to a strop can of course further refine the edge, but only if the paste is finer than the sharpening implements you used prior to that.

Looking forward to hearing lots of real world experience from people on this. I want to know more.
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im wondering if you saw the science of sharp page on stropping. his photos show whats happening and your right i dont think theres magic with a few strokes but as a SR shaver i can tell you depending on your edge it is night and day to remove honing aggression. normal knife use i feel the same as you. it just cleans up the edge to see cutting paper differences etc. ive tried so many strops and compounds and most of them take the keenness away until a certain sized micron. even then you can really take away from keenness by over doing it.
 
311climber said:
ive tried so many strops and compounds and most of them take the keenness away until a certain sized micron. even then you can really take away from keenness by over doing it.
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I don't know what you mean by ''keeness'' (toothy edge?) but as I can remember those 'scienceofsharp' stropping articles the author discovered with his tests everything happens in the first 20 or 30 strokes on the pasted strop and additional strokes don't change much. If I remember correctly he did up to 300 strokes on pasted strop and the edge didn't show much change.

There are also some photos about stropping on clean leather and clean linen strops (without stropping compound). The results are somehow different as ''common internet wisdom'' suggests ... no cutting ... just some adhesive wear and plastic flow of material. In some cases the clean leather was just drawing the burr and not removing it.

According to authors definition of ''keenness'' and ''sharpness'' stropping on loaded strop reduces sharpness and increases keenness by refining the edge and increasing the edge angle. At least this goes for razors .... most of his experiment were done on straight razors.
 
TheOne45 said:
I don't know what you mean by ''keeness'' (toothy edge?) but as I can remember those 'scienceofsharp' stropping articles the author discovered with his tests everything happens in the first 20 or 30 strokes on the pasted strop and additional strokes don't change much. If I remember correctly he did up to 300 strokes on pasted strop and the edge didn't show much change.

There are also some photos about stropping on clean leather and clean linen strops (without stropping compound). The results are somehow different as ''common internet wisdom'' suggests ... no cutting ... just some adhesive wear and plastic flow of material. In some cases the clean leather was just drawing the burr and not removing it.

According to authors definition of ''keenness'' and ''sharpness'' stropping on loaded strop reduces sharpness and increases keenness by refining the edge and increasing the edge angle. At least this goes for razors .... most of his experiment were done on straight razors.
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ive read his articles multiple times. im not sure if im swapping terms for keenness and sharpness but if i remember correctly loaded strops are drastic compared to bare and the angle does increase like you had mentioned. I just remember he did like 500 plus strops over that ding in the edge on bare and it did do quite a bit of burnishing and flow back to a cleaner state. not so much removal of stock on bare. i think most of his logic is sound of course having the imagery to back up theory. Ive gotten plenty of great shaves from his hone with whatever grit you want low or high in coarseness and finish with something that doesnt shed, get rid of the burr and strop accordingly. lots of good shaves from that technique since it sounds like you know the edge is the only thing that matters in a shave not the bevel itself. his stuff is great reading.
 
311climber said:
ive read his articles multiple times. im not sure if im swapping terms for keenness and sharpness but if i remember correctly loaded strops are drastic compared to bare and the angle does increase like you had mentioned. I just remember he did like 500 plus strops over that ding in the edge on bare and it did do quite a bit of burnishing and flow back to a cleaner state. not so much removal of stock on bare. i think most of his logic is sound of course having the imagery to back up theory. Ive gotten plenty of great shaves from his hone with whatever grit you want low or high in coarseness and finish with something that doesnt shed, get rid of the burr and strop accordingly. lots of good shaves from that technique since it sounds like you know the edge is the only thing that matters in a shave not the bevel itself. his stuff is great reading.
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in the pasted strop part two he says in terms of of our definitions of keen and sharp keenness is improved at the expense of sharpness. not sure if im still backwards on my wording or if the strop adds keenness and reduces sharpness from the stone. seems like the ladder
 
TheOne45 said:
I don't know what you mean by ''keeness'' (toothy edge?) but as I can remember those 'scienceofsharp' stropping articles the author discovered with his tests everything happens in the first 20 or 30 strokes on the pasted strop and additional strokes don't change much. If I remember correctly he did up to 300 strokes on pasted strop and the edge didn't show much change.

There are also some photos about stropping on clean leather and clean linen strops (without stropping compound). The results are somehow different as ''common internet wisdom'' suggests ... no cutting ... just some adhesive wear and plastic flow of material. In some cases the clean leather was just drawing the burr and not removing it.

According to authors definition of ''keenness'' and ''sharpness'' stropping on loaded strop reduces sharpness and increases keenness by refining the edge and increasing the edge angle. At least this goes for razors .... most of his experiment were done on straight razors.
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and it looks like a loaded strop dramatically micro convexes a sharp edge. within 3 strokes with diamond paste. im assuming crox would be slower of course. but your right he continues with the original burnishing and angle gain come from the first 10 laps of crox and additional laps dont increase the angle drastically but 500 laps brought an degree bevel of 19.9° at 100 laps up to 21.3° once at 500 laps. thats still quite the change
 
TheOne45 said:
I don't know what you mean by ''keeness'' (toothy edge?) but as I can remember those 'scienceofsharp' stropping articles the author discovered with his tests everything happens in the first 20 or 30 strokes on the pasted strop and additional strokes don't change much. If I remember correctly he did up to 300 strokes on pasted strop and the edge didn't show much change.

There are also some photos about stropping on clean leather and clean linen strops (without stropping compound). The results are somehow different as ''common internet wisdom'' suggests ... no cutting ... just some adhesive wear and plastic flow of material. In some cases the clean leather was just drawing the burr and not removing it.

According to authors definition of ''keenness'' and ''sharpness'' stropping on loaded strop reduces sharpness and increases keenness by refining the edge and increasing the edge angle. At least this goes for razors .... most of his experiment were done on straight razors.
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and your right i accidentally said stropping reduces keenness when its opposite. apologies
 
311climber said:
and your right i accidentally said stropping reduces keenness when its opposite. apologies
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I would not pay too much attention to those terms. He also like to use different words for ''sharpening'' - honing, polishing, lapping, refining the edge and similar. I don't use fancy words; I just call my sharpening process ''sharpening my knife'' from coarsest diamond stone to finest strop I have.
I was reading his explanation of ''sharp'' and ''keen'' and couldn't fully understand the difference. At the end of the day those terms don't mean much. Important thing is to know what edge you get when you do something and how this affects cutting ability.

To add; most of his 'sharpening 'experiments were made on straight razors. I think razors behave differently (to some extent) as knives during sharpening and stropping because of the different geometry. Still; you can learn a lot from his articles and get a feeling what you will get when you do something. He also wrote some knife related articles. One of them is ''Seven misconceptions about knife burr''. Very informative.
 
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