Stropping: angle plus pressure

I have never figured out how some barbers can slap a razor so fast on a hanging strap while it jumps up and down and keep an edge!!????
 
I have never figured out how some barbers can slap a razor so fast on a hanging strap while it jumps up and down and keep an edge!!????


As mentioned in Post No. 94, stropping a razor on a belt is different than stropping a knife on a flat strop. I don't strop razors, but my understanding is that the razor is laid flat on the belt for the entire stropping stroke. The height of the razor spine keeps the angle constant. Knives use a steeper edge angle and don't work that way. With a razor, you have a natural guide to keep the angle constant, so all you have to do is maintain the right pressure so you don't roll the edge. And, as you say, you flip the razor for the return spring on the spine of the blade. You never have to let the spine leave the leather, although you have to maintain the correct tension on the belt. With knives, you want to lift the blade straight up at the end of a stroke so the angle isn't changed at the very end. If you laid a knife blade flat, as with the razor, the edge would not contact the strop, and you would just smooth off the edge shoulder.

I tried to post a gif showing the technique, but I can't figure out this new format. The gif -- showing how the razor is flipped on the spine -- is found in the link below.

Here's a good link to razor stropping:
http://straightrazorplace.com/srpwiki/index.php/Razor_stropping
 
I just learned about stropping relatively recently and have experimented with it. I have two strops that I made myself. They are three inches wide by twelve inches long. Each has the suede side on one side and the smooth side on the other. One is charged with green compound on the sued side and the other is charged with white compound on the suede side. The one with the white compound on the suede side has .5 micron diamond paste on it. (I am not so happy with the paste and am going to go to the liquid.) I also have an old belt hanging up.

First I strop on the green a few times, then the white, then the diamond, then the plain leather. Generally speaking, using very light pressure finding the proper angle as suggested here, give good results.

However, my early experience has been with older knives that I acquired in the 90s...not of the new "super steals."

I just got a ZT 562 CF in CPM 20 V and it could shave easily out of the box. Stropping it may have dulled it a bit.

After doing some reading what may have happened is that on this knife I used the wrong angle or too much pressure.

I discovered another interesting thing in my research. It may be the case that the newer particle steels do better at slicing things such as rope if they are left at around 600 grit. No, the blade won't have the mirror finish...it may not slice paper as well...but it will do better with tougher tasks. Indeed this may be the case for all steels. I don't know.

I just purchased a PM 2 and Military in CPM 110 V, a Crooked River in CPM 30 V, as well as some less expensive knives in non-premium steels. I have not experimented with stopping the Crucible steels and I just might consider not doing so, that for those knives function may be more important than form. I can live without a mirror finish. That said, like everyone else here, it is hard to resist tinkering with our knives.

I would love to hear other's opinions about this.
 
I know I got a ZT 0566 in Elmax and the edge was some what sharp when I got but it dulled really fast,from what I read on this forum a few years ago that when they sharpen the knife at the factory when they use a belt sander to sharpen the edge it can make the metal hot and witch in turn makes an extremely smaller upper layer on the surface of the steel on the edge brittle and cause's it to wear off faster.

I do believe that can happen in some case's because once I sharpened my ZT 0566 the edge lasted for along time,I wonder if that's what happened when you stropped you took off some of the brittle metal.

I just learned about stropping relatively recently and have experimented with it. I have two strops that I made myself. They are three inches wide by twelve inches long. Each has the suede side on one side and the smooth side on the other. One is charged with green compound on the sued side and the other is charged with white compound on the suede side. The one with the white compound on the suede side has .5 micron diamond paste on it. (I am not so happy with the paste and am going to go to the liquid.) I also have an old belt hanging up.

First I strop on the green a few times, then the white, then the diamond, then the plain leather. Generally speaking, using very light pressure finding the proper angle as suggested here, give good results.

However, my early experience has been with older knives that I acquired in the 90s...not of the new "super steals."

I just got a ZT 562 CF in CPM 20 V and it could shave easily out of the box. Stropping it may have dulled it a bit.

After doing some reading what may have happened is that on this knife I used the wrong angle or too much pressure.

I discovered another interesting thing in my research. It may be the case that the newer particle steels do better at slicing things such as rope if they are left at around 600 grit. No, the blade won't have the mirror finish...it may not slice paper as well...but it will do better with tougher tasks. Indeed this may be the case for all steels. I don't know.

I just purchased a PM 2 and Military in CPM 110 V, a Crooked River in CPM 30 V, as well as some less expensive knives in non-premium steels. I have not experimented with stopping the Crucible steels and I just might consider not doing so, that for those knives function may be more important than form. I can live without a mirror finish. That said, like everyone else here, it is hard to resist tinkering with our knives.

I would love to hear other's opinions about this.
 
I strop using leather, denim, canvas, or rubber.
No compounds on the strop.
My strop is the belt I'm wearing, or an old retired belt, my pants leg, my boot upper, or a piece of old bicycle tube.

Back around 1960 or so, I was taught that stropping was to remove any wire edge that may have formed while using the stones.
I was also taught to "shave" the stones, and to never pull the edge over the stones, since pulling the blade pretty much guaranteed a wire edge, which back then was something you wanted to avoid.
Push, Stop, Lift was the technique I was taught.
I was also taught that a knife, like a barber's straight razor, did not always need a stone to freshen up the edge. 9 times out of 10 stropping would restore the edge. (Even after skinning and dressing 3 or 4 deer.)
 
Man I am struggling greatly at stropping. No matter what I do it seems to dull the edge. I’m using balsa wood and a leather strop.

My edge just almost slices phone book paper. Shouldn’t I be able to bring it back the shaving sharp with a strop? I can’t seem to get it any sharper.
 
Balsa wood is very soft and can mess up the edge. Better off to use (IMO) basswood. A bit stiffer than balsa and won’t give under the blade as much.
 
Man I am struggling greatly at stropping. No matter what I do it seems to dull the edge. I’m using balsa wood and a leather strop.

My edge just almost slices phone book paper. Shouldn’t I be able to bring it back the shaving sharp with a strop? I can’t seem to get it any sharper.
Hi,
What did you do exactly using what equipment exactly?

If you can slice paper but cannot shave,
you probably need to back to stone and do a few more strokes, ex 10-30 passes per side





Balsa wood is very soft and can mess up the edge. Better off to use (IMO) basswood. A bit stiffer than balsa and won’t give under the blade as much.
Hi,
what is softer, leather or balsa?
its not the tools its how you use them
oh noes, shoelaces untied, better buy a new pair of shoes :D
 
I hear what your saying, but leather kind of follows the knife "kinda", where as balsa crushes. As you say though, its how you use the tool, and you can use balsa with good success. I was merely thinking it may be easier with basswood.
I have a D2 blade I convexed pretty ugly when I first tried leather strop...Part of MY learning curve,lol Took alot longer to straighten it out than it did to bugger up.
 
I’m still having a really hard time figuring out stropping. Maybe part of the problem is the leather on my strop but I also don’t understand the pressure thing.
A lot of people say to use really light pressure basically just the weight of the knife, but then I watch some videos like the Dutch Bushcraft Knives channel and you can see they are using quite a bit of pressure.
 
I’m still having a really hard time figuring out stropping. Maybe part of the problem is the leather on my strop but I also don’t understand the pressure thing.
A lot of people say to use really light pressure basically just the weight of the knife, but then I watch some videos like the Dutch Bushcraft Knives channel and you can see they are using quite a bit of pressure.

One can get away with using greater pressure on a strop, if they keep the angle conservatively low. Keep it somewhat lower than the actual edge angle, and it'll keep the leather from wrapping around the apex, which tends to round off the edge. A skilled hand can apply quite a lot of pressure on a leather strop and minimize the damage done, by keeping the angle low enough to protect the apex.

Also, depending on whether compound is used in stropping or not, that makes a big difference in how forgiving the strop will be, if the held angle is kind of high or if pressure is fairly heavy. A bare leather strop can be used pretty 'casually' without worrying too much about the angle or pressure, because the bare leather is very, very slow to abrade the steel. Bare leather is better for simply scrubbing very weak, thin burrs off the edge, and it won't do a whole lot beyond that. But with compound, since it will cut the steel much more aggressively, any error in held angle or pressure will magnify problems with rounding the edge.
 
I guess I been stropping wrong. :(
I always use a dry plain leather strop; no polishing compound.
I only strop to get rid of any wire edge that may have formed when sharpening on a stone. (AKA: "Oops. I messed up")

(When I was taught how to freehand sharpen 59 or 60 years ago, it was driven into my thick skull that a wire edge was bad, and "you messed up!") (My grandfather and Great Grandfather used language somewhat stronger than "messed up". I cannot use that language here because there are women and children present with sensitive ears ... or eyes, since they are reading this, I suppose ...)
I was taught to hold the edge around 45 degrees to the strop to remove that daRn wire edge, and use enough pressure to bow the strop.

Stropping will also "fix" any rolled edge from using the knife, too. I rarely have use a stone on my blades. (and even then I use the finest grit I have, either a Arkansas stove==ne, or the unglazed ring on the bottom of an (empty) coffee mug, if I need anything coarser.)
I try to sharpen to a 15 to 20 degree inclusive angle, as I was taught all those years ago. ("You want to shave the stone! Use a low angle! I SAID A LOW ANGLE!!!! You're sharpening a knife! Not an Axe!")
(They felt a 30 - 35 degree inclusive angle was good for an axe - not a knife)
 
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I guess I been stropping wrong. :(
I always use a dry plain leather strop; no polishing compound.
I only strop to get rid of any wire edge that may have formed when sharpening on a stone. (AKA: "Oops. I messed up")

(When I was taught how to freehand sharpen 59 or 60 years ago, it was driven into my thick skull that a wire edge was bad, and "you messed up!") (My grandfather and Great Grandfather used language somewhat stronger than "messed up". I cannot use that language here because there are women and children present with sensitive ears ... or eyes, since they are reading this, I suppose ...)
I was taught to hold the edge around 45 degrees to the strop to remove that daRn wire edge, and use enough pressure to bow the strop.

Stropping will also "fix" any rolled edge from using the knife, too. I rarely have use a stone on my blades. (and even then I use the finest grit I have, either a Arkansas stove==ne, or the unglazed ring on the bottom of an (empty) coffee mug, if I need anything coarser.)
I try to sharpen to a 15 to 20 degree inclusive angle, as I was taught all those years ago. ("You want to shave the stone! Use a low angle! I SAID A LOW ANGLE!!!! You're sharpening a knife! Not an Axe!")
(They felt a 30 - 35 degree inclusive angle was good for an axe - not a knife)


I never use a strop to remove a burr -- only to refine the apex to a higher degree of sharpness.

Burrs can easily be removed by edge-leading strokes of a stone. The idea is to progressively use finer grits, lighter strokes and shorter strokes. Any edge-leading stroke will begin to create a new burr. The coarser the grit, the harder the pressure, the longer the strokes, the more of a new burr will be created.

When you're sharpening at such a narrow angle (7.5 dps) and then you remove the burr at a 45 degree angle, you're basically breaking the burr off. The burr will go away, but you're left with a ragged, weak, sub-optimal apex.

If you instead remove the burr with very short, very light edge-leading strokes with a stone, you'll have an apex that will respond well to proper stropping. That stropping will refine the edge and give you a noticeably sharper apex.

When you get your edge to the burr stage, you're dealing with extremely small issues of metal and geometry -- measured in fractions of microns. The more brutal your technique, the worse that edge will be. Stropping with a loaded leather removes very little metal -- just enough to refine an already clean apex.
 
I see this post has been running for ten years now and still relevant to what many on BF want to accomplish. The technique I gleaned here and the green compound took my factory edge Busse and made it sharper in just a few minutes. 8D502757-E25E-4A4D-B916-BC43FBE3001C.jpeg
 
I haven't said my piece here yet? Can't be. So here it goes:
i use the bevel angle as stropping angle (stropping angle = bevel angle), with notable pressure, on a hard wood surface. my key is : controlling the exact angle. I can do so with my right elbow, like a violinist stroking the fixed instrument (knife) with her bow (thin hard wood stick strop).

If the reader still can't imagine why\how, think of a sword! A sword is big, fat, heavy, cumbersome. You would never think of stropping its blade on a knivesplusstropblock, you'd break your wrist. So you'd rather hold the sword like a cello (with your left arm), mark the entire edge with a Sharpie, and then pass the strop like a cello's bow playing the instrument (with your right hand). By controlling the angle of your right elbow, you control the stropping angle to match the bevel angle perfectly.

Using hard wood (instead of leather), in form of a paint stirring stick, with a fast cutting compound, and notable pressure becomes the natural choice for "playing the cello". Of course you don't need to apply notable pressure; do as you please, the fast cutting compound does the stropping job anyway, no matter how much pressure you apply.

And since it's hard wood and you're matching the bevel angle 100%, there's no chance of rounding off the apex.

Only little practice is needed. Basically it's Stropping For Dummies. And i can recommend it for big and medium sized blades. (I even do it for small sized knives like SAK but that's just me.) You never see this technique on youtube but just imagine if a youtuber did a video on stropping a sword, how would his technique look like? Probably not a sword-on-leather technique but a wood-to-sword technique!

A sword would be too heavy on a leather strop block, or leather paddle strop. Think about it. Similar thinking applies to axes, hatches, clunky tools. Imho they're too heavy for my wrist, too heavy on leather, you'd get rounded apexes!

Thanks for giving my technique a serious try! Beware it's fast cutting, me, loving it, having no patience with green compound leathers ;-)
 
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Greetings All
I hope to gain some valuable insights from you all.
I sharpen with a 1000 & 3000 grid stones, for stropping I use Sharpal Green Buffing Compound on the rough side of the leather. On the smooth side, I use DMT 1 micron diamond spray.

For some knives such as Spyderco Tenacious, Boker Magnum Parker Hunter & Opinel No 8, i can get decent edge after stropping. Able to slice the pages of telephone book.

But for other knives: Kershaw Oso Sweet, KA-Bar Dozier (Aus 8) & Buck Bantam BLW, the edges get dull after stropping.

Techniques for both sets are similar; didn't press down hard, try to angle the knife apex on the leather.

I appreciate your feedback. Thanks.

Cheers & Clear Sky
 
Put your hand on your leg.
Move slowly your hand againt your hip. Look at the fabrik just before you hand, it creates a bulb.

Change the pressure and study how the bulb changes.

This happens also with a leather strop but in lesser scale = the bulb change the edge angle and make it steeper.

If you strop in 1-2 degrees lower angle, the bulb will rice below the edge (under the cutting edge) and help you with the stropping - instead of working against you.
 
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