Stropping on cardboard

[HeavyHanded]

I prefer paper over a hard surface to cardboards, have used used shipping tubes to good effect. Higher carbide content doesn't work as well as finer grained stainless or carbon steels.

Am able to maintain an edge for a good bit of time with plain paper over a Washboard, and to visibly burnish the edge to a higher polish. I seldom use leather anymore.

 

[maximus83]

I prefer paper over a hard surface to cardboards, have used used shipping tubes to good effect. Higher carbide content doesn't work as well as finer grained stainless or carbon steels.

Am able to maintain an edge for a good bit of time with plain paper over a Washboard, and to visibly burnish the edge to a higher polish. I seldom use leather anymore.

I know you've spoken to this elsewhere, but there's so many videos and things I can't remember which one you addressed it. What kind of paper do you use? Does it make a big difference? For instance if I just use computer printer paper wrapped around my bench stone, would that work?

 

[HeavyHanded]

I know you've spoken to this elsewhere, but there's so many videos and things I can't remember which one you addressed it. What kind of paper do you use? Does it make a big difference? For instance if I just use computer printer paper wrapped around my bench stone, would that work?

Copy paper or good quality writing paper as long as it isn't too thick. Newsprint or really cheap paper seem not to work well, maybe a result of too much recycled content = shorter fiber lengths etc. Some of the better writing paper with higher linen content seems to have higher silica content but IDK for sure.

Wrap the paper around the coarse side of the stone and compress the paper by rubbing with pressure with a rag, paper towel, even a wood dowel, piece of PEX etc can be used. This will also let you know if there is any loose grit on the surface (major no-no with this strategy).

If using with no compound a stout amount of pressure can be used - several pounds at first. On a smooth stone this will not really generate enough unit pressure to burnish the edge, but the voids and high spots on a coarse stone amplify unit pressure by reduced footprint - exactly as they do with abrasive points when grinding - larger abrasive sizes really work because of the increased shoulder to shoulder spacing as much as the increased size of the grit - the two are interrelated. A 10 micron sized abrasive mounted to a "bed of nails" spaced out to 120 grit will grind more like 120 grit than 10 micron. Unit pressure goes through the ceiling - a plugged coarse grit stone grinds like a poor quality medium grit stone because the clearance voids are full. The contribution of the reduced footprint is massive.

If you use with compound a relatively high pressure can be used as well, but have to be very careful of you angle control and stone surface. One or two high angle swipes and the surface might not be abrasive enough to recover that angle. Any spots that are particularly proud can actual fold and deform the edge - again, any loose grit is a real no-no.

A few final swipes are a higher angle with a lot less pressure add a nice finishing touch.

I pushed this out with plain paper on an Aus8 blade once and kept is shaving armhair for weeks of daily use using only a Washboard and plain paper. In fact the intervals between needing touchup became longer with repeated use until it finally crapped out.

 

[maximus83]

^Super interesting, thanks for all that background.

So to play this out, using the stones I have on hand, does this approach work to do it without compound or swarf?

• Get a blade sharp with let's say a 12-15 dps secondary bevel, and a 20 dps micro bevel.
• Wrap computer paper around my American Mutt bench stone and compress it.
• Use edge-trailing strokes with stout pressure at a slightly lower angle than the micro-bevel.
  • Q: Should I use roughly the same angle that was used on the secondary bevel?
• Do a few final edge-trailing swipes at the same angle as the micro-bevel.

Related item:

• FortyTwoBlades has suggested in separate PMs that there's a way you can refine the edge/strop directly on the Arctic Fox bench stone, without using paper. But that it takes "finesse", which I'm still in the process of acquiring . Again, trying to discover the most basic minimalist/simplest approach possible, could it work to use a higher-grit stone like the Arctic Fox or the fine side of any Norton combi stone, or a F or EF DMT stone, and accomplish the same thing as "stropping" but without needing paper or compounds? Just doing it based on a combination of the right sharpening pressure, angle, and movements.

 

[HeavyHanded]

^Super interesting, thanks for all that background.

So to play this out, using the stones I have on hand, does this approach work to do it without compound or swarf?

• Get a blade sharp with let's say a 12-15 dps secondary bevel, and a 20 dps micro bevel.
• Wrap computer paper around my American Mutt bench stone and compress it.
• Use edge-trailing strokes with stout pressure at a slightly lower angle than the micro-bevel.
  • Q: Should I use roughly the same angle that was used on the secondary bevel?
• Do a few final edge-trailing swipes at the same angle as the micro-bevel.

Related item:

• FortyTwoBlades has suggested in separate PMs that there's a way you can refine the edge/strop directly on the Arctic Fox bench stone, without using paper. But that it takes "finesse", which I'm still in the process of acquiring . Again, trying to discover the most basic minimalist/simplest approach possible, could it work to use a higher-grit stone like the Arctic Fox or the fine side of any Norton combi stone, or a F or EF DMT stone, and accomplish the same thing as "stropping" but without needing paper or compounds? Just doing it based on a combination of the right sharpening pressure, angle, and movements.

You'd want to play around with it but basically for a less refined edge I strop at the same edge angle, slightly higher angle if a more refined edge. Microbevel split the difference.

You can backhone on many stones as long as they have some mobility to the abrasive. The more hard fixed the abrasive the trickier/less useful this approach is. On softer waterstones it works fantastic, pretty much required to get best results. On something like a DMT the effect is not worth chasing.

 

[FortyTwoBlades]

I can finish on the Arctic Fox with edge-leading strokes without issue, but finishing with edge-trailing strokes can definitely help if you're having trouble with getting results with edge-leading strokes. Light pressure with alternating full-length strokes is the ticket. However, I'm experienced enough with holding angles that I can hold the stone in my hand and work on it without need for a table, so that probably helps. Inconsistency in your strokes can make it difficult to bring the edge to a fully aligned apex because you hit the apex on one side, then not on the other, and so forth.

 

[maximus83]

I can finish on the Arctic Fox with edge-leading strokes without issue, but finishing with edge-trailing strokes can definitely help if you're having trouble with getting results with edge-leading strokes. Light pressure with alternating full-length strokes is the ticket. However, I'm experienced enough with holding angles that I can hold the stone in my hand and work on it without need for a table, so that probably helps. Inconsistency in your strokes can make it difficult to bring the edge to a fully aligned apex because you hit the apex on one side, then not on the other, and so forth.

So it sounds like you really don't "strop" at all in any traditional sense. You just apex (sharpen), then do some lighter strokes at the same angle on the same stone. Can't get much simpler than that. That's what I aspire to. I will try that approach and the paper wrapped approach, compare, and skip stropping on my leather paddle altogether and see how it goes.

 

[FortyTwoBlades]

So it sounds like you really don't "strop" at all in any traditional sense. You just apex (sharpen), then do some lighter strokes at the same angle on the same stone. Can't get much simpler than that. That's what I aspire to. I will try that approach and the paper wrapped approach, compare, and skip stropping on my leather paddle altogether and see how it goes.

That's what I typically do, yes. But if you have difficulty with that, use edge trailing strokes as if stropping and it may make it easier for you. If my edge off the stone isn't cleanly popping hair I'll usually just strop lightly on my palm or thigh and that's all it takes to get it fully trued up. But I don't usually need to--just on really soft steels.

 

[awestib]

So it sounds like you really don't "strop" at all in any traditional sense. You just apex (sharpen), then do some lighter strokes at the same angle on the same stone. Can't get much simpler than that. That's what I aspire to. I will try that approach and the paper wrapped approach, compare, and skip stropping on my leather paddle altogether and see how it goes.

On some knives (and maybe also on some stones), I just can not get an edge clean enough by just edge leading alternating strokes. One of my VG10 kitchen knives and the fine side of the Norton is at times on of those couples. And the tiny burr that I know is still there needs quite a bit of work of stropping on paper +- compound on the washboard or on the coarse side of the Norton (at times with elevated angles) to get rid of. The easier way then is stropping on denim with Mother'sMag or similar (AlOx) with the trade off of a more significant microconvex and no more "bite".

It seems there is no free lunch!

 

[maximus83]

^Understood on this. Looking around, I realize that stropping is a semi-controversial subject. Some folks go the route 42 does which IMO, is edge refinement but not really "stropping" in traditional sense. I like that simplicity of method and if I can get good results, that what I'll do. I also like the approach HeavyHanded uses with paper, also extremely simple. However, reading around a bit including Sal Glesser's comments about stropping over at Spyderco, it does seem there's kind of a complex story here. When you strop in traditional sense (say on leather or cardboard, per the OP), it seems like you're doing one kind of "edge refinement" that prepares the edge for certain types of cutting. When you refine a different way, say just directly on a higher grit stone with super light strokes, it sounds like an experienced sharpener on a quality stone can still get great results, but you're going to get a slightly different TYPE of refined edge that is optimized for different cutting tasks. I don't know if this is all correct, doing a fair amount of background reading to increase my understanding around stropping options and approaches.

 

[HeavyHanded]

^Understood on this. Looking around, I realize that stropping is a semi-controversial subject. Some folks go the route 42 does which IMO, is edge refinement but not really "stropping" in traditional sense. I like that simplicity of method and if I can get good results, that what I'll do. I also like the approach HeavyHanded uses with paper, also extremely simple. However, reading around a bit including Sal Glesser's comments about stropping over at Spyderco, it does seem there's kind of a complex story here. When you strop in traditional sense (say on leather or cardboard, per the OP), it seems like you're doing one kind of "edge refinement" that prepares the edge for certain types of cutting. When you refine a different way, say just directly on a higher grit stone with super light strokes, it sounds like an experienced sharpener on a quality stone can still get great results, but you're going to get a slightly different TYPE of refined edge that is optimized for different cutting tasks. I don't know if this is all correct, doing a fair amount of background reading to increase my understanding around stropping options and approaches.

The term "stropping" can be so many things. I addition to a piece of loaded leather, I view the use of lapping films and such as a form of stropping. Backhoning on resinoid or soft binder waterstones is stropping. Thin abrasive mud on the edge of a cutting board used with a backhone pass is stropping.

The amount of give the backing has combined with the abrasive size and how tacky the binder/ how well fixed the abrasive all influence the outcome when stropping, and this leads to many different and often conflicting observations as well as some outright incorrect conclusions.

The rough equivalent on hard stones might be the use of multiple finer abrasives at one or two slightly increasing angles when microbevelling.

Ultimately the geometry is the largest single factor in how well something cuts for how long. Finish weighs in more heavily when the edge is used for primarily draw or pressure cutting.

Everything is a trade-off.

 

[maximus83]

Everything is a trade-off.

Yeah starting to see that. For years and until just recently, I had a very simplistic understanding, I just thought everybody should strop, and everybody should use some type of leather. That's it. The reality is far more complex.

What would be interesting--though I don't know if it's POSSIBLE given how many different approaches there are--is if somebody could prepare some kind of guidance as in you want this kind of edge optimized for this kind of cutting, you should strop using this approach. But I suppose even there, if one person writes down some guidance, 10 more people would pop up and say no do it this way.

So what I'm doing is just reading around a bit until I find out what are the most common approaches that people use that seem to work, then I narrow those down to simple/minimalist approaches that don't require buying a bunch of junk, and then just try things until I find what seems to work. Not very scientific, but about all I have time for given my day job.

Based on what experienced sharpeners here in the forum have seen: Is it fair to say that there's at least consensus around this basic point, that some type of "edge refinement step" (aka stropping) AFTER you do your sharpening/apexing is a good thing, and that the main benefit is to improve edge alignment by reducing micro-burrs? And that, HOW you strop should be determined by what kind of tasks you want to optimize the edge for?

 

[Obsessed with Edges]

^Understood on this. Looking around, I realize that stropping is a semi-controversial subject. Some folks go the route 42 does which IMO, is edge refinement but not really "stropping" in traditional sense. I like that simplicity of method and if I can get good results, that what I'll do. I also like the approach HeavyHanded uses with paper, also extremely simple. However, reading around a bit including Sal Glesser's comments about stropping over at Spyderco, it does seem there's kind of a complex story here. When you strop in traditional sense (say on leather or cardboard, per the OP), it seems like you're doing one kind of "edge refinement" that prepares the edge for certain types of cutting. When you refine a different way, say just directly on a higher grit stone with super light strokes, it sounds like an experienced sharpener on a quality stone can still get great results, but you're going to get a slightly different TYPE of refined edge that is optimized for different cutting tasks. I don't know if this is all correct, doing a fair amount of background reading to increase my understanding around stropping options and approaches.

What makes the most difference, ultimately, is how much refinement gets done on the stones first. If that's done well, it reduces the need or the importance of stropping as a whole. If one is looking for polish, that can be done with a wise choice of stones alone, especially if that choice is one that minimizes burr formation as well. Stropping with compound is an easier way to polish an edge, if one's finishing touches on stones aren't taken quite as far, and can certainly be sufficient for 99% of cutting tasks anyway. But as technique improves on stones, the need to do most or all of the polishing refinement on a strop will diminish.

Convexing issues attributed to stropping can also me minimized by stropping on firmer or hard substrates. Eliminate the use of leather for that, and instead go to firm or hard wood instead. That's actually the more effective means for polishing as well, as it'll work faster and leave the edge crisper than if done on leather. And the loss of 'bite' that may happen in stropping can also be minimized by using a somewhat less aggressive polishing compound (or NO compound at all), or taking fewer passes at lighter pressure, or a combination of the two. And knowing when to quit, in stropping, is just as important, so the finished result ends up exactly as you want it.


David

 

[maximus83]

Thanks David, yes that kind of rings true to what I've observed in the past simply using my DMT stones. I know that if you're a really A-list sharpener, you should be able to get a folder to hair whittling sharp just on a single coarse stone. I confess I have NEVER yet been able to make that happen. However, in the past when I've done a simple 3-grit progression using DMT as in C, F, EF, and sometimes finishing with 3 to 5 very light strokes per side on the Sharpmaker UF hone, I couldn't tell any difference at all with those results versus finishing with the leather strop paddle + compound. In fact, the strop-less approach seemed to get slightly superior results for me. Someone will say that's just because you didn't strop right on the leather. Which may well be true. Just saying to your point, it DOES seem possible to get pretty stellar results without stropping in the traditional sense.

 

[FortyTwoBlades]

Convexing issues attributed to stropping can also me minimized by stropping on firmer or hard substrates.

Or by stropping at a lower angle than used on the stones, to compensate for the deflection of the soft substrate.

 

[Obsessed with Edges]

Thanks David, yes that kind of rings true to what I've observed in the past simply using my DMT stones. I know that if you're a really A-list sharpener, you should be able to get a folder to hair whittling sharp just on a single coarse stone. I confess I have NEVER yet been able to make that happen. However, in the past when I've done a simple 3-grit progression using DMT as in C, F, EF, and sometimes finishing with 3 to 5 very light strokes per side on the Sharpmaker UF hone, I couldn't tell any difference at all with those results versus finishing with the leather strop paddle + compound. In fact, the strop-less approach seemed to get slightly superior results for me. Someone will say that's just because you didn't strop right on the leather. Which may well be true. Just saying to your point, it DOES seem possible to get pretty stellar results without stropping in the traditional sense.

Stropping results can be extremely ephemeral and widely variable, and can change with the smallest change in a single variable. It's likely possible some 'improvement' (defined according to who-knows-what kind of criteria) can be had in stropping, after coming off the stones. But, one needs to ask if the 'improvement' is actually necessary for the end-use goals of the edge being sharpened. For example, most of us love to see hair-popping or shaving edges resulting from our sharpening process. But, if the edge being sharpened isn't actually going to be used for shaving, there may not be any benefit in going quite that far, and therefore no justifiable expectation of seeing stropping take it that far, every time. Most shaving edges are temporary, and will disappear after the first few cuts in some tasks (woodworking edges, cardboard cutting, etc). So, even if stropping may not obviously produce any 'improvement' in the edge, we may not have to interpret that as a negative, if that 'improvement' is expected to be a shaving-sharp edge. It may not be important anyway, if the existing edge is already essentially perfect for the task we're actually sharpening for.

I've been fiddling with a woodworking chisel in the last few days, sharpening and polishing the edge (bevel and back side), and seeing just how far I can take it, in sharpness. I set the edge to full apex on Fine & EF DMT hones, from both the front and back side. And per my earlier posting, I'm doing all the polishing on a hard substrate (MDF, with aluminum oxide compound). I've had it tree-topping hair from my forearm, which is fun. But I've noticed that after just a cut or two into some wood (which is what it's made for, after all), that tree-topping edge diminishes pretty quick. But it still goes through wood like a dream, and does so for a reasonable amount of time. So it's gravy, and exactly what it needs to be.


David

 

[HeavyHanded]

Just saying to your point, it DOES seem possible to get pretty stellar results without stropping in the traditional sense.

I can get the results without a strop. On many of my woodworking tools as often as not I've been known to stop on the stones. This can be right off of a fine Crystalon if I'm doing rough work, or off the 8k Suzuki Ya waterstone or any of my 8k finish stones the edge will normally treetop arm hair. But then, backhoning on polishing grade waterstones qualifies as a type of stropping in my book.

I will still normally make a pass or two on a couple sheets of paper on CrO oxide, but not always. I mostly use it bare minimum to check for residual burrs as they tend to shine up faster than the rest of the edge.

If I'm using a smooth steel or microbevel on high VC steel I will seldom strop as an additional step.

When sharpening for $ I pretty much finish 100% of the time on a hard strop. It is just too fast and provides a buffer against any possible residual burrs. I also tend to sharpen/reset the angle to < 30°, so a little strop action can toughen up the edge just as a microbevel would.

 

[brasileiro]

So, edge refinement, strop and burr removal are different things?

I.e. Refinement: I can refine an edge when working with stone. Is refinement a stone progression on very well worked bevel?

Burr removal: Is the clearance off of fatigue metal or metal particles that still are stick on apex. May I work it with stone, leather, paper...?

Strop: So is strop the polishment or semi polishment of an edge or apex or both? Or is about the motion like Trailing motion?

I'd read the topic "Stropping, angle plus pressure", but now I'm confused.

Thanks.

 

[HeavyHanded]

So, edge refinement, strop and burr removal are different things?

I.e. Refinement: I can refine an edge when working with stone. Is refinement a stone progression on very well worked bevel?

Burr removal: Is the clearance off of fatigue metal or metal particles that still are stick on apex. May I work it with stone, leather, paper...?

Strop: So is strop the polishment or semi polishment of an edge or apex or both? Or is about the motion like Trailing motion?

I'd read the topic "Stropping, angle plus pressure", but now I'm confused.

Thanks.

In my opinion, "Stropping" is the act of backhoning on an abrasive surface with some give, some mobility to the abrasive, some combination of the two.

Backhoning on a hard fixed abrasive generally yields no tangible benefit - is normally inferior to an edge leading pass at the finish step. The strop takes advantage of the increased uniformity the abrasive presents due to mobility and conformability of the surface (if that makes sense). It allows a wide variety of grit to be used, as well as particles in smaller size ranges that normally are only found in fairly rare stone formations or in comparatively expensive manufactured stones.

Some of this effect is seen in the higher uniformity of finish produced by lapping films and wet/dry relative to vitreous stones in the same grit range.

These characteristics will normally help to eliminate any residual burrs left from grinding as the abrasive will shift rather than pull the steel out to a burr at the end of its scratch trough, or deform it out of the path on a leading pass. This will normally allow refinement of the edge and subsequent touchups without being 100% accurate to the existing angle as well. This will normally toughen up an edge somewhat by applying a slight or not so slight microconvex on the order of a microbevel.

There is potential to dub the edge. Over time, the apex will take on the curvature equal to the amount of deflection of the surface. There is also less feedback, so a few higher angle passes will round the edge and one might blame it on the strop instead of user error. Some strops are so soft they are almost useless for ongoing touchups, others are so hard they tend to form burrs if overused.

Applications like a knife board are really somewhere between. Surely at the finer end it would be tough to not call it stropping, but using 80 or 120 grit on a board is a bit of a stretch.

 

[stitchawl]

I've posted this before, but I guess it bears repeating here...
Leather is not magic. Neither is cardboard, paper, your jeans or the palms of your hands.
What they all have in common are 'silicates...' those tiny abrasive particles, MUCH smaller than 98% of what are found in various compounds, and these are the 'magic' to be had in stropping on bare surfaces.
All carbon-based lifeforms contain silicates to some degree. Green grass has a lot of silicates, and when the cows eat the grass, they now have silicates in their skin. Vegetables have silicates so when you eat them, you have silicates in your skin. Trees have silicates, and when you grind them up and make paper, the paper has silicates. Jeans are made of cotton, cotton has silicates so your jeans now have that magic micro-abrasive quality that allows us to strop on our thighs.

Leather, properly processed, has MORE silicates than cotton cloth. Especially horse hide. It has more silicates per square inch than cow hide. So does kangaroo hide. BUT NOT A LOT MORE! Just more. Without real science (and so just making up numbers,) if it takes 6-8 strokes on Horse hide, it may take 8-10 strokes on cowhide and 12 strokes on paper or on your jeans. There is no difference in the quantity of silicates in copy paper or a shirt cardboard, and it's those silicates that are doing the honing, not the smooth or rough surface of the paper/cardboard strop. Magazine covers are a horse of a different color. They are 'coated stock.' The coating is a fine clay, which is abrasive in its own right. And because leather lasts longer, barbers use leather strops rather than cardboard toilet tubes. Looks more professional, too.

Different stropping materials do give us different feedbacks while we are stropping. And we get used to the feedback of the strops that we use, so we may feel that one is 'better' than another. Rougher surfaces really have little effect when stropping, other than giving different feedbacks. The bottom line is that it is the silicates that are doing the work. If you doubt this, just try stopping on a rough piece of Cordura Nylon and see what happens. Then try stopping on your jeans or a piece of news print paper. The magic is in the silicates.