Got a couple issues here. 1. Don't compare abrasives from different manufactures by "grit". Go by the size of the abrasive in microns. For instance, a Shapton 8,000 stone is 1.84 microns and a Norton 8,000 stone is 1.2 microns. 2. You mentioned that the Tormek cuts faster than the red, green, etc paste. There is a reason for that. The Tormek paste is more abrasive. In fact, it has an abrasive of 3 microns. Your 8,000 grit stone is below 2 microns. You're DULLING your blade by using the Tormek paste after your 8,000 grit stone. The green stropping compound is 0.5 microns. And you don't want that on a thick spongey layer of leather. Go for a thin and relatively stiff veg tan leather. Or even MDF or the brown side of a cereal box.
The grit difference here seems to put these results into question. I had the same suspicion when he mentioned that the compound cuts faster. Thanks for confirming the details.
You have a valid point. Shapton 8000g is advertised as 1.84 micron while the tormek is 3 micron. This explains why I overshot the baseline sharpness to be sharper than ~110 ish on the stone sharpening blade. However, the 3 micron abrasive was more than fine enough to bring the stripped blade back toward baseline sharpness. So I was not dulling the stropping blade and the results are still better explained by the squishy nature of the leather causing a rounding effect. To your point, if it’s better to use honing compound on a piece of harder surface, why not just use a higher grit stone?
@@WoodcraftBySuman I think a good reason to prefer buffing compound is the cost. I don't have an 8000 grit stone, so I go from a 1200 grit diamond stone directly to stropping with green buffing compound. Rob Cosman doesn't buff, but that 16000 grit stone he uses cost $160 CAD. A large stick of green compound from Lee Valley costs a tenth of that.
Yup, I was taught the strop is for final hone and polish and working off the burr, not for actual sharpening. There is good evidence that steel quality and bevel angle are the biggest contributors to sharpness and edge longevity.
Very much. Stropping can be used for "sharpening" on a pinch, but that works best for knives than this sorta blade. IMO it is actually preferable to "sharppen" the knife on the back of another knife first, just to straigthen up the edge, then re-polis on a strop. But htat is a regular knife with its double sided sharpening and thin blades, not a beefy blade with a chisel gring like a tool. Give it a few strokes on your highest stone if it is not dull (then it has to go down to a lower stone), a couple on the strop, takes about the same time, and you're golden.
@@TheOriginalAndBestTim The compounds used for stropping wear away the metal just like a stone, so if you can put some fine stropping compound on something rigid like a flat hard piece of wood, it will behave similar to a fine stone. Strops are generally made of something that compresses a little though, and that dreaded rounding over of the bevel is also what helps work off the burr and polish the last bit of the edge quickly.
Keep up the great work, Suman. As a neuroscientist/experimental psychologist, I really appreciate your efforts in terms of experimental design, data dissemination, and visualization. You’re carving a lovely niche in the UA-cam woodworking community, and I can’t wait to see what you come up with next!
A wise man once told me that stropping " technically does cause micro roundover and I think it makes the edge dull quicker because its a tad more blunt to begin with." So I stopped stropping and it saves me a TON of time! Oh wait! That was you in the comments of your "i don't know why more people don't sharpen like this" video. Your dedication to the scientific process for testing woodworking practices is unmatched! I really appreciate you going through all of the effort and compiling the data in a concise and informative fashion. Mixing these types of videos into the mix with build videos is great. That's one of the things I enjoy about JKM, yet your content is uniquely yours. Keep up the great work!
@@WoodcraftBySuman I heard from Cliff Stamp that stropping "with excessive pressure or time" can not only round over the edge, but also change the very tip of the blade to be more brittle. He always prefer removing the burr by light passes on a stone instead of stropping.
Hi Suman, great video. I actually did a very similar experiment trying to prove the effectiveness of a strop. In my test, I stropped my blade after 400 strokes on hard maple and the sharpness on my blade went from about 500 to 250 on BESS scale after few stroppings. However, that didn't really last very long. I was back to 500+ range after only about 50 strokes. For stropping to be really effective, I found you need to strop in about every 50 strokes. With this approach I was able to maintain 300-350 sharpness even after 600 strokes.
I love your use of scientific method to demonstrate your conclusions. It isn't just about an opinion like so much in woodworking. I've seen too many times where people present opinion as if it where the absolute truth without data. Very nicely done.
Great test and I was surprised by the dramatic results. I have been stropping for decades and have found several things that may improve your results. As many have noted, using a soft leather is very bad. Stropping with wet compound is also counter productive since it leaves the leather even softer and the compound squishes up around the apex. I use diamond powder on thin leather and have found that if I don't let the diamond dry completely before use it will dull my stone honed edges. When the diamond surface becomes loaded and less effective, I give it a spray of water and agitate the surface to bring fresh diamonds into play. When dry, it works like new. Any time I can't get my desired results in less than 10 stropping passes I know I need to do a better job on the stones. Almost all my knives are "super steels" and attempting to strop on anything other than diamond or boron carbide is useless. I suspect V11 is similar (I have V11 plane blades but have always used diamond stropping with them.) Just some observations from a 71 year old woodworker with an obsession for sharp stuff!
@@WoodcraftBySuman I have several high grit stones including a 16k shapton but I find that the softer texture and feedback from the strop gives me more reliable results. I can feel and hear the exact moment my strop is "on edge" whereas with the shapton I need to gauge it based on angle alone. Lower grit stones remove enough material that minor angle errors are quickly compensated. Most of my sharpening is on knives where I can't use the hollow grind trick for angle setting. I do use hollow grind on plane blades and chisels but have never found any benefit in going above 5K in sharpening them so the strop is just a pass or two to ensure that the burr is gone in woodworking. I'm fine when they shave arm hair. My knives I usually take to hair whittling sharpness just because it took so long to learn how that I like to stay in practice!
Awesome video, but I was under the impression that the stropping was an addition to after final honing. I.e. a final polish to remove any nicks. There is no doubt that the the blade is sharp after the 8K stone, but what are the shavings like? Are there streaks on the piece and/or shaving? Can you go straight to finish? I suppose that the edge could be viewed using a jewelers lens, or other means, to see if there are any nicks on the edge that might cause streaking by just using 8k. Btw I don't strop, just finish with 16k stone.
Love the test and you cant argue with empirical evidence. I still strop in my shop and always will. For me it is a factor of convenience. A strop lives on my bench. When my tool dulls i run the blade over the strop a few times and i am back to work. The tool will dull overtime and eventually needs to go back to the stone. Data is great but it is important not to get bogged down in it. If i can still plane figured woods it is good enough. The strop saves me time to function the way i want to function. There are a thousand ways to get to a sharp tool and none of them are wrong! As a side note i dont know what type of leather was used byt horsebutt is the best accompanied with green compound.
Thank you for being so thorough in documenting your testing methodology. It gives me a lot more confidence in your results that you took multiple test cuts and averaged them, as well as comparing the two blades under identical conditions to give a sense of the natural variability in the materials and the process.
This video show it’s better to use a stone to sharpen and hone. Your collaboration with Johnathan Katz Moses taught us that the media for sharpening is irrelevant. Both excellent videos dispelling some myths. I would love to see a follow up comparing the different methods for sharpening: hollow grind/freehand, flat grind/jig, and convex grind (aka Paul Sellers). Which holds the best edge? Gets the sharpest? Consistently? Speed? Etc.
Strop is not a substitute for 8000 or higher grit stones. You can get only the polish level of your compound. If the stone is higher grit than a compound no surprise it will produce a better edge. Most people use strops after sharpening on a 1000 grit stone just to save some money by eliminating a need for additional higher grit stone.
Grit alone is not the only factor that determines how sharp an edge is. The steel you're sharpening is a factor too. If it wasn't then it wouldn't matter what tools you had. Steel is an alloy though. So steel is a complex material. Steel has a grain structure. You can't see it like wood but it's there.
Interesting investigation, Suman. I have experience using a 4 water stone system and a 3 diamond stone and a strop system. Based on experience, the water stone system gave a much better edge. So I agree with the basic premises of your video that it is POSSIBLE to get a better edge on stones. But I much prefer the diamond stone and a strop system. The water stone system is very messy and time consuming to set up and maintain the stones. The average working sharpness of my tools is much better with the strop because I actually use it often vs. avoiding sharpening because of the stone. BTW - I use a 5 micron green bar compound that is roughly equivalent to my 4000 grit water stone. Works for me.
This is like the scientific method’s peer review and pressure testing processes in action for hobbyist woodworkers. Great content with backed up conclusions. I think that the comments pointing out flaws, oversights, or recommendations for improving the methodology have been great. Thanks for putting this together and having the courage to open yourself up to the inevitable trolls to provide the nuggets of good info to slip thru for those of us interested in finding them.
Haha dude as someone that has been through the peer review process many times, I feel like this is worse. Folks expect me to go through every detail on a YT video driven by algorithm that favor simplication and brevity. Folks claim a harder backed surface should be used: yes but a stone does the same thing. If stropping on MDF, the results will likely trail behind stone sharpened edge. Folks will claim this is not the intention of stropping- it’s just to refresh the edge after sharpening. Yup- but many folks will stop a few times between full sharpening. And that is the intention of the video- when refreshing the edge, stropping shows inferior result after just one such attempt. The reiteration of stropping to refresh the edge was to test just how far that envelope can be pushed. This is one way to look at the topic of sharpening vs stropping. Nevertheless- this has been a fun experience.
Great video with outstanding content. Sharp blades that dull quickly are just impractical. Suman did an excellent job of designing a test that changes what I thought I knew about the benefits of stropping. Going to be retiring my strop and acquiring a fine grit stone.
I use a strop, but not the way you showed here. I refresh the edge by going to a medium stone for a couple passes, then stropping a few times. The method I use allows me to avoid spending money on an expensive fine stone because my cheap strop does the job quite well. Some people have money to burn and they love spending it. People, like myself, prefer to keep as much money in their pockets as possible.
Interesting. First of all , thanks for all the effort you put in. I didn't see how you dealt with the back of the blades in your sharpening regime because after teaching many sharpening seminars I see that most peoples blades are ever so slightly "rounded" on the back ( about a 1/32 of an inch behind the cutting edge) I came to realize that like the face/cutting edge the ,back of the blade wears (just to a smaller degree). This can be corrected with a technique popularized by English woodworker David Charlesworth by simply using a very thin "riser" to elevate the blade insuring contact on the back of the blade right at the cutting edge.To the people who complain this introduces a unwanted back bevel I have measured the angle at less than 1/2 a degree and considering I don't use anything coarser than 6000x [which isn't much more than a polishing step] I have been very happy with the resulting very sharp cutting action.
Your work and your conclusions impressed me. Many thanks for that! I will stop stropping my chisels and other planer blades, just giving it a test without stropping for some weeks. I love videos like this, with no gimmicks. And yes, you are human (but in a very good sense), like most of us (hopefully). That's another plus.
Depends on how you used to strop. Strops were never intented for sharpening, only for final smoothing after using a stone. So the premise of this video that a strop is somehow replacing stone sharpening is kind of pointless
This is very good to know. I am a beginner and from what I’ve watched its always been said to strop. Your video makes better sense to me, thanks for the clarification.
Rounding over always happens of course due to the greater pressure at the very edge of the bevel, since it is compressing the strop there. But if your stropping angle and pressure is consistent, the pressure will reach an equilibrium where it is increasingly rounded-over as it gets closer to the edge. That is to say, there is only so much rounding over that will happen for a given stropping medium, bevel angle, angle of the edge to the strop, and pressure. This is documented somewhere on the Science of Sharp blog but it is also a pretty intuitive concept. But most people (including me) just freehand strop, so every time we strop to a higher sharpness, well, that bevel gets just a bit more rounded over.
Thank you for this very interesting video. Although I strop my blades most of the times, I ALWAYS feel like they're duller after doing so, but somehow convinces myself that I must be wrong. This is definitely helpful!
Excellent video, that makes me reconsider stropping. How about one on how to sharpen planer blades for the Dewalt 735. I hate buying new blades all the time and haven’t come up with a good way to resharpen them effectively.
Great video. I had my suspicions about this very thing, which recently led me to switch from my Norton water stones (which require soaking) to diamond plates and Shapton stones (just need a quick spritz). Now, I find it just as easy to touch up my blades and chisels on my Shaptons as it would be to do a quick stropping!
Will you please test stropping with that green compound directly on a MDF board, a generic glass plate that can be found at a hardware store, one of those engineered flat/leveled tiles/stones, and any other “flat” object that consumers can easily find and see if they produce any better results? It would be worthwhile to see the effects of stropping in those instances and to determine if leather stropping is a relic of the past
Leather is not a relic of the past. As much as I hate to admit it, leather stropping produces better results than mdf when it was tested on another video I did with Jonathan Katz Moses.
I think this is interesting food for thought as a place to start. But like many others have said, who only strops their steel? For tools, knives and straight razors, it was always presented to me as a way to polish the edge and straighten out any burr that remained. I don't know one way or another if it's vital for woodworking, but the quality of the feel of the blade on your face is definitely improved by stropping a razor. I'd love to see a comparison between the stone sharpened blade, and one that has been sharpened then stropped. Possibly with some comparison between multiple compounds.
I sharpen on a 1000 grit diamond stone then strop with veritas compound . Maybe there's no difference in sharpness but it takes out all the messing about with different stone grades .
Outstanding work! If I were ruch I would buy you a ticket to some of those Japanese hand plain competitions with wide Japanese hand plains. The winner is chosen by measuring the "thinnest " shaving with a micrometer....!! I beleave there are valuable things to be learned here...!! Talk about a different approach! The plain looks like a wooden brick. The plain iron is a super thick combination of hard and soft steel! With adjustments by hammer. Like everything Japanese....there is a deep....deep set of traditions coupled with a myriad of very Suttle details. So .....how about the ultimate combination of east/west. Definitive measurable results investigation......? I believe you are just the guy.... All the best!! just jim
Interesting video. I sharpen with a Worksharp so I don’t need to hollow grind. I just give it a quick whizz when it loses its edge. I use a diamond disc in it from China. These are cheap. If the edge gets notched I change the disc to a lower grit initially. For finish I change to a higher grit. I sometimes buff on a bench buffer. It certainly makes it shine. Anything compressible is going to round the edge when stropping. I will stop buffing seeing your results. It’s all logical.
Ouch! All those years of watching straight-razors being sharpened on a strop.... Never questioned it worked and just kept using the tool. But I always start on a new project at the stone to freshen my tools, and stropped them as I go.
There is no „the“ strop. Leathers vary and compounds do as well. You can go from 400 stone directly to a strop (with diamond compound) and get a razor. If you sharpen on 8000 grit stone or even finer and strop afterwards on 6 or 3 micron, you may be dulling your knife/tool. The important thing is - get rid of the burr in any way that works best for you, but you may have to buy a microscope (cheap handheld will do fine) to identify the micro burr. It needs to go!! 😅
I concur with Handlebar Workshops. I also am of the belief that many folk over sharpen... No real need to go past 1200 and a few swipes on the strop to achieve a workable and durable edge. The Old Timers I learned from only ever went to 220 and then stropped... You could shave with their blades. Sure, they resharpened more often, but that isn't a bad habit to get in to really.
I guess that would depend on the kind of woodworking you so. For fine woodworking and joinery, there is no way I’m using 1200 + stropped edge. We have better materials to get sharper edge that is more convenient than ever before. If you’re happy with your method, all the power to you.
@@WoodcraftBySuman Guess it comes down to age and 40 years of fine woodworking with the tools that I know. I see you are using the Veritas blades made from modern steels, these are game changers and behave completely different to the, shall we call them, traditional steels. Honestly, 1200 and a quick strop works fine on the old tool steels, takes no more than 30 seconds to sharpen up and be back to work...(with LOTS of practice, that is) so that is a tradeoff I am happy to make. Having said that, If I was still a young fella I would totally invest in Veritas planes etc. I recently retired my old Marples Cabinet chisels with a set of Narex cryogenic treated ones and yeah, they are indeed a game changer.
Thanks Chris! I wish I could produce more videos- they take so darn long. Haha. I think there is still value in stropping, especially for carving tools where the edge is non linear and would be nearly impossible to sharpen on a stone
Thanks. I'm a bit confused. I thought the conclusion drawn from video with jkm was that you had to strop to get to the best sharpness, and that it dulled quickly anyway so don't go nuts sharpening too often. I sort of concluded that in between sharpening, stropping on hard leather would help edge retention. This is saying that it is not the case. Care to comment/elaborate a little? Thanks.
This video is about Re-stropping as a method of resharpening. Conventionally, if you sharpen and then top off the blade with stropping, you’ll get a good edge. But after use, if you’re trying to re-strop to sharpen over and over again, the blade takes longer to get sharp and dulls quicker bc the tip gets rounded and produces higher angle of attack. Stropping is still a good does but don’t use it too much between sharpening.
@@WoodcraftBySuman Gotcha. So what you would do is to sharpen+strop, and don't repeat these steps too much because edge dulls quickly from use. If anything, one or at most two restrops before sharpening again. Thanks
A+ for method, but stropping is never supposed to be without re-honing on a stone. It's not a replacement, the idea is just that you can afford the strop compound more easily than a 16k or 30k grit ceramic stone. You're totally right about the rounding of the edge, which is best counteracts by using very stiff leather that is actually on the thin side--much thinner than the leather in your close up. Mounted to some 3/4 ply, it provides a polishing surface with much less give. Just my thoughts!
Stropping is fundamentally different than honing is. It isn't a cost cutting method. You're actually looking for a different effect. Stropping polishes the edge and removes any wire burr that may exist.
stropping polishes and de burrs and finely hones the edge. you don't press hard and you swap between side every 5-10 strokes maybe 40 strokes each side and you have a razer edge, IF you edge was continuous and already set by a stone.. white compound isn't as fine as green compound either and you need your leather stiff and glued down to a flat block not like in the movies. you can round over an edge with soft leather because it will push over and around the3 edge of the blade.. also with a 9000grit diamond stone you are way past what many will have, a lot of people use like 400 -1000 - 1200 then strop to razer edge while the stones are for alignment and flattening.
Like some of your other viewers, I only strop after sharpening to remove any left over burr if it doesn't get removed using a couple of strokes and the ruler trick on the flat side of the plane blade on my stone, and then it's only between 10 and 20 strokes on the strop.
Or you could use the strop to clean up the marks from your "1000 grit"/fine diamond stone and don't bother with those higher grits at all. That is what I do and I have patches of handtool pattern baldness on my arms.
funny thing about that testing method, it still leaves an edge duller than I find ideal for woodworking. I can still shave with an iron that has reached a state I considered dull. But then I can also get axe sharp enough to shave with.
Interesting, I can see that using a bevel up plane makes any bevel angle change is impactful. Whereas for a bevel down plane it wouldn't make much if any odds (see woodbywright plane iron tests for this). Most people don't strop instead of stones, they strop with stones. So the effort to get the edge back to baseline via a strop is not relevant to most people. Also, if you look at those that are proponents of the stropping method, they are typically stopping at a lower grit stone (circa 1k-1.5k, often diamond plates). So the strop is replacing your 8k, not following it. The bit I can't quite figure out, and bares more investigation is why the stropped blade dulls faster (but starts from the same approx starting level). Normally having a higher angle (which many would agree a strop can create) is more durable, but again, is this a difference with the bevel up plane? Is the higher angle putting more 'work' into the edge as it is turning the wood through a higher angle therefore dulling it faster. Would we see the same in a bevel down plane? Do you feel like a follow up video with a bevel down?
Thanks for the great test. I have noticed when I strop on leather that the blade is not as sharp as when I strop on mdf. Don't know how that compares to just stone sharpening...
Tormek honing compound has an average rating of about 3 microns which equates to roughly 8000 grit (the actual grit will vary). The idea of stropping is that the polish you use is a high grit than your last stone. So for anyone who stops at, for example, a fine DMT diamond stone generally rated at 25 micron and then strops with tormek compound, they would see a difference. But people who use ceramic stones up to 16k grit and then tormek compound would actually be ruining their finely polished hone.
Great job on using the scientific method. I was curious myself about stropping, because I've never used it for my woodworking and always wondered if it really did anything. I'll stick with using the stones.
Do you think using compound on a plywood would make difference? I sharpen to 1k grit on a diamond stone and strop. I definitely notice my blade dulls faster when I strop? Otherwise I'll just get an 8k grit plate and ditch the stropping all together.
Very interesting. I'd like to see a few more experienced woodworkers try this setup to confirm or disagree with these results. After all, this is science! Nice video.
I would welcome other folks trying it out. We can only get better data and refined results by more folks doing it. Though…I spoke to well known YT woodworker yesterday and it seems like he might take a swing at it.
You're finding about stropping is different on this video than the one you did later with Katz. Is there a change in the hardness of the strop between the 2 sets of tests? The later tests found a soft leather was bad, but the hard leather worked. And surprisingly, MDF was a failure (and nor explained thoroughly).
Stropping is something we do after we use stones. Not instead of stones. The only caveat is using a strop to prolong the edge of carving tools. Even then we take recourse to the stones when the strop stops working. This video is a useful illustration that a strop is not made for removing significant wear. It's a refinement step after the stones.
Weird. I haven't seen anyone use only a strop to sharpen. They usually use a fine stone followed by the strop. Does the stropping after stone sharpening make the edge more dull compared with using the stone alone?
This is interesting because if you watch a video by David W called harbor freight chisel part 2 he buffs the crud out of the edge and it gets sharp and stays sharp. I think he said it puts a super tiny high angle microbevel that is next to impossible to recreate by hand.
Hello, Suman; I'll be 68 in few months & I've been able to sharpen all kinds of things for about 40 yrs. But until last year I never used a strop w/ polishing compound. Initially I was pretty disappointed w/ the results. It really does round the edge to strop on leather. To be clear, I've actually stropped knives on cardboard, newspaper, my boot or shoe, my palm even, for years. Just never tried it w/ compound on a leather strop. As stated, pretty disappointed. I got better results stropping w/ compound on a piece of wood than leather. Researching, I found most leather strops are too thick & too soft so that's where it fails. I have a Morakniv "Craftline Basic 511 High Carbon Steel". It is sharper now than when it was new. I strop it on the plastic sheath, no compound. So I agree w/ you, don't waste time "stropping", w/ compound, just sharpen & go. BTW, When I want to get a really sharp edge I finish by 'sword sharpening'. Have a GREAT day, Neighbor!
Interesting numbers that makes a lot of sense for 8000 grit, but would be curious to see how this things work in a more "average woodworker" scenario. I've never gone above 1200 grit (diamond) before hitting the strop, and I cut much more than 25 strokes with a plane/chisel before deciding it's dull enough to touch up (usually only 3-4 swipes on the strop … until that stops working as well and I take it back to the diamond). I also don't go out of my way to create a micro-bevel (or rather … I rely on the squishy leather strop to do that for me), and that might play into things. The touch-up to me is about speed. Having the strop next to me on the bench Paul Sellers style means I can touch up the edge in 5-10 seconds, vs digging out the stone, lubricant, jig, etc. Don't forget to do a final strop flat on the back of the blade, too, to bend the bur back over (same reason you hone a knife between sharpenings).
Just want to point out that in this video- I’ve done 300 linear ft of shavings before resharpening or stropping. The blades are still sharp enough to keep going but there is enough data to demonstrate the dulling process of the two methods. What type of stropping compounds are you using after 1200? I’m curious to know the level of sharpness you’re hitting with your method.
@@WoodcraftBySuman Yes, but I suspect that at the point you start to resharpen, the blades would still be sharper than most people start. I just use the green jeweler's stuff, usually 3-4 semi-fast pulls against the face of the blade and one slow one against the back to knock off any burr that develops. Looking into some posts about knives, it seems stropping is more about straightening/removing a burr (which might not exist with back/forth/figure-8 sharpening like we do with planes/chisels) than about making a blade sharper. Similar to using a honing steel with a knife (and now I'm curious enough to ask a friend who sharpens knives professionally).
that's why you setup your stones so they're always there to be used, rather than a strop. you can remove the bur from sharpening on your stones the same way you use the strop for it. There's just no real benefit to using a strop over stones, it's just a matter of setting up your workflow to make the stones easily accessible rather than a strop. it takes me about 30 seconds to sharpen a blade with stones and I know they're sharp without having to worry. you're always going to need to properly sharpen your tools, so might as well keep the stones at the ready. I used to pack mine all up too, but it became obvious those were one of the things I would need frequently, so I just leave them out now.
I do agree that this is an interesting rebuttal to the "scary sharp" system some woodworkers like to show off (8000+ and then strop). However, like I said, I'd be curious to see this kind of comparison done with a more "regular person" kind of sharp. An ultra-sharp edge dulls faster, so the difference in round-over from re-stropping starting at 8000 and starting at 1200 may not be nearly as noticeable (heck, you might not even be able to *start* as sharp as the dullest of Suman's tests). As I understand it, one of the main reasons for using a strop is specifically to avoid needing to use/pay for/maintain high-grit stones. In my case, it gets me sharper than 1200 grit and that's more than good enough for everything I do.
Love your videos, your a woodworking project farm in the making!! I use 3/4 MDF and rub my polishing compound on the MDF with a sharpening guide I feel it works much much better than leather
For sure. A hard backed surface would likely generate much better results and likely fall in line with results from the stone. Personally, I’d rather just use the stone but I realize not everyone wants to spend that much money when starting out. Thanks for the compliment and for watching. Appreciate ya
@@WoodcraftBySuman yes the cost is much less. it's hard for me to justify the cost of some diamond stones. I knew there was a reason rob cosman finishes with a 16,000 grit stone
This is a fantastic video! Thank you for doing this. From what I've learned reading about the Unicorn Sharpening method the micro bevel can reduce edge damage from chopping impact with chisels. I would love to hear what you think about that. But you've clearly proven it's a waste to strop a plane blade!
Geometry of an edge is king when determining how well it cuts. Your results support this as the Geometry when stropping each time changes ever so slightly. Using the flat stones you are returning to your baseline each sharpening session. Stropping to re sharpen/hone a edge can be effective but eventually returning to baseline is needed. Great Video.
Maybe I'm nuts, but would deburring or stropping on the backside of the iron help correct the rounding? Maybe you're doing that but I just missed it? Either way I think that logic would apply to both a sharpened or stropped iron.
Interesting video! But there may be a problem with the strop. Either the technique, the compound, the leather or all together. I would argue a ~1-3 micron DIAMOND compound on a harder leather could do much better cause it cuts faster and lasts longer than those normal compounds. But at the end it doesnt really matter if you „hone“ your tool on a stone or a strop, both is basically sharpening and what works best for you, IS best.
Can u compare the sharpness of an 20°, 25°, 30° and maybe 35° angle on the plane blade over the number of passes taken? I like your Video, great effort.
Let me ask you this, If you took both blades, one sharpened on a stone and the other sharpened on a stone, followed by stropping, right from the beginning, what is the results like then? I'm asking, because bringing the iron back to baseline seems to be important to use the stones, but to get that shiny edge would require the strop. Would the strop hold up longer if you sharpened by stone first and then immediately stop? Here's something else to consider, the quality of the edge. The stone sharpening may indeed be sharper, but the shavings might be coarser. What I mean is, the condition of the finished surface after each iron shaved on them. Was the stropped iron capable of making smoother shavings?
The data gathered is good. However, you are missing the 3rd test sample that is sharpened + honed/polished blade. This third sample would out perform both, however only just a bit better than the stone sharpened sample. Stropping was never intended to replace sharpening, it is just to refine the edge just a bit more, for that Extra icing on top.
Very cool video. I usually only use my leather strop on my carving gouges which are more difficult to freehand sharpen on the stones. When I do strop my plane irons (not often), I use a wood/MDF strop with diamond paste. I wonder how that would have fared vs the leather strop. The rigidity of the MDF/wood wouldn't round the edge like the leather did and increase the effective cutting angle.
I suspect stropping on a rigid surface would minimize the micro rounding of the tip. But I would argue, why strop in the first place? Bc compound on mdf is basically a sharpening stone. Perhaps just use the sharpening stone?
@@WoodcraftBySuman totally agree with you. IMO, stropping is only a worthwhile thing if you don't have a 8000 grit stone, don't want the mess of a waterstone, or for use on some carving tools where the plushness of the leather works to your benefit.
Very interesting video ! But I wonder if there is a difference between bevel up or classical bevel down hand planes. I imagine the stropping is bending the edge into the correct shape if it is classical bevel down hand plane. If you imagine the wood bending the edge of the blade, if the blade is bevel up the edge is bended towards the back side of the blade and this you can't repair by stropping the bevel. BUT if the blade is used bevel down the wood pushes the edge towards the bevel side of the blade and this you could correct with stropping! I am not sure if this is understandable. Just an idea.
You bring up a great point. For bevel down planes, there is probably negligible difference. Though, I still think stropping is a bit more cumbersome than just hitting it with a higher grit stone.
Question regarding higher grit shaptons. I’ve watched your collab with JKM and have also watched many of Rob Cosman’s sharpening videos. You both seem to agree that the 30,000 shapton is not worth the expense. RC’s method of sharpening with a 1,000 stone and finishing on a 16,000 shapton always seems to produce an amazing surface on wood with very little effort/pushing on his part (obviously you have to factor in technique and tool setup here as well). With that said curious to know if you have experience or testing with the shapton 16,000 vs stopping at 8,000. I buy into the concept of honing on a higher grit stone vs stropping and would like to learn if the 16,000 is worth it. Thanks and enjoyed your videos on the topic!
Hi- yes I also have the 16k stone and it does get the edge sharper than 8k stone. But it is mostly an academic exercise because reality is, once you’ve taken a few shavings on a blade off of 16k stone, you’re likely to settle back towards 8k equivalent sharpness. I did some trial run of this scenario and while I didn’t record the data, the conclusion I came to was 8k is plenty good and is a nice sweet spot sharpness for most tooling steel, especially PMV-11.
The first mistake is using thick leather that compresses rounding the edge. The second is using a compound equal to or courser than the grit of the last stone. Try using a .3 micron paste on kangaroo hide that has been adhered to float glass. The thin leather does not compress rounding the edge and the compound is so fine that it can only polish an edge not create one.
Great job, I have had the suspicion that stropping on leather might tend to round over the tip of the blade. Based on your results, it's looking that way!
While your methodology allows you to achieve repeatable test results, you are not just testing stropping itself, you are also testing your strong technique. I'm not a fan of your technique. I suggest: Don't push so hard on the leather strop and try again. I don't use that much pressure when I sharpen, why would I use that much pressure when I strop? Also, try different honing compounds on your strop.
What steel are those blades? The Tormek Paste may be your culprit. In "super-steels" it's composition can erode the steel, but the not the carbides. The the unsupported carbide crystals then get ripped out of the edge. This leaves a jagged and poor performing edge. I appreciate your tests, and I have had similar results in the past, but I have returned to stropping after reading the book "Knife Deburring: Science behind the lasting razor edge" by Dr Vadim Kraichuk
Got a couple issues here.
1. Don't compare abrasives from different manufactures by "grit". Go by the size of the abrasive in microns. For instance, a Shapton 8,000 stone is 1.84 microns and a Norton 8,000 stone is 1.2 microns.
2. You mentioned that the Tormek cuts faster than the red, green, etc paste. There is a reason for that. The Tormek paste is more abrasive. In fact, it has an abrasive of 3 microns. Your 8,000 grit stone is below 2 microns. You're DULLING your blade by using the Tormek paste after your 8,000 grit stone.
The green stropping compound is 0.5 microns. And you don't want that on a thick spongey layer of leather. Go for a thin and relatively stiff veg tan leather. Or even MDF or the brown side of a cereal box.
thank you! this needed to be said.
The grit difference here seems to put these results into question. I had the same suspicion when he mentioned that the compound cuts faster. Thanks for confirming the details.
You have a valid point. Shapton 8000g is advertised as 1.84 micron while the tormek is 3 micron. This explains why I overshot the baseline sharpness to be sharper than ~110 ish on the stone sharpening blade. However, the 3 micron abrasive was more than fine enough to bring the stripped blade back toward baseline sharpness. So I was not dulling the stropping blade and the results are still better explained by the squishy nature of the leather causing a rounding effect. To your point, if it’s better to use honing compound on a piece of harder surface, why not just use a higher grit stone?
@@WoodcraftBySuman I think a good reason to prefer buffing compound is the cost. I don't have an 8000 grit stone, so I go from a 1200 grit diamond stone directly to stropping with green buffing compound. Rob Cosman doesn't buff, but that 16000 grit stone he uses cost $160 CAD. A large stick of green compound from Lee Valley costs a tenth of that.
@@HandlebarWorkshops gonna suck this video off later
Hi, I only use the strop to polish the edge after stone sharpening. I didn't think the strop was intended for actual sharpening.
Yup, I was taught the strop is for final hone and polish and working off the burr, not for actual sharpening. There is good evidence that steel quality and bevel angle are the biggest contributors to sharpness and edge longevity.
Yeah me nieither.
Very much. Stropping can be used for "sharpening" on a pinch, but that works best for knives than this sorta blade. IMO it is actually preferable to "sharppen" the knife on the back of another knife first, just to straigthen up the edge, then re-polis on a strop. But htat is a regular knife with its double sided sharpening and thin blades, not a beefy blade with a chisel gring like a tool.
Give it a few strokes on your highest stone if it is not dull (then it has to go down to a lower stone), a couple on the strop, takes about the same time, and you're golden.
@@TheOriginalAndBestTim The compounds used for stropping wear away the metal just like a stone, so if you can put some fine stropping compound on something rigid like a flat hard piece of wood, it will behave similar to a fine stone. Strops are generally made of something that compresses a little though, and that dreaded rounding over of the bevel is also what helps work off the burr and polish the last bit of the edge quickly.
Keep up the great work, Suman. As a neuroscientist/experimental psychologist, I really appreciate your efforts in terms of experimental design, data dissemination, and visualization. You’re carving a lovely niche in the UA-cam woodworking community, and I can’t wait to see what you come up with next!
Your pun is appreciated
Thanks Thomas! I'm really glad you're digging the approach. We've got some fun ones ahead ☺
A wise man once told me that stropping " technically does cause micro roundover and I think it makes the edge dull quicker because its a tad more blunt to begin with." So I stopped stropping and it saves me a TON of time!
Oh wait! That was you in the comments of your "i don't know why more people don't sharpen like this" video. Your dedication to the scientific process for testing woodworking practices is unmatched! I really appreciate you going through all of the effort and compiling the data in a concise and informative fashion. Mixing these types of videos into the mix with build videos is great. That's one of the things I enjoy about JKM, yet your content is uniquely yours. Keep up the great work!
That is hilarious. I can’t believe that comment came full circle in this video. Haha. Appreciate your thoughts as always.
And it seems to take more honing to resharpen.
@@WoodcraftBySuman I heard from Cliff Stamp that stropping "with excessive pressure or time" can not only round over the edge, but also change the very tip of the blade to be more brittle. He always prefer removing the burr by light passes on a stone instead of stropping.
Stropping : and all others
What a pleasure to see the scientific mathod applied to woodworking.
Thank you Suman.
I like this guy; been watching woodworking on UA-cam for decades, and it’s rare I see interesting new video topics. Nice work friend!
I am not a woodworker or craftsman of any kind and I watch all your videos. They’re awesome!
Hi Suman, great video. I actually did a very similar experiment trying to prove the effectiveness of a strop. In my test, I stropped my blade after 400 strokes on hard maple and the sharpness on my blade went from about 500 to 250 on BESS scale after few stroppings. However, that didn't really last very long. I was back to 500+ range after only about 50 strokes. For stropping to be really effective, I found you need to strop in about every 50 strokes. With this approach I was able to maintain 300-350 sharpness even after 600 strokes.
I love your use of scientific method to demonstrate your conclusions. It isn't just about an opinion like so much in woodworking. I've seen too many times where people present opinion as if it where the absolute truth without data.
Very nicely done.
Great test and I was surprised by the dramatic results. I have been stropping for decades and have found several things that may improve your results. As many have noted, using a soft leather is very bad. Stropping with wet compound is also counter productive since it leaves the leather even softer and the compound squishes up around the apex. I use diamond powder on thin leather and have found that if I don't let the diamond dry completely before use it will dull my stone honed edges. When the diamond surface becomes loaded and less effective, I give it a spray of water and agitate the surface to bring fresh diamonds into play. When dry, it works like new. Any time I can't get my desired results in less than 10 stropping passes I know I need to do a better job on the stones. Almost all my knives are "super steels" and attempting to strop on anything other than diamond or boron carbide is useless. I suspect V11 is similar (I have V11 plane blades but have always used diamond stropping with them.) Just some observations from a 71 year old woodworker with an obsession for sharp stuff!
Rick- I’m curious to know- why not just use higher grit stone like the Shapton ceramic? Seems easier to me. Would love to know your thoughts.
@@WoodcraftBySuman I have several high grit stones including a 16k shapton but I find that the softer texture and feedback from the strop gives me more reliable results. I can feel and hear the exact moment my strop is "on edge" whereas with the shapton I need to gauge it based on angle alone. Lower grit stones remove enough material that minor angle errors are quickly compensated. Most of my sharpening is on knives where I can't use the hollow grind trick for angle setting. I do use hollow grind on plane blades and chisels but have never found any benefit in going above 5K in sharpening them so the strop is just a pass or two to ensure that the burr is gone in woodworking. I'm fine when they shave arm hair. My knives I usually take to hair whittling sharpness just because it took so long to learn how that I like to stay in practice!
Does it matter whether one uses diamond "spray" or the emulsion from a syringe?
Awesome video, but I was under the impression that the stropping was an addition to after final honing. I.e. a final polish to remove any nicks. There is no doubt that the the blade is sharp after the 8K stone, but what are the shavings like? Are there streaks on the piece and/or shaving? Can you go straight to finish? I suppose that the edge could be viewed using a jewelers lens, or other means, to see if there are any nicks on the edge that might cause streaking by just using 8k.
Btw I don't strop, just finish with 16k stone.
The man who puts the science in woodworking. Nicely done, Suman!
Love the test and you cant argue with empirical evidence. I still strop in my shop and always will. For me it is a factor of convenience. A strop lives on my bench. When my tool dulls i run the blade over the strop a few times and i am back to work. The tool will dull overtime and eventually needs to go back to the stone. Data is great but it is important not to get bogged down in it. If i can still plane figured woods it is good enough. The strop saves me time to function the way i want to function. There are a thousand ways to get to a sharp tool and none of them are wrong! As a side note i dont know what type of leather was used byt horsebutt is the best accompanied with green compound.
Thank you for being so thorough in documenting your testing methodology. It gives me a lot more confidence in your results that you took multiple test cuts and averaged them, as well as comparing the two blades under identical conditions to give a sense of the natural variability in the materials and the process.
Thanks! Even if I don’t mention it explicitly in other videos, my results are always averaged samples. A single data point is unreliable, as you know.
This video show it’s better to use a stone to sharpen and hone. Your collaboration with Johnathan Katz Moses taught us that the media for sharpening is irrelevant. Both excellent videos dispelling some myths.
I would love to see a follow up comparing the different methods for sharpening: hollow grind/freehand, flat grind/jig, and convex grind (aka Paul Sellers). Which holds the best edge? Gets the sharpest? Consistently? Speed? Etc.
Strop is not a substitute for 8000 or higher grit stones. You can get only the polish level of your compound. If the stone is higher grit than a compound no surprise it will produce a better edge. Most people use strops after sharpening on a 1000 grit stone just to save some money by eliminating a need for additional higher grit stone.
Grit alone is not the only factor that determines how sharp an edge is. The steel you're sharpening is a factor too. If it wasn't then it wouldn't matter what tools you had. Steel is an alloy though. So steel is a complex material. Steel has a grain structure. You can't see it like wood but it's there.
Interesting investigation, Suman. I have experience using a 4 water stone system and a 3 diamond stone and a strop system. Based on experience, the water stone system gave a much better edge. So I agree with the basic premises of your video that it is POSSIBLE to get a better edge on stones.
But I much prefer the diamond stone and a strop system. The water stone system is very messy and time consuming to set up and maintain the stones. The average working sharpness of my tools is much better with the strop because I actually use it often vs. avoiding sharpening because of the stone. BTW - I use a 5 micron green bar compound that is roughly equivalent to my 4000 grit water stone. Works for me.
I would recommend ceramic stones. No need to soak. Always ready to go like a strop but much better results.
@@WoodcraftBySuman great suggestion. a ceramic stone would definitely be on the list of contenders if I became dissatisfied with the strop,
This is like the scientific method’s peer review and pressure testing processes in action for hobbyist woodworkers. Great content with backed up conclusions. I think that the comments pointing out flaws, oversights, or recommendations for improving the methodology have been great. Thanks for putting this together and having the courage to open yourself up to the inevitable trolls to provide the nuggets of good info to slip thru for those of us interested in finding them.
Haha dude as someone that has been through the peer review process many times, I feel like this is worse. Folks expect me to go through every detail on a YT video driven by algorithm that favor simplication and brevity.
Folks claim a harder backed surface should be used: yes but a stone does the same thing. If stropping on MDF, the results will likely trail behind stone sharpened edge. Folks will claim this is not the intention of stropping- it’s just to refresh the edge after sharpening. Yup- but many folks will stop a few times between full sharpening. And that is the intention of the video- when refreshing the edge, stropping shows inferior result after just one such attempt. The reiteration of stropping to refresh the edge was to test just how far that envelope can be pushed. This is one way to look at the topic of sharpening vs stropping. Nevertheless- this has been a fun experience.
Great video with outstanding content. Sharp blades that dull quickly are just impractical. Suman did an excellent job of designing a test that changes what I thought I knew about the benefits of stropping. Going to be retiring my strop and acquiring a fine grit stone.
I use a strop, but not the way you showed here.
I refresh the edge by going to a medium stone for a couple passes, then stropping a few times.
The method I use allows me to avoid spending money on an expensive fine stone because my cheap strop does the job quite well.
Some people have money to burn and they love spending it. People, like myself, prefer to keep as much money in their pockets as possible.
Interesting. First of all , thanks for all the effort you put in. I didn't see how you dealt with the back of the blades in your sharpening regime because after teaching many sharpening seminars I see that most peoples blades are ever so slightly "rounded" on the back ( about a 1/32 of an inch behind the cutting edge) I came to realize that like the face/cutting edge the ,back of the blade wears (just to a smaller degree). This can be corrected with a technique popularized by English woodworker David Charlesworth by simply using a very thin "riser" to elevate the blade insuring contact on the back of the blade right at the cutting edge.To the people who complain this introduces a unwanted back bevel I have measured the angle at less than 1/2 a degree and considering I don't use anything coarser than 6000x [which isn't much more than a polishing step] I have been very happy with the resulting very sharp cutting action.
Your work and your conclusions impressed me. Many thanks for that! I will stop stropping my chisels and other planer blades, just giving it a test without stropping for some weeks. I love videos like this, with no gimmicks. And yes, you are human (but in a very good sense), like most of us (hopefully). That's another plus.
Depends on how you used to strop. Strops were never intented for sharpening, only for final smoothing after using a stone. So the premise of this video that a strop is somehow replacing stone sharpening is kind of pointless
This is very good to know. I am a beginner and from what I’ve watched its always been said to strop. Your video makes better sense to me, thanks for the clarification.
Rounding over always happens of course due to the greater pressure at the very edge of the bevel, since it is compressing the strop there. But if your stropping angle and pressure is consistent, the pressure will reach an equilibrium where it is increasingly rounded-over as it gets closer to the edge. That is to say, there is only so much rounding over that will happen for a given stropping medium, bevel angle, angle of the edge to the strop, and pressure. This is documented somewhere on the Science of Sharp blog but it is also a pretty intuitive concept.
But most people (including me) just freehand strop, so every time we strop to a higher sharpness, well, that bevel gets just a bit more rounded over.
Thanks for all the effort you put into this test! Saves a lot of unnecessary work.
Excellent video Suman. I didn't find it dull at all! I appreciate you putting the time in to show us the science behind it.
Thank you for this very interesting video. Although I strop my blades most of the times, I ALWAYS feel like they're duller after doing so, but somehow convinces myself that I must be wrong.
This is definitely helpful!
There is technique to it. I always end up dulling my blades when stropping. It means we're screwing it up.
Excellent video, that makes me reconsider stropping. How about one on how to sharpen planer blades for the Dewalt 735. I hate buying new blades all the time and haven’t come up with a good way to resharpen them effectively.
I wish all videos were this good.
Great video. I had my suspicions about this very thing, which recently led me to switch from my Norton water stones (which require soaking) to diamond plates and Shapton stones (just need a quick spritz). Now, I find it just as easy to touch up my blades and chisels on my Shaptons as it would be to do a quick stropping!
i strop often and keep workin. love the videos
Good info. I will have to rethink my methods.
Will you please test stropping with that green compound directly on a MDF board, a generic glass plate that can be found at a hardware store, one of those engineered flat/leveled tiles/stones, and any other “flat” object that consumers can easily find and see if they produce any better results? It would be worthwhile to see the effects of stropping in those instances and to determine if leather stropping is a relic of the past
Leather is not a relic of the past. As much as I hate to admit it, leather stropping produces better results than mdf when it was tested on another video I did with Jonathan Katz Moses.
I think this is interesting food for thought as a place to start. But like many others have said, who only strops their steel? For tools, knives and straight razors, it was always presented to me as a way to polish the edge and straighten out any burr that remained.
I don't know one way or another if it's vital for woodworking, but the quality of the feel of the blade on your face is definitely improved by stropping a razor.
I'd love to see a comparison between the stone sharpened blade, and one that has been sharpened then stropped. Possibly with some comparison between multiple compounds.
I sharpen on a 1000 grit diamond stone then strop with veritas compound . Maybe there's no difference in sharpness but it takes out all the messing about with different stone grades .
Outstanding work!
If I were ruch I would buy you a ticket to some of those Japanese hand plain competitions with wide Japanese hand plains. The winner is chosen by measuring the "thinnest " shaving with a micrometer....!! I beleave there are valuable things to be learned here...!!
Talk about a different approach! The plain looks like a wooden brick. The plain iron is a super thick combination of hard and soft steel! With adjustments by hammer.
Like everything Japanese....there is a deep....deep set of traditions coupled with a myriad of very Suttle details.
So .....how about the ultimate combination of east/west. Definitive measurable results investigation......?
I believe you are just the guy....
All the best!!
just jim
Dude- this video and it's scientific aspect has been so helpful!
Great video and tests my young friend. Thanks for saving my arm...
Mostly echoing everyone else - I love your approach and explanations. Keep it up! 👍👍
Interesting video. I sharpen with a Worksharp so I don’t need to hollow grind. I just give it a quick whizz when it loses its edge. I use a diamond disc in it from China. These are cheap. If the edge gets notched I change the disc to a lower grit initially. For finish I change to a higher grit. I sometimes buff on a bench buffer. It certainly makes it shine. Anything compressible is going to round the edge when stropping. I will stop buffing seeing your results. It’s all logical.
Ouch! All those years of watching straight-razors being sharpened on a strop.... Never questioned it worked and just kept using the tool. But I always start on a new project at the stone to freshen my tools, and stropped them as I go.
There is no „the“ strop. Leathers vary and compounds do as well.
You can go from 400 stone directly to a strop (with diamond compound) and get a razor. If you sharpen on 8000 grit stone or even finer and strop afterwards on 6 or 3 micron, you may be dulling your knife/tool.
The important thing is - get rid of the burr in any way that works best for you, but you may have to buy a microscope (cheap handheld will do fine) to identify the micro burr. It needs to go!! 😅
I concur with Handlebar Workshops. I also am of the belief that many folk over sharpen... No real need to go past 1200 and a few swipes on the strop to achieve a workable and durable edge. The Old Timers I learned from only ever went to 220 and then stropped... You could shave with their blades. Sure, they resharpened more often, but that isn't a bad habit to get in to really.
I guess that would depend on the kind of woodworking you so. For fine woodworking and joinery, there is no way I’m using 1200 + stropped edge. We have better materials to get sharper edge that is more convenient than ever before. If you’re happy with your method, all the power to you.
@@WoodcraftBySuman Guess it comes down to age and 40 years of fine woodworking with the tools that I know. I see you are using the Veritas blades made from modern steels, these are game changers and behave completely different to the, shall we call them, traditional steels. Honestly, 1200 and a quick strop works fine on the old tool steels, takes no more than 30 seconds to sharpen up and be back to work...(with LOTS of practice, that is) so that is a tradeoff I am happy to make. Having said that, If I was still a young fella I would totally invest in Veritas planes etc. I recently retired my old Marples Cabinet chisels with a set of Narex cryogenic treated ones and yeah, they are indeed a game changer.
Great video, I really appreciate you taking the time and energy to do this experiment.
Very informative! Thanks for taking the time to test and to share! You've gained a new subscriber.
I'm throwing out my strop right now... You are a hero.
If you made 20 videos a week I would watch all of them, this is awesome!!
This makes me wonder why a company like Veritas makes a strop?
Thanks Chris! I wish I could produce more videos- they take so darn long. Haha. I think there is still value in stropping, especially for carving tools where the edge is non linear and would be nearly impossible to sharpen on a stone
Thanks. I'm a bit confused. I thought the conclusion drawn from video with jkm was that you had to strop to get to the best sharpness, and that it dulled quickly anyway so don't go nuts sharpening too often. I sort of concluded that in between sharpening, stropping on hard leather would help edge retention. This is saying that it is not the case. Care to comment/elaborate a little? Thanks.
This video is about Re-stropping as a method of resharpening. Conventionally, if you sharpen and then top off the blade with stropping, you’ll get a good edge. But after use, if you’re trying to re-strop to sharpen over and over again, the blade takes longer to get sharp and dulls quicker bc the tip gets rounded and produces higher angle of attack. Stropping is still a good does but don’t use it too much between sharpening.
@@WoodcraftBySuman Gotcha. So what you would do is to sharpen+strop, and don't repeat these steps too much because edge dulls quickly from use. If anything, one or at most two restrops before sharpening again. Thanks
@@tzuohann yup! You got it. Cheers!
A+ for method, but stropping is never supposed to be without re-honing on a stone. It's not a replacement, the idea is just that you can afford the strop compound more easily than a 16k or 30k grit ceramic stone.
You're totally right about the rounding of the edge, which is best counteracts by using very stiff leather that is actually on the thin side--much thinner than the leather in your close up. Mounted to some 3/4 ply, it provides a polishing surface with much less give.
Just my thoughts!
Stropping is fundamentally different than honing is. It isn't a cost cutting method. You're actually looking for a different effect. Stropping polishes the edge and removes any wire burr that may exist.
stropping polishes and de burrs and finely hones the edge. you don't press hard and you swap between side every 5-10 strokes maybe 40 strokes each side and you have a razer edge, IF you edge was continuous and already set by a stone.. white compound isn't as fine as green compound either and you need your leather stiff and glued down to a flat block not like in the movies. you can round over an edge with soft leather because it will push over and around the3 edge of the blade.. also with a 9000grit diamond stone you are way past what many will have, a lot of people use like 400 -1000 - 1200 then strop to razer edge while the stones are for alignment and flattening.
Very impressive presentation 👍
Like some of your other viewers, I only strop after sharpening to remove any left over burr if it doesn't get removed using a couple of strokes and the ruler trick on the flat side of the plane blade on my stone, and then it's only between 10 and 20 strokes on the strop.
Or you could use the strop to clean up the marks from your "1000 grit"/fine diamond stone and don't bother with those higher grits at all. That is what I do and I have patches of handtool pattern baldness on my arms.
funny thing about that testing method, it still leaves an edge duller than I find ideal for woodworking. I can still shave with an iron that has reached a state I considered dull. But then I can also get axe sharp enough to shave with.
Interesting, I can see that using a bevel up plane makes any bevel angle change is impactful. Whereas for a bevel down plane it wouldn't make much if any odds (see woodbywright plane iron tests for this).
Most people don't strop instead of stones, they strop with stones. So the effort to get the edge back to baseline via a strop is not relevant to most people. Also, if you look at those that are proponents of the stropping method, they are typically stopping at a lower grit stone (circa 1k-1.5k, often diamond plates). So the strop is replacing your 8k, not following it.
The bit I can't quite figure out, and bares more investigation is why the stropped blade dulls faster (but starts from the same approx starting level). Normally having a higher angle (which many would agree a strop can create) is more durable, but again, is this a difference with the bevel up plane? Is the higher angle putting more 'work' into the edge as it is turning the wood through a higher angle therefore dulling it faster. Would we see the same in a bevel down plane?
Do you feel like a follow up video with a bevel down?
Excellent video and tests. Thanks
Extremely thorough, great work!
This was super informative! Nice to see some actual data behind recommendations. Now to get an 8,000 grit stone and look into hollow grinding
Thanks for the great test. I have noticed when I strop on leather that the blade is not as sharp as when I strop on mdf. Don't know how that compares to just stone sharpening...
Great approach and data collection!
Good work, Suman! Thank you 😊
Very interesting! Great video!
Tormek honing compound has an average rating of about 3 microns which equates to roughly 8000 grit (the actual grit will vary). The idea of stropping is that the polish you use is a high grit than your last stone. So for anyone who stops at, for example, a fine DMT diamond stone generally rated at 25 micron and then strops with tormek compound, they would see a difference. But people who use ceramic stones up to 16k grit and then tormek compound would actually be ruining their finely polished hone.
Great job on using the scientific method. I was curious myself about stropping, because I've never used it for my woodworking and always wondered if it really did anything. I'll stick with using the stones.
should have tried it with finer honing compound. And yes it's normal to strop with 50-100 strokes. But with very light pressure.
This is some project farm level comparisons here. Good work
Do you think using compound on a plywood would make difference? I sharpen to 1k grit on a diamond stone and strop. I definitely notice my blade dulls faster when I strop? Otherwise I'll just get an 8k grit plate and ditch the stropping all together.
Very interesting. I'd like to see a few more experienced woodworkers try this setup to confirm or disagree with these results. After all, this is science! Nice video.
I would welcome other folks trying it out. We can only get better data and refined results by more folks doing it. Though…I spoke to well known YT woodworker yesterday and it seems like he might take a swing at it.
You're finding about stropping is different on this video than the one you did later with Katz. Is there a change in the hardness of the strop between the 2 sets of tests? The later tests found a soft leather was bad, but the hard leather worked. And surprisingly, MDF was a failure (and nor explained thoroughly).
I love this science based woodworking stuff. Great video!
Stropping is something we do after we use stones. Not instead of stones.
The only caveat is using a strop to prolong the edge of carving tools. Even then we take recourse to the stones when the strop stops working.
This video is a useful illustration that a strop is not made for removing significant wear. It's a refinement step after the stones.
Great video!
Weird. I haven't seen anyone use only a strop to sharpen. They usually use a fine stone followed by the strop. Does the stropping after stone sharpening make the edge more dull compared with using the stone alone?
Try stropping on a rigid piece of material like MDF or even hard maple. You'll not get the rounding over of the edge that way.
This is interesting because if you watch a video by David W called harbor freight chisel part 2
he buffs the crud out of the edge and it gets sharp and stays sharp.
I think he said it puts a super tiny high angle microbevel that is next to impossible to recreate by hand.
Nice work.
Impressive video for sure. This is helpful for me (newer to the hand tool game) 😊
This was great Suman! Amazing effort man! Don’t listen to Jon and Scotty. This video will go viral. :)
Hello, Suman;
I'll be 68 in few months & I've been able to sharpen all kinds of things for about 40 yrs.
But until last year I never used a strop w/ polishing compound.
Initially I was pretty disappointed w/ the results.
It really does round the edge to strop on leather.
To be clear, I've actually stropped knives on cardboard, newspaper, my boot or shoe, my palm even, for years.
Just never tried it w/ compound on a leather strop.
As stated, pretty disappointed.
I got better results stropping w/ compound on a piece of wood than leather.
Researching, I found most leather strops are too thick & too soft so that's where it fails.
I have a Morakniv "Craftline Basic 511 High Carbon Steel".
It is sharper now than when it was new.
I strop it on the plastic sheath, no compound.
So I agree w/ you, don't waste time "stropping", w/ compound, just sharpen & go.
BTW, When I want to get a really sharp edge I finish by 'sword sharpening'.
Have a GREAT day, Neighbor!
Interesting numbers that makes a lot of sense for 8000 grit, but would be curious to see how this things work in a more "average woodworker" scenario. I've never gone above 1200 grit (diamond) before hitting the strop, and I cut much more than 25 strokes with a plane/chisel before deciding it's dull enough to touch up (usually only 3-4 swipes on the strop … until that stops working as well and I take it back to the diamond). I also don't go out of my way to create a micro-bevel (or rather … I rely on the squishy leather strop to do that for me), and that might play into things. The touch-up to me is about speed. Having the strop next to me on the bench Paul Sellers style means I can touch up the edge in 5-10 seconds, vs digging out the stone, lubricant, jig, etc. Don't forget to do a final strop flat on the back of the blade, too, to bend the bur back over (same reason you hone a knife between sharpenings).
Just want to point out that in this video- I’ve done 300 linear ft of shavings before resharpening or stropping. The blades are still sharp enough to keep going but there is enough data to demonstrate the dulling process of the two methods. What type of stropping compounds are you using after 1200? I’m curious to know the level of sharpness you’re hitting with your method.
@@WoodcraftBySuman Yes, but I suspect that at the point you start to resharpen, the blades would still be sharper than most people start. I just use the green jeweler's stuff, usually 3-4 semi-fast pulls against the face of the blade and one slow one against the back to knock off any burr that develops. Looking into some posts about knives, it seems stropping is more about straightening/removing a burr (which might not exist with back/forth/figure-8 sharpening like we do with planes/chisels) than about making a blade sharper. Similar to using a honing steel with a knife (and now I'm curious enough to ask a friend who sharpens knives professionally).
that's why you setup your stones so they're always there to be used, rather than a strop. you can remove the bur from sharpening on your stones the same way you use the strop for it. There's just no real benefit to using a strop over stones, it's just a matter of setting up your workflow to make the stones easily accessible rather than a strop. it takes me about 30 seconds to sharpen a blade with stones and I know they're sharp without having to worry.
you're always going to need to properly sharpen your tools, so might as well keep the stones at the ready. I used to pack mine all up too, but it became obvious those were one of the things I would need frequently, so I just leave them out now.
I do agree that this is an interesting rebuttal to the "scary sharp" system some woodworkers like to show off (8000+ and then strop). However, like I said, I'd be curious to see this kind of comparison done with a more "regular person" kind of sharp. An ultra-sharp edge dulls faster, so the difference in round-over from re-stropping starting at 8000 and starting at 1200 may not be nearly as noticeable (heck, you might not even be able to *start* as sharp as the dullest of Suman's tests). As I understand it, one of the main reasons for using a strop is specifically to avoid needing to use/pay for/maintain high-grit stones. In my case, it gets me sharper than 1200 grit and that's more than good enough for everything I do.
Love your videos, your a woodworking project farm in the making!! I use 3/4 MDF and rub my polishing compound on the MDF with a sharpening guide I feel it works much much better than leather
For sure. A hard backed surface would likely generate much better results and likely fall in line with results from the stone. Personally, I’d rather just use the stone but I realize not everyone wants to spend that much money when starting out. Thanks for the compliment and for watching. Appreciate ya
@@WoodcraftBySuman yes the cost is much less. it's hard for me to justify the cost of some diamond stones. I knew there was a reason rob cosman finishes with a 16,000 grit stone
Great job ! I m sticking to my stones !
Amazing work!!!!
This is a fantastic video! Thank you for doing this. From what I've learned reading about the Unicorn Sharpening method the micro bevel can reduce edge damage from chopping impact with chisels. I would love to hear what you think about that. But you've clearly proven it's a waste to strop a plane blade!
Actually covering chisels and will touch on some element of edge retention two videos from now. Thanks for watching. Glad it was helpful information.
Geometry of an edge is king when determining how well it cuts. Your results support this as the Geometry when stropping each time changes ever so slightly. Using the flat stones you are returning to your baseline each sharpening session. Stropping to re sharpen/hone a edge can be effective but eventually returning to baseline is needed. Great Video.
Maybe I'm nuts, but would deburring or stropping on the backside of the iron help correct the rounding? Maybe you're doing that but I just missed it? Either way I think that logic would apply to both a sharpened or stropped iron.
Interesting video! But there may be a problem with the strop.
Either the technique, the compound, the leather or all together.
I would argue a ~1-3 micron DIAMOND compound on a harder leather could do much better cause it cuts faster and lasts longer than those normal compounds.
But at the end it doesnt really matter if you „hone“ your tool on a stone or a strop, both is basically sharpening and what works best for you, IS best.
Can u compare the sharpness of an 20°, 25°, 30° and maybe 35° angle on the plane blade over the number of passes taken? I like your Video, great effort.
It took 3 full days of hand planing and testing to get the data. Maybe some day but my arms are still tired lol
@@WoodcraftBySuman thats a lot of work you put into this video. thanks
Yeh but that mirror finish looks awesome. 😊
Let me ask you this, If you took both blades, one sharpened on a stone and the other sharpened on a stone, followed by stropping, right from the beginning, what is the results like then? I'm asking, because bringing the iron back to baseline seems to be important to use the stones, but to get that shiny edge would require the strop. Would the strop hold up longer if you sharpened by stone first and then immediately stop?
Here's something else to consider, the quality of the edge. The stone sharpening may indeed be sharper, but the shavings might be coarser. What I mean is, the condition of the finished surface after each iron shaved on them. Was the stropped iron capable of making smoother shavings?
Great work.
The data gathered is good. However, you are missing the 3rd test sample that is sharpened + honed/polished blade. This third sample would out perform both, however only just a bit better than the stone sharpened sample.
Stropping was never intended to replace sharpening, it is just to refine the edge just a bit more, for that Extra icing on top.
Very cool video. I usually only use my leather strop on my carving gouges which are more difficult to freehand sharpen on the stones. When I do strop my plane irons (not often), I use a wood/MDF strop with diamond paste. I wonder how that would have fared vs the leather strop. The rigidity of the MDF/wood wouldn't round the edge like the leather did and increase the effective cutting angle.
I suspect stropping on a rigid surface would minimize the micro rounding of the tip. But I would argue, why strop in the first place? Bc compound on mdf is basically a sharpening stone. Perhaps just use the sharpening stone?
@@WoodcraftBySuman totally agree with you. IMO, stropping is only a worthwhile thing if you don't have a 8000 grit stone, don't want the mess of a waterstone, or for use on some carving tools where the plushness of the leather works to your benefit.
Great video thanks for all your effort
Very interesting video ! But I wonder if there is a difference between bevel up or classical bevel down hand planes. I imagine the stropping is bending the edge into the correct shape if it is classical bevel down hand plane.
If you imagine the wood bending the edge of the blade, if the blade is bevel up the edge is bended towards the back side of the blade and this you can't repair by stropping the bevel. BUT if the blade is used bevel down the wood pushes the edge towards the bevel side of the blade and this you could correct with stropping!
I am not sure if this is understandable. Just an idea.
You bring up a great point. For bevel down planes, there is probably negligible difference. Though, I still think stropping is a bit more cumbersome than just hitting it with a higher grit stone.
Question regarding higher grit shaptons. I’ve watched your collab with JKM and have also watched many of Rob Cosman’s sharpening videos. You both seem to agree that the 30,000 shapton is not worth the expense. RC’s method of sharpening with a 1,000 stone and finishing on a 16,000 shapton always seems to produce an amazing surface on wood with very little effort/pushing on his part (obviously you have to factor in technique and tool setup here as well). With that said curious to know if you have experience or testing with the shapton 16,000 vs stopping at 8,000. I buy into the concept of honing on a higher grit stone vs stropping and would like to learn if the 16,000 is worth it. Thanks and enjoyed your videos on the topic!
Hi- yes I also have the 16k stone and it does get the edge sharper than 8k stone. But it is mostly an academic exercise because reality is, once you’ve taken a few shavings on a blade off of 16k stone, you’re likely to settle back towards 8k equivalent sharpness. I did some trial run of this scenario and while I didn’t record the data, the conclusion I came to was 8k is plenty good and is a nice sweet spot sharpness for most tooling steel, especially PMV-11.
@@WoodcraftBySumanthanks for the reply, my bank account likes that answer!
The first mistake is using thick leather that compresses rounding the edge. The second is using a compound equal to or courser than the grit of the last stone. Try using a .3 micron paste on kangaroo hide that has been adhered to float glass. The thin leather does not compress rounding the edge and the compound is so fine that it can only polish an edge not create one.
Great job, I have had the suspicion that stropping on leather might tend to round over the tip of the blade. Based on your results, it's looking that way!
While your methodology allows you to achieve repeatable test results, you are not just testing stropping itself, you are also testing your strong technique.
I'm not a fan of your technique.
I suggest:
Don't push so hard on the leather strop and try again. I don't use that much pressure when I sharpen, why would I use that much pressure when I strop?
Also, try different honing compounds on your strop.
Did you use the 8000 grit stone to remove the foil on the blade after sharpening? Because that's why I strop my blades.
Thank you for the awesome content!
Suman. Did you stropped also the back of the blade?
Yes back was stropped a few times to polish the leading edge
What steel are those blades?
The Tormek Paste may be your culprit. In "super-steels" it's composition can erode the steel, but the not the carbides. The the unsupported carbide crystals then get ripped out of the edge. This leaves a jagged and poor performing edge.
I appreciate your tests, and I have had similar results in the past, but I have returned to stropping after reading the book "Knife Deburring: Science behind the lasting razor edge"
by Dr Vadim Kraichuk