Unicorn on planes

A side note...

Jim Matthews

if this approach allows more of us to achieve a working, sharp edge *earlier* in our training, it has real promise as a time saver.

Brian Boggs has some deep musings on how to achieve a lasting plane edge, by avoiding burr formation. It relies on some expensive gear from Hap Stanley.

I have a feeling that your current approach will be better, faster and cheaper.

agree

Bill Tindall, E.Tn.

The two potential benefits are more durable edges and more easily obtained practically sharp edges. Both these possibilities are "needle moving" developments.

It don't move the needle to report a sharpening procedure with vintage ARK stones or that chisels made in 1880 or under a Japanese shade tree are sufficiently robust. But if -hollow grind, refine with almost anything, buff- provides a useful edge, anyone can quickly, cheaply and reliably achieve a useful result. That moves the needle of the woodworking progress meter.

Re: A side note...

David Weaver

burr formation isn't a problem, I'm not sure why HAP is fascinated with that.

failing to remove all of the burr and the scratches that came with it are definitely a problem. If it's not removed, then small damage starts where it is in use.

Warren would probably say this part of the discussion is like learning to use both legs before walking, but I don't know that a lot of people look too far past what you can see (And don't do enough work in a row to notice what you can feel).

Harrelson's in a spot - he has to make money. I don't.

Winston mentioned somewhere earlier what you're saying - that if this even is just a successful sharpening method that's easy to complete (which few people actually do from the start), then that's a benefit in itself. Dealing with a chisel that fails little or a plane iron that fails little and takes 30 seconds and one minute (respectively) to hone with little equipment cost is great.

The part of this that's difficult to communicate is the feel part, but I don't think the feel part is that demanding compared to something like sharpening a razor. I think it's doable for beginners.

The strategy for planes...

David Weaver

Low primary ( 20 degrees?)

* a small secondary with a 1k diamond stone, just above that - probably 23 if guessing, just like the chisel

* work the back of the plane iron on something for about 10 solid seconds to remove prior wear (I like the washita for this still - really fine media takes more than that to get all of the wear out)

* then buff the plane iron bevel side as if you're polishing the whole thing for a couple of brisk passes (vs intentionally increasing the angle on chisels) and the resulting edge is good

I like to run flat face of the iron across the corner of the buffing wheel (which has no cutting power) to ensure that no bits of wire edge remain)

Question

Bill Tindall, E.Tn.

You description was clear. Now the plane is used and it gets dull which means a rounded nose and loss of clearance. Step 1 would be the 23 degrees (approx) followed by Unicorn? 20 degrees would be ground only after the 23 degree bevel became inconveniently long for abrading?

I get the benefit on a chisel where the robust Unicorn edge resists mechanical damage.

I am not seeing the benefit to a plane blade where the failure is loss of metal worn from the bevel side of the blade. The time zero situation is a thin tip which will wear faster than a blunt tip, and we begin the wearing process with a pass over the buffer before we begin planing. I believe data if you have it, but if we are talking theory I don't see a Unicorn Profile blade planing as long as conventional grind.

thought experiment.....Seems we could get to the same place starting at 20, secondary refined at 23 and gently planing so as to not chip until we established the Unicorn Profile by planing wear instead of buffing.

where chipping stops..

David Weaver

..damage to edges at the level of scrutiny that I had in my testing only stops occurring around 32 or 33 degrees or so. 30 is usually enough to eliminate it, but not always.

Simpler and softer steels are a little bit more tolerant, but you give up some edge life on those when they're on the softer side.

You're right about what I suggested - it's just more or less 23 degrees and then buff, but no intentional raising of the angle (the buffer will do that a little). I'm guessing that the reason the edge doesn't sustain damage but still cuts well is because it's slimmer all the way down but really close in final angle to what my preferred angles were before.

Winston brought up (when I mentioned that there's no real fruit here) that if this leads to more success for people sharpening completely, that's still a gain.

It's quick, but the back end still does need stone attention. The bevel side just needs a middle stone and then buffing.

Somewhere down the road I guess I'll do another stroke test to see how much if any of the edge life I'm giving up vs. honing by hand. Planing the entire indian rosewood billet from rough sawn yesterday suggests "not much".

I would not get shavings as fine as the ones I linked to with a washita, though - they look more like a yarn lattice if you get close to there with the washita.

An edge that doesn't take damage is a minimum passing requirement, though, so if I can't make that happen every time (consistently), then i'll be back to the stones.

It is all those...

John in NM

If you want fast, really fast, go right from a hollow grind to the buffed edge. Sharp like scary sharp wanted to be. Plane against the grain in horribly behaved wood without tear out if the cut is light.

However, that will not give you a lasting edge. I found that edge lasted about as long as it took to plane a difficult drawer front or two. Might still be sharp but it wasn't sharp enough for the tough task I was working on. David's method will take a hair longer (seconds ) but that will be well worth it for longevity if that holds the edge better.

Fixing the problem of edge life will be a marked improvement, probably this will be my go to method if I ever get back to building furniture - too busy on gunstocks and grips right now, another house build to follow, so I'm just gonna watch for another couple years and see what all you guys all come up with. I have little doubt it will be fantastic though

How this applies to knives...

David Weaver

If you have a knife and you do something with it to set the edge (mostly with stones and then a strop), take the opportunity here to tune a knife edge up to something like would normally take eons.

The gimmick is the same.

A thin primary (a thin bladed knife or hollow ground is nice) and then a secondary that's shallower than you'd normally use and then buff it.

The effect is the same. I have a very late model buck 110 knife. If you just sharpen it with stones and compare it to the wonderful tidioute knives in 1095, it suffers lots of ills.

If you unicorn it, you'd never know it had ills in the first place.

talk about slicing tomatoes

Bill Tindall, E.Tn.

Tomatoes tremble when the Unicorn edge approaches. I just Unicorned my chip carving knife I keep at the bench for marking and whittling bits. Never been this sharp before. Fine India, buffer, keen.

I remember reporting that you could go from 80 to green compound, on a dry wheel setup, and being told it wouldn't work, and then someone tried it.  Not the best idea, since buffing was never intended to do that, and it probably doesn't on some steels.  But if you hang around this place long enough, decades are required, the in group will finally come around.  Like buffing compound has been in the LV Catalog probably since the late 70s.  And prior to that people used those 4 stick sets.

I don't doubt that this method works, where the evidence is probably lacking is that it works better than buffing that people have been doing for a long time.  Keep in mind that while it took the long march through Shapton, powdered diamonds (thank you for that tip), every known oil stone, etc... to get to buffing on this board, many shops have buffing equipment as standard equipment.  These would include all manner of metal working shops, including hobby knife shops, guitar shops, wood turning shops (due to the preference for some form of power grinding), and so forth.  None of this is new.  Plus we have shops that send tons of stuff out razor sharp (from razorblade shops like Gillette), to a lot of our own tool makers.  Only in a few cases are these hand sharpened, it is all power sharpening.  Even tools like high end Japanese stuff is power sharpened.

Speaking of which, PM printed an article decades ago that without fanfare claimed that what was really happening each time Gillette came out with more blades, or other revolutionary technology like pivots or wet strips, was that they had simply mastered a higher level of edge sharpening.  But saying "new sharper edges" wasn't what people needed to hear, it would probably even scare some people.  And I guess people would not want to pay for the revolution, unless you couldn't mount the new thing on the razor.  Plus there is the whole patent issue also.  So whatever blade companies do to sharpen with power has been under study and improvement for decades and regular progress may be happening every time they come out with some kind of new gizmo.

80 grit to the buffer here wouldn't work well, or at least as well. it's more like hone shallower and a step short of final polishing (no need for the final polish if it's going to be buffed off). the challenge in this case as someone asked if I'd do it after buffing chisels - or come up with a method and parameters - you want enough clearance, you still want a bright finish and at least in my view, if you're using a smoothing plane that will plane 1000 feet off of a hone, you don't want to buff the edge and have it limited on clearance then with an edge life of about 200 feet. Most of the time when someone brings up planing now, they're making a smoothing cut, which introduces the need to have clearance, uniformity and also not to spoil the profile (usually very small camber). Someone who I thought was a legit woodworker but isn't reported to me a very long time ago that tage frid would use a belt sander and then a cork belt to finish an edge - that worked like crap, but I tried it! You'd have to find the right cork belt. Then he denied that he mentioned that or claimed lack of memory and then that frid used a belt sander and a buffer (possible of course), but changing accounts and no hands on experience are evidence of someone reading fine woodworking and parroting what they read while they take a break from preparing tax returns professionally - and failing to have the confidence to admit it. which I guess is a forever problem on forums, or was while they were thriving. for every 1 person actually doing something, you'd get 20 who wanted to be in the conversation parroting and a few who really took the parroting overboard and wanted to carefully curate the idea they weren't a parrot. 

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the fanfare that surrounds razor blades in publications is bordering on stupidity. I find it to be unlikely that consumer razor blades can't be made in a geometry and coating that wouldn't last longer, but there's no incentive for blademakers to do it, and I think that this knowledge probably existed before the double edge razor blade and the engineers or lab people or whatever at Gillette would've known it in the first weeks and then maybe decided how they would handle things. 

Every five years or so, we get articles like the most recent that I can recall "MIT scientists have discovered what causes razor blades to dull". 

It's deflection. As soon as I got a microscope that could see deflection, I put an astra blade under it and could see little nicks. they're minor after the first day, but they propagate. The other common factor that people don't grasp is that if soap scum and organic particles make sort of a glue line or a hill somewhere on a bevel, they are going to create problems in a cartridge or double edge razor - either mocking a fatter bevel that pushes the skin away, or blocking behind the blade. Larrin thomas (metallurgist) posted that he thought that was what generally dulled blades - it's both, but the former is more immediate and happens regardless of whether or not you use a DE razor and take it apart. 

There are several competing issues at hand here:
1) if your blade feels dull at the start, even if it has long life, most people won't buy it - they lack the insight to take two types and compare them and say "well, I actually like this one better in the long term". they like the sugar high of the sharp blade

2) blades, especially DE blades, need to be able to tolerate rough handling, which means they need to be tempered soft enough to bend and the steel type needs to be the same. straight razors are typically a cleaned up file steel, but DE razor blades are more often a very small carbide stainless steel like AEB-L or something else similar. The stability of the edge against deflecting isn't as good as they're both not as hard, and they don't have the array of carbides to slow down dislocations

3) too sharp with a razor blade is not difficult to get to. Too sharp results in shaving a hair, and the skin that lifts behind the hair is cut off. The sharper, the more cleanly and more skin is cut off to the point that you could have a moderate bleed from the skin, but at smaller amounts, a pink face and a lot of irritation that's uncomfortable. Better DE blades arrive in this condition, sharp enough to create some razor burn, but damage to the edge usually relieves it in a couple of days. Would it be better to deliver a razor blade with slightly more rounding at an apex that would cut hair and not skin? I don't know - I think it would, but it would eliminate the whole "wow, that's the sharpest" buzz that people seem to like, and then the razor blades would last longer and be consumed less quickly. Plus, you shave if you're kind of uninitiated in what's going on and whatever feels like less hair no matter what you do right after the shave - like if you can't feel any stub in any direction at any pressure, I'm sure that draws people in. 

But, I would guess that from the start, Gillette and merkur and others were highly dependent on revenue from blades because my cheap assed relatives would've bought one razor and used it for fifty years if they could, but they pushed their razor blades through a hole in the back of their medicine cabinets. 

With a straight razor, if you do things right, you can quickly find the spot where a razor will cut hair cleanly, not cut the pores at the back of the skin and with linen and leather, hundreds of shaves can be had without honing. 

that leads to the last issue - you cannot set an edge up on anything such that it will both feel really sharp as a razor and last forever. The situation could be improved, but even on a much stiffer straight razor edge, you will get some kind of deflection or degradation, and there's no way I know of to strop a DE razor blade in a way that's accurate the same way you can strop a straight razor. maybe a straight razor stropped-like edge with a hard coating could do a little better, but who knows. 

the last article about razor dulling was probably four or five years ago. We're due for another one soon. it's almost like coast to coast AM talking about flying saucers  for people to believe that somehow astra, gillette, and so on would exist for a hundred years or more and someone in the engineering or research part of the company would never put a razor blade under a microscope and document what dulls a razor blade. 

PM probably wrote their article after hearing from the PR department at gillette. All of those blades are sharpened and then they are coated. It's not really relevant to woodworking, but it should be at least interesting to people on the basis of curiosity. Of course, it's been done by machines - i'm sure it's been done by machines since they first started producing them. 

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Last comment - what happens on forums and online a lot is "I said I did this a long time ago", which is probably true for a lot of people. what doesn't happen is someone saying that manages to actually describe it so someone else could do it, and quite often whoever is doing something goes on to do something different not long after, so the method must not have been that great, at least at the bench. When I scraped my floors, I used 80 grit paper on a high speed steel iron mounted to a little push cart so I could sit and scrape shellac off of the floors for large parts of two days. While I could describe that to someone, if I said I sharpened scrapers with 80 grit paper and nothing else and did it on a thousand board feet of wood, it wouldn't yield much useful for someone who gives it a shot at the bench. For all the times, someone told me they used felt, leather, a buffer, or whatever, the only person I can remember who actually did nothing but buffing tools was a sculptor/carver on sawmill creek who has work at the smithsonian. Randall rosenthal or something. that stuck in my mind because he showed his work. 

An accountant telling me what tage frid does and then disappearing when I follow up to figure it out doesn't do anyone any good, it just solves the mystery later on when I find out they aren't much of a woodworker. Safe to say, of the dozen or so people who talked about buffing or using leather or hard felt, none actually could answer anything in a way that let any of us prove it was any good. 

And even when you do - I'd be willing to bet most who read the unicorn articles tried it, found it worked and then maybe went on to something else - like whatever Rex something or other (can't remember his name) on youtube suggested. I think we've learned fairly well that most people are in the sport of imagining they'll do things and consuming media as entertainment rather than trying to be a better maker in their shops.

similar experience here - old cabinet, had the back wallpapered over by someone at some point and when I pulled it out, probably several pounds of razor blades fell out. All old "gilette blue" or something like that, carbon steel and not that rusty given what they were, but a little. 

Whoever built the house originally was very brand loyal!

Not that anyone will be interested, and Tom - not all of that was really directed at you, more the reflection back about how much discussion there was and how little it seemed to be turned to action by anyone else. if it was bad back then, it's turbocharged into imagining woodworking now with people now recommending "go watch paul sellers" as a supposed answer to a specific question. or "rex" or "james wright".

...anyway, not that anyone is interested, here is an astra (russian, stainless, coated - good blade) razor blade from a long while ago. One shave. 
https://i.imgur.com/37Awh1o.jpg

These are not as finely finished as feather high stainless, but feather blades are notorious for razor burn with the supposed advice on the razor forums eons ago of "just shave the first two shaves and grin and bear the razorburn, they're a great blade on the third shave". these will still razorburn, though. When they are undamaged, the edge is pretty straight, and importantly, a very gradual angle so that they will cut hair without being in perfect shape at the edge. 

I took this picture above around 2018 or so, maybe earlier, and later uploaded it to imgur when someone sent me the MIT article. At the time, I thought maybe I could modify the edge of a DE blade and get it to last much longer than the factory profile, but they are soft and there is no good way to handle them that's practical - at least not for gain (I use them only when traveling). 

https://news.mit.edu/2020/why-shaving-dulls-razors-0806 

It's somewhat shocking that this stuff gets published as if it hasn't been seen before, but the article is correct - the edge gets deflected, and there is progressive damage. It's almost identical to what happens with chisels. Have to admit the SEM images of the cut in process are pretty cool, though. And their comment about seeing little abrasion  - ditto, straight razor picture below shows nothing, though public comments about "I have really abrasive skin that dulls razors immediately" is common among the razor enthusiasts. Too, the article doesn't make the same grand claims as the PR-like headlines that accompanied it, making it sound like this has never been seen or known. 

here is a straight razor with about 8 months of shaves (figure at the time, i shaved about 5 of 6 days, maybe a little more). The edge has been burnished by linen and leather (the type of leather and the quality of the linen actually matters - and almost all of it was good 100 years ago, and little is now)....
https://i.imgur.com/wtduVAt.jpg

so, at 200 ish shaves, the straight razor looks like that with none of the defects that the commercial razor has. It shaves great at this level of edge kind of rounding. Do we believe that razor manufacturers couldn't duplicate this shape. do we believe that an engineer in 1890 wouldn't have known the same thing vs. a dumb guy like me who just manages to walk into this stuff out of curiosity and very intermittent experimenting? It's an interesting thing for engineers to cut their teeth on, but could've been done at a fourth tier state school in memphis or the yukon vs. somewhere like MIT, and the conclusion would've been the same.

One comment for David - re:  people saying they did this or that a long time ago.

Yes, 100% correct.  Doing it and not being able to communicate it to others - I and others have done various versions of the Unicorn, but you guys described it, experimented, and described the variations that yielded better results.  No one else bothered.  No one else took microscope photos of the edges.

I used to only use the technique for very special situations - it was seeing those photos that got it to click for me that I should buff after a honing as a regular method.  Now my regular method is probably a bit different than what you would call Unicorning, but it does work for me and it is lightning fast compared to anything else, so I spend more time doing better work with sharper tools.  So even though I knew about a variation of the method, I benefited greatly from the work you guys did in accurately describing your experiments and putting up pictures of it.  No one else who used variations of this bothered to communicate.

For that reason, as far as I'm concerned, you guys get the credit for moving us forward.

thanks John, what you're saying is kind of the point. The article describes something as a main focus, but realistically, it's less about doing something specific and more about understanding what's going on at the edge after that because you probably won't want to do "full unicorn" on good chisels or on plane irons. I pretty much buff to finish plane irons across the board now, and how much goes on chisels is less about a dogmatic method and more about the goal. The same would be true without a buffer - adjusting the tip. 

I tried a leather clad wheel, MDF, cork belt, hard felt, medium felt - nobody could provide any legitimate information about doing something as well or better than just honing with stones. usually not as well, but in place of. 

It doesn't do much good to provide another option if it's not that great. 

Tage Frid comes up all the time for the belt sander and then whatever else (buffer, felt belt, cork belt). Why is it that everyone who brings that up doesn't do it, and can't describe how to make it useful? Anything useful sticks, and fits among whatever else someone has tried, leaving plenty of resolution brain-wise so that you could say "Yeah, I could also do that and be fine, but this is why i do Y instead of X", or "generally if you're using a buffer anything from A to K could be useful, but L through Q results in a rounded over dull tool".

I remember the Frid thing being an anecdote from one of his students - it was in an interview in FWW with Hank Gilpin.  His point was more that it doesn't much matter how you get to sharp so long as you get to sharp enough to be useful.  I took the anecdote with a grain of salt, understanding the message and figuring it was exaggerated some.  I'm sure there are lots of other versions, he had a lot of students.

I can't imagine a cork belt working all that well.... I guess it would depend on how you apply an abrasive compound and what it is.  Felt seems easier.  Man, I'm not sure I've even seen a cork belt for sale, even in the lapidary world.

I remember trying a loose canvas wheel on a buffer at work around 2022, and found it too subtle for my impatience.  It seemed like it would be just the thing for someone who has done a better job honing than I usually do.  I like firm felt though, I can go from a hollow grind or moderately rough hone to something useful in seconds.  I've even done axes this way, it works great for me, and no one at work will borrow my knife - they are all afraid

I found cork belts, I think at Supergrit at the time. Supergrit is less than 10 minutes from the house where I grew up, and I just passed it again this weekend (it's only open during the week, though, and really isn't a walk-in building). 

I threw the two belts away that I bought, having purchased them wondering how they'd be usable. I'd bet they have some function or had some function with a more coarse honing compound deburring or cleaning up something else that deburred. 

They are not smooth enough for tools and battered the edge of the tool I have. 

Thanks for the background on the actual comment about Frid - the point is valid, you should be able to get sharp on anything, it's more about understanding what you want the tool to be like than the steps to use some specific media. But it's funny how at least three people have told me what Frid did or demonstrated and couldn't manage to say that they just read about it and didn't actually see it. Not even when asked further about particulars. 

One of the erratic posters on here is a source of that, or former posters, but it's become clear over the years that loud criticism of everything was from an imaginary foundation. One of reading google and relaying what's in fine woodworking or other publications. 

hard felt at a lower speed works, as you say - nobody was actually doing what they claimed beyond maybe trying, thus we never really got particulars. Leather and felt need to be slower and absolutely can't slap an edge. My obvious preference - stitched cotton wheels, less critical for the speed, and as you found out with the loose wheels - it's hard to figure out if you need to pack a lunch. I launched an iron with a leather disc and noticed how aggressive it was at high speed even honing away clearance. It could probably be mastered pretty easily, but it also has to stay clean. The felt wheels may be thrown away or some may be laying under an incredible layer of wood and metal dust - they could've been the stopping point for all I know at 500rpm instead of 3500 rpm. I gave them all a pretty good try!

I'd bet the koch system does the unicorn to some extent - they won't explain much for obvious reasons, and I attempted to buy one as they were ceasing to distribute them in the US at the time - a waste of money, but curiosity is a strong thing. It turned out that woodcraft wouldn't do much of anything to make it worth buying and another retailer who had a machine for about 1/3rd off ended up being a google listing scam. I'm not sorry I didn't get it, because of the reality that reselling stuff like that is a pain if you can even find a half price buyer. 

For toolmaking, we get a huge array of surface conditioning belts, which you probably have experience with - they're kind of like scotchbrite wheels, but vary more in hardness and level of fineness. I can't imagine that in terms of small production for a craft shop that there's much of a place where cork belts fit in now.

Added later 01 min 27 s:

https://www.supergrit.com/2-x-48-compact-grain.html

well, next time i'm home during the week, I could see if they work better at a mile a minute belt speed. The listing says they're used mostly for glass. I'd lay them in a pile of metal shavings at some point and realize it was a stupid thing to experiment again. Interesting to see they're still around, and I'm sure they were mostly for glass 15 years ago, too.