Burrs and Steel

I've used some of Gunmike1's knives after he put an edge on them, and they are among the sharpest I've ever used. For what it's worth, I often test my grits by push cutting either newspaper or yellow pages before moving on to the next finer level of grit. And that includes the DMT coarse as well.

A few years ago, we had some fun testing how sharp our edges were by how far away from the point of hold we could push cut. I averaged about 2 - 3 inches, a couple of times got to 4. Mike wasn't happy until his were at least 4 inches.
 
Forming an edge with little-to-no burr developing doesn't take superhuman skills. It merely takes concentration and mindful application. And that's why I just plow away mindlessly with a 'formula' and waste a lot of time and steel before getting the edges I like (the ones that are a pain for whittling hair because they'll sever the strand before you feel it 'catch') or before realizing I needed more work at the extra-coarse or coarse level.

The list of people I know who sharpen that way is slowly growing even though it currently only contains people in North and South America. USA, Canada, and Argentina so far.
 
sodak said:
I've used some of Gunmike1's knives after he put an edge on them, and they are among the sharpest I've ever used.
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He got one of his knives sharpened by Ben Dale (Spyderco R2 with STR splinter-picker tip modification) and saw it as something to exceed instead of seeing it as the pinnacle of sharpness.
 
Again, sorry for coming off as rude but if you read the link I posted it conflicts with a lot of what you have said. I am not saying a edge of that sharpness is not possible at that grit but comparing a TK edge to one applied by a DMT xx-coarse is a lot different, different edge thickness and sharpening abrasive. I myself have used a 120 grit belt sander and produced a amazing edge but again the edge is being formed in different ways its not the same as doing it by hand with a diamond stone.

Having a edge pro will also change the game, I do almost all my sharpening by hand and the ability to remove a burr by hand on a stone is next to impossible. Just because you cant feel the burr does not mean that it is not their. Furthermore sharpening techniques and ideas that some imply may work for that person but it does not mean that they are correct. Now I'm not saying this to be rude but re-read the link I have provided and if you understand what is being said you will realize what I am trying to say.
 
knifenut1013,

Mike freehands his edges as well. He props his hones at an angle and sharpens with the blade perpendicular to the ground and thoroughly inspects them with a radioshack microscope (I give the guy props for sticking with that microscope - I think mine is giving me an astigmatism).

The other sharpeners I know who try their darnedest to form unburred edges are dividedly evenly with two EdgePro users and two freehanders.

As for Dr. Verhoeven's paper, it's excellent and ground-breaking, but it is not the only word nor the final word on sharpening. There are many variables Verhoeven couldn't possibly hope to explore, so I don't fault him for not finding them, but am not skeptical of some whose experience differs. The cutting-into-the-stone idea was popularized by Ed Fowler before Cliff started using it. Bob Dozier and his employees were making coarse edges that push-cut paper and shaved hair long before Verhoeven's paper led you to believe it's not possible.
 
Again I am not saying that a coarse edge can't shave or cut paper but a DMT XX-coarse is not leaving a edge in the same condition as if you were to use sandpaper or a waterstone.

I am simply trying to point out the facts of what is really happening to a edge and no one seems to understand.
 
No one's arguing it's not the same condition nor is anyone arguing that a finer edge with otherwise equal attributes will do a better job.
 
thombrogan said:
No one's arguing it's not the same condition nor is anyone arguing that a finer edge with otherwise equal attributes will do a better job.
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True but the argument seems to be about the formation of a burr at the edge. Techniques like cutting into the stone has no effect on reducing the formation of a burr while sharpening.
 
When you sharpen two equal angles one side is reduced more changing the angle causing a burr to form on the side not contacting the abrasive. This happens because you are now cutting into the other bevel and if you keep going your knife will look like a chisel with a burr on the flat side. Cutting into a stone to dull the knife before sharpening only means that you now must grind the edge back to a point and if you grind one side slightly more than the other the burr will be back just like before. This is simple geometry, two angles meeting at the center line of the blade.
 
knifenut1013 said:
Cutting into a stone to dull the knife before sharpening only means that you now must grind the edge back to a point and if you grind one side slightly more than the other the burr will be back just like before.
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The amount of steel removed from lightly cutting into the stone is minimal and it seems better to "waste" a few extra steps with a medium hone than to judiciously chase a burr for an hour.
 
knifenut1013 said:
When you sharpen two equal angles one side is reduced more changing the angle causing a burr to form on the side not contacting the abrasive. This happens because you are now cutting into the other bevel and if you keep going your knife will look like a chisel with a burr on the flat side. Cutting into a stone to dull the knife before sharpening only means that you now must grind the edge back to a point and if you grind one side slightly more than the other the burr will be back just like before. This is simple geometry, two angles meeting at the center line of the blade.
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First, when you have put a blade through tough use the simple geometry question becomes complicated by the question of how deep into the steel have I weakened it? When I used my Spyderco Manix to take massive chunks out of a 1x3 piece of wood with hard chops and then tough prying to break off large pieces of wood how much steel behind the edge can that weaken? I don't know, but for whatever reason I have found I get less sharpening burrs when I cut into the stone prior to sharpening. Let's just agree to disagree on that.

It can be argued that sharpening to a burr is excess sharpening (my arguement), as you have already got the sides to meet and the sharpening is now causing a burr because you went too far. I would rather sharpen the slightest bit less than "perfect" and not have to remove the burr (if a knife is tree topping hair at DMT Fine I am getting pretty close to the limits of sharpness at that grit depending on steel) than have to start chasing the burr. As for Tom Krein's edges being so thin, I either own or have handled 10 Tom Krein regrinds and own 2 of his customs, some with edge thicknesses as low as .004"-.005" (got 3 of those around the house) and the thickest one has a .010" edge. Do these ultrathin edges help with pushcutting newspaper, I'm pretty sure they do. I just find it hard to comprehend that you refuse to believe anyone that doesn't follow your principles can get a good edge. There is life beyond one excellent piece of academic work.

Anyway, I guess I can go back and read Dr. Verhoeven's paper again. IIRC he was using much different sharpening systems and mediums than I do, and different angles than I do as well, but I should refrain from comment until I read it again because I don't remember all of the details of his shapening tools and techniques at this point. I don't recall an edge pro or many other excellent sharpening systems on the market being used in the paper, though, so it would be hard to call it the final word on sharpening unless he tried every system and technique on the market, though it is definately the most in depth scientific paper out there on sharpening that I have seen. The last time I read it I was a pretty novice sharpener, and since have used my own real world experience and tips and tricks from other sharpeners to help me refine my approach to sharpening. Anyway, I did remember learning a lot from Dr. Verhoeven like not using steels and that edge trailing strokes cause burring easier than edge leading strokes, which is why I even use edge leading strokes on my lapping film unless I have had too much coffee, in which case I strop. If you try edge leading strokes with a burred edge or unsteady hand you will rip right into that lapping film, especially the .05 micron stuff.

Let us just agree to disagree on this one, and I will read Verhoeven for the fourth time (it's been awhile). Just out of curiousity, what is your full sharpening routine? Do you always full bevel sharpen or do you use microbevels? Just curious as to how you get your edges, as they are definately impressive from the pics I have seen.

Mike
 
Verhoeven, IIRC, used a Tormek to sharpen, with the final process a leather wheel on his Tormek with CrOx. I think. The 2 things I really liked were the way he could take serious close ups of the edges and measure them, and his laser thing for measuring the angle. That's where I learned that a really sharp edge is 0.5 microns or less.

IMO, and I might be wrong, there is a lot of weakened steel right behind a well used edge. Especially on my knives, trust me. Cutting into the stone will remove that weak stuff.

Thanks for the reminder, Thom, I do now remember Ed Fowler doing that on his videos. But you have to use a light touch, as with most sharpening. Which is why I use an Edgepro...
 
thombrogan said:
I know most of them end on a strop loaded with 0.25 micron diamond powder goodness.
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Well, I reread the paper and it was excellent. However, since I have a dearth of AEB-L razor blades at 60RC I have to wonder how ZDP 189, CPM-D2, VG-10, and others would fare in the testing. It is very in depth, yet very limited in scope when you think of all of the various steels, edge thicknesses, and types of cutlery we have. And, he was using 1 micron diamonds, not .25, so no wonder why he was only matching razor blade sharpness :D! The finding of waterstoness cutting cleaner and faster is definately the same as I have experienced, and hell yes you get better edges the finer in grit you go. Another thing that I find dead true is the edge quality going in half when you cut the angle in half, and having to use lighter pressure at smaller angles. It makes sense that 600 grit at 40 degrees would equal 300 grit at 20 degrees, all else being equal. Further studies on edge retention of each of those blades would have been great, but I would imagine a few more years of Dr. Verhoeven's time were better spent than checking that out. Maybe we could clone Dr. Verhoeven and get about 20 guys just like him to put our favorite steels, knives, and sharpening contraptions to test sharpness and edge retention!

The bottom line is we all want sharp edges and have differing ways to get them. After years of reading about and trying different sharpening techniques and experiencing the sharpness others are able to produce with differing techniques I don't let Dr. Verhoeven's excellent paper stop me from believing there are several ways to get tremendous sharpeness.

Mike
 
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Brent Beach writes about wear-bevels on his woodworking tools, but he grinds a series of three, disctinct microbevels and sometimes grinds a relief bevel and always raises a burr with each of the three microvebels.

Funny how we all have "the way" of making edges. I just c-dawg mine and enjoy the ride.
 
Let us just agree to disagree on this one, and I will read Verhoeven for the fourth time (it's been awhile). Just out of curiousity, what is your full sharpening routine? Do you always full bevel sharpen or do you use microbevels? Just curious as to how you get your edges, as they are definately impressive from the pics I have seen.
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My sharpening method is single bevel, I use many different sharpening medias but most often is my DMT benchstones. When I sharpen a blade I keep the edge on the stone and move back and forth from tip to choil like shown in this vid http://www.youtube.com/watch?v=rTxFtK4shVY. I like this method best because in the end the edge has a very small convex to it. I have found that this edge geometry is more stable/stronger than a stright cut bevel, holds a edge longer and makes touch-up's easier. I only use micro bevels on scandi type blades but that is because most of them are mora's and 1095 at that angle tends to chip and deform on even soft wood. I don't use a micro bevel on anything else because of the way I sharpen and I have always thought it was cheating to get a sharp edge. My last stone used is always a 3 micron either DMT or spyderco, spyderco being the better of the two and IMO the spyderco is 2 or 1 micron. After I am finished using stones I move on to my diamond compound where I have two different methods/surfaces on witch they are applied. The most common is leather, I like leather because it increases the convex shape of the bevel and allows for quicker finishing of the blade but if taken to fine (past .5 microns) it tends to over polish and round the edge. The rounding of the edge is most likely my fault because I use heavy pressure but like they say you can't teach a old dog new tricks.:p My other method is to use the diamond paste on MDF this eliminates the possibility of rounding the edge and seems to make the diamonds work faster. Its also harder because you must hold a more perfect angle but the results for some steels at 0.25 microns is incredible. After the stones (3 micron) the step down usually goes 3 micron diamond paste to clean up what the stone didn't then 1, 0.5, and if I'm feeling lucky 0.25.

I agree with you I am done beating this dead horse, this summer I will be making some videos on sharpening that will cover everything simply because I am not very good at writing and I feel that I could better express myself through live demonstration. Please don't take what I say as offensive I truly don't mean it to be but like my GF says I can be a dick sometimes.
 
knifenut1013 said:
I agree with you I am done beating this dead horse, this summer I will be making some videos on sharpening that will cover everything simply because I am not very good at writing and I feel that I could better express myself through live demonstration.
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No, no, no!!!! While sometimes threads get a little heated, when it comes to sharpening, we SPECIALIZE in kicking dead horses! That's the FUN part! When everyone else gets called in for supper, we pull out our flashlights and keep playing! :D

I swear, half the time I don't know what is more fun, making an edge, or using it.

My freehand skills are so-so, so next on my list are the paper wheels and a trip to Harbor Freight for a 1750 rpm bench grinder. Richard has sucked me in to the power tool side. Luckily, I've saved up some real cheap kitchen knives for the occasion (practice) - they were wedding presents, and we've never used them. And this is year 26 for my wife and I, so I don't think we'll probably ever use them.

Since Gunmike1 started talking smack about razors and sharpness, well, that's just fighting talk... ;)
 
Sounds like a good method you have going there Knifenut. As for finishing on a hard surface versus leather you do have to watch your angle more, and like I was mentioning about my edge leading strokes on my lapping film over glass you have to be dead on with your angle, but at .3 and .05 microns the sharpness can be staggering when you get it right.

I don't think of my microbevels as cheating to get sharpness, as I use them to conserve steel by full bevel sharpening less and to sturdy up my edges after my sometimes insanely thin backbevels when they bring out chipping. Then again my opinion is biased ;). With a microbevel you can get several sharpenings in before the microbevel becomes noticeable and requires completely sharpening the back bevel. And yes, it is way quicker and easier to get consistently sharp edges, but again I first got into them after watching the Sharpmaker video and listening to Cliff on the forums, and I haven't looked back since. Especially now that I have had back surgery saving time and effort are very important to me, so microbevels, the Sharpmaker, and some of Richardj's paper wheels might start pushing my benchstones aside.

Mike
 
Freehand skills take many years to perfect but there is no replacement for the sharpness achived by a edge that has been progressively reduced through the grits. I don't doubt that the paper wheels will give you a sharp edge but if your only so-so at freehand the paper wheels won't fix that.
 
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