Sharpening Knives. Maybe I've been doing it wrong!

[Blackhawk]

Over many years I've tried many ways of sharpening pocket knives. I started with the typical flat oilstone, briefly tried the "kitchen" sharpeners, spent a lot of time with both round and flat diamond sharpeners, have used ceramic Crock sticks in several configurations and sizes, and currently am using a Lansky system with course, medium, and fine stones.

While I usually manage to sharpen my knives enough for the task at hand, I have always worked toward the finest edge I could manage, and possibly that is wrong. I was watching a guy sharpen one of my pocket knives at a gun show. He was using sharpening wheels on a benchgrinder-type machine. After dressing up the edge to what he thought was best, he TURNED OFF THE GRINDER AND USED THE KNIFE EDGE TO SLOW THE WHEEL TO A STOP, still maintaining the same angle. He explained that this puts a slight burr on the edge of the blade, kind of like micro serrations, as the wheel slows, and this cuts much better than a super-fine edge. I've got to confess that this was the sharpest I've ever seen that particular knife.

Would it be a good idea to sharpen blades as best as possible, then attempt to replicate that slightly burred edge with a couple of strokes of a course stone?

 

[MOTOR51]

Over many years I've tried many ways of sharpening pocket knives. I started with the typical flat oilstone, briefly tried the "kitchen" sharpeners, spent a lot of time with both round and flat diamond sharpeners, have used ceramic Crock sticks in several configurations and sizes, and currently am using a Lansky system with course, medium, and fine stones.

While I usually manage to sharpen my knives enough for the task at hand, I have always worked toward the finest edge I could manage, and possibly that is wrong. I was watching a guy sharpen one of my pocket knives at a gun show. He was using sharpening wheels on a benchgrinder-type machine. After dressing up the edge to what he thought was best, he TURNED OFF THE GRINDER AND USED THE KNIFE EDGE TO SLOW THE WHEEL TO A STOP, still maintaining the same angle. He explained that this puts a slight burr on the edge of the blade, kind of like micro serrations, as the wheel slows, and this cuts much better than a super-fine edge. I've got to confess that this was the sharpest I've ever seen that particular knife.

Would it be a good idea to sharpen blades as best as possible, then attempt to replicate that slightly burred edge with a couple of strokes of a course stone?

I was always under the impression that you were suppose to get rid of the burr thus producing a fine edge. I will tell you that polishing or stropping after sharpening has made a big difference for me.


Sent from my iPad using Tapatalk

 

[DAVE_M]

I'll break it down for you:

Over many years I've tried many ways of sharpening pocket knives. I started with the typical flat oilstone, briefly tried the "kitchen" sharpeners, spent a lot of time with both round and flat diamond sharpeners, have used ceramic Crock sticks in several configurations and sizes, and currently am using a Lansky system with course, medium, and fine stones.

You should either be freehand sharpening or using a guided system (Lansky, Apex, Wicked Edge, etc.)

While I usually manage to sharpen my knives enough for the task at hand, I have always worked toward the finest edge I could manage, and possibly that is wrong. I was watching a guy sharpen one of my pocket knives at a gun show. He was using sharpening wheels on a benchgrinder-type machine. After dressing up the edge to what he thought was best, he TURNED OFF THE GRINDER AND USED THE KNIFE EDGE TO SLOW THE WHEEL TO A STOP, still maintaining the same angle. He explained that this puts a slight burr on the edge of the blade, kind of like micro serrations, as the wheel slows, and this cuts much better than a super-fine edge. I've got to confess that this was the sharpest I've ever seen that particular knife.

Using the edge to stop the wheel is a bit odd, because that is not necessary to get a "toothy" edge (is what most call it). It's not actually micro serrations, but a jagged/uneven edge, that acts like a saw. While it works well for some things, a highly polished edge is better for others. It's essentially preference.

Would it be a good idea to sharpen blades as best as possible, then attempt to replicate that slightly burred edge with a couple of strokes of a course stone?

That's going to ruin any edge that you just put on your knife, by removing metal that you don't need to be removing.

If you don't mind my asking. What angle are you using on your Lansky sharpener? What steel are you sharpening?

 

[DAVE_M]

I was always under the impression that you were suppose to get rid of the burr thus producing a fine edge. I will tell you that polishing or stropping after sharpening has made a big difference for me.


Sent from my iPad using Tapatalk

That would be correct, and you don't always have to "sharpen" the edge by removing metal. Stropping a knife, fairly often, will yield a sharp long lasting edge.

 

[Emperor]

I bought one of these at the Sportsman Show last year. It's almost idiot proof.

 

[Blackhawk]

If you don't mind my asking. What angle are you using on your Lansky sharpener? What steel are you sharpening?

Most of my pocket knives fall in the $50-200 range, and variously (I looked these up): 9Cr13CoMoV at 58-60 Rc, AUS-8, Sandvick13C26 at 58-60 Rc, VG-10 at 59-60 Rc. I don't have my Lansky set in front of me but I believe I use the 25 degree setting for all sharpening.

 

[Jmfox3]

Ditto what DAVE_M said. The Ken Onion Work Sharp is the best tool I've ever used. It is quick, full proof, and doesn't overheat the blade.

 

[Metryshooter]

Sharpening a blade really depends on its intended usage. Some are better with a slight toothy edge, others polished.
I use the mouse pad method. I use a neoprene mouse pad with a piece of sandpaper on it. Depending on how bad the edge is where you start. Its very fast and the added benefit is that you develop a convex edge which will hold longer. I've taken some knives all the way up to .03 micron (80-100k grit) using fiber optic lapping paper, and to say the edge was razor would be a gross understatement.
Here's an example:
http://m.youtube.com/watch?v=GqYfDnEHpTQ

 

[DAVE_M]

Most of my pocket knives fall in the $50-200 range, and variously (I looked these up): 9Cr13CoMoV at 58-60 Rc, AUS-8, Sandvick13C26 at 58-60 Rc, VG-10 at 59-60 Rc. I don't have my Lansky set in front of me but I believe I use the 25 degree setting for all sharpening.

9cr13, aus-8, and sandvick are very easy to sharpen, but don't have the greatest edge retention. The VG-10 should be slightly more difficult to sharpen, and hold an edge slightly longer. However, to answer your question, you should be sharpening them to what you need them to be. A knife used to cut zipties all day, doesn't need to be polished to 1000grit, but a knife used to cut food, should be stropped to remove the burrs.

 

[Pas Tout La]

Whatever the fella at Cabela's does works. He sharpened my Benchmade Griptilian then handed it to me and warned me to be careful because it was so sharp it would cut my shadow. I put it back in my pocket and when we got in the truck, I pulled it out to test the edge and sliced my damn finger open....... My wife just looked at me with a **** eating grin and never said a word. Ole boy was right. That sucker was SHARP!

I know with my kitchen knives I'll sharpen them every few weeks depending on how much use each knife gets. A few passes through the el cheapo knife sharpener and then I run it on the honing steel before every use. They stay sharp and handle whatever I ask of them.

 

[FRANKEIGHT]

I recently bought a Worksharp and that , to me is the best thing I have ever used

 

[DAVE_M]

I recently bought a Worksharp and that , to me is the best thing I have ever used

Worksharps are good for reprofiling, but remove way too much material for sharpening needs.

 

[FRANKEIGHT]

I must disagree with that

Worksharps are good for reprofiling, but remove way too much material for sharpening needs.

 

[Doctor481]

I have tried many methods but finally picked up a WorkSharp Ken Onion.
It is fast, the edge is repeatable. I sharpened 13 kitchen knives from dull to razor in 22 minutes.
It can be used to reprofile with the coarser grit belts; to sharpen the finer grit belts are used.
There are some touch up situations I only use the 6000 grit belt.

 

[beauxdog]

A coworker brought a Work Sharp to show us how good it works. I know 5 of us bought one and one guy bought 3. It's the best thing for us not savy enough to sharpen knives. A good leather strop would be a good addition to it. It's easy and quick. I saw the guys from Benchmade using them at the ShotShow to sharpen customers knives. Good enough for me. Northern Tools was the cheapest source that I have found.

Beauxdog

 

[Gus McCrae]

Warning, this might be a long post.... This is just what I learned, what I do, and may not be right.

I had tough luck sharpening a knife at one time. It sounds simple to sharpen a knife.... and in some ways it is... but when you need details, it ain't that simple. My goal is just to have a good sharp edge that can at least pull/pop hairs on my arm and push cut somewhat easily through paper.... I need a good working edge, but not perfection. Getting shaving sharp really requires an even finer finish. If you want super edges, you will need to build on what I'm saying here.

The simple version to keep in your mind is that you remove metal from one side, then the other until you get an even point. Then there's the details.

Tools
The best tool I ever bought for sharpening knives is a 30X, hand held, lighted, microscope. That's what really taught me how to sharpen knives. I don't use it much anymore because I now better understand what is going on when I apply steel to stone. The biggest thing I learned is that sharpening steel where you have a big dink, heavily rolled edge, or re-profiling is just a bunch of work when using stones. This is even more true when dealing with those super steels so many folks are fond of. The one I use is very similar to this: http://www.amazon.com/SE-MW10084-Illuminated-Microscope-Magnification/dp/B000OVHVVQ

Another tool I really like, is the DMT aligner. I add the extra coarse stone to my set [Black (Extra Coarse Grit), Blue (Coarse Grit), Red (Medium Grit), Green (Fine Grit)]. I use the black when re-profiling. If you got the money and funds, the best tool of this type is probably the wicked edge.... the cost and the fact that I just need my blades sharp and not perfect keeps me with the DMT aligner. The Lansky system is similar, but I like the DMT diamond stones more than the Lansky stuff.... The seem to remove metal better. The DMT aligner kit: http://www.amazon.com/DMT--PROKIT-A...F8&qid=1443793159&sr=1-1&keywords=DMT+aligner



Using the microscope, you can see both sides of the bevel (the edge, it's basically a bevel right?), before you start sharpening on a factory edge, you will likely see the grain perpendicular to the edge with a certain coarseness (Factories use special sand belt machines at one grit to do all of the sharpening). When you start with your first (coarse stone), you should see that old edge get erased with your new edge. You will notice it may take many strokes on the stone to completely erase the old edge, and you can tell if you are not at the exact same angle as the original edge (which was usually freehand and not necessarily that consistent anyways). If you are at a different angle, you will see your new edge cover only part of the old edge. If you keep it at your angle and not conform to the original (which you may want to do), you are re-profiling the edge. When you change to finer grit, you will see this again, and again.... the finer you get, the closer to a mirror you will get.


The Process
Now, what about my process for sharpening? Using the above, I start with the coarse stone (extra if I'm re-profiling) and work one side of the blade until it is completely new. This will often result in the edge curling over to the other side. You can feel this curl by dragging your finger perpendicular to the edge in the direction from the spine to the edge of the blade. I then flip the sides and repeat. This sets up the angle.

Only after the above, I work each side in an even number of strokes starting from 10-20 and then half the number of strokes each time I return to the first edge and repeat until one stroke on each side. For example:

Side 1: 10 strokes
Side 2: 10 strokes
Side 1: 5 strokes
Side 2: 5 strokes
Side 1: 2 strokes
Side 2: 2 strokes
Side 1: 1 strokes
Side 2: 1 strokes

After the coarse stone, I like to drag the edge through some wood. This basically rips that thin little curling edge off and leaves you with the strong edge. I then move on to the next finer stone... then the next finer.... then the next.... etc.

How fine should you get? Well, I'm not looking for perfect. I need a knife that can easily slide through the chest cavity of a deer, cleanly slice open a bag of chips, easily saw through rope, and cut fine wedges of my apple. When you have a coarse edge, the blade will easily slice through most things, but it will need more of a sawing action to do so. This is actually fine for some blades that are used for some tasks. If you want an edge that will easily cut without sawing, you need a finer finish on your edge. I find that for the green stone in the DMT kit is really plenty fine. I often stop at the red. I also find that some steels seem to like the more toothy edge anyways (Case SS is an example).

I often test the edge after each stone to see that one little spot doesn't need a little extra attention (the tip often gets missed). I place the edge on top of my thumbnail with just the weight of the knife pushing the blade into my thumbnail. I then slide perpendicular to the blade along the nail to see if the blade has actually pushed into the thumbnail. If it has a little grab, that's good. If it slides easily, it's rolled or dull at that spot. I check up and down the edge.

What angle? The finer the angle, the easier it will slice, but the weaker it will be as the metal has to be thinner. 15 degrees per side (30 degrees all inclusive) is pretty much the all around best, but if you are planning on abusing the blade, you may open it up to 20 degrees per side.


Further Advancement and learnings
I was fine using this process until I started carrying a Case Peanut. The Peanut is just too small to work with the DMT aligner.... I was forced to learn freehand. I used the same stones (they just cut so well), and the same microscope to see what was going on. After enough practice, I learned how to consistently hold that little knife to get that edge. I now mostly freehand. I then moved on to other cutting mediums for touch ups..... the other day I sharpened my little peanut on the bottom of a coffee cup. It worked great!

Something else I noticed, when looking directly at the edge, you shouldn't be able to see the edge at all. Sometimes, you might see a fine sliver of light on the edge. That's where the metal was blunted or rolled.

At the factory, they often just sharpen it on a special belt or wheel. They don't usually change grits and it's usually not fine at all. I think often it's fairly coarse (320 grit?). You shop sander is probably too fast for this. You need to be real careful with powered equipment that isn't for this job. You can ruin the heat treat which is probably the most important property of the steel.

Steels
I like your plain ole common steels with a good heat treat. Some of the super steel stuff really requires lots of work and your are about forced to using diamond stones and maybe even special powered sharpening tools to work the edge. themcfarland had one of those Zero Tolerance knives that he likes to open soup cans and whittle old leaf springs with. He asked me to fix up the edge for him. Because of the way it was used, I decided to open up the angle to give it a stronger edge. It took me a whole football game to get that knife where I wanted it.... It uses S30V steel.... Holds and edge forever, but takes forever to sharpen. I like 1095 Carbon, D2, 440C Stainless, and whatever Case's Surgical Stainless is. Oh, I throw in that the heat treat is important to edge life and how sharp you can get a blade.... but the harder it is, the harder to sharpen.

To answer the original question: The fella probably can sharpen a knife, but what he said is a bunch of hokum. An actual burr on the edge won't make it cut better in any way shape or form. Since he isn't changing grit, he's not really doing anything to change the bevel surface.... though it's possible to argue that the slower speed will allow the edge to end up a little more toothy, but I doubt you'd see much difference if you looked at it under the microscope.

 

[Gus McCrae]

A video of the Wicked Edge..... which is pretty sweet, just to pricey for me.

 

[Win1917]

....... My wife just looked at me with a **** eating grin and never said a word. Ole boy was right. That sucker was SHARP!

I know with my kitchen knives I'll sharpen them every few weeks depending on how much use each knife gets. A few passes through the el cheapo knife sharpener and then I run it on the honing steel before every use. They stay sharp and handle whatever I ask of them.

I have to keep any sharpened kitchen knives where my wife can't reach them. Too careless, an accident waiting to happen...that or tearing up nicely sharpened edges doing things like cutting pizza on a pizza stone