Beginner to knife sharpening - a few questions

[Jtsessions]

Yeah, short stroke sharpening seems to be helping. My dominant side bevels are looking really really even with little rounding - it's the opposite bevel. It's typically composed of 1/2 angles and looks almost like a composite ground blade. I also tend to notice a lot of "dimples" sometimes in either bevel, which seems like it's just a symptom of general angle inconsistency.

EDIT: When I say dimples, it looks like a bunch of really tiny ruts parallel to the bevel - kind of like it's been blunted from a few angles. It looks "crinkled," almost. A bit like tin foil. This is on a very very small scale, and the edge itself looks solid. Taken as a whole, the bevel looks flat and smooth. I'm not really sure what's causing this if my overall bevel is smooth and I'm using a high grit stone. Any ideas?

Opposite bevel inconsistency is obviously due to the non-dominant hand, but I'm having a lot of trouble fixing it, even using my dominant hand to guide the blade :s

Lastly, a quick question:

The people who get their knives "shaving sharp" - are they getting them that way with 1000 grit stones, or does it really mostly require you to finish with a 3000+ stone to get that sharpness? I'm wondering if the plateau that I'm hitting is due to a combination of skill and technique, because I'm not yet skilled enough to know just how far 1000 grit will take me.

 

[HeavyHanded]

Yeah, short stroke sharpening seems to be helping. My dominant side bevels are looking really really even with little rounding - it's the opposite bevel. It's typically composed of 1/2 angles and looks almost like a composite ground blade. I also tend to notice a lot of "dimples" sometimes in either bevel, which seems like it's just a symptom of general angle inconsistency.

EDIT: When I say dimples, it looks like a bunch of really tiny ruts parallel to the bevel - kind of like it's been blunted from a few angles. It looks "crinkled," almost. A bit like tin foil. This is on a very very small scale, and the edge itself looks solid. Taken as a whole, the bevel looks flat and smooth. I'm not really sure what's causing this if my overall bevel is smooth and I'm using a high grit stone. Any ideas?

Opposite bevel inconsistency is obviously due to the non-dominant hand, but I'm having a lot of trouble fixing it, even using my dominant hand to guide the blade :s

Lastly, a quick question:

The people who get their knives "shaving sharp" - are they getting them that way with 1000 grit stones, or does it really mostly require you to finish with a 3000+ stone to get that sharpness? I'm wondering if the plateau that I'm hitting is due to a combination of skill and technique, because I'm not yet skilled enough to know just how far 1000 grit will take me.

I'd have to guess those small dimples you're seeing are places where your grind path doesn't match the surrounding area. The edge can be tilted to match or change the cutting edge angle per side, or it can be pivoted to change the grind direction between the leading edge and the stone. Lots of folks, me included, will lay the blade on the stone at 30 degrees or so to the grinding path. This seems to encourage less wobble.

Here is good thread started by Magnaminous G where I posted a written description of my technique and a few pics that might better illustrate what I'm trying to say.

http://www.bladeforums.com/forums/s...-knife-sharpeners-(freehand)?highlight=advice

And this is the visual effect that might further illustrate this:

I do all my sharpening, both sides of the blade, holding the handle with my right (dominant) hand and using the fingertips of my left hand for feedback and drive. Its normal to have a "better" side when freehanding, I always try to push the burr to the left side of the blade so I can remove it with my stronger performing side. Try to see what you're doing when working your good side and recognize how that isn't happening on the side you struggle with, both will improve.

You can do a tremendous job with relatively coarse stones - shaving arm hair at least. As you get into the 1000 grit ANSI you're into the 2000 or higher range on JIS which seems to be the most commonly used standard on the forum (the chart linked below shows the difference between different abrasive size standards)
http://www.bladeforums.com/forums/showthread.php/856708-The-Grand-Unified-Grit-Chart

It should do this more and more cleanly as you climb up through your progression. For a face-shaving edge that's comfortable you'll need at least one finer stone and a good strop. With what you have currently, you can get to an edge you could shave with, but you'll be needing some hot lather to make that work with comfort! In any event, by the time you have learned to squeeze the most from your current set-up you might not want to buy any other stones, and if you do, you'll be in a better position to get your moneys worth.

Martin

 

[Jtsessions]

I'd have to guess those small dimples you're seeing are places where your grind path doesn't match the surrounding area. The edge can be tilted to match or change the cutting edge angle per side, or it can be pivoted to change the grind direction between the leading edge and the stone. Lots of folks, me included, will lay the blade on the stone at 30 degrees or so to the grinding path. This seems to encourage less wobble.

Martin

Got it! Thanks for the advice and method! I'll study that in depth as I make my next attempt at this.

If I'm hearing you right, you're talking about pivoting the blade left or right relative to the stone, right? Won't the burr form along the length of the blade on the other side? I'm not sure I'm following how this will make weak side sharpening more consistent, and I'd like to make sure I understand conceptually as that helps promote improvement.

One more: If I only pick up one stropping compound for now, which should it be? Sounded like you thought ~1 micron chrome oxy or diamond paste might be solid contenders - I just want a sharp, nice looking edge.

Thanks for sticking with me!

 

[HeavyHanded]

Got it! Thanks for the advice and method! I'll study that in depth as I make my next attempt at this.

If I'm hearing you right, you're talking about pivoting the blade left or right relative to the stone, right? Won't the burr form along the length of the blade on the other side? I'm not sure I'm following how this will make weak side sharpening more consistent, and I'd like to make sure I understand conceptually as that helps promote improvement.

Sounds like we might be loosing each other on this one. Basically I'm saying you can tilt the angle at which you grind - edge becomes more or less acute - this one is fairly obvious. You can also change the grind path - this picture shows what I mean. Its from the Mag G thread I linked to in the above post - the whole thing is well worth a read, not just my posting.

By holding the knife with its edge at an angle to the path you're grinding on, you promote better stability - less likely to rock on the bevel than if you held it at right angles to the grind path.

You also want a burr to form along the entire edge - nice and small, but all along the edge, and then flip it, all along the opposite edge. Then remove it by very lightly grinding it off - just enough pressure for the abrasive to remove the burr, not enough to flip it back over again. Good angle control will make every aspect a lot easier, so start there.

My comments about weak side sharpening are just to simply observe the differences in how you control your angle holding and how you sweep the edge across the stone. Adapt from the strong side to the weak side, it won't be a 1 to 1 conversion, but there will be some things you're doing without even noticing on the strong side that can be emulated on the weak. Close observation of both will help both sides.

One more: If I only pick up one stropping compound for now, which should it be? Sounded like you thought ~1 micron chrome oxy or diamond paste might be solid contenders - I just want a sharp, nice looking edge.

Thanks for sticking with me!

For just one, I have to recommend Flexcut Gold. Its mostly aluminum oxide in a fairly hard binder. Works well for hand stropping. Has a range of abrasive sizes going from sub-micron up to about 3 micron. For basic stropping it works very well and does so on some tough steels down through soft kitchen cutlery - makes a near mirror finish. Available at Woodcraft among other places.

Martin

 

[Jtsessions]

Ah, your comments about grind path weren't also ones about weak hand sharpening; I was confused.

I did read the entire technique and appreciate that you went to such lengths to demonstrate it, as I can certainly learn from it Thanks so much!

I'll try the grind path bit as well; Thanks so much!

 

[HeavyHanded]

Ah, your comments about grind path weren't also ones about weak hand sharpening; I was confused.

I did read the entire technique and appreciate that you went to such lengths to demonstrate it, as I can certainly learn from it Thanks so much!

I'll try the grind path bit as well; Thanks so much!

I hope it helps. If you're feeling like punishing yourself with a couple of sharpening videos, here are a couple I did with a plain Home Depot combination stone and stropping on paper with compound. I used some Craftsman black in the video, but could have used Flexcut or any other crayon/grease stick compound, in addition to simply using the mud from a silicon carbide stone.
https://www.youtube.com/watch?v=9s8334LgzDU
https://www.youtube.com/watch?v=03VXUEC5j-w
https://www.youtube.com/watch?v=apLoiggAlA8

Through those, I have a bunch of videos - more than enough to torture yourself for a few hours. I consider myself angle-holding challenged, so a fair amount of my banter (when audible ) is directed toward angle control and burr removal.

I also sell a sharpening widget linked through my signature, and made a few videos to help folks get an idea how it works, and a bunch of more general sharpening tips. Just skip the first one - its entirely about the widget (I call it the Washboard) and really has no general sharpening tips that are relevant to your current set-up. The remaining ones might be useful for technique - just have to remember that sandpaper and a stone are very different in that most of the sandpaper work is going be trailing, and on a stone you can do a lot more scrubbing and finish edge leading. Both utilize a light leading touch for final burr removal and some sort of trailing action on a strop-like surface as a final finish (plain paper/newspaper can work very well for this). I do go into some detail re pre-loading the wrist and using the fingertips of the drive hand to minimize edge angle variation.

Murray Carter has a bunch of videos that also show the short scrubbing motion on his 1k using rock-solid technique.

Martin

 

[Jtsessions]

Gotcha!

When you say trailing, you're referring to running the blade across the surface backwards (stropping uses this method, for instance), right?

I appreciate the resources I'll take a look and see what I can pick up.

If I'm still having trouble, I may make a video of my own when I get back home to my C920 camera tomorrow and can show the details on the bevel. I'll probably do my thing and talk through my frame of mind, then show the bezel to better illustrate what's going on to make it easier to pick up on problems. If I get a chance to, I'd be really thankful if you took a look!

I'll keep in touch Thanks again!

 

[tiguy7]

Free handing is simple if you use a VEE jig and point your edge toward the ground. I made a VEE jig that is adjustable and holds many different sizes and grits of stones. The turnbuckles allow adjustment to 0.1 degrees with a digital clinometer. When my basic taper is established and polished, I switch to the Sharpmaker to shine up the tapers and remove the burr. View attachment 388004

 

[bgentry]

When you say to stop before I roll over the point, does that mean that if I slide the blade across the stone from the base of the blade to the end, it'll be ok as long as I'm still sharpening parallel to the secondary point? I've heard people say not to "roll over" it before but wasn't sure what they meant, exactly.

I think you've got the idea. One way to say this is to tell you what NOT to do. Don't sweep the knife blade over the stone "cutting" the secondary point into the stone. Instead, sharpen the flat part of the edge with back and forth motions. Then sharpen the front flat part of the edge in a similar way, again without sweeping motions.

What you are trying to avoid is having the point cut into the stone at all. If it's already rounded, you may have to spend extra time on each side of the point, grinding until the roundness is ground away, leaving a flat edge in it's place. Two flat edges meeting at an angle should form a sharp point!

Good luck,

Brian.

 

[Jtsessions]

I just spent 30 minutes on one of my tantos using only a 1000 grit arkansas stone with mineral oil. I started with a grind path angle of 45 degrees, grinding the blade at the ~20ish degrees that it was previously set at. I made extremely small circles, focusing entirely on creating the most consistent polishing/smoothing motion that I could muster. I'd stop to check the bevel every few seconds to make sure that I was proceeding in the right direction.

After about 15 minutes, I checked the bevel one last time and felt pretty proud - it was about 90% smooth and only had a few dimples with almost zero rolling. This is typical of me for the past few days. I then checked for a burr and had built up a sizable one on the opposite side of the blade. I spent the next 15 minutes carefully working the other side and checking for the burr. It took 10 minutes to even notice that the burr had changed, and the next five did nothing for it. There's still a noticeable burr that I can only feel when I flick my thumb across the blade in both directions and can feel that one of the sides is sharper, and it goes up the length of the blade, but I have no idea how to get it any smaller - it seemed like I had worked on it forever with little improvement.

When I was finished, both bevels were very reasonably even and looked amazing. Flicking my thumb across the blade in either direction yielded the feeling of incredibly unprecedented sharpness. I felt rather satisfied.

So I took the blade and tried to shave arm hair. Nothing happened. "No matter, I bet it's sharper than what I've done before but not quite yet sharp enough." So I tried it on paper, which is my usual test. Trying to slice straight downwards, even with substantial force, just bent the paper. Trying to slice at an extremely acute angle worked about 50% of the time, with the other 50% just creating VERTICAL TEARS several inches deep into the paper.

It just seems like no matter how perfect the blade looks and no matter how careful I am, I can't bring it up to what feels like an acceptably competent sharpness. Worst of all, I have NO IDEA what I'm doing wrong - I've gotten better about the bevel rolling and have fixed that some, but it seems to have made ZERO DIFFERENCE in the sharpness of the blade, etc.

The most discouraging part is the lack of ability to diagnose whatever the hell I'm doing wrong Gonna try to make a video tomorrow detailing my methods, hoping it'll help.

Thanks again for all of the advice, everyone.

EDIT: Just took the factory-perfect angle of my less-than-satisfactorily sharp Ka-bar 5054 to my 1k grit stone, and within ~20 passes total was able to carefully bring up a burr and take it off the opposite side. Used the sharpie test and maintained the angle -PERFECTLY-. The bevel STILL looks factory-done. The cleanness of the initial angle helped me to "snap to" the proper angle as well, and after I finished, the blade was (with a bit of help) push cutting paper and shaving hair off my arm - this is the first I've seen of a blade doing this. Wow. I really want to be able to get blades that are dull to this state.

Knowing that I was able to do this to a blade that was halfway there but not to others, any idea what my general problem might be?

EDIT AGAIN:

Sorry for the wall of text!

I took a look at my recon 1, tip first, edge up, and noticed that the blade geo was off. The dominant side bevel was about 22, but the non dominant side was nearly flat! It looked like a chisel grind!!

I took it to my coarse ceramic and tried to set the new edge to 22 or so, LIGHTLY stroking burrs off as they came. After about 20 relatively firm strokes and zero progress, I reached for my substantially more awkward portable smith's stone. It's a diamond stone, and I figured that it'd work faster and make a more discernible difference. I worked with it, keeping the angle as consistent as possible. Within a few minutes, the second bevel was within ~15% of the angle of the first. I walked up through the stones and finished it off, then hair tested it. It feels relatively close, but the angle isn't perfect. I figure I'll take some time later to really perfect the angle.

I'm REALLY noticing substantially better angle consistency with a combination of suggestions from other users. Thanks everyone! I'm proud that I both knew what to do to fix the geometry and selected the stone best suited for the task, and it feels really fulfilling that I'm seeing progress in this way. My two tanto are starting to feel less like tools and more like sidekicks. I'm hoping that the new 4k grit ice bear and leather strop with DMT-3 (1, 3, 6 micron diamond paste) will really help to put that finishing touch on these blades.

Please don't hesitate to keep advice/observations coming; I really appreciate this help and am positively beaming after tonight's incremental successes!

 

[HeavyHanded]

If the bevels aren't set and clean, the 1k is too fine a stone to be using. The 350 or 650 are a better choice for a bunch of reasons. Feedback increases as you go down in grit count - more coarse = more feedback. When beginning it really helps to gain most of your functional understanding and technique on the rough stones first, from angle holding to burr removal.

Uneven grinds on a factory edge are very common - I generally work them back to more symmetrical grind over time - not worth removing a lot the knife's functional lifetime just to even it out in one whack.

Sounds like you're doing very well. Dealing with burrs can be a tough chore. For finding them and making sure they're gone, the back-drag method is invaluable and also helps remove them more easily. Strong overhead lighting is a must. If the burr winds up being large when working on a fine stone, you're probably better off dropping back down to a rougher grit to remove it and re-start on the finer stone. Otherwise there will be a real tendency to elevate the spine trying to make the fine stone work more aggressively, and this can easily result in a somewhat rounded edge.

Martin

 

[Jtsessions]

If the bevels aren't set and clean, the 1k is too fine a stone to be using. The 350 or 650 are a better choice for a bunch of reasons. Feedback increases as you go down in grit count - more coarse = more feedback. When beginning it really helps to gain most of your functional understanding and technique on the rough stones first, from angle holding to burr removal.

Uneven grinds on a factory edge are very common - I generally work them back to more symmetrical grind over time - not worth removing a lot the knife's functional lifetime just to even it out in one whack.

Sounds like you're doing very well. Dealing with burrs can be a tough chore. For finding them and making sure they're gone, the back-drag method is invaluable and also helps remove them more easily. Strong overhead lighting is a must. If the burr winds up being large when working on a fine stone, you're probably better off dropping back down to a rougher grit to remove it and re-start on the finer stone. Otherwise there will be a real tendency to elevate the spine trying to make the fine stone work more aggressively, and this can easily result in a somewhat rounded edge.

Martin

Gotcha;

Sounds like setting an even bevel is the role of lower grit stones, and that finer grit stones simply refine that edge. If I mess up the evenness of a bevel with a finer stone and can't quickly rectify it with said stone, I should drop down in coarseness. Is this correct?

Secondly, if I want to change the angle of a bevel, what grit is best suited for this in general?

Thank you!

 

[HeavyHanded]

Gotcha;

Sounds like setting an even bevel is the role of lower grit stones, and that finer grit stones simply refine that edge. If I mess up the evenness of a bevel with a finer stone and can't quickly rectify it with said stone, I should drop down in coarseness. Is this correct?

Secondly, if I want to change the angle of a bevel, what grit is best suited for this in general?

Thank you!

Sadly, if you pooch the refining of a bevel and its anything more than a few stray passes at a slightly off angle, you might as well quickly go back to a rougher stone. As you get better, you'll have fewer mistakes and be able to grind a lot faster and still hold your angles, so will be less and less of an issue. If you've set the bevel and mess up on a medium stone, you can probably stay right on it and not drop back down. Only as you get into the polishing stones that they can't do much corrective work.

For changing inclusive angles I'd use the coarse side of a combination stone - 120-180 grit, or comparable sandpaper. On a waterstone, 220 or 240 grit should work. All depends how much steel has to come off and how tough that steel is. You can do it with your 320 but might be slow or might be OK.

 

[Jtsessions]

Sadly, if you pooch the refining of a bevel and its anything more than a few stray passes at a slightly off angle, you might as well quickly go back to a rougher stone. As you get better, you'll have fewer mistakes and be able to grind a lot faster and still hold your angles, so will be less and less of an issue. If you've set the bevel and mess up on a medium stone, you can probably stay right on it and not drop back down. Only as you get into the polishing stones that they can't do much corrective work.

For changing inclusive angles I'd use the coarse side of a combination stone - 120-180 grit, or comparable sandpaper. On a waterstone, 220 or 240 grit should work. All depends how much steel has to come off and how tough that steel is. You can do it with your 320 but might be slow or might be OK.

Gotcha,

I'm usually afraid that I'll take off too much steel with a coarse stone. I know it's really hard to quantify, but just how much can a good blade take from a coarse stone before I cause it damage? It'd be nice to know that it's got a bit more "life" to it than I think it does right now

Thanks again!

 

[HeavyHanded]

Gotcha,

I'm usually afraid that I'll take off too much steel with a coarse stone. I know it's really hard to quantify, but just how much can a good blade take from a coarse stone before I cause it damage? It'd be nice to know that it's got a bit more "life" to it than I think it does right now

Thanks again!

If you're lowering the inclusive angle, all the steel coming off is behind the cutting edge, so not a problem. Yes with successive grinding you will slowly work the cutting edge away and into the back bevel, so do not take off more from the apex than needed. However there is no avoiding it, you have to remove some of the apex material to grind a new cutting edge. If the bevels are set to a reasonable degree, start with a medium grit instead of a really coarse one. If it takes too long to grind the new apex, switch to a rougher stone. If you see good progress, just keep going with the less aggressive grit. This part is a bit of trial and error till you get a feel for what each stone can do for you in a given application.

 

[Jtsessions]

If you're lowering the inclusive angle, all the steel coming off is behind the cutting edge, so not a problem. Yes with successive grinding you will slowly work the cutting edge away and into the back bevel, so do not take off more from the apex than needed. However there is no avoiding it, you have to remove some of the apex material to grind a new cutting edge. If the bevels are set to a reasonable degree, start with a medium grit instead of a really coarse one. If it takes too long to grind the new apex, switch to a rougher stone. If you see good progress, just keep going with the less aggressive grit. This part is a bit of trial and error till you get a feel for what each stone can do for you in a given application.

Gotcha, that makes sense.

Continued on my recon 1's new edge and got it to shave hair with a little rough raking!!! I've never gotten it this sharp before. My bevels are looking really good now, and I swapped back and forth between stones as needed to great effect (I got a rough burr at one point on my 1k, then dropped to the ~700 to fix it. Didn't notice it coming off, so I went down to the coarse, took it off, lightly touched up with the medium, then back up to fine)

I'm feeling great about this now!

What should I do when the bevel angles look relatively close, the bevels are smooth, and the knife is acceptably sharp, but I want more out of the blade? If it's a problem of edge geometry (off by a degree or two) I don't want to start at coarse and try to get it even closer (too much steel loss for a small gain). What else can I do to take my edges to the next level?

 

[HeavyHanded]

Gotcha, that makes sense.

Continued on my recon 1's new edge and got it to shave hair with a little rough raking!!! I've never gotten it this sharp before. My bevels are looking really good now, and I swapped back and forth between stones as needed to great effect (I got a rough burr at one point on my 1k, then dropped to the ~700 to fix it. Didn't notice it coming off, so I went down to the coarse, took it off, lightly touched up with the medium, then back up to fine)

I'm feeling great about this now!

What should I do when the bevel angles look relatively close, the bevels are smooth, and the knife is acceptably sharp, but I want more out of the blade? If it's a problem of edge geometry (off by a degree or two) I don't want to start at coarse and try to get it even closer (too much steel loss for a small gain). What else can I do to take my edges to the next level?

Once you get the basics, it starts to come down more to pressure control (along with angle control). Depending on how much pressure you use, any stone or diamond plate can produce a range of edge finishes - up to a point. Anyway, you'll want to reduce pressure, this will get more from whatever stone you're working - the abrasive won't bite as deep and the apex will become more narrow overall. The edge will become "cleaner" - fewer irregularities - will shave better and start to draw cut with less efficiency but press cut with increasing efficiency. You will need some muscle memory to do this well, tactile feedback will diminish with the drop in pressure applied and you'll need to hold your target angle with less environmental input. There is a tendency to elevate the spine so it catches more and "feels" more pronounced - don't do it. Just have patience. This is where using a Sharpie to color the edge and see what part of the bevel is untouched can save a lot of grief.

A quick and dirty way to improve any edge straight off the stones at any grit level, and double check for burrs, is to strop on newspaper or writing paper. Just wrap it tight around one of your stones. The rough side of a combination stone works very well for this, but any unyielding surface will work. Takes about 20 or 30 passes/side. This won't do much for a used edge, but as a finishing technique fresh off the stones, is surprisingly effective and very tolerant of pressure variation - in fact a little extra pressure won't hurt at all. A side effect is that it will polish and reveal any remaining burrs - you might have to go back to the stones after stropping on paper, but well worth the time. Is also a good intro to stropping with abrasives and holding good angle control.

Do not forget, there are applications where a coarse edge is the better choice over a highly refined one, so learning to make a "clean" coarse edge is a good skill to have - will also help with making clean edges at higher grit value.

Martin

 

[Jtsessions]

Once you get the basics, it starts to come down more to pressure control (along with angle control). Depending on how much pressure you use, any stone or diamond plate can produce a range of edge finishes - up to a point. Anyway, you'll want to reduce pressure, this will get more from whatever stone you're working - the abrasive won't bite as deep and the apex will become more narrow overall. The edge will become "cleaner" - fewer irregularities - will shave better and start to draw cut with less efficiency but press cut with increasing efficiency. You will need some muscle memory to do this well, tactile feedback will diminish with the drop in pressure applied and you'll need to hold your target angle with less environmental input. There is a tendency to elevate the spine so it catches more and "feels" more pronounced - don't do it. Just have patience. This is where using a Sharpie to color the edge and see what part of the bevel is untouched can save a lot of grief.

A quick and dirty way to improve any edge straight off the stones at any grit level, and double check for burrs, is to strop on newspaper or writing paper. Just wrap it tight around one of your stones. The rough side of a combination stone works very well for this, but any unyielding surface will work. Takes about 20 or 30 passes/side. This won't do much for a used edge, but as a finishing technique fresh off the stones, is surprisingly effective and very tolerant of pressure variation - in fact a little extra pressure won't hurt at all. A side effect is that it will polish and reveal any remaining burrs - you might have to go back to the stones after stropping on paper, but well worth the time. Is also a good intro to stropping with abrasives and holding good angle control.

Do not forget, there are applications where a coarse edge is the better choice over a highly refined one, so learning to make a "clean" coarse edge is a good skill to have - will also help with making clean edges at higher grit value.

Martin

Gotcha! What sorts of applications would a coarse edge do better with? Rope? And what exactly is a clean coarse edge? I would have assumed that it meant polished IE touched off at higher grit, but that doesn't seem to be what you mean.

 

[Chris "Anagarika"]

This is one of the best learning Q&A thread! If both of you don't mind, please link it into the sticky (Mag's one).

Martin,
Even for me, a lot of the advice here is a good reminder of the do and don'ts.
Thank you! :thumbup:

Jtsession,

Thank you for taking the tips to practice & ask further.

I recalled sometime back an OP that simply ask, then argue, and ask again, but never (deduction from the way he/she asked) try and put effort to learn. Sharpening needs to be experienced then thought of, not staying in pure theoritical realm.

Good luck in your journey. You'll find it challenging and rewarding with several A-HA moment

 

[HeavyHanded]

Gotcha! What sorts of applications would a coarse edge do better with? Rope? And what exactly is a clean coarse edge? I would have assumed that it meant polished IE touched off at higher grit, but that doesn't seem to be what you mean.

Rope is one, any job that will dull an edge quickly no matter what edge it has (no point in constantly sharpening to a higher level), applications that involve cutting fibrous, low density materials. I discovered at work through trial and error that a coarse edge lasted a lot longer cutting clay-coated heavy papers. Have to experiment a bit, but any time a more refined edge won't perform well at a task, or dulls quickly, you should be considering a change of strategy. Instead of more polishing, maybe more of a draw cut will sever the material in question with less pressure and less down time.

To me, a clean edge is one that's been formed well on the stones, and deburred to the limit of whatever abrasive was used to grind the edge. Some stropping on plain paper or hard leather to finish will bring it up a notch or two without eliminating the edge irregularities. These types of edges perform with less efficiency when used to press cut, so just need to be aware of the intended task. In general (IMHO), a medium grit edge in the 800-1200 range will work best across the widest variety, with more or less finish falling into a range where the edge has a specific purpose (chopping, carving, shaving on the one end - hard use, low pressure draw cutting on the other).

This thread got into the topic a bit more, I added some micrographs for visual comparison.
http://www.bladeforums.com/forums/s...th-edge-aggression!?highlight=edge+aggression