The Seven Secrets of Sharpening
- Thread starter bgentry
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Yes, just from a text editor (TextEdit on a Mac). I'm honestly sorry I can't just post my writing on this subject. It's making me second guess what I've written with all of this build up around it!
If this doesn't get resolved in a day or two, I'll probably just post it in tiny chunks that the forum will accept. I really don't want to do that because I think it interferes with the readability. Let's hope the forum software starts accepting arbitrarily long posts without issue.
Brian.
Here's my magic word for sharpening: SHARPIE
Use a Sharpie and never again mess up an edge. With any technique, any device, any method... use a Sharpie and know when you've done it right.
(This is 62 years of personal experience talking, but only the last 50 of 'em using a Sharpie.)
Stitchawl
Use a Sharpie and never again mess up an edge. With any technique, any device, any method... use a Sharpie and know when you've done it right.
(This is 62 years of personal experience talking, but only the last 50 of 'em using a Sharpie.)
Stitchawl
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Brian, with all the delay this had better be a cross between Indiana Jones and Verhoeven!!!
Just kidding
...you might want to close this out and make a new one - seems like once the forum demons decide you shouldn't post in given thread you are genuinely skrwed. And it doesn't stop even if you slip one thru, every post is a slog in the mud.- Joined
- Mar 7, 2001
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- 4,608
A strong direct light over the apex is secret no. 8 as I have just found out the hard way.
Martin & others having said about this, I thought I knew it, but it's a different game when I put the camera flashlight onto the apex
Martin & others having said about this, I thought I knew it, but it's a different game when I put the camera flashlight onto the apex
My thought process is this, your goal is a fully apexed burr free edge.
Doesn't matter how you get there but getting there is the important part. Dropping the angle of the bevel and all the other stuff is just icing on the cake and things to worry about if you feel like it after you get proficient in the above.
Doesn't matter how you get there but getting there is the important part. Dropping the angle of the bevel and all the other stuff is just icing on the cake and things to worry about if you feel like it after you get proficient in the above.
fishface5
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I had a problem posting long text once it was due to some unknown glitch in one single letter that bf wouldn't accept. Try editing the post by adding and saving one paragraph at a time and when it won't save a paragraph add each sentence at a time until it won't save, then each word until you find the offending bit of code.
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Brian, with all the delay this had better be a cross between Indiana Jones and Verhoeven!!!
Just kidding
I've noticed that too. There've been times when I couldn't post much, or at all, in a specific thread on the site; it kept choking on whatever I tried, even with small entries. But at the same time, I was posting anywhere and everywhere else with little or no apparent issues. Seems like something gets corrupted in the post submittal process, and the site doesn't seem able to handle it. Maybe restarting in a new thread might be the workaround, or at least it might confirm if the size of the postings is just the main issue by itself (though I don't think it is, else a lot of others on the site would likely also be fighting it at the same time).
I've noticed that the formatting of text alone (bolded/underlined/etc) inserts an awful lot of bulk into submitted posts, even a single/few sentences. I can't help but wonder if that sometimes chokes the system with so much raw data embedded in relatively simple edits.
David
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Secret #1: Feeling the bevel on the stone.
This is idea is simple and powerful. Lets define terms real quick. When I say bevel I mean the final bevel leading to the cutting edge. I also refer to this as the cutting bevel. The cutting bevel is really two flat planes that intersect to form the cutting edge. One on the right, one on the left, and where they meet in the middle, we have the edge that does the cutting. Simple.
Now, if the bevels are flat, we should be able to hold that flat bevel flat against a stone. In fact, we should be able to *feel* when the bevel is touching the stone in a reasonably flat way: Not with edge digging in to the stone. Not with the edge standing WAY off of the stone. But flat.
If you hold a knife with the handle in your hand and you move your wrist to angle the blade up and down against the stone, you can feel when it becomes flat. On some blades it almost seems to click into place. Now, if you take your other hand and press down *right* on top of the edge bevel, you can REALLY feel when it becomes flat against the stone. This feeling is so strong in some blades, that you can almost hold the blade in place on the stone without using the handle. Just your off hand, pressing the bevel flat to the stone. This is just an illustration of how strong the feeling in the off hand can be.
Play with this, using both hands, and youll certainly feel when you get the bevel flat on the stone. This is one of the primary and key ways to maintaining a constant angle. If you can feel it, you can maintain it. When I first figured this out, my sharpening consistency immediately increased.
This two handed approach to sharpening naturally leads us to Secret #2.
Brian.
Secret #1: Feeling the bevel on the stone.
This is idea is simple and powerful. Lets define terms real quick. When I say bevel I mean the final bevel leading to the cutting edge. I also refer to this as the cutting bevel. The cutting bevel is really two flat planes that intersect to form the cutting edge. One on the right, one on the left, and where they meet in the middle, we have the edge that does the cutting. Simple.
Now, if the bevels are flat, we should be able to hold that flat bevel flat against a stone. In fact, we should be able to *feel* when the bevel is touching the stone in a reasonably flat way: Not with edge digging in to the stone. Not with the edge standing WAY off of the stone. But flat.
If you hold a knife with the handle in your hand and you move your wrist to angle the blade up and down against the stone, you can feel when it becomes flat. On some blades it almost seems to click into place. Now, if you take your other hand and press down *right* on top of the edge bevel, you can REALLY feel when it becomes flat against the stone. This feeling is so strong in some blades, that you can almost hold the blade in place on the stone without using the handle. Just your off hand, pressing the bevel flat to the stone. This is just an illustration of how strong the feeling in the off hand can be.
Play with this, using both hands, and youll certainly feel when you get the bevel flat on the stone. This is one of the primary and key ways to maintaining a constant angle. If you can feel it, you can maintain it. When I first figured this out, my sharpening consistency immediately increased.
This two handed approach to sharpening naturally leads us to Secret #2.
Brian.
Secret #2: The Japanese Stroke
Japanese cutlery of all types, is generally regarded as being some of the finest available; ranging from kitchen knives to general purpose blades to swords. Again, generally speaking, Japanese cutlery is some of the sharpest available. The traditional method of Japanese sharpening hasnt changed in hundreds of years. Theres probably a good reason for that.
To give you an idea of what it looks like, and the basics, check out this video:
https://www.youtube.com/watch?v=SKeSRDMRpY0
There are many variations of this technique. The essential parts for me are:
1. Two hands help increase control over the blade dramatically.
2. The off hand, which presses on top of the blade focuses the grinding to specific areas.
3. The off hand can be used to help with angle control, especially if the thumb of the off hand is placed on the spine of the blade.
Youll notice that almost every sharpener using this technique sharpens with the dominant hand holding the handle for both sides of the blade. This means that on one side, the edge is facing you. On the other side, the spine faces you. You can absolutely produce fantastic edges doing it this way. But I like to do it a little differently. I like the spine facing me at all times, so I can judge the height off of the stone. So when sharpening the left side of the blade, I hold the handle in my RIGHT hand. When sharpening the right side of the blade, I hold the handle in my LEFT hand. This promotes a consistent sight picture of the blade no matter which side Im sharpening. You can do it either way: Dominant hand only on the handle, or ambidextrous switching.
Lets talk about the off hand pressure. The usual advice is to use 2 or 3 fingers of the off hand to press down on the edge bevel. The area directly underneath your fingertips will get most of the grinding action. Even if 6 or 7 inches of blade are touching the stone, the 1 to 1.5 inches under your fingertips are where the grinding will happen. This is why you see everyone sliding their fingers along the bevel as they go: To distribute this concentrated grinding force along the whole blade. This ability to focus the grinding force provides you a tremendous amount of control. It lets you grind in ways that you just cant do using one hand only.
I sometimes use 3 fingers, sometimes 2. When I really want to concentrate on just the tip of a blade, Ill use one finger and even roll that finger to adjust where the grinding is happening. Sometimes using only a small part of the finger tip to really focus the grinding.
Note that you can also grind more at the shoulder of the blade by moving the pressure closer to the spine. You can focus it closer to the edge by moving your fingers forward. You can experiment with your finger position and see how it affects the grinding on the blade.
Heavy Handed has a lot of good advice about hand and finger position when doing a two handed stroke. His isnt exactly the same as a traditional Japanese stroke, but that doesnt matter. What matters is the principles and how they work. My technique doesnt look all that much like the videos youll see either. But my technique works for me and it works much better than the one handed stroke I had been doing for so many years before I tried the Japanese Stroke. It all comes down to control over the grinding on the edge bevels. The Japanese Stroke gives me a degree of control that's unmatched by any one handed approach and that makes it essential for me.
Brian.
Japanese cutlery of all types, is generally regarded as being some of the finest available; ranging from kitchen knives to general purpose blades to swords. Again, generally speaking, Japanese cutlery is some of the sharpest available. The traditional method of Japanese sharpening hasnt changed in hundreds of years. Theres probably a good reason for that.
To give you an idea of what it looks like, and the basics, check out this video:
https://www.youtube.com/watch?v=SKeSRDMRpY0
There are many variations of this technique. The essential parts for me are:
1. Two hands help increase control over the blade dramatically.
2. The off hand, which presses on top of the blade focuses the grinding to specific areas.
3. The off hand can be used to help with angle control, especially if the thumb of the off hand is placed on the spine of the blade.
Youll notice that almost every sharpener using this technique sharpens with the dominant hand holding the handle for both sides of the blade. This means that on one side, the edge is facing you. On the other side, the spine faces you. You can absolutely produce fantastic edges doing it this way. But I like to do it a little differently. I like the spine facing me at all times, so I can judge the height off of the stone. So when sharpening the left side of the blade, I hold the handle in my RIGHT hand. When sharpening the right side of the blade, I hold the handle in my LEFT hand. This promotes a consistent sight picture of the blade no matter which side Im sharpening. You can do it either way: Dominant hand only on the handle, or ambidextrous switching.
Lets talk about the off hand pressure. The usual advice is to use 2 or 3 fingers of the off hand to press down on the edge bevel. The area directly underneath your fingertips will get most of the grinding action. Even if 6 or 7 inches of blade are touching the stone, the 1 to 1.5 inches under your fingertips are where the grinding will happen. This is why you see everyone sliding their fingers along the bevel as they go: To distribute this concentrated grinding force along the whole blade. This ability to focus the grinding force provides you a tremendous amount of control. It lets you grind in ways that you just cant do using one hand only.
I sometimes use 3 fingers, sometimes 2. When I really want to concentrate on just the tip of a blade, Ill use one finger and even roll that finger to adjust where the grinding is happening. Sometimes using only a small part of the finger tip to really focus the grinding.
Note that you can also grind more at the shoulder of the blade by moving the pressure closer to the spine. You can focus it closer to the edge by moving your fingers forward. You can experiment with your finger position and see how it affects the grinding on the blade.
Heavy Handed has a lot of good advice about hand and finger position when doing a two handed stroke. His isnt exactly the same as a traditional Japanese stroke, but that doesnt matter. What matters is the principles and how they work. My technique doesnt look all that much like the videos youll see either. But my technique works for me and it works much better than the one handed stroke I had been doing for so many years before I tried the Japanese Stroke. It all comes down to control over the grinding on the edge bevels. The Japanese Stroke gives me a degree of control that's unmatched by any one handed approach and that makes it essential for me.
Brian.
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Secret #3: Following the Curve of the Blade
Many blades have a curve near the tip. One of the most common problems in sharpening is failure to grind this curved section of the blade correctly. Incorrect sharpening of the curved part leads to dullness in the curve, blunt tips, and ugly uneven bevels in these areas. Theres all kinds of advice about how to follow the curve, and its all mostly correct. But its really, really hard to illustrate the proper technique with words alone. So lets take a look at the master himself, Ken Schwartz, explaining what to do and showing how to do it:
https://www.youtube.com/watch?v=JFhUXgYS0Os
This approach to following the normal line (the lines he marked on the blade) is *the* way to make sure you follow the curve of the blade when sharpening it. Of course, you should use secret #1 to help you feel the bevel on the stone, and secret #2 to give you good control over the blade as you grind along the curved portion.
Incidentally, the technique that Ken shows, also leads to ultra sharp tips. As long as you grind ALL the way to the tip and stop before you go past it, your tips will get needle sharp. Again, secrets #1 and 2 are your friends here to help you get to the tip, feel the tip, and focus the pressure where the grinding is supposed to happen.
There are many approaches to making a nice smooth bevel as you go through the curve. I like a technique that Jason B uses that I call the swing. A video is worth a thousand words here, so lets watch Jason do it:
https://www.youtube.com/watch?v=XgOXvtJDm5E&feature=youtu.be&t=12m13s
Watch again on a blade with a more dramatic curve and youll see the swing in action:
https://youtu.be/2VizLyNOr0s?t=11m20s
Watch him do both sides of the blade and youll see the U shape hes describing, but turned sort of at an angle. Like the U is leaning in two dimensions both backwards and to the side. Again, the video is worth 1000 words.
Follow the curve of the blade, and youll make edges that are sharp from the heel, all the way to the tip, and everywhere in between.
Brian.
Many blades have a curve near the tip. One of the most common problems in sharpening is failure to grind this curved section of the blade correctly. Incorrect sharpening of the curved part leads to dullness in the curve, blunt tips, and ugly uneven bevels in these areas. Theres all kinds of advice about how to follow the curve, and its all mostly correct. But its really, really hard to illustrate the proper technique with words alone. So lets take a look at the master himself, Ken Schwartz, explaining what to do and showing how to do it:
https://www.youtube.com/watch?v=JFhUXgYS0Os
This approach to following the normal line (the lines he marked on the blade) is *the* way to make sure you follow the curve of the blade when sharpening it. Of course, you should use secret #1 to help you feel the bevel on the stone, and secret #2 to give you good control over the blade as you grind along the curved portion.
Incidentally, the technique that Ken shows, also leads to ultra sharp tips. As long as you grind ALL the way to the tip and stop before you go past it, your tips will get needle sharp. Again, secrets #1 and 2 are your friends here to help you get to the tip, feel the tip, and focus the pressure where the grinding is supposed to happen.
There are many approaches to making a nice smooth bevel as you go through the curve. I like a technique that Jason B uses that I call the swing. A video is worth a thousand words here, so lets watch Jason do it:
https://www.youtube.com/watch?v=XgOXvtJDm5E&feature=youtu.be&t=12m13s
Watch again on a blade with a more dramatic curve and youll see the swing in action:
https://youtu.be/2VizLyNOr0s?t=11m20s
Watch him do both sides of the blade and youll see the U shape hes describing, but turned sort of at an angle. Like the U is leaning in two dimensions both backwards and to the side. Again, the video is worth 1000 words.
Follow the curve of the blade, and youll make edges that are sharp from the heel, all the way to the tip, and everywhere in between.
Brian.
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Secret #4: Observation.
Now were really getting somewhere! Weve got solid techniques for controlling the blade during sharpening and grinding the entire thing the way we want to. But how do we know if were doing it right? Are we making nice flat bevels? Is our angle correct through the curve of the blade? In short, are we doing what we think we are?
The answer is secret #4, Observation. Im embarrassed to say, that for many, many years, I didnt know where I was grinding while sharpening a knife. I couldnt point to the grind lines that I had made, or even know what they looked like. Because I wasnt looking! Its really embarrassing to admit, but its true.
So start with the obvious: LOOK at the edge bevels as you grind them. Do a little work. Stop. Look at the bevel to see what youve done. Now, looking for grind marks in shiny steel isnt quite as easy as it sounds. The edge bevels are typically less than 1/8 inch wide, and most are much thinner with 1/16 being more typical. Im going to give you two powerful observational techniques that you can use to help with this:
1. The reflected light technique.
2. The sharpie technique.
Reflected Light:
Another embarrassing thing for me to admit: An old man told me about this technique around 12 years ago. I thought he was nuts and pretty much totally ignored his advice. Around 6 or 7 years later, I read someone else giving the same advice and I tried it. Holy WOW! It works. Heres how you do it:
Stand under (or to the side of) a bright light source. The sun works well, as do strong overhead lights. Now, hold the blade so that you catch a reflection of this bright light on the edge bevel. If you move the blade around some, youll find that you can reflect a nice bright line off of the edge bevel, and by changing the angle slowly, you can play this line of light along the entire length of the bevel. This will show you details that you didnt know were there. Youll see variations in bevel width. Youll see nicks and imperfections. Youll also see grind lines much more clearly.
This same technique can be used straight down on the cutting edge. Hold the blade with the edge facing the ceiling. Have the handle pointed at your chest and the point facing straight out away from you. Look straight down at the cutting edge. Now, move the point slowly down towards the floor, and then up towards the ceiling. With a truly sharp blade, you wont see anything because the cutting edge is too narrow to reliably reflect light. But a blade with any dull spots, nicks, or other problems, will reflect light. These bright spots on the edge are your key to finding where the edge is dull and needs work. I cant overemphasize this technique enough. Its like carrying around a microscope. Except all you need is light and your eyes. Try this!
The Sharpie Technique:
Lets say youre sharpening a blade, and youve done 4 or 5 strokes along the whole length. You think youve got the angle right. You think it feels correct. But how do you know if youre getting to the cutting edge or not? You can observe the bevels and look for the grind lines. If the grind lines are in the right place, then youre doing your job correctly. But this is hard to do. The bevel is narrow and grind lines can be hard see clearly. So lets make it easy.
Grab a sharpie or a marker of some sort in a dark color. Now, color the edge bevels with the sharpie so that they are no longer silver and are covered in black marker (or another dark color). Again, Im talking about the final edge bevels of the blade that are 1/32 to 1/8 of an inch wide.
Now, do a few strokes and observe the bevel. If the marker is only being removed near the shoulder of the bevel, it means you are grinding at too low of an angle. If the marker is only being removed in an ultra-thin line near the cutting edge, your grind angle is too high. What you want to see is no marker at all. It should get removed, evenly, from the whole edge bevel. This indicates that you are grinding flat on the bevel, which you can feel using secret #1. Well, now you can SEE it too.
If you do this with enough blades, youll probably find that you arent really grinding in some spots on the blade hardly at all. This is most common at the very tip and at the choil (heel). Sharpie can help you correct this so that you hit the whole blade during sharpening.
Observation should form a feedback loop when sharpening. Do a little work. Observe. Adjust if necessary. Do a little work. Observe. Adjust if necessary. Repeat. The goal is to have the observation confirm that you are grinding correctly. Or to show you minor variations that you might want to correct. When you start doing this, youll have to correct often. Thats ok. Its expected. As you gain more experience, youll correct less often and make smaller and smaller corrections. Dont be afraid to apply the sharpie many times during sharpening. Its not uncommon to reapply 4, 5, or 6 times on each side. If you want to get it perfect, youll want to observe often.
Note that observation is not just a visual thing. Secret #1 is actually an observational technique too. You use your sense of touch to feel where the bevel is. Touch can tell you other things as you progress. Sound plays a role also. Grinding at too high an angle produces a sound as the blade digs into the stone. Too low an angle sounds (and feels!) different.
You shouldnt try to do ALL of this all at the same time. Youll overwhelm yourself with too much input. But as you progress, youll notice things. Pay attention.
This is one of the longer explanations in this series. Thats because its one of the most important of all of the secrets. This one can really change sharpening for you. It did for me.
Brian.
Now were really getting somewhere! Weve got solid techniques for controlling the blade during sharpening and grinding the entire thing the way we want to. But how do we know if were doing it right? Are we making nice flat bevels? Is our angle correct through the curve of the blade? In short, are we doing what we think we are?
The answer is secret #4, Observation. Im embarrassed to say, that for many, many years, I didnt know where I was grinding while sharpening a knife. I couldnt point to the grind lines that I had made, or even know what they looked like. Because I wasnt looking! Its really embarrassing to admit, but its true.
So start with the obvious: LOOK at the edge bevels as you grind them. Do a little work. Stop. Look at the bevel to see what youve done. Now, looking for grind marks in shiny steel isnt quite as easy as it sounds. The edge bevels are typically less than 1/8 inch wide, and most are much thinner with 1/16 being more typical. Im going to give you two powerful observational techniques that you can use to help with this:
1. The reflected light technique.
2. The sharpie technique.
Reflected Light:
Another embarrassing thing for me to admit: An old man told me about this technique around 12 years ago. I thought he was nuts and pretty much totally ignored his advice. Around 6 or 7 years later, I read someone else giving the same advice and I tried it. Holy WOW! It works. Heres how you do it:
Stand under (or to the side of) a bright light source. The sun works well, as do strong overhead lights. Now, hold the blade so that you catch a reflection of this bright light on the edge bevel. If you move the blade around some, youll find that you can reflect a nice bright line off of the edge bevel, and by changing the angle slowly, you can play this line of light along the entire length of the bevel. This will show you details that you didnt know were there. Youll see variations in bevel width. Youll see nicks and imperfections. Youll also see grind lines much more clearly.
This same technique can be used straight down on the cutting edge. Hold the blade with the edge facing the ceiling. Have the handle pointed at your chest and the point facing straight out away from you. Look straight down at the cutting edge. Now, move the point slowly down towards the floor, and then up towards the ceiling. With a truly sharp blade, you wont see anything because the cutting edge is too narrow to reliably reflect light. But a blade with any dull spots, nicks, or other problems, will reflect light. These bright spots on the edge are your key to finding where the edge is dull and needs work. I cant overemphasize this technique enough. Its like carrying around a microscope. Except all you need is light and your eyes. Try this!
The Sharpie Technique:
Lets say youre sharpening a blade, and youve done 4 or 5 strokes along the whole length. You think youve got the angle right. You think it feels correct. But how do you know if youre getting to the cutting edge or not? You can observe the bevels and look for the grind lines. If the grind lines are in the right place, then youre doing your job correctly. But this is hard to do. The bevel is narrow and grind lines can be hard see clearly. So lets make it easy.
Grab a sharpie or a marker of some sort in a dark color. Now, color the edge bevels with the sharpie so that they are no longer silver and are covered in black marker (or another dark color). Again, Im talking about the final edge bevels of the blade that are 1/32 to 1/8 of an inch wide.
Now, do a few strokes and observe the bevel. If the marker is only being removed near the shoulder of the bevel, it means you are grinding at too low of an angle. If the marker is only being removed in an ultra-thin line near the cutting edge, your grind angle is too high. What you want to see is no marker at all. It should get removed, evenly, from the whole edge bevel. This indicates that you are grinding flat on the bevel, which you can feel using secret #1. Well, now you can SEE it too.
If you do this with enough blades, youll probably find that you arent really grinding in some spots on the blade hardly at all. This is most common at the very tip and at the choil (heel). Sharpie can help you correct this so that you hit the whole blade during sharpening.
Observation should form a feedback loop when sharpening. Do a little work. Observe. Adjust if necessary. Do a little work. Observe. Adjust if necessary. Repeat. The goal is to have the observation confirm that you are grinding correctly. Or to show you minor variations that you might want to correct. When you start doing this, youll have to correct often. Thats ok. Its expected. As you gain more experience, youll correct less often and make smaller and smaller corrections. Dont be afraid to apply the sharpie many times during sharpening. Its not uncommon to reapply 4, 5, or 6 times on each side. If you want to get it perfect, youll want to observe often.
Note that observation is not just a visual thing. Secret #1 is actually an observational technique too. You use your sense of touch to feel where the bevel is. Touch can tell you other things as you progress. Sound plays a role also. Grinding at too high an angle produces a sound as the blade digs into the stone. Too low an angle sounds (and feels!) different.
You shouldnt try to do ALL of this all at the same time. Youll overwhelm yourself with too much input. But as you progress, youll notice things. Pay attention.
This is one of the longer explanations in this series. Thats because its one of the most important of all of the secrets. This one can really change sharpening for you. It did for me.
Brian.
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Secret #5: Selective Grinding:
If you sharpen enough blades, sooner or later youre going to find one thats more dull or damaged in one spot than all the others. This is very common, particularly near the front of the blade. People tend to use the point and the first few inches more than the rest of the blade, so it tends to be the dullest part.
Youll also find blades where, despite your best efforts at holding the correct angle, some of the sharpie just doesnt get removed on some parts of the blade. These areas need more work than the rest; so more grinding is required.
So the answer is simple: Grind more in the spots that need it more. Its so obvious, I cant believe I never thought of doing it until someone mentioned it. Its totally ok and expected to do 10, 15, or even 20 back and forth strokes on one concentrated area of the blade.
For example, if the tip is very blunt, I might sharpen normally all the way to the tip. Then spend 5 to 10 extra strokes *right* on the tip, using my finger pressure (from secret #2) to apply the grinding force to the part of the tip Im trying to grind. After doing repeated strokes, Ill then do several full length strokes to blend the bevel together. Use your judgement, and Observe the blade. If you start to widen the bevel at the spot you are working on, youve gone too far. Blending strokes along the entire bevel, in between concentrating grinding in one spot, will help prevent you from making the bevel too wide, or otherwise making it cosmetically unappealing.
Of course you want to use Observation the entire time to check your work. Check to make sure youre removing the sharpie. Check the bevel widths and see if they are changing as you grind. In some cases, you might be trying to increase the width of an area that wasnt properly ground before. This is very common with factory edges, especially at the heel of the blade.
Selective grinding will save you time and steel. By selectively grinding the areas that need it, youll save steel in the areas that dont. Youll save time by only grinding in the areas that need it.
Brian.
If you sharpen enough blades, sooner or later youre going to find one thats more dull or damaged in one spot than all the others. This is very common, particularly near the front of the blade. People tend to use the point and the first few inches more than the rest of the blade, so it tends to be the dullest part.
Youll also find blades where, despite your best efforts at holding the correct angle, some of the sharpie just doesnt get removed on some parts of the blade. These areas need more work than the rest; so more grinding is required.
So the answer is simple: Grind more in the spots that need it more. Its so obvious, I cant believe I never thought of doing it until someone mentioned it. Its totally ok and expected to do 10, 15, or even 20 back and forth strokes on one concentrated area of the blade.
For example, if the tip is very blunt, I might sharpen normally all the way to the tip. Then spend 5 to 10 extra strokes *right* on the tip, using my finger pressure (from secret #2) to apply the grinding force to the part of the tip Im trying to grind. After doing repeated strokes, Ill then do several full length strokes to blend the bevel together. Use your judgement, and Observe the blade. If you start to widen the bevel at the spot you are working on, youve gone too far. Blending strokes along the entire bevel, in between concentrating grinding in one spot, will help prevent you from making the bevel too wide, or otherwise making it cosmetically unappealing.
Of course you want to use Observation the entire time to check your work. Check to make sure youre removing the sharpie. Check the bevel widths and see if they are changing as you grind. In some cases, you might be trying to increase the width of an area that wasnt properly ground before. This is very common with factory edges, especially at the heel of the blade.
Selective grinding will save you time and steel. By selectively grinding the areas that need it, youll save steel in the areas that dont. Youll save time by only grinding in the areas that need it.
Brian.
Secret #6: The Burr:
At this point we have a lot of good techniques. We should be able to grind a bevel very evenly and consistently along its entire length. We can check to see that we are grinding where we are supposed to and make corrections as necessary. Theres just one thing missing. How do we know when to stop? The answer, is secret #6, The Burr.
The burr has been discussed and detailed in a lot of sharpening literature. Im just going to briefly cover what it is and then get to what I think is important. What is the burr? The burr is a curl of metal that forms when grinding reaches the edge. The burr is a positive indication that you have ground the bevel until it hit the apex. In most cases, this means you are done grinding on that side of the blade. Heres a picture showing the burr forming on the opposite side from the grinding.
http://www.knifeplanet.net/wp-content/uploads/2015/10/raising-the-burr.jpg
The burr tells you that you are done grinding. Form a burr on one side of the blade, full length. Then grind the other side of the blade until you get a second full length burr on the other side. Now remove the remaining burr. This tiny paragraph is a summary of a complete sharpening of a blade. Thats it.
If theres a secret about the burr, its this: You must make a full length burr on each side of the edge in order to correctly grind the edge bevels. Full length is the important part here. Many people, myself included, check for a burr and as SOON as we detect a burr in one spot, we switch to the other side of the blade. This is wrong. Once you have a burr formed in one section of the edge, you should continue sharpening until you can detect the burr along the ENTIRE length of the blade. Use secret #5, selective grinding, to concentrate your work on the areas that dont have a burr yet. Do blending strokes. At some point, you will probably be grinding an area less than 1 inch wide. The burr will have formed on the whole edge, except for this one section. Continue grinding in that area until you get a burr, or that part of the blade will never be truly sharp. This is the real secret of the burr.
The three important aspects of the burr are:
1. How to form a burr.
2. How to detect the burr.
3. How to remove the burr when you are done.
Forming a burr:
This is simple. Just keep grinding, using all of your tools and techniques, until the edge bevel reaches the apex and a burr will form. Keep going until you have a burr along the entire edge from heel to tip.
Detecting the burr:
There are many, many different ways of detecting this delicate curl of metal. Feeling with your finger tips seems to be the most popular way. Here are a few for you to try. If you need help with this, seek out other resources that detail burr detection. This is a HUGELY important part of sharpening, so you want to get it right.
A. Sliding your fingers off of the edge. Move your fingers from spine to edge on the blade, trying to feel the curl of the burr digging into your finger prints. This illustration should explain it well:
http://www.egullet.com/imgs/egci/sharpen/sharpen13.jpg
He is moving his fingers *away* from the edge. Hes not trying to cut himself. Hes moving away from the edge, trying to feel the curl of the burr.
B. Testing for sharpness, both directions. Have you used your thumb to test a blade for sharpness by moving across the edge? You can use this to detect the burr. Stroke your thumb on the edge as normal feeling for sharpness. Now spin the blade around so the left and right sides of the blade swap places. Do your test for sharpness again. Did it feel sharper one way than the other? If so, the side that felt sharper has a burr. Thats because the burr is thinner than the real edge, and it digs into your finger prints more deeply. This works surprisingly well with a little experimentation.
C. The fingernail catch. Slide your fingernail from spine to edge on the blade. When it reaches the edge, it should just slide right off of the blade. If you have a nice big burr though, the burr will catch your fingernail and stop it. Its sort of an amazing feeling actually. This is a very positive test that you pretty much cant get a false positive from. It either catches your fingernail and stops it, or it doesnt.
Burr Removal:
Once youve raised a burr on one side, switched sides, and then raised a full length burr on the opposite side, you want to remove the burr completely, leaving behind a clean crisp edge. Again, there are many many ways of doing this. Seek out another resource for more complete directions and techniques for burr removal. Im just going to highlight a few that I like.
A. The double angle technique. Lets say youve been sharpening at roughly 15 degrees per side. Youve formed the burr twice and youre ready to remove it. Put the side with the burr down on the stone. Now raise your angle to roughly 30 degrees. It doesnt need to be exact at all. Just a much higher angle than you were using. Now, do 1 or 2 very, very light strokes. Not even the weight of the blade. Flip the blade over and do 1 very light stroke on that side. If youve done it correctly, the burr should be essentially gone from both sides. Check and see. If some burr remains do another single light stroke on the side with the burr and check again. Once its gone, lower the angle back down to the original and do one light stroke per side, switching sides after each stroke. Do perhaps 3 to 5 of these original angle strokes and your blade should be done.
B. Drawing through wood, cork, or felt. Just lightly running the length of the blade through end grain of wood, a wine cork, or hard packed felt can rip the burr off. This is most useful when the burr is very small or there are just little burr chunks remaining on the edge. Notice the gray or black residue thats left on the cork or wood. Experiment with this and see how it works for you.
C. Deburring directly on the stone. If you are very careful with light strokes, you can remove the burr fully, at the original angle, just by using light pressure and checking after each stroke. Ken Schwartz advocates doing sideways strokes, parallel to the stone (not forward, not backwards, but sideways) to grind the burr off. Ive had limited success with this and I only mention it because Ken is exceptionally skilled. Ive had my best results removing the burr at the original angle by doing forward strokes only.
What if you cant seem to form a burr? Use secret #4 observation. Use the reflected light technique to see if the blade edge is reflecting light. If it reflects light, its dull enough that more grinding is necessary to form a burr. Reflected light (directly on the edge) is a really good way to monitor your progress. Once the reflections disappear, you are very close to forming a burr.
Learn to detect the burr consistently. Work on making a full length burr every time you sharpen. On both sides. If youve never formed a full length burr before, youre probably going to be rather surprised by the resulting edge. I know the first time I did it, it changed everything for me. I couldnt believe that I just hadnt been grinding for long enough. My edges improved markedly once I got this figured out.
Learn to deburr fully. This can be tricky. If my example methods above dont work well for you, seek out the advice and techniques of others. Burr removal is absolutely essential to forming clean, crisp, durable edges.
Master this and youll be well on your way to making outstanding edges.
Brian.
At this point we have a lot of good techniques. We should be able to grind a bevel very evenly and consistently along its entire length. We can check to see that we are grinding where we are supposed to and make corrections as necessary. Theres just one thing missing. How do we know when to stop? The answer, is secret #6, The Burr.
The burr has been discussed and detailed in a lot of sharpening literature. Im just going to briefly cover what it is and then get to what I think is important. What is the burr? The burr is a curl of metal that forms when grinding reaches the edge. The burr is a positive indication that you have ground the bevel until it hit the apex. In most cases, this means you are done grinding on that side of the blade. Heres a picture showing the burr forming on the opposite side from the grinding.
http://www.knifeplanet.net/wp-content/uploads/2015/10/raising-the-burr.jpg
The burr tells you that you are done grinding. Form a burr on one side of the blade, full length. Then grind the other side of the blade until you get a second full length burr on the other side. Now remove the remaining burr. This tiny paragraph is a summary of a complete sharpening of a blade. Thats it.
If theres a secret about the burr, its this: You must make a full length burr on each side of the edge in order to correctly grind the edge bevels. Full length is the important part here. Many people, myself included, check for a burr and as SOON as we detect a burr in one spot, we switch to the other side of the blade. This is wrong. Once you have a burr formed in one section of the edge, you should continue sharpening until you can detect the burr along the ENTIRE length of the blade. Use secret #5, selective grinding, to concentrate your work on the areas that dont have a burr yet. Do blending strokes. At some point, you will probably be grinding an area less than 1 inch wide. The burr will have formed on the whole edge, except for this one section. Continue grinding in that area until you get a burr, or that part of the blade will never be truly sharp. This is the real secret of the burr.
The three important aspects of the burr are:
1. How to form a burr.
2. How to detect the burr.
3. How to remove the burr when you are done.
Forming a burr:
This is simple. Just keep grinding, using all of your tools and techniques, until the edge bevel reaches the apex and a burr will form. Keep going until you have a burr along the entire edge from heel to tip.
Detecting the burr:
There are many, many different ways of detecting this delicate curl of metal. Feeling with your finger tips seems to be the most popular way. Here are a few for you to try. If you need help with this, seek out other resources that detail burr detection. This is a HUGELY important part of sharpening, so you want to get it right.
A. Sliding your fingers off of the edge. Move your fingers from spine to edge on the blade, trying to feel the curl of the burr digging into your finger prints. This illustration should explain it well:
http://www.egullet.com/imgs/egci/sharpen/sharpen13.jpg
He is moving his fingers *away* from the edge. Hes not trying to cut himself. Hes moving away from the edge, trying to feel the curl of the burr.
B. Testing for sharpness, both directions. Have you used your thumb to test a blade for sharpness by moving across the edge? You can use this to detect the burr. Stroke your thumb on the edge as normal feeling for sharpness. Now spin the blade around so the left and right sides of the blade swap places. Do your test for sharpness again. Did it feel sharper one way than the other? If so, the side that felt sharper has a burr. Thats because the burr is thinner than the real edge, and it digs into your finger prints more deeply. This works surprisingly well with a little experimentation.
C. The fingernail catch. Slide your fingernail from spine to edge on the blade. When it reaches the edge, it should just slide right off of the blade. If you have a nice big burr though, the burr will catch your fingernail and stop it. Its sort of an amazing feeling actually. This is a very positive test that you pretty much cant get a false positive from. It either catches your fingernail and stops it, or it doesnt.
Burr Removal:
Once youve raised a burr on one side, switched sides, and then raised a full length burr on the opposite side, you want to remove the burr completely, leaving behind a clean crisp edge. Again, there are many many ways of doing this. Seek out another resource for more complete directions and techniques for burr removal. Im just going to highlight a few that I like.
A. The double angle technique. Lets say youve been sharpening at roughly 15 degrees per side. Youve formed the burr twice and youre ready to remove it. Put the side with the burr down on the stone. Now raise your angle to roughly 30 degrees. It doesnt need to be exact at all. Just a much higher angle than you were using. Now, do 1 or 2 very, very light strokes. Not even the weight of the blade. Flip the blade over and do 1 very light stroke on that side. If youve done it correctly, the burr should be essentially gone from both sides. Check and see. If some burr remains do another single light stroke on the side with the burr and check again. Once its gone, lower the angle back down to the original and do one light stroke per side, switching sides after each stroke. Do perhaps 3 to 5 of these original angle strokes and your blade should be done.
B. Drawing through wood, cork, or felt. Just lightly running the length of the blade through end grain of wood, a wine cork, or hard packed felt can rip the burr off. This is most useful when the burr is very small or there are just little burr chunks remaining on the edge. Notice the gray or black residue thats left on the cork or wood. Experiment with this and see how it works for you.
C. Deburring directly on the stone. If you are very careful with light strokes, you can remove the burr fully, at the original angle, just by using light pressure and checking after each stroke. Ken Schwartz advocates doing sideways strokes, parallel to the stone (not forward, not backwards, but sideways) to grind the burr off. Ive had limited success with this and I only mention it because Ken is exceptionally skilled. Ive had my best results removing the burr at the original angle by doing forward strokes only.
What if you cant seem to form a burr? Use secret #4 observation. Use the reflected light technique to see if the blade edge is reflecting light. If it reflects light, its dull enough that more grinding is necessary to form a burr. Reflected light (directly on the edge) is a really good way to monitor your progress. Once the reflections disappear, you are very close to forming a burr.
Learn to detect the burr consistently. Work on making a full length burr every time you sharpen. On both sides. If youve never formed a full length burr before, youre probably going to be rather surprised by the resulting edge. I know the first time I did it, it changed everything for me. I couldnt believe that I just hadnt been grinding for long enough. My edges improved markedly once I got this figured out.
Learn to deburr fully. This can be tricky. If my example methods above dont work well for you, seek out the advice and techniques of others. Burr removal is absolutely essential to forming clean, crisp, durable edges.
Master this and youll be well on your way to making outstanding edges.
Brian.
Secret #7: The Coarse Stone:
A lot of beginners are told to not use too coarse of a stone to start with. The idea being that they can do less damage to a blade with a finer stone. I think this advice is backwards and flat out wrong. Heres why:
A coarse stone:
Shows grind lines more easily, thus allowing you to monitor your progress more easily (secret #4).
Allows you to make progress faster, thus preventing fatigue. Fatigue destroys angle holding ability, which makes edges worse.
A feedback loop is formed by grinding flat on a coarse stone: The edge bevels become flatter faster, thus increasing the *feeling* of the bevel on the stone (secret #1), which improves the ability of the sharpener to hold a consistent angle, which makes the overall edge better and flatter.
I think everyone should start any big sharpening job with a very coarse stone. How coarse? I like the DMT XXC, which is 120 micron, or about 100 grit. This is very similar to a Norton Coarse Crystolon (silicon carbide), which also grinds very fast Im told. Essentially, unless you have a some really exotic super coarse stone, you should start every big sharpening job with the coarsest stone you own.
Lets define that: A big sharpening job is one where you will significantly grind the bevels. You might be removing nicks, sharpening an abused or neglected blade, or even changing the edge angle to a lower angle. These jobs need a coarse stone. Touchups and minor sharpening dont qualify.
Here are a few things many people, even experienced sharpeners, dont know about coarse stones:
1. They can make really sharp edges. Something in the 220 to 350 grit range, like a DMT C, can make edges that pop hair off of your arm. I was totally shocked the first time I made a hair shaving edge from a DMT C. Now I can make an even sharper edge from the DMT C. Sharpness does not equal refinement. In other words, a fine stone is not necessary for a very sharp edge. A fine stone is only necessary for a polished edge.
2. Edges made on coarse stones can cut abrasive materials *better* than highly polished edges. In my experience, the difference between a ~600 grit edge and a ~100 grit edge, when cutting cardboard is about a 2 to 3 times edge holding difference. The 100 grit edge holds its edge for much longer when cutting things like cardboard.
In summary: The coarse stone is your friend. It will get you results faster, which actually means youll get better results because you dont get fatigued as fast. It will give you better psychological results as well, promoting your feeling of accomplishment. This is no small task when learning a new skill. Or even practicing an old skill. Coarse stones can make very sharp edges. Coarse edges can last longer for abrasive cutting tasks.
If you dont have a stone thats at least ~200 grit, you need one. This is another one of the secrets that dramatically improved my sharpening. I hope it does for you too.
Brian.
A lot of beginners are told to not use too coarse of a stone to start with. The idea being that they can do less damage to a blade with a finer stone. I think this advice is backwards and flat out wrong. Heres why:
A coarse stone:
Shows grind lines more easily, thus allowing you to monitor your progress more easily (secret #4).
Allows you to make progress faster, thus preventing fatigue. Fatigue destroys angle holding ability, which makes edges worse.
A feedback loop is formed by grinding flat on a coarse stone: The edge bevels become flatter faster, thus increasing the *feeling* of the bevel on the stone (secret #1), which improves the ability of the sharpener to hold a consistent angle, which makes the overall edge better and flatter.
I think everyone should start any big sharpening job with a very coarse stone. How coarse? I like the DMT XXC, which is 120 micron, or about 100 grit. This is very similar to a Norton Coarse Crystolon (silicon carbide), which also grinds very fast Im told. Essentially, unless you have a some really exotic super coarse stone, you should start every big sharpening job with the coarsest stone you own.
Lets define that: A big sharpening job is one where you will significantly grind the bevels. You might be removing nicks, sharpening an abused or neglected blade, or even changing the edge angle to a lower angle. These jobs need a coarse stone. Touchups and minor sharpening dont qualify.
Here are a few things many people, even experienced sharpeners, dont know about coarse stones:
1. They can make really sharp edges. Something in the 220 to 350 grit range, like a DMT C, can make edges that pop hair off of your arm. I was totally shocked the first time I made a hair shaving edge from a DMT C. Now I can make an even sharper edge from the DMT C. Sharpness does not equal refinement. In other words, a fine stone is not necessary for a very sharp edge. A fine stone is only necessary for a polished edge.
2. Edges made on coarse stones can cut abrasive materials *better* than highly polished edges. In my experience, the difference between a ~600 grit edge and a ~100 grit edge, when cutting cardboard is about a 2 to 3 times edge holding difference. The 100 grit edge holds its edge for much longer when cutting things like cardboard.
In summary: The coarse stone is your friend. It will get you results faster, which actually means youll get better results because you dont get fatigued as fast. It will give you better psychological results as well, promoting your feeling of accomplishment. This is no small task when learning a new skill. Or even practicing an old skill. Coarse stones can make very sharp edges. Coarse edges can last longer for abrasive cutting tasks.
If you dont have a stone thats at least ~200 grit, you need one. This is another one of the secrets that dramatically improved my sharpening. I hope it does for you too.
Brian.
- Joined
- Mar 7, 2001
- Messages
- 4,608
Brian,
Good stuff! :thumbup:
I guess there's no secret #8. It's right there within #4.
I'm surprised at what I see, even on edges I shave with.
Good stuff! :thumbup:
I guess there's no secret #8. It's right there within #4.
I'm surprised at what I see, even on edges I shave with.
- Joined
- Jun 24, 2013
- Messages
- 4,162
Wow. So much knowledge. Will come back here many times.
Thank you for your work.
Thank you for your work.
- Status