I am a little bit confused about burrs

[Mark Tomaras]

I’ve been practicing my sharpening for the past seven or eight months. I’m making progress slowly but surely, but of course with each bit of progress comes the realization that there are more details that you are overlooking.

Here is how I have been dealing with burr formation and what I am confused about. In the usual fashion, I will sharpen one side of the blade until I get a nice even burr. Then I will switch to the other side and sharpen that side until I get a burr. Finally I will remove the burr with some gentle edge leading strokes.

recently I saw some instruction about flipping sides of the knife more frequently while sharpening. I am confused about how to monitor the burr formation if I am switching sides while sharpening before a full and even burr forms on one side.

can the community please enlighten me with more details on sharpening practices, burr formation, and removal?

thank you!

 

[HumbleHomeCook]

My vote goes to sticking with full burr formation before flipping. But I also will do both sides two or more times with successively lighter pressure.

 

[sansho]

i've noticed that it seems to go faster if you split the difference and sharpen on both sides to build up the burr.

like let's say it's a knife i've never sharpened before, so i'm setting a new primary bevel with probably a different angle. i'm sharpening side A, but it just feels like it's taking forever. burr isn't happening. then i flip to side B and go for a while, then go back to A and bam. burr is happening.

idk

 

[HumbleHomeCook]

i've noticed that it seems to go faster if you split the difference and sharpen on both sides to build up the burr.

like let's say it's a knife i've never sharpened before, so i'm setting a new primary bevel with probably a different angle. i'm sharpening side A, but it just feels like it's taking forever. burr isn't happening. then i flip to side B and go for a while, then go back to A and bam. burr is happening.

idk

I agree, if I'm more or less re-profiling the edge bevel then yes, I will often flip back and forth to maintain an even grind before getting focused on the burr. But for standard sharpening I raise a burr, flip, raise a burr.

 

[Mark Tomaras]

i've noticed that it seems to go faster if you split the difference and sharpen on both sides to build up the burr.

like let's say it's a knife i've never sharpened before, so i'm setting a new primary bevel with probably a different angle. i'm sharpening side A, but it just feels like it's taking forever. burr isn't happening. then i flip to side B and go for a while, then go back to A and bam. burr is happening.

idk

Would you say that a burr that forms is the same burr for either side, as in, the burr is the burr for the blade? Or would you say that one should sharpen to form a burr on one side, and that burr is distinct from the burr on the other side?

I’m trying to understand if a blade forms a burr universally, or if each side of the knife forms its own burr under sharpening.

 

[tostadas]

I usually like to do both sides evenly and gradually until I develop a burr, which may not happen on the first pass.

Reason being, you will not create the burr until you reach the apex. And let's say the knife is super thick, the location of that apex will not necessarily be centered. And when you look for a burr again on the other side, you may get it quicker due to the apex being offset. So while the knife is technically sharpened, your edge will not be 50/50. So you will need to remove additional steel until you get that apex back to where it needs to be.

In the greatly exaggerated sketch below, I try to show this with a completely unsharpened edge. The top shows sharpening one side until apex, the bottom shows switching sides more frequently.

 

[ian]

There’s only one burr at any given time. I think what happens is that you raise a burr on one side, and that burr sort of hangs off to the other side because of the angle at which you were sharpening. When you switch to the other side, that burr may be partially abraded away. However, some of it can remain, and that part may at the end be part of the left side burr, although it usually isn’t noticeable when felt from the first side until you apex the edge on the second side.

@tosdadas’ point about apex location is a good one. I’d add in to that that it may be possible that there is also some burr produced on the other side that flips, which is why you feel it sooner, although I don’t think you’ll likely feel much before you do hit the apex, so maybe that effect is negligible. Also, I wouldn’t stress too much about moving the apex location at the moment. It’s probably very subtle in a normal sharpening.

 

[captaincaed]

I try to be as even as I can within reason until a burr is formed. Then make sure you can form the burr of.pretty even size on both sides, heel to tip.

I wouldn't recommend going all the way for a burr on one side, then switching. The illustration by tostdas above is fantastic and I can't do better.

The trick is to be patient until you begin to form a burr. If the process seems to take forever, check your sharpening angle. If that's where you want it, try a coarser stone for a couple minutes. If that fails, return to the boards here!

 

[HumbleHomeCook]

OP, I find Shawn's video on sharpening excellent:

 

[Benuser]

I start on one side far behind the edge and only little by little raise the spine, until the very edge has been reached. With new or unknown blades, I check with a marker and a loupe, as a burr can appear before the very edge has been reached. And I want to be sure not to overlook a microbevel.
After flipping sides I lightly deburr. And start again, behind the edge. I want to make sure the burr that eventually appears is a new one, and not the flipping old burr from sharpening the first side.

 

[Mark Tomaras]

There’s only one burr at any given time. I think what happens is that you raise a burr on one side, and that burr sort of hangs off to the other side because of the angle at which you were sharpening. When you switch to the other side, that burr may be partially abraded away. However, some of it can remain, and that part may at the end be part of the left side burr, although it usually isn’t noticeable when felt from the first side until you apex the edge on the second side.

@tosdadas’ point about apex location is a good one. I’d add in to that that it may be possible that there is also some burr produced on the other side that flips, which is why you feel it sooner, although I don’t think you’ll likely feel much before you do hit the apex, so maybe that effect is negligible. Also, I wouldn’t stress too much about moving the apex location at the moment. It’s probably very subtle in a normal sharpening.

Thank you for this insightful and detailed explanation!

 

[Nemo]

Here is how I have been dealing with burr formation and what I am confused about. In the usual fashion, I will sharpen one side of the blade until I get a nice even burr. Then I will switch to the other side and sharpen that side until I get a burr. Finally I will remove the burr with some gentle edge leading strokes.

...

can the community please enlighten me with more details on sharpening practices, burr formation, and removal?

You have received some good advice on how to go about forming the burr.

The next step is to reduce the burr by abrasion. This is often overlooked by beginners. It’s important because a fat burr will leave a fat apex if you snap it off while a fine burr will leave a fine apex. I use @Sailor 's reducing pressure method, as described in his knifeplanet.net sharpening school video. You will likely feel, and perhaps see bits of burr break off in the lighter pressure stages.

Any finer stones than the coarsest stone you will use should be used only to polish the edge with very light pressure.

The next step is to remove the burr. There are many techniques described. I use feather-light edge leading strokes followed by a longitudinal stroke along the edge. I sometimes use a few light passes trough cork or hard felt to remove any straggling bits of burr. People also describe stropping at slightly higher than edge angle passes as deburring techniques.

I then use a @Dave Martell technique of repeating the last couple of steps of sharpening. This could be feather light sharpening on my finest two stones, or the lightest two pressure levels if I'm just doing a touch up on a fine stone. Followed by deburring again. I was pretty impressed with the results of this approach.

The alternative is to use @Kippington 's deburring method (search the forum for "Kippington deburring video"). It seems very counter-intuitive but works very well. It allows you to bypass the reducing of the burr stages. You do end up with a microbevel, which is fine for kitchen use and ideal for highly alloyed steels (but not as good for shaving).

FWIW, I tend to use the KDM for high alloy steels and traditional deburring for carbon steels.

 

[Delat]

I then use a @Dave Martell technique of repeating the last couple of steps of sharpening. This could be feather light sharpening on my finest two stones, or the lightest two pressure levels if I'm just doing a touch up on a fine stone. Followed by deburring again. I was pretty impressed with the results of this approach.

This is good stuff I picked up from Nemo last year. I don’t have the patience to repeat much of the sharpening, so I adopted a grossly simplified version where I just repeat a few light edge-trailing strokes on my final stone after burr removal, then go through the deburring motions again. It definitely made a difference in the final edge for me - thanks @Nemo .

 

[Nemo]

This is good stuff I picked up from Nemo last year. I don’t have the patience to repeat much of the sharpening, so I adopted a grossly simplified version where I just repeat a few light edge-trailing strokes on my final stone after burr removal, then go through the deburring motions again. It definitely made a difference in the final edge for me - thanks @Nemo .

It's really just my summation of learnings from Sailor, Dave Martell and Kippington, so they should get the credit for it.

 

[mpier]

I’m definitely a counter and a flipper, I do the exact same amount of passes on both sides before I check for a burr and repeat the process with less passes if I do not feel a burr at first. I also try and keep the burr as minimal as possible. I find it may take a few more passes on the first stone to get the burr but in the long run gives me a much better edge overall.

 

[Mark Tomaras]

I’m definitely a counter and a flipper, I do the exact same amount of passes on both sides before I check for a burr and repeat the process with less passes if I do not feel a burr at first. I also try and keep the burr as minimal as possible. I find it may take a few more passes on the first stone to get the burr but in the long run gives me a much better edge overall.

I have been counting and flipping for a while, and then I thought I would try to go by feel. Perhaps a hybrid approach is good. Do you wait for a burr to flip, or have a more systematic counting approach?

 

[mpier]

I have been counting and flipping for a while, and then I thought I would try to go by feel. Perhaps a hybrid approach is good. Do you wait for a burr to flip, or have a more systematic counting approach?

I flip first do the same amount of strokes or passes then check for the burr and it almost always shows up but by doing it that way at least for me the burr tends to be on the finer side, not so heavy, harder to feel but much easier to remove.

 

[ModRQC]

I'll usually switch hands twice on the coarser stone in burr formation. I do not however do the first switch without having the start of a burr. I just don't get it hairy straight away, if you will. More interested by the consistency of the bevel cut related with burr formation at the early stage.

I don't see trouble either way - flipping before the burr or not - as long as you're consistent with both sides towards your goal with the blade at hand. I like to have a sign otherwise than what I see, so seeing a bevel that's cut right and getting to the apex consistently enough that I can feel a small consistent burr rising all along helps and I just don't like switching without the latter.

Just wanted to add I always check the other side to the burr as well. Very informative. The idea is to not just trust what's supposed to be there and often is, but also to verify if there's something where there should NOT be. Angle inconsistency - which is not necessarily a mark of poor skills but sometimes has to do with a blade profile you're less familiar with or some thicker point of the blade - or not flipping the burr entirely - which is not necessarily a sign that your strokes aren't right, but inconsistent pressure or different fingers placement from one side to the other - keep you informed of where/on what side you might need to adjust - or not.

 

[Benuser]

Just wanted to add I always check the other side to the burr as well. Very informative. The idea is to not just trust what's supposed to be there and often is, but also to verify if there's something where there should NOT be. Angle inconsistency - which is not necessarily a mark of poor skills but sometimes has to do with a blade profile you're less familiar with or some thicker point of the blade - or not flipping the burr entirely - which is not necessarily a sign that your strokes aren't right, but inconsistent pressure or different fingers placement from one side to the other - keep you informed of where/on what side you might need to adjust - or not.

Good point, especially with unknown, poorly maintained blades. With my old eyes I do need a permanent marker and a loupe to make sure I'm not overlooking inconsistencies. We tend to feel a burr where it is supposed to be, and suppose it's the same along the entire edge, as that's what happens with our own, scrupulously maintained knives. Reality can be different. Check for it.

 

[Delat]

I started off raising a full burr on one side, then I started flipping the knife once I felt a bit of a burr starting anywhere. The full burr would pop pretty quickly once I flipped.

These days I just go by feel. When it feels like I’ve done enough strokes and I suspect a burr is about to start, I go ahead and flip and that does the trick. I don’t love spending time with the stones and this saves me some time.

This is with knives that already have decent edges though and just need minor touchup, not super dull or unknown edges.

 

[Bico Doce]

The alternative is to use @Kippington 's deburring method (search the forum for "Kippington deburring video").

Thank you for referencing this, I had never heard or seen this method before. The video blew my mind. The results he got with zdp-189 in a matter of minutes with one course stone and a piece of paper was crazy. It made me rethink how I sharpen - this idea that you “need” a progression of grits. Maybe this should be in the unpopular opinions thread .

I tested the Kip method with a Munetoshi white 2 gyuto (a far cry from zdp-189) on a chosera 400. I finished it up by stropping on balsa wood/leather and 1/.5 micro diamond paste and it was about as sharp as I could have hoped for - clean slicing thru paper towel.

 

[HumbleHomeCook]

Thank you for referencing this, I had never heard or seen this method before. The video blew my mind. The results he got with zdp-189 in a matter of minutes with one course stone and a piece of paper was crazy. It made me rethink how I sharpen - this idea that you “need” a progression of grits. Maybe this should be in the unpopular opinions thread .

I tested the Kip method with a Munetoshi white 2 gyuto (a far cry from zdp-189) on a chosera 400. I finished it up by stropping on balsa wood/leather and 1/.5 micro diamond paste and it was about as sharp as I could have hoped for - clean slicing thru paper towel.

You absolutely do not need a progression and a knife should always be sharp off the coarsest stone being used. A lot of people think they can grit their way into sharpness but it doesn't work that way. Finer grits just add refinement and keenness.

 

[Bico Doce]

You absolutely do not need a progression and a knife should always be sharp off the coarsest stone being used. A lot of people think they can grit their way into sharpness but it doesn't work that way. Finer grits just add refinement and keenness.

When going thru a progression of stones, is the aim to create a burr at each stone? I personally only have only aimed for a burr on the coarsest stone but I’m interested to hear if anyone does it and the reasons/results from that method

 

[HumbleHomeCook]

When going thru a progression of stones, is the aim to create a burr at each stone? I personally only have only aimed for a burr on the coarsest stone but I’m interested to hear if anyone does it and the reasons/results from that method

That's one of the many sharpening topics of debate. I think this is another personal preference thing. Unless I'm just doing a very light touch up, I aim for a burr on all my stones. It's just how I sharpen and have confidence in my apex. The burr gets lighter as I work up but I still try to achieve one.

Many others do not.

 

[Bico Doce]

That's one of the many sharpening topics of debate. I think this is another personal preference thing. Unless I'm just doing a very light touch up, I aim for a burr on all my stones. It's just how I sharpen and have confidence in my apex. The burr gets lighter as I work up but I still try to achieve one.

Many others do not.

Is there max grit you stop at when creating burrs? I imagine you’re not creating a burr with a 8k stone

 

[HumbleHomeCook]

Is there max grit you stop at when creating burrs? I imagine you’re not creating a burr with a 8k stone

My finest stone is a SG4k.

 

[Nemo]

Thank you for referencing this, I had never heard or seen this method before. The video blew my mind. The results he got with zdp-189 in a matter of minutes with one course stone and a piece of paper was crazy. It made me rethink how I sharpen - this idea that you “need” a progression of grits. Maybe this should be in the unpopular opinions thread .

I tested the Kip method with a Munetoshi white 2 gyuto (a far cry from zdp-189) on a chosera 400. I finished it up by stropping on balsa wood/leather and 1/.5 micro diamond paste and it was about as sharp as I could have hoped for - clean slicing thru paper towel.

No problem.

The KDM is also useful when the geometry BTE is very thin. See my thread "Aus8 burrs".

Keep in mind, the KDM will leave a microbevel (albeit a very clean one) which will slightly reduce sharpness and significantly increase edge stability. It's still more than sharp ebough for anything you would use a double bevel knife for but maybe not quite as good at push cutting kitchen paper.

The other downside of a microbevel is that it can be difficult to touch up. See @Benuser 's interesting thread "maintaining a microbevel".

I definitely agree that your most important stone is the coarsest stone in your progression. The knife should be sharp after this. On subsequent stones, you would ideally polish the edge to the point where a burr is barely raised but I like to be certain that I have hit the edge, so on subsequent stones, I polish with very light pressure until I can just feel a burr. It shouldn't take much if your apex is already crisp.

FWIW, I rarely go beyond Chosera 3k (about 4k JIS) these days, unless I am showing off my kitchen paper cutting abilities to myself on a carbon steel blade. Having said that, you can definitely create a burr on an 8k stone.

 

[Benuser]

No particular effort is needed to raise a burr once you're further in the progression. They just appear. After all, the bevels have met before with the coarser stones. Even with very fine stones there's one within a few strokes, unless you really do your best to avoid them, e.g. by flipping sides after every single stroke. That said, hard to establish whether it's a new burr or a remnant of the old one, you didn't entirely remove on the previous stone.
By the way, especially on coarser stones, make sure to have a light touch so you only abrade the burr and not push it to the other side without abrading much of it. And don't let your stroke be so long it creates a new burr, which would be a waste of material, as often seen with edge trailing strokes.

 

[cotedupy]

The alternative is to use @Kippington 's deburring method (search the forum for "Kippington deburring video"). It seems very counter-intuitive but works very well. It allows you to bypass the reducing of the burr stages. You do end up with a microbevel, which is fine for kitchen use and ideal for highly alloyed steels (but not as good for shaving).

May I ask you and perhaps @Kippington a q. regarding this...

I've started doing this a bit; not always but sometimes, particularly on knives or stones where I'm having trouble deburring, or getting rid of wire edges, and finding it works very nicely . Is there any difference, practical or theoretical, between this method and what people call 'jointing'?

They seem the same to me, or am I missing something...?

 

[ian]

May I ask you and perhaps @Kippington a q. regarding this...

I've started doing this a bit; not always but sometimes, particularly on knives or stones where I'm having trouble deburring, or getting rid of wire edges, and finding it works very nicely . Is there any difference, practical or theoretical, between this method and what people call 'jointing'?

They seem the same to me, or am I missing something...?

Seems pretty similar, but with “jointing” people are using a 90 degree angle and breadknifing, whereas with Kipp’s method the angle’s not quite as high and part of the point is to have some movement in the direction perpendicular to the edge. In other words, with jointing the point seems to be to completely remove the burr with one stroke, whereas with Kipp’s method you fold the burr over to one side with the high angle pass, and then cut it off from the other side. The principle is similar though.