Micro burrs: at what point is a burr a non-issue?

[Jamesh Bond]

Recent threads have got me wondering about micro burrs, Bigfoot, and my own sanity.

Here we go.

My sharpening technique is pretty dang good, and I'd confidently say I'm current on the necessary knowledge of the art. However, in spite of my best efforts, I nearly ALWAYS end up with what appears to be microscopic burr on the length of my edges when I finish with ceramics. Yes, I know the tricks, and have tried everything to remove it. I can get it off if I really try, but at the cost of time, frustration, and edge precision. Incidentally, my go-to sharpening method no longer uses those ceramics to finish. Now I just avoid the problem in the first place.

But nevertheless. . .

This post isn't about burr
removal. I'll figure that out as I practice.

What I'm posting about is this:
Even though I can SEE this "micro burr" thing, it doesn't actually seem to be a problem. I can't remove it through sharpening, dragging through wood, stropping, or even use.

I've sliced tons of cardboard and whittled wood, fully expecting my knife to go dull as the burr breaks off. But the knife keeps cutting, still shaving hair and slicing paper cleanly. Yet I can see it the whole time, if I look very carefully in the right light.

Needless to say, this goes against everything I understand about burrs and wire edges, so I started questioning my sanity and eyes. Thought MAYBE I was seeing a tiny microbevel, thinking it was a burr. I highly doubt it tho. Magnification is difficult, but doesn't appear to show a bevel. Looks like a "foil" edge.

This observation has been going on a long time, with predictable and repeatable results.

In summary, I'm pretty sure many of my edges are sporting micro burrs, but are showing none of the problems they are known to cause. Performance and edge retention are fine. The only way I even know about the existence of the burr is because I know to look. OCD much??

So I'm wondering your thoughts on this interesting phenomenon.

Is there always some remnant of a burr, no matter what? I just have super evolved sight and senses that allow me to see it when most of the sharpening world can't?

Why can I see it, yet not notice it's affects?

Why is my knife still cutting well?
Why hasn't the burr came off?

Its peculiar to be sharpening and using my knives the same way as everyone else with the only difference in my story being the existence of that little wire edge.

So am I seeing things? Or are other people simply NOT seeing this, and assume they removed it?

Or am I as insane as I've grown to suspect?

Yikes. So strange!

Looking forward to your answers and insights on this one. Been bothering me for quite awhile now.

Thx!

 

[ToddS]

Are you finishing with an edge trailing stroke on the hone?

I prefer to distinguish between a burr and a foil-edge, where a burr is thicker and usually the result of repeated abrasion on one side. A foil edge is much finer and results from edge-trailing strokes. Typically, a foil is difficult to see without a 500x microscope and too thin to feel with your fingers the way you can with a burr. These foils are very flexible, and don't break off easily.


In my experience, stropping on a hanging denim strop loaded with metal polish will remove these foils with 100% efficiency. Try this and if whatever you "see" is still there, then I don't think it's a foil.

 

[Gaston444]

I can't see some micro folds if they are small, but everyone can feel them by the grabbing of some whitish material from the nail. It will grab on one side and not on the other. If you don't use the nail method (or magnifiers), probably most people think they don't have a fold and they cut with them anyway...

As long as its below nail grabbing, it doesn't exist to me.

Micro-folds can last for slicing, but they won't last for chopping into wood: They usually fold to one side under that kind of strain, even if not right away. I've also found that batoning at or below 15 degrees per side creates micro-folds, which means I avoid this particular "trick" like the black plague, but most have either more open edges or don't notice...

Many knives, especially customs or some full height heavy re-grinds, will create micro-folds while chopping wood at or below 15 degrees per side, but a minority won't. Generally more reliable at not doing this -and still not chip- are factory knives, especially those made in Japan...

Gaston

 

[Jamesh Bond]

Thx for responding, Todd.

However burr removal techniques are not what I'm after in this thread. I have the knowledge i need for that.

I'm aware that my wordy attempts to be through and explain clearly always end up muddying my point tho! Lol.

What I'm after is hopefully something that can explain the strange paradox I seem to be experiencing.

Take care.

 

[Jamesh Bond]

Gaston.

My issue isn't behaving like a micro fold either. Although I'm not chopping (folding edc), I did a lot of heavy whittling to see what would happen.

No loss of cutting ability. Yet the anomaly remains visible.

That's what baffles me so!

Thx.

 

[awestib]

Recent threads have got me wondering about micro burrs, Bigfoot, and my own sanity.

Here we go.

My sharpening technique is pretty dang good, and I'd confidently say I'm current on the necessary knowledge of the art. However, in spite of my best efforts, I nearly ALWAYS end up with what appears to be microscopic burr on the length of my edges when I finish with ceramics. Yes, I know the tricks, and have tried everything to remove it. I can get it off if I really try, but at the cost of time, frustration, and edge precision. Incidentally, my go-to sharpening method no longer uses those ceramics to finish. Now I just avoid the problem in the first place.

But nevertheless. . .

This post isn't about burr
removal. I'll figure that out as I practice.

What I'm posting about is this:
Even though I can SEE this "micro burr" thing, it doesn't actually seem to be a problem. I can't remove it through sharpening, dragging through wood, stropping, or even use.

I've sliced tons of cardboard and whittled wood, fully expecting my knife to go dull as the burr breaks off. But the knife keeps cutting, still shaving hair and slicing paper cleanly. Yet I can see it the whole time, if I look very carefully in the right light.

Needless to say, this goes against everything I understand about burrs and wire edges, so I started questioning my sanity and eyes. Thought MAYBE I was seeing a tiny microbevel, thinking it was a burr. I highly doubt it tho. Magnification is difficult, but doesn't appear to show a bevel. Looks like a "foil" edge.

This observation has been going on a long time, with predictable and repeatable results.

In summary, I'm pretty sure many of my edges are sporting micro burrs, but are showing none of the problems they are known to cause. Performance and edge retention are fine. The only way I even know about the existence of the burr is because I know to look. OCD much??

So I'm wondering your thoughts on this interesting phenomenon.

Is there always some remnant of a burr, no matter what? I just have super evolved sight and senses that allow me to see it when most of the sharpening world can't?

Why can I see it, yet not notice it's affects?

Why is my knife still cutting well?
Why hasn't the burr came off?

Its peculiar to be sharpening and using my knives the same way as everyone else with the only difference in my story being the existence of that little wire edge.

So am I seeing things? Or are other people simply NOT seeing this, and assume they removed it?

Or am I as insane as I've grown to suspect?

Yikes. So strange!

Looking forward to your answers and insights on this one. Been bothering me for quite awhile now.

Thx!

Could it be just a certain "different" light reflection (microbevel with a slightly different grind pattern for instance)? Does not sound like a burr or wired edge to me!

 

[HeavyHanded]

Recent threads have got me wondering about micro burrs, Bigfoot, and my own sanity.

Here we go.

My sharpening technique is pretty dang good, and I'd confidently say I'm current on the necessary knowledge of the art. However, in spite of my best efforts, I nearly ALWAYS end up with what appears to be microscopic burr on the length of my edges when I finish with ceramics. Yes, I know the tricks, and have tried everything to remove it. I can get it off if I really try, but at the cost of time, frustration, and edge precision. Incidentally, my go-to sharpening method no longer uses those ceramics to finish. Now I just avoid the problem in the first place.

But nevertheless. . .

This post isn't about burr
removal. I'll figure that out as I practice.

What I'm posting about is this:
Even though I can SEE this "micro burr" thing, it doesn't actually seem to be a problem. I can't remove it through sharpening, dragging through wood, stropping, or even use.

I've sliced tons of cardboard and whittled wood, fully expecting my knife to go dull as the burr breaks off. But the knife keeps cutting, still shaving hair and slicing paper cleanly. Yet I can see it the whole time, if I look very carefully in the right light.

Needless to say, this goes against everything I understand about burrs and wire edges, so I started questioning my sanity and eyes. Thought MAYBE I was seeing a tiny microbevel, thinking it was a burr. I highly doubt it tho. Magnification is difficult, but doesn't appear to show a bevel. Looks like a "foil" edge.

This observation has been going on a long time, with predictable and repeatable results.

In summary, I'm pretty sure many of my edges are sporting micro burrs, but are showing none of the problems they are known to cause. Performance and edge retention are fine. The only way I even know about the existence of the burr is because I know to look. OCD much??

So I'm wondering your thoughts on this interesting phenomenon.

Is there always some remnant of a burr, no matter what? I just have super evolved sight and senses that allow me to see it when most of the sharpening world can't?

Why can I see it, yet not notice it's affects?

Why is my knife still cutting well?
Why hasn't the burr came off?

Its peculiar to be sharpening and using my knives the same way as everyone else with the only difference in my story being the existence of that little wire edge.

So am I seeing things? Or are other people simply NOT seeing this, and assume they removed it?

Or am I as insane as I've grown to suspect?

Yikes. So strange!

Looking forward to your answers and insights on this one. Been bothering me for quite awhile now.

Thx!

In my experience once the burr gets "too small to see with the naked eye" it is not going to be an issue for 90% of all knife tasks. I've gone back and taken a look at some of my hasty sharpening jobs, meaning I did no more QC than rub across with fingerpads to check for more catch on one side of the blade or other and a quick look by naked eye in OK lighting. The edges hold up fine. Looked at later I can usually see some left over burring in spots. Woodworking tools really benefit from 100% burr free, most utility cutting it really is not a big deal.

Is more of a QC thing to ensure max life, but even then there are times the burr won't matter much.

I suspect many people have smaller wire edges that will never be an issue - I've even whittled a hair with a burred edge off of a ceramic hone. Better not to have them but I'd rather leave some remnant here and there than to round the edge with too many high angle passes or excessive stropping.

Is dependent on the steel and the abrasive type in addition to practices.

 

[Jamesh Bond]

Awestib, I really wanted to believe I was seeing what you just said! At least that would make sense.

But I've stared at these a ton, and they stand out in a certain way that microbevels don't.

I have pretty good eyes for close up, and a decent 10 power magnifier. Maybe a higher quality zoom would reveal it to be a microbevel, but at my current capabilities it still looks indisputably burr-like!

Thx.

 

[Jamesh Bond]

In my experience once the burr gets "too small to see with the naked eye" it is not going to be an issue for 90% of all knife tasks. I've gone back and taken a look at some of my hasty sharpening jobs, meaning I did no more QC than rub across with fingerpads to check for more catch on one side of the blade or other and a quick look by naked eye in OK lighting. The edges hold up fine. Looked at later I can usually see some left over burring in spots. Woodworking tools really benefit from 100% burr free, most utility cutting it really is not a big deal.

Is more of a QC thing to ensure max life, but even then there are times the burr won't matter much.

I suspect many people have smaller wire edges that will never be an issue - I've even whittled a hair with a burred edge off of a ceramic hone. Better not to have them but I'd rather leave some remnant here and there than to round the edge with too many high angle passes or excessive stropping.

Is dependent on the steel and the abrasive type in addition to practices.

That second to last paragraph is exactly why I switched my finishing method to end on DMT Fine. I can remove all traces of visible burrs on that in a couple passes, no problem. And the more aggressive edge cuts longer too. Been trying for years on the ceramics, but my technique just isn't there yet. I either settle with that visible and unnoticeable burr, or destroy my edge trying to raise the angle to cut it off. Frustrating.

Thx.

 

[Chris "Anagarika"]

This is exactly I wish we all can be physically together and compare notes.
It is VG10?

 

[Jamesh Bond]

Aus-8, 8cr, 154cm right off the top of my head.

 

[Chris "Anagarika"]

I never experienced the same with 8Cr. That's why I wish we all sit around & compare notes.
You can then show us what you see, etc.

This experience & knowledge sharing will expedite the collective knowledge growth!

 

[Jamesh Bond]

Agreed!

 

[Spey]

I was initially just going to make a short comment w/ plan to follow the thread as I was interested to see how might develop. Then thought might jump in with a few Q's to see if I might help.

... , in spite of my best efforts, I nearly ALWAYS end up with what appears to be microscopic burr on the length of my edges when I finish with ceramics.

Incidentally, my go-to sharpening method no longer uses those ceramics to finish. Now I just avoid the problem in the first place.

But nevertheless. . .

This post isn't about burr
removal. I'll figure that out as I practice.

What I'm posting about is this:
Even though I can SEE this "micro burr" thing, it doesn't actually seem to be a problem. I can't remove it through sharpening, dragging through wood, stropping, or even use.


This observation has been going on a long time, with predictable and repeatable results.

Couple questions related to the text above (capped from the OP).

Are you experiencing this phenomenon only when finishing with ceramics?

I am initially assuming your definition of "ceramics" does not include SiC stones (even though they contain ceramics), but that "ceramics" relate to the gray and white ceramic sticks & stones (I don't typically use these types of ceramics). Or, maybe you are using ceramics to define composite stones vs diamond embedded plates. Help me get on same page with this.

RE: the "predictable & repeatable results".
Is the described "bur" always on the same side (relative to last worked side), and is that side opposite the last side worked? (I am assuming yes)

Previoualy asked (more or less ...), are your finishing strokes (metal removal strokes) edge-leading or edge-leading?

Hand guided or fixed guide sharpening?

I mean to express no level of proficiency, other than best attempts to understand what I see & feel during sharpening. What I feel & see (under good light source), becomes keenly more clear as I use a loupe or microscope (what I mean by this, experience with higher magnification is greatly educational to what I see & feel without magnification). As an in-betweener I sometimes use my brinell hardness scope (lower magnification than microscope, but has embedded scale that is helpful in other ways). With that said, I don't believe a bur is an eventuality that I am having and unaware ..., but am interested to learn from others experiences and willing to share for common good.

Look forward to following where this goes (as comparison to what I think ;-)

Regards,

 

[Obsessed with Edges]

If 'seeing' this anomaly along the apex is in the form of seeing a thin band of reflected light, it could just be a very fine microbevel, and not a burr or wire edge at all. I did the same thing for years, as it was easy for me to unintentionally elevate the angle slightly in the last pass or two on the hone. Doing so will leave an extra, hair-thin bevel behind the apex, which will reflect light just like a folded burr would do. Especially if the microbevel is on just one side, it'll look exactly like a folded burr, by naked eye.

If a burr or wire was actually there, and it was prominent enough to actually SEE it by naked eye, it'd also be pretty easy to see it's effects on cutting as well. Shaving hair (from both sides of the apex) and cleanly slicing paper are two tests that will always reveal even tiny burrs, if they're even slightly folded or turned to one side or the other. And if they're really fine burrs, they will be folded after the first cut in most any material, even if they initially were aligned straight along the apex.


David

 

[Jamesh Bond]

I was initially just going to make a short comment w/ plan to follow the thread as I was interested to see how might develop. Then thought might jump in with a few Q's to see if I might help.



Couple questions related to the text above (capped from the OP).

Are you experiencing this phenomenon only when finishing with ceramics?

I am initially assuming your definition of "ceramics" does not include SiC stones (even though they contain ceramics), but that "ceramics" relate to the gray and white ceramic sticks & stones (I don't typically use these types of ceramics). Or, maybe you are using ceramics to define composite stones vs diamond embedded plates. Help me get on same page with this.

RE: the "predictable & repeatable results".
Is the described "bur" always on the same side (relative to last worked side), and is that side opposite the last side worked? (I am assuming yes)

Previoualy asked (more or less ...), are your finishing strokes (metal removal strokes) edge-leading or edge-leading?

Hand guided or fixed guide sharpening?

I mean to express no level of proficiency, other than best attempts to understand what I see & feel during sharpening. What I feel & see (under good light source), becomes keenly more clear as I use a loupe or microscope (what I mean by this, experience with higher magnification is greatly educational to what I see & feel without magnification). As an in-betweener I sometimes use my brinell hardness scope (lower magnification than microscope, but has embedded scale that is helpful in other ways). With that said, I don't believe a bur is an eventuality that I am having and unaware ..., but am interested to learn from others experiences and willing to share for common good.

Look forward to following where this goes (as comparison to what I think ;-)

Regards,

Im referring to hand sharpening on Spyderco Med and Fine Profile rods, AlOx, I believe.

I have no issue producing excellent quality, precise edges on my DMT C/F, also by hand, so I now use that exclusively. The phenomenon is also absent, so I usually only use this.

The strange burr I'm seeing only happens with the Spyderco Ceramics. It shows up from both sides.

I usually finish with leading strokes, but sometimes switch to trailing. Happens both ways.

Im assuming it to be a burr because I know ceramics are prone to producing them. And I know my technique could always be the cause.

I'm just weirded out that it doesn't exhibit any actual effects.

 

[Jamesh Bond]

If 'seeing' this anomaly along the apex is in the form of seeing a thin band of reflected light, it could just be a very fine microbevel, and not a burr or wire edge at all. I did the same thing for years, as it was easy for me to unintentionally elevate the angle slightly in the last pass or two on the hone. Doing so will leave an extra, hair-thin bevel behind the apex, which will reflect light just like a folded burr would do. Especially if the microbevel is on just one side, it'll look exactly like a folded burr, by naked eye.

If a burr or wire was actually there, and it was prominent enough to actually SEE it by naked eye, it'd also be pretty easy to see it's effects on cutting as well. Shaving hair (from both sides of the apex) and cleanly slicing paper are two tests that will always reveal even tiny burrs, if they're even slightly folded or turned to one side or the other. And if they're really fine burrs, they will be folded after the first cut in most any material, even if they initially were aligned straight along the apex.


David

I'm really starting to lean more and more this way. I think your post solidified it.

Its the only thing that makes sense.

 

[HeavyHanded]

Im referring to hand sharpening on Spyderco Med and Fine Profile rods, AlOx, I believe.

I have no issue producing excellent quality, precise edges on my DMT C/F, also by hand, so I now use that exclusively. The phenomenon is also absent, so I usually only use this.

The strange burr I'm seeing only happens with the Spyderco Ceramics. It shows up from both sides.

I usually finish with leading strokes, but sometimes switch to trailing. Happens both ways.

Im assuming it to be a burr because I know ceramics are prone to producing them. And I know my technique could always be the cause.

I'm just weirded out that it doesn't exhibit any actual effects.

The only media I can produce functional sharp burred edges off of is ceramics. I know I am not mistaking them, and the edges cut well, pass a crossgrain newsprint test and in some cases whittle hair. I suspect the difference is off of other media it is a true grinding artifact and off the ceramics its got a healthy dose of burnishing added in which can slightly draw out the edge as it work hardens it.

A good test is to give the edge a moderate smack directly into a hardwood dowel or similar. The edge will throw back light where its been hit as this burrs folds up. I normally need a loupe to see them, so if you're able to see with the naked eye you probably are seeing a burr. A microbevel will show light back at a more obtuse angle, the burr shows at a more acute - edge down, you will have to tilt the blade more to see the microbevel, the burr presents as a halo just off the apex.

I don't get this off of other media, tho did used to get a similar issue when backhoning on waterstones. If too much force was used the edge will curl slightly and look almost like a burr, almost like a wire, almost like a clean edge depending on how far it curled.

Interrogate them thoroughly, but always trust your eyes.

 

[Obsessed with Edges]

I'm really starting to lean more and more this way. I think your post solidified it.

Its the only thing that makes sense.

If it is just a microbevel that's reflecting light, it'll be much, much easier to actually verify it with well-lit magnification at 10X or better. That's how I eventually figured out what I was doing. That extra, unintended bevel looks pretty hideous under well-lit and sufficient magnification, and is a rude slap in the face, when one begins to believe the edge is in better shape than it really is. Been there, done that.

All that aside, if you're not seeing any impediment to cutting, i.e., if the edge shaves from both sides (a turned burr only does this well from one side), and slices light paper cleanly and repeatedly with no snagging or slipping, I wouldn't worry too much about what you think you're seeing. It very likely IS just a microbevel, at that point, as burrs won't perform that consistently in such tests. The cosmetics of the edge will improve in time, with sharpening experience, and you'll start noticing you're not seeing that thin band of reflected light anymore, along the apex. That's the path I went down.

Any significant burrs that I've ever made that were visible by naked eye, were always an impediment to cutting, and cutting performance varied and/or degraded from one pass to the next with most of them, as they'll always move/turn with a few cuts in most anything beyond shaving tests. Really heavy, stiff burrs won't necessarily move so easily, but they'll reveal themselves in more obvious ways, by feel with the fingertips, or by obvious differences in cutting from each side of the apex, or just in poor cutting overall.


David

 

[Spey]

Look forward to following where this goes (as comparison to what I think ;-)

OwE, pretty much nailed what I was thinking (unintentionally induced additional micro-bevel), also previously described by awestib.

Im referring to hand sharpening on Spyderco Med and Fine Profile rods, AlOx, I believe.

I have no issue producing excellent quality, precise edges on my DMT C/F, also by hand, so I now use that exclusively. The phenomenon is also absent, so I usually only use this.

The strange burr I'm seeing only happens with the Spyderco Ceramics. It shows up from both sides.

I usually finish with leading strokes, but sometimes switch to trailing. Happens both ways.

Im assuming it to be a burr because I know ceramics are prone to producing them. And I know my technique could always be the cause.

I'm just weirded out that it doesn't exhibit any actual effects.

RE: "Im assuming it to be a burr because I know ceramics are prone to producing them."
This statement is part of why I flagged this thread to follow (hoping to learn something).
What known information is there related to ceramics forming a bur differently than other stones?

Food for thought regarding what you see & feel vs what you might see under higher magnification then learn to feel from new observations.

Described phenomenon showing up on both sides would be a fair indication that what you are seeing is not a bur. A bur is typically only on one side of a blade (opposite the last side worked). A bur can be on both sides of an edge, but not in the same location (but could be left-side near the ricasso and right-side near the belly, etc. if the left-side and right-side bevels do not consistently reach the apex along the entire edge). This is why it's good learning practice to work an edge until a bur is consistent along the entire edge, destress/remove the bur then proceed to achieve a consistent bur on the opposite side (this gives the user a see & feel reference indicating the bevel extends to the cutting edge with consistency along the entire edge) before proceeding to the next step.

Thank you for confirming by "ceramics" you are referring to Spyderco ceramics. If you are also possibly referring to using the stones/rods in the V-stand configuration (and this is integral in creating the phenomenon described, I will offer up a couple thoughts and considerations that might help).

• Eyeballing & hand-holding an angle through a full vertical stroke on the stones is guesstimation of feel and visual acuity.
• Example-1: the top of the stone typically flexes outward with pressure and returns as your get closer to the fixed-base (the angle of the stone is changing slightly dependant on the amount of pressure and the distance from the base - angle effectively decreasing slightly closer to base).
• Example-2: rarely is the angle of the stone exactly the angle of the edge-bevel desired (as measured from the center-line of the spine-to-edge).
• In my experience using this type of device, I am typically holding the blade slightly angled (left or right) to achieve the desired angle to the cutting edge. Example: my early generation V-stick ceramic sharpener has holes set at 15 & 25 degrees - with a blade that has a 2-degree primary bevel and 17-degree secondary or micro I sight and hold the blade so that the primary bevel is vertical (15-degree stone angle + 2-degree primary) as the stone is stroked).
• In my mind, it helps to have a visual sight-line to follow through the stroke (moving my head left or right slightly to sight one of the primary bevel planes vertically helps me to keep a consistent angle through the entire stroke (it's tough to look at the back of the spine without a secondary reference, kinda akin to only having a rear gun sight, the part of the blade contacting the stone is obscured until it exceeds the angle of the primary-bevel).
• If your stone stand (assuming Spyderco Sharpmaker) has the base that allows one or two stones to be placed horizontally during sharpening (latest generation), I would suggest you experiment with this position and see if you can use those stones to produce an edge without the described phenomenon. The goal would be to replicate how you sharpen with other stones, eliminating some of what I described above related to the v-stone vertical stroke sharpening. I find this to be a more controllable method (easier to keep a consistent angle throughout the stroke).

In general I think the v-guide positioning of the stones is more about quick touch-ups of an edge for those that are ok with an additional slightly convex edge bevel (what I think you are seeing).