Very difficult to remove burrs

C

chuckasher55

Joined
Dec 4, 2005
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I have been sharpening knives (all my own as I have about 180 knives) for a couple of years. About 40% are paper cutting, shaving sharp. Most of these are made of steels (usually high end steels) that form burrs that fragment and fall apart easily when I am trying to remove them. There are some exceptions that are made from more ductile steels also.

However, many of my knives form burrs that will not go away, no matter what I do. Some of the knives are made of steels such as ATS34, VG10, AUS8 and a variety of cheaper steels. I have watched many YouTube videos of how to solve this problem and nothing works. Some of these techniques suggested using whetstones (light edge leading strokes), strops, paper wheels, progressing through finer and finer grits to thin the burr, etc., etc., etc. Nothing seems to work. I have also tried about everything else that I can think of as well.

Any suggestions would be greatly appreciated!
 
What direction are you moving the blade across the stone?

Have you tried running the edge on a piece of wood in a sawing motion?

What stones are you using? How fine are you taking it when it still has a burr?
 
chuckasher55 said:
I have been sharpening knives (all my own as I have about 180 knives) for a couple of years. About 40% are paper cutting, shaving sharp. Most of these are made of steels (usually high end steels) that form burrs that fragment and fall apart easily when I am trying to remove them. There are some exceptions that are made from more ductile steels also.

However, many of my knives form burrs that will not go away, no matter what I do. Some of the knives are made of steels such as ATS34, VG10, AUS8 and a variety of cheaper steels. I have watched many YouTube videos of how to solve this problem and nothing works. Some of these techniques suggested using whetstones (light edge leading strokes), strops, paper wheels, progressing through finer and finer grits to thin the burr, etc., etc., etc. Nothing seems to work. I have also tried about everything else that I can think of as well.

Any suggestions would be greatly appreciated!
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Have you tried higher angle passes?...

 
You are over sharpening. The burr is getting too big. Slowly approach the apex and keep the burr small.

To remove stubborn burrs, raise your sharpening angle. Use light pressure with a fine stone. A few passes on each side. Check it for a burr. If it’s not gone, try another light pass.
 
i feel you
https://www.bladeforums.com/threads/really-detect-the-micro-burr-we-were-wrong….1674162/

with very ductile cheap steels (see blades made 40+ yrs ago) raising the angle or 2x micro beveling doesn't do the trick. even stropping on pasted leather wouldn't.
the only method then is to reduce the pressure more and more, 1 pass per side, and using neither edge-leading nor edge-trailing strokes but strokes exactly perpendicular, i.e. edge-following.
this will eventually weaken and shear off the burr WITHOUT re-creating a fresh microburr in the process.
I'd recommend fine stones or pasted wood for that, i.e. a hard surface not leather.

much patience and the massive reduction of pressure are key here, not the stroke direction per se. you could use edge-trailing or edge-leading instead, sure.

but at some point you'll realize that removing the microburr from a ductile blade steel is a futile exercise:
as soon as you push-cut some nonsoft material with it, the fine ductile apex rolls over to one side, forming a "microburr" on its own right.

hold the knife still in your left hand, and in your right hand use a pasted paint stirring wood stick to fast push-stroke along the edge, with minimal pressure. this unorthodox stropping technique can clean the edge from (already weakened) microburrs.
 
It's vaguely possible that you have "weak steel" at the very edge. A controversial person in the sharpening community recommends that you "destress" the edge of a blade each time you sharpen it, by removing this weak steel.

The method is simple: Cut directly into the stone (as if you were trying to cut it in half) with your blade. But do this very lightly. Three strokes is probably enough for almost any blade unless it has visible damage.

One this is done you will have a very FLAT edge that reflects light if you look at it edge on. This same person recommends "no burr" sharpening after this flattening step. Here's how "no burr" goes:

Find the reflection on the edge. Make 100% sure you can see the reflection. You should stand under a bright light and move the edge around until you can clearly see the reflection off of the flat spot you have made where the edge should be.

Now sharpen one side for a bit (maybe 30 strokes or so). Flip the blade over and do about the same amount of strokes. Check for a reflection again. Repeat. You should see the reflected area getting smaller and smaller as you bring the edge back to a point.

Eventually, the reflection will disappear entirely. This means that the edge is now kind of sharp. It's pretty close. Now you do alternating strokes, one side one stroke, the other side one stroke. Check for sharpness in your usual ways as you do these. You can do 5 or 10 alternating strokes and then check. Repeat as necessary.

You should get your blade extremely sharp this way and it should form almost no burr. You might form a bit on one side or the other, but it should be a very very small burr which you can remove easily.

Try lightening your strokes as you go through the final stages. Crossing over your scratch pattern can also help to refine the edge and remove small burrs.

I don't do this method often, but I've had great success with it. I hope you do too.

Brian.
 
Good suggestions outlined previously in this post. Another method that works for me many times is to end with light pressure strokes - and comb the burr to one side, take a light stroke or two, comb it to the other side and take a light stroke. You can use a wooden dowel. You can also cut directly into the wood lightly. If you have a softer strop it will show if any burr is left, you’ll have drag marks. Keep working on that part of the edge that has a burr. Works for me.
 
ecallahan said:
Another method that works for me many times is to end with light pressure strokes - and comb the burr to one side, take a light stroke or two, comb it to the other side and take a light stroke. You can use a wooden dowel.
Click to expand...

This is an excellent suggestion. I've used this VERY successfully in the past. Here's a video demonstration of the technique. There's a lot of good detail here if you pay attention.


Brian.
 
chuckasher55 said:
I have been sharpening knives (all my own as I have about 180 knives) for a couple of years. About 40% are paper cutting, shaving sharp. Most of these are made of steels (usually high end steels) that form burrs that fragment and fall apart easily when I am trying to remove them. There are some exceptions that are made from more ductile steels also.

However, many of my knives form burrs that will not go away, no matter what I do. Some of the knives are made of steels such as ATS34, VG10, AUS8 and a variety of cheaper steels. I have watched many YouTube videos of how to solve this problem and nothing works. Some of these techniques suggested using whetstones (light edge leading strokes), strops, paper wheels, progressing through finer and finer grits to thin the burr, etc., etc., etc. Nothing seems to work. I have also tried about everything else that I can think of as well.

Any suggestions would be greatly appreciated!
Click to expand...

ATS-34 and VG-10 are among the top few on my list of steels with very tenacious, stubborn burrs, even at relatively high hardness. With those two in particular, a good quality stone makes a huge difference in how much burr forms in the first place. And second, making sure to lighten pressure substantially as you're apexing makes a big difference too. But in cases when there's already a big, stubborn burr there, the clean-cutting stone of good quality and used with a light touch will eventually get the edge cleaned up. Both of these steels will form huge & STRONG burrs if pressure is too heavy on any stone. Burrs like that won't be fazed by many strops, unless the compound used is very aggressive. So focus on keeping the touch light.

By their elemental makeup, either of those steels would theoretically do OK on aluminum oxide stones, which are technically hard enough to cut all the steel's components, including it's carbides. But I've noticed many times, an aluminum oxide stone will struggle a bit on these steels, in cleaning up the edge. I've preferred to finish on a diamond hone instead, for these steels, because they'll cut the steel cleanly at a very light touch. That's exactly what's needed for these.

You can raise the angle a bit, if you want to. I've always preferred instead to just keep lightening the pressure as I finish at the same angle, making the burr thin & weak enough that it'll break away on a simple strop (little or no compound), or with just a few more featherlight passes on the hone, or it'll come off in the first cut or two when the knife is put back into use.
 
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115Italian said:
You are over sharpening. The burr is getting too big. Slowly approach the apex and keep the burr small.
Click to expand...
This ^^
Have you tried many light alternating strokes on a ceramic rod?
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I have spent a lot of time with the finest of the Spyderco triangle ceramic rods and I find the edge will hold onto the bur on cheep steel even when going edge leading only where as the same rod on decent alloys are much improved by the same rod and never even form a bur of any significance and they loose it quick.
chuckasher55 said:
VG10, AUS8
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I sharpen these very regularly and have decent success ESPECIALLY with the VG10.
bgentry said:
It's vaguely possible that you have "weak steel" at the very edge. A controversial person in the sharpening community recommends that you "destress" the edge of a blade each time you sharpen it, by removing this weak steel.
Click to expand...
That would be Cliff Stamp.
I've learned some stuff from him and agree on a number of things.
However I never destress edges. I have great results with edge retention as long as the steel is decent (M4, M390, HAP-40, extra hard White Paper Steel etc).

That said I can see there is something to removing the fatigured, weak steel but practically speaking . . . science says . . . the steel will be harder (work hardened) not softer though perhaps fractured.

It is soft but ductile steel that forms a bur not overly hard brittle steel which is what work hardened steel will be (for the most part banning H1 etc). H1 is improved by work hardening it.
[fatigured I created a new word and like it so I left it in]

As far as dragging the edge into a hunk of wood to literally TEAR the bur off . . .
:(
I know some , one, super pro, highly trained, highly respected knife makers have recommended this.
:eek: all I can say is MADNESS :(
There are wilder skies than these to remove a bur.
I suppose if one wants a jagged assed old saw like knife edge then go for it . . .
even then . . . nah dude, nah.

Nothing seems to work. I have also tried about everything else that I can think of as well.
Any suggestions would be greatly appreciated!
Click to expand...
I didn't see a sharpening jig listed there; specifically The Edge Pro Apex.
It helps me sharpen at the same angle on both sides and yet not form much of a bur as I sneak up on the very apex ( just enough to know I am getting down to the actual cutting edge).

For the excellent alloys I listed above the edge deburs as I progress through three, four or five stones. I do nothing to encourage this other than sharpen at the same angle for all the stones and take a few edge leading strokes on the final pass of each stone followed by a couple of edge trailing strokes very lightly alternating side to side.

For the sucky bur preserving alloys (most under hardened stainless alloys) I steepen the angle of the stone on the Edge Pro about a degree or even less and take some edge leading strokes lightly followed by more strokes but edge trailing.
This usually does the trick.
If this doesn't do the trick toss the knife in the trash (I'm sort of kidding . . . sort of).
or
delve into the dark arts
get a three legged chicken and sacrifice it in a ring of salt on a full moon
then break out the strops.

seeing as three legged chickens are getting more and more scarce due to all the soft crap knives out there.

I NEVER go there. Life is too short.
 
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Wowbagger said:
However I never destress edges. I have great results with edge retention as long as the steel is decent (M4, M390, HAP-40, extra hard White Paper Steel etc).

That said I can see there is something to removing the fatigured, weak steel but practically speaking . . . science says . . . the steel will be harder (work hardened) not softer though perhaps fractured.
Click to expand...

Whether or not "destressing" actually removes bad steel or not is probably open for debate and probably (as you said) dependent upon the exact steel we are talking about.

However, this operation (destressing) has a great side benefit: It gives you a positive indicator of your edge being "not sharp", which you can see. You can then use that positive indicator to gauge your progress and you will know when you are *almost* sharp and ready for alternating passes on each side. So this becomes a great aid in doing "no burr sharpening". As I said, I have had great success with this method the few times I have used it.

You seem to indicate that your approach to sharpening with your favorite tool (the legendary Edge Pro) is similar: trying to "sneak up on the edge" so you form very little or no burr at all. I'm not very good at that unless I use the method I outlined above. Otherwise I tend to make very obvious burrs.

Brian.
 
For VG10 and AUS8, I just perform my standard method of:

1) Form a burr on one side
2) Form a burr on the other side
3) Very light, edge leading, alternating passes
4) Very light, edge trailing strokes on CrO strop (2 or 3 passes usually does it)
5) Very light, edge trailing strokes on bare hard leather (1 or 2 passes usually does it)

Done.

For me with the steels that like to hold a burr (420HC seems to be my most stubborn) I find I need to really be mindful of my initial sharpening passes and recognizing when I have a burr without over doing it (I burr sharpen, always, but that doesn't mean it has to be excessive) and then for deburring, angle control is really important. Some steels are more forgiving of "sloppy" deburring strokes than others.

If the knife isn't overly dull, I'll often use a soft Arkansas on these steels. I find it works very well and leaves a great edge. I typically use SiC and/or AlO stones if the edge needs more work.

What makes you sure deburring is your issue? How are you gauging sharpness compared to the other steels you use? Just trying to understand what you're experiencing. :)
 
bgentry said:
This is an excellent suggestion. I've used this VERY successfully in the past. Here's a video demonstration of the technique. There's a lot of good detail here if you pay attention.


Brian.
Click to expand...
When all else fails, this is what always works for me on those endless burrs/foil edges.
 
bgentry said:
: It gives you a positive indicator of your edge being "not sharp", which you can see. You can then use that positive indicator to gauge your progress and you will know when you are *almost* sharp and ready for alternating passes on each side. So this becomes a great aid in doing "no burr sharpening".
Click to expand...
Exactly, yes . . . I am aware of Apex style sharpening. I can tell the same thing on my finger nail before I sharpen ; where it is dinged, flattened, rolled . . . where it is almost shave sharp (or is still shave sharp). Then I just keep that in mind while I use the Edge Pro or in the case of a few of my knives just use the Spyderco Ultra Fine Triangle rod free hand (if there are no dings and no rolls or only the very slightest hint of a misaligned edge).

I simply can not bring my self to scrape off "all that steel" on a stone to get the flattened apex.
Nails on a chock board to me. But what do I know; I'm stropaphobic as well.

bgentry said:
Otherwise I tend to make very obvious burrs.
Click to expand...
I think it was the great and powerful Cliff Stamp that said :" Use light pressure on the softer steels and more firm pressure on the really tough / hard stuff (high vanadium etc).
By this, grace will be bestowed on the faithful in the form of less distorted edges and more refined . . ."

Well you get the picture.
 
Thanks for all the tips and advice. Since I last posted two things have happened to help me with my problem with burrs. First, a little info that I don't think I mentioned earlier. I sharpen my knives with 1x30 belt sanders (I have 3) and have always sharpened edge-trailing. This leaved a pretty large burr and, as you know, I have trouble getting rid of it.

However, I have found that if I sharpen my knives at a very shallow angle (about 10 degree or even a little less) the burrs produced are much, much easier to remove and the blade become VERY sharp. Last evening I sharpened 6 knives in about an hour. I know that sharpening at such shallow angles, however, produces very sharp but fragile edges.

The second thing I have learned was taught to me by a knife making friend of mine. He showed me how he sharpens edge-leading so that it is possible to clearly see how the belts make contact with the knife edge. He was able to take three of my problem knives and quickly make them paper cutting, shaving sharp using this method of sharpening. I am now attempting to learn how to sharpen in this way. This technique would keep my bevels to more conventional angles.

Any advice that you think could help me would be greatly appreciated.
 
chuckasher55 said:
Thanks for all the tips and advice. Since I last posted two things have happened to help me with my problem with burrs. First, a little info that I don't think I mentioned earlier. I sharpen my knives with 1x30 belt sanders (I have 3) and have always sharpened edge-trailing. This leaved a pretty large burr and, as you know, I have trouble getting rid of it.

However, I have found that if I sharpen my knives at a very shallow angle (about 10 degree or even a little less) the burrs produced are much, much easier to remove and the blade become VERY sharp. Last evening I sharpened 6 knives in about an hour. I know that sharpening at such shallow angles, however, produces very sharp but fragile edges.

The second thing I have learned was taught to me by a knife making friend of mine. He showed me how he sharpens edge-leading so that it is possible to clearly see how the belts make contact with the knife edge. He was able to take three of my problem knives and quickly make them paper cutting, shaving sharp using this method of sharpening. I am now attempting to learn how to sharpen in this way. This technique would keep my bevels to more conventional angles.

Any advice that you think could help me would be greatly appreciated.
Click to expand...

Sounds like you'll be giving us advice pretty soon... once you learn your friend's technique. ;)
 
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