Hard D2 and burr removal

[SwissHeritageCo]

I've been in the process of convexing all of my D2 knives. In doing that, I've had trouble removing the burr on a few of the knives that have a harder temper (around 62hrc). Typically I'll mitigate the burr during the sharpening process but a couple of them are proving resilient. I'm pleased with the geometry/finish and ideally I'd like not to round over the edge and have to resharpen again.

What I'm curious about is if doing alternating strops on an ultra fine stone like a spyderco might weaken the burr to the point I can finish on plain leather, but what I'm reading from past threads is I need to be sharpening and not stropping the blade on something a bit more coarse. Truth be told, I'm very good at free hand sharpening but I've always had difficulty with burr removal on harder steels. Did anyone else used to have this problem those doesn't anymore? I'd love to know how you remedied it.

 

[pholder]

I have read that some will draw the edge against wood and that removes the burr. I don’t know if that works, I have never had burr issues. Good luck with your search

 

[Crag the Brewer]

I've not had issues with making D2 knives......
but I use a Gossman Survival tool/steel, to finish my edges, and I cut a lot of cardboard in testing.

 

[Joseph Bandeko]

Here’s what I do for final burr removal:
First with very light pressure I pull (don’t push) the edge across the stone, then check and make sure I’ve pushed the burr over, then flip the blade and do the same thing on the others side, and I keep doing this, one light pass on each side until I feel like the burr is as small/thin as I can get it on the stone, I then take a piece of wood (doesn’t have to be very hard) and with a fair amount of pressure draw the edge across the edge of the wood, that should push the burr over even more, I then use a leather strop with green compound on it and simply strop until the remaining burr is gone.
And sometimes with really stubborn burrs I will take it back to the stone like halfway through stropping and give it an extremely light pulling pass on each side (making sure the first pass is on the side the burr is on), and sometimes that will break the burr off all together.

 

[chalby]

I find it easier to do very light edge leading passes on the finishing stone(or even a finer stone) to deburr. It's more of a drawing motion across the stone with slight edge leading. Generally I find I don't need to do many passes; maybe 3 or 4, sometimes a few more depending on the steel. You can also do the same thing with a slightly raised angle from the sharpening angle to micro-bevel. Then I do a handful of very light passes on a strop.

I used to basically do a very light stropping motion on the stone a few years ago, but found it needs more passes than edge leading to deburr fully.

 

[SwissHeritageCo]

Here’s what I do for final burr removal:
First with very light pressure I pull (don’t push) the edge across the stone, then check and make sure I’ve pushed the burr over, then flip the blade and do the same thing on the others side, and I keep doing this, one light pass on each side until I feel like the burr is as small/thin as I can get it on the stone, I then take a piece of wood (doesn’t have to be very hard) and with a fair amount of pressure draw the edge across the edge of the wood, that should push the burr over even more, I then use a leather strop with green compound on it and simply strop until the remaining burr is gone.
And sometimes with really stubborn burrs I will take it back to the stone like halfway through stropping and give it an extremely light pulling pass on each side (making sure the first pass is on the side the burr is on), and sometimes that will break the burr off all together.

Thank you I'm going to try this to the letter, grateful for the insight.

I find it easier to do very light edge leading passes on the finishing stone(or even a finer stone) to deburr. It's more of a drawing motion across the stone with slight edge leading. Generally I find I don't need to do many passes; maybe 3 or 4, sometimes a few more depending on the steel. You can also do the same thing with a slightly raised angle from the sharpening angle to micro-bevel. Then I do a handful of very light passes on a strop.

I used to basically do a very light stropping motion on the stone a few years ago, but found it needs more passes than edge leading to deburr fully.

Thank you I'll try it non raised first, I've done the raised strop method and it works but Ido worry about rounding the edge. Got a really nice convex edge and hopefully I can manage breaking the burr without microbeveling it. Wouldn't be the end of the world, but I feel like it's a skill I need to refine.

Appreciate the help gentlemen!

 

[chalby]

Thank you I'm going to try this to the letter, grateful for the insight.



Thank you I'll try it non raised first, I've done the raised strop method and it works but Ido worry about rounding the edge. Got a really nice convex edge and hopefully I can manage breaking the burr without microbeveling it. Wouldn't be the end of the world, but I feel like it's a skill I need to refine.

Appreciate the help gentlemen!

IMO, the key is use the lightest touch as you can manage while still being able to have a smooth constant contact with the stone along the whole edge. I personally don't think the direction you do it matters as much as that.

Deburring was for me the final frontier for getting consistently good results sharpening.

Good luck!

 

[old4570]

A lot of people seem to be reaching for compounds these days , like Diamond Spray .. ( DBK )
A mild abrasive to wear down the bur .. While stropping ..
I've been playing with Autosol , and it looks to work a treat !

For sharpening :
A) I form the bevel I want ( burrs both ways )
B) Then do alternate sharpening ( one side , then swap to the other side ) for around 10 passes then check for a bur .. If I feel a bur ill repeat for another 10 passes .. ( 20 is usually more than enough )
C) Then strop and check for scratching on the leather .. ( Bur scratches up the leather ) & strop till the scratching goes away
D) Compound will speed things up + polish the edge ( If you like )

 

[Obsessed with Edges]

The first D2 blade I convexed (on sandpaper) benefited much more from edge-leading passes on a diamond hone, to refine the apex and thin the burr to an extent it became much easier to clean up. I'd originally tried to do everything on the sandpaper from start to finish. But D2 is tricky to finish at the apex using anything that might struggle to efficiently and completely cut the steel and its carbides. The SiC sandpaper fell short of the mark, in that regard. The burr would thin to some extent - but the edge's sharpness was disappointing with either the burr getting in the way or edge-rounding issues, as are a given to some extent on anything with any give to the substrate under the abrasive. But finishing edge-leading on a diamond hone made it easy - I used a Fine (600) DMT. Since then, I ALWAYS finish D2 with edge-leading strokes on a diamond hone. I have stropped D2 on a hard strop of wood (like basswood, for example) using 3-micron DMT diamond paste, if pursuing a polished finish. That works well to polish D2 and the edge's sharpness won't suffer for it. Other stropping compounds of aluminum oxide or other lesser abrasives will again aggravate things, tending to leave the apex rounded off and not as thin as it could be.

 

[LostCause]

I never had burr issues with D2, but I never convexed D2 either

 

[Guy McVer]

I'm very good at free hand sharpening but I've always had difficulty with burr removal on harder steels. Did anyone else used to have this problem those doesn't anymore? I'd love to know how you remedied it.

It sounds like you may be spending too much time on one side before switching. This can let the burr build up too much. Sometimes the trick is not to let the burr build up in the first place. This may sound like heresy to some people who are used to intentionally forming a burr as part of the sharpening process, but it's not actually necessary.

 

[LostCause]

It sounds like you may be spending too much time on one side before switching. This can let the burr build up too much. Sometimes the trick is not to let the burr build up in the first place. This may sound like heresy to some people who are used to intentionally forming a burr as part of the sharpening process, but it's not actually necessary.

I noticed the same long time ago. So I started to count 5 strokes per side and had no such issues ever since. It could be that.

 

[777 Edge]

D2 - having very large carbides, does not necessarily benefit as much as a fine carbide steel does with trailing edge sharpening finishing. I would go for burr minimisation and leading edge sharpening, then minimal stropping for your finishing. Both for convex and regular V edge sharpening.

 

[Obsessed with Edges]

I never had burr issues with D2, but I never convexed D2 either

For the most part, I also haven't seen many burring issues with D2 when sharpening edge-leading on stones. But, as with many others steels I've ground / convexed / sharpened on sandpaper, I have seen the sandpaper create some BIG honkin' burrs as compared to grinding or sharpening on hard stones, edge-leading. I attribute that to the trailing-edge manner in which sharpening is usually done on sandpaper and also perhaps the slight loss of aggression in cutting steels with the slight cushion or give of the paper and/or substrate under it, under pressure from the blade.

Based on what I've seen with sandpaper, I could see the same issues coming up in powered belt sharpening as well, if done edge-trailing.

 

[SwissHeritageCo]

The first D2 blade I convexed (on sandpaper) benefited much more from edge-leading passes on a diamond hone, to refine the apex and thin the burr to an extent it became much easier to clean up. I'd originally tried to do everything on the sandpaper from start to finish. But D2 is tricky to finish at the apex using anything that might struggle to efficiently and completely cut the steel and its carbides. The SiC sandpaper fell short of the mark, in that regard. The burr would thin to some extent - but the edge's sharpness was disappointing with either the burr getting in the way or edge-rounding issues, as are a given to some extent on anything with any give to the substrate under the abrasive. But finishing edge-leading on a diamond hone made it easy - I used a Fine (600) DMT. Since then, I ALWAYS finish D2 with edge-leading strokes on a diamond hone. I have stropped D2 on a hard strop of wood (like basswood, for example) using 3-micron DMT diamond paste, if pursuing a polished finish. That works well to polish D2 and the edge's sharpness won't suffer for it. Other stropping compounds of aluminum oxide or other lesser abrasives will again aggravate things, tending to leave the apex rounded off and not as thin as it could be.

Well damn, all of my fine abrasives are ceramic so this makes sense. I've been needing to order one of those fine/ultrafine diamond pocket stones anyway and I suppose now is a good time. Thank you. I don't think I'll go the diamond paste route, not sure why I'm adverse to the thought of diamond paste but the abrasion of the diamonds and edge leading makes perfect sense. I do most of my convex sharpening on pocket stones with a loose wrist in the direction of spine to edge, while maintaining a rocking motion... The edge is getting hit in both directions (trailing/leading) but for finishing the burr, leading shouldn't be a problem.

Edit to add: my progression was diamond, diamond, ceramic, ceramic, strop.

It sounds like you may be spending too much time on one side before switching. This can let the burr build up too much. Sometimes the trick is not to let the burr build up in the first place. This may sound like heresy to some people who are used to intentionally forming a burr as part of the sharpening process, but it's not actually necessary.

Yep, that's me. When I'm reprofiling (like I've been doing the past few days) I'm removing lots of steel to form properly form the convex and to thin it out. Lots of time on one side before flipping to the other. Burr's have only been an issue for me on heavy sharpenings such as these, not so much on regular maintanence. Something I'll keep in mind moving forward for sure.

D2 - having very large carbides, does not necessarily benefit as much as a fine carbide steel does with trailing edge sharpening finishing. I would go for burr minimisation and leading edge sharpening, then minimal stropping for your finishing. Both for convex and regular V edge sharpening.

This is good info and while I can't give up my trailing edge part of the sharpening process just yet because it helps me maintain the convex, I can definitely finish up the last leg with strictly edge forward.


Still have a couple blades up for burr removal tonight, so thanks again for the excellent information - it's much appreciated!

 

[Obsessed with Edges]

Well damn, all of my fine abrasives are ceramic so this makes sense. I've been needing to order one of those fine/ultrafine diamond pocket stones anyway and I suppose now is a good time. Thank you. I don't think I'll go the diamond paste route, not sure why I'm adverse to the thought of diamond paste but the abrasion of the diamonds and edge leading makes perfect sense. I do most of my convex sharpening on pocket stones with a loose wrist in the direction of spine to edge, while maintaining a rocking motion... The edge is getting hit in both directions (trailing/leading) but for finishing the burr, leading shouldn't be a problem.

Edit to add: my progression was diamond, diamond, ceramic, ceramic, strop.

[...]

I've sometimes avoided ceramics for burring issues - more so when I've done much heavy grinding or polishing with them. Ironically, if I use them very, very minimally with the lightest touch I can manage, I've also liked them for microbeveling and deburring in lieu of stropping. They have their place in my sharpening schemes, but maybe in a very narrow niche. I actually use them often, but in a very minimal number of passes to keep edges tuned up.

I've also used that rocking, back & forth scrubbing motion on stones to do some convexing. I usually do that on a diamond hone lubricated with oil, mainly for hogging off metal to thin & shape the grind behind the edge. Much faster grinding that way, going both directions. But as I mentioned before, I still like to do all the finishing with edge-leading passes only, for the sake of the apex itself.

 

[bedrock]

Sorry to bring this up again BUT: Ive lately been having a hell of a time with the burr on a couple of S35VN blades. The steel is soft enough to form a pretty good burr but hard enough that it takes forever to wear it off with light strokes. I’ve finally gotten rid of it by doing slightly trailing strokes on the ribbed side of a work sharp field ceramic. You can feel the burr easily and even see pieces come off with the naked eye. This leaves me with a pretty dull edge that takes a lot of light strokes to get sharp. My old method of a few light trailing strokes before moving to a finer grit doesn’t seem to be working any more. I guess the problem is the burr is a lot thicker than the ones I used to get on the same blades but I don’t know why.

 

[chalby]

Sorry to bring this up again BUT: Ive lately been having a hell of a time with the burr on a couple of S35VN blades. The steel is soft enough to form a pretty good burr but hard enough that it takes forever to wear it off with light strokes. I’ve finally gotten rid of it by doing slightly trailing strokes on the ribbed side of a work sharp field ceramic. You can feel the burr easily and even see pieces come off with the naked eye. This leaves me with a pretty dull edge that takes a lot of light strokes to get sharp. My old method of a few light trailing strokes before moving to a finer grit doesn’t seem to be working any more. I guess the problem is the burr is a lot thicker than the ones I used to get on the same blades but I don’t know why.

It sounds like you need to weaken the burr. I would try adding maybe 2 or 3(or more) sharpening passes on each side using lighter pressure before you start trying to deburr.

It also sounds like you may be making it harder for yourself by creating too large of a burr. You could try spending less time on each side when you are trying to initially form the apex. In other words swap sides more often gradually lessen the pressure as you get towards the end of the sharpening phase.

 

[Obsessed with Edges]

Sorry to bring this up again BUT: Ive lately been having a hell of a time with the burr on a couple of S35VN blades. The steel is soft enough to form a pretty good burr but hard enough that it takes forever to wear it off with light strokes. I’ve finally gotten rid of it by doing slightly trailing strokes on the ribbed side of a work sharp field ceramic. You can feel the burr easily and even see pieces come off with the naked eye. This leaves me with a pretty dull edge that takes a lot of light strokes to get sharp. My old method of a few light trailing strokes before moving to a finer grit doesn’t seem to be working any more. I guess the problem is the burr is a lot thicker than the ones I used to get on the same blades but I don’t know why.

Agree with chalby's reply above. The burr is likely still too thick. Progressively lighter, edge-leading passes on the coarser grit stage should thin the burr more, before moving to finer grit stages. Any burr that's too tough to remove on a strop or on finer hones will always need more thinning at the coarser steps first.

I've personally never liked using edge-trailing passes on stones to remove burrs from ductile steels like this ('ductile' means softer and more prone to hanging on). Edge-leading passes will work better to both thin the burr and then to scrub it off, leaving only very fine and thin remnants that are much easier to remove by stropping on most anything. The idea being with edge-leading leading passes, once the burr gets sufficiently thin, it'll roll to one side and then fold underneath the bevel contacting the stone when you flip the blade, after which it can easily be abraded away. Edge-trailing will tend to make these burrs deflect up & away from the stone and they'll just keep deflecting away from it each time the blade is flipped to do the alternate side.

And depending on what type of abrasive is being used, like natural stones, AlOx, etc., if it has trouble with more wear-resistant steels such those with much vanadium carbide, it could also make it more difficult to adequately thin the edge to remove the burr. That also contributes to that dullness you're seeing after the burr is removed.