Giving an edge more bite

[Lennyo3034]

My EDC is a BM 710 in M4. This is one of the older ones with lower RC than they currently offer. I sharpened it on the Edge pro, stopping at the 600 grit stone (or maybe 1000, I don't remember). It had an excellent edge after this, with the perfect amount of bite in my opinion. I've put it through it's paces in the few months since sharpening (whittling wood, cutting cardboard, gutting fish, etc.) and I usually strop with green compound to restore the edge. In fact, I probably strop too often, usually once a week or sometimes I just do it because I'm bored. The edge is still extremely sharp, able to whittle hair, however I feel it's lost the bite that it used to. One example was when I had to but zip ties yesterday. I noticed slicing at them didn't work very well and I basically had to push cut. Having cut zip ties in the past, I know that a knife with more bite would have been able to slice it easily.

So my question is: Is there an easy way to restore the knife's bite? I was thinking of running it on a hone a couple times then strop, but wanted to check here to see if there is a better way. I have access to: Edge Pro, lansky V sharpener (similar to sharpmaker), work sharp travel sharpener (with ceramic hone).

 

[Obsessed with Edges]

If you liked the bite from the EP's 600 stone, I'd just go back to that. Might be able to use that hone to just add a fresh 600-grit microbevel (just barely wider than your current edge angle), and leave the remainder of the bevel behind it 'as is'. The apex of the edge is really the only portion benefitting from the bite left by the 600, so it may not be necessary to completely re-grind the bevels to 600, if you don't want to.

I sometimes use a diamond rod or other relatively coarse hone to add bite to otherwise more refined edge bevels, doing essentially the same as what I've described above, leaving a toothier microbevel behind the apex.

Chances are, your Lansky V-sharpener and the ceramic on the WorkSharp will leave your edge more refined, and likely won't restore that same 'bite' left from the original sharpening; white ceramics in particular will likely leave it more polished. Some 'brown' or 'grey' ceramics can leave some nice bite, but you'll have to experiment to see if that'll work for you (if you have them). Spyderco's 'brown' ceramics leave something similar to 1200-grit wet/dry sandpaper, in finish, and other 'brown' or 'grey' ceramics I've tried aren't too different from that (with a very specific exception: my Fallkniven DC-4, which has the toothiest 'brown' ceramic I've ever seen).

Don't know what edge angle you're sharpening to, but zip-tie cutting could still possibly improve at higher finish, if the edge angle is thinned somewhat. In cutting of materials like these, the geometry behind the apex becomes more important, more so than the edge finish itself; thicker edges will always have more difficulty in cutting tougher materials like plastic, wood or heavy cardboard, especially after the apex dulls even a little bit. The 'bite' left by the 600 hone on your edge might've been the only thing working for that, if the geometry behind the apex was very wide at all (35°-40° or wider). At 30° or lower (inclusive), polished edges at 2000+ grit can work excellently for tasks like this, so long as the steel will support it (most decent blade steels will handle 30° inclusive, easily).


David

 

[Lennyo3034]

The edge on this particular one is around 35 degrees inclusive, and I'm hesitant to take it narrower than that since I have rolled the edge on this knife before. My Lansky V actually came with medium grey stones as well so I will give that a try. Should I stop afterwards? Or would a sharpmaker be worth investing in even though I already have an Edge pro? I don't like doing touch ups on the edge pro because I can never find the right angle.

 

[lonestar1979]

Just use medium lansky ceramics and don't strop afterwards.Should get plenty of bite.I get hair whittling edge on my brown stones on sharpmaker, so theres no need for stropping,just practice.DMT diamond stones are also excellent for getting an edge with a lot of bite.

 

[Jason B.]

You have lost bite because you are stropping with a compound not properly able to grind the steel. This causes rounding at the apex regardless of your angle control.

Easiest way to solve your issue is to stop stropping and just use your stones. You can strop a little after sharpening wth stones but it's not a something I would recommend for prolonged maintenance.

 

[Vegas Blade]

I think you have effectively stropped your "bite" away. I often hear o folks who get these great edges, then strop for that last final touch. Stropping too heavily, or improperly will roll an edge, and/ or smooth it. Thus, your 600 grit edge is now a 1000+ post strop. Just my thoughts.

 

[HeavyHanded]

If you like the bite and are looking for a maintenance strategy, you'll be better served with some freehand methods. Stropping unless done on a very hard backing is going to be difficult to manage over the long term. If you were shooting for something a bit more refined, in the range of an approximate 1000 grit or so, the options open up a bit. Backhoning on softer waterstones gives an edge with great bite at the 2-4k range. In the 600 range a fixed abrasive will give better results.

I'd try to figure out how to get consistent angle control from the EP, stop at 600 grit and strop on some newspaper. When you have a preferred edge finish, can be very tough to reproduce it by other means.

 

[M0NK]

If you like the bite and are looking for a maintenance strategy, you'll be better served with some freehand methods. Stropping unless done on a very hard backing is going to be difficult to manage over the long term. If you were shooting for something a bit more refined, in the range of an approximate 1000 grit or so, the options open up a bit. Backhoning on softer waterstones gives an edge with great bite at the 2-4k range. In the 600 range a fixed abrasive will give better results.

I'd try to figure out how to get consistent angle control from the EP, stop at 600 grit and strop on some newspaper. When you have a preferred edge finish, can be very tough to reproduce it by other means.

Solid advice. I think sometimes it's easy to forget simple things like a finish strop on newspaper (or any dull mass-print paper, yellowpages, etc) will usually do the trick.

Personally, I use a woodworker's strop (I don't get newspaper anymore), it's just leather glued onto a hardwood block (nap-side up), add the paste of your choice. Flexicut yellow is easy to find.

 

[M0NK]

If you like the bite and are looking for a maintenance strategy, you'll be better served with some freehand methods. Stropping unless done on a very hard backing is going to be difficult to manage over the long term. If you were shooting for something a bit more refined, in the range of an approximate 1000 grit or so, the options open up a bit. Backhoning on softer waterstones gives an edge with great bite at the 2-4k range. In the 600 range a fixed abrasive will give better results.

I'd try to figure out how to get consistent angle control from the EP, stop at 600 grit and strop on some newspaper. When you have a preferred edge finish, can be very tough to reproduce it by other means.

Solid advice. I think sometimes it's easy to forget simple things like a finish strop on newspaper (or any dull mass-print paper, yellowpages, etc. that uses clay in their process) will usually do the trick.

Personally, I use a woodworker's strop (I don't get newspaper anymore), it's just leather glued onto a hardwood block (nap-side up), add the paste of your choice. Flexicut yellow is easy to find.

 

[Obsessed with Edges]

The edge on this particular one is around 35 degrees inclusive, and I'm hesitant to take it narrower than that since I have rolled the edge on this knife before. My Lansky V actually came with medium grey stones as well so I will give that a try. Should I stop afterwards? Or would a sharpmaker be worth investing in even though I already have an Edge pro? I don't like doing touch ups on the edge pro because I can never find the right angle.

No harm in trying your Lansky grey stones, since you have them. I don't think spending extra money on the Sharpmaker will give you the 600-1000 grit 'bite' you're looking for, UNLESS you also invest in the optional diamond hones for it. May not be the best option right now.

The mention of removing the teeth in your edge by overstropping with your chosen compound is valid. Green compound won't handle the vanadium carbides in the steel well, so the end result will be rounding/burnishing of those same carbides along the apex (I went through exactly the same thing in trying to strop, strop and strop S30V with green compound). Focusing on minimizing burr formation while using stones, by steadily lightening pressure as the edge becomes more refined, will reduce the dependency on stropping to clean those burrs up and, therefore, will make it easier to retain the bite you prefer in your edges. At the very least, choosing a compound better suited to vanadium carbide-heavy steels like M4, and using it sparingly, will work better to not only clean burrs up, but enhance sharpness as you work. For anything with vanadium carbides in it, I'd be using diamond compound, or CBN should work too, though I haven't tried it. The best stropping is usually done in just a handful of passes, after the edge is refined as much as possible coming off the stones.

The other suggestion to move towards freehand methods is always a good goal to set, and will eventually render moot the limitations of using a guided system for touch-ups. I gradually distanced myself from using my Lansky guided system for some of the same reasons. So long as one focuses on keeping the apex crisp, and protecting it from counter-productive errors which dull the apex as it's being refined, the bevels don't have to be perfectly flat to produce a laserbeam-like slicing edge. Focus on keeping the angle 'conservatively low' as you work, so you're just 'kissing' the apex into a more refined condition.


David