Tried different approaches to stropping

[maximus83]

HH, this all makes sense. Consistent with what you said, I can compare my 2 preferred methods after experimenting:

1. Stropping on basswood + compound.
2. Stropping with light strokes on a high-grit stone.

Basically (1) is accomplishing the same end result as (2), although doing it a little differently. Both are "honing" the edge ever so slightly, both are aligning the edge, both are removing tiny burrs, both are polishing and slightly removing some toothiness. Both require you to grab a sharpening implement. It's not any more of a hassle to grab my wood block preloaded with compound than it is to grab my Ptarmigan, although theoretically, knowing you can "strop" on a stone, a person would never need to buy the wood block or compound in the first place. Since I already have them, it doesn't matter in my case.

So, point taken. There's more than one way to finish your edge and get great results. If I had to choose one for when I'm home and have all my stuff, and knowing what I know now, I think I'd stick with the stone-based approach and never bother getting the compound, the wood blocks, the leather, and all the other stuff I acquired and tried over the years. Just for simplicity and having less junk. I DO think it's a worthwhile skill though to develop your "improvised sharpening/stropping" skills, so that one can maintain your edge to some degree no matter where you are. Being able to strop effectively on a coffee mug, your jeans, a car window, a piece of bark using campfire ashes, etc., seems like a useful skill to have.

For me, hard-backed stropping is one of the best ways to go. I find it to remove less steel and maintain geometry plenty close enough to reset on a hard stone from time to time without removing any more steel than a blown out microbevel, maybe less. The lifespan of my knives has increased considerably since I adopted this as the primary means of touch-up.

Any hard stone is ultimately grinding a new flat into the steel over the wear bevel. This works great if the angle is constant every time such as a Sharpmaker. Odd angle swipes can add up rapidly and necessitate a reset with a rougher stone, as most polishing grade stones can't readily recover anything but the slightest loss of angle/geometry. This is true of hard strops as well. With a rougher stone as a finisher you are likely removing more steel per recondition, but doing so less often - mostly a push.

When maintaining on a hard stone I normally make a few passes at the original angle with a rougher stone anyway, and then refresh the microbevel. The upside is I have to do a full reset less often, the downside is I need two abrasive surfaces. The end result is not much different from a hard strop.

That said, I do use both strategies. Commercial sharpening I only make a few passes on the hard strop coming off the microbevel stone. In my personal use even if I set out to maintain only on hard stones, much of the time I will eventually default to the hard strop as I find it to be a lot faster when I'm in a hurry and no real loss of cutting efficiency. I have a tough time sticking with any one stone type or strategy though. It all works, and you only acquire and keep skills by doing.

 

[maximus83]

You can also use a few scrub passes and then finish with a couple of backhone passes.

Interesting, I never thought of scrubbing on the fine stone at this final stage. Immediate though is I'd wonder about it taking the toothiness off my edge (for working edges where I don't care about polish). Can you detail on how the scrubbing helps you at this stage?

Related item: I'm wondering about the differences of doing final backhoning on a lower grit AlOx stone, like the AF, rather than the Ptarmigan. Needless to say I'll try both. Looking to hear FortyTwoBlades view on that.

 

[FortyTwoBlades]

Interesting, I never thought of scrubbing on the fine stone at this final stage. Immediate though is I'd wonder about it taking the toothiness off my edge (for working edges where I don't care about polish). Can you detail on how the scrubbing helps you at this stage?

Related item: I'm wondering about the differences of doing final backhoning on a lower grit AlOx stone, like the AF, rather than the Ptarmigan. Needless to say I'll try both. Looking to hear FortyTwoBlades view on that.

Scrubbing would increase the polish if that's what you were shooting for, but that's not necessarily always the case.

Backhoning on a lower grit stone works fine, especially if you don't have a finer stone on hand. I find using a finer stone tends to help in really truing things up nicely, though. By their very nature they're slow-cutting when used that way, which is desirable at that stage.

 

[HeavyHanded]

Interesting, I never thought of scrubbing on the fine stone at this final stage. Immediate though is I'd wonder about it taking the toothiness off my edge (for working edges where I don't care about polish). Can you detail on how the scrubbing helps you at this stage?

Related item: I'm wondering about the differences of doing final backhoning on a lower grit AlOx stone, like the AF, rather than the Ptarmigan. Needless to say I'll try both. Looking to hear FortyTwoBlades view on that.

Yes, it lays in a slightly finer edge. It also makes it possible to do larger jumps with the microbevel from a rougher stone. If the angle of the micro is very shallow you can very gradually lay in the finer edge. This strategy really makes it possible to customize the edge to a high degree, though it will change character over time anyway.

Another thing to pay close attention to - not all polishing stones can be used with a backhone pass without raising a burr. I'd rule out Arkansas, ceramics, EEF DMT, India stones etc. The more fixed the abrasive the less effectively this strategy will work compared to just doing a leading pass. Either way it is far more liable to raise a small burr than a hard strop.

It is also more likely to fold the apex over at a near microscopic scale though this won't really effect the edge performance a lot (check out Science of Sharp for SEM images of this phenomena). Very light pressure must be used.

It all comes down to how hard, fixed the abrasive is. On my Norton waterstones I can backhone on the 1k and not really raise a burr due to the ready release of abrasive, on my India or Crystalon stones this doesn't work. Even on my lower grit Juuma waterstones this is not really possible beyond a few extremely light passes to finish.

 

[maximus83]

Yes, it lays in a slightly finer edge. It also makes it possible to do larger jumps with the microbevel from a rougher stone. If the angle of the micro is very shallow you can very gradually lay in the finer edge. This strategy really makes it possible to customize the edge to a high degree, though it will change character over time anyway.

Another thing to pay close attention to - not all polishing stones can be used with a backhone pass without raising a burr. I'd rule out Arkansas, ceramics, EEF DMT, India stones etc. The more fixed the abrasive the less effectively this strategy will work compared to just doing a leading pass. Either way it is far more liable to raise a small burr than a hard strop.

It is also more likely to fold the apex over at a near microscopic scale though this won't really effect the edge performance a lot (check out Science of Sharp for SEM images of this phenomena). Very light pressure must be used.

It all comes down to how hard, fixed the abrasive is. On my Norton waterstones I can backhone on the 1k and not really raise a burr due to the ready release of abrasive, on my India or Crystalon stones this doesn't work. Even on my lower grit Juuma waterstones this is not really possible beyond a few extremely light passes to finish.

So you mentioned microbevel. I used to use one, but recently as I've been ramping up sharpening proficiency, I've been going without one and getting pretty good results. Do you feel like a microbevel is the way to go for best balance of edge performance and durability? The reason I've been avoiding it: I can't really see--or feel--what's going on with a microbevel or what the angle is. If I come back to sharpen it later, I have no way of knowing what the microbevel WAS. Although here, I assume the response is just you reset the micro every time you do a maintenance sharpening. So I've been keeping it simple and creating an edge with no micro. At first this was really really hard, because my sharpening skills weren't proficient and I couldn't keep a consistent angle. Creating a microbevel in the past actually enabled me to kind of bypass this problem. But now I'm able to be--though not perfectly consistent in my angles--SUFFICIENTLY consistent that I can get a good edge bevel and get it really sharp. When I come back to sharpen it later, I can see and feel the sharpening angle, so it's easy for me to maintain it too. But maybe I'm missing something here.

 

[HeavyHanded]

So you mentioned microbevel. I used to use one, but recently as I've been ramping up sharpening proficiency, I've been going without one and getting pretty good results. Do you feel like a microbevel is the way to go for best balance of edge performance and durability? The reason I've been avoiding it: I can't really see--or feel--what's going on with a microbevel or what the angle is. If I come back to sharpen it later, I have no way of knowing what the microbevel WAS. Although here, I assume the response is just you reset the micro every time you do a maintenance sharpening. So I've been keeping it simple and creating an edge with no micro. At first this was really really hard, because my sharpening skills weren't proficient and I couldn't keep a consistent angle. Creating a microbevel in the past actually enabled me to kind of bypass this problem. But now I'm able to be--though not perfectly consistent in my angles--SUFFICIENTLY consistent that I can get a good edge bevel and get it really sharp. When I come back to sharpen it later, I can see and feel the sharpening angle, so it's easy for me to maintain it too. But maybe I'm missing something here.

I've come to like them for shortcutting a finer edge. They also allow me to tailor the type of edge I'm making.

How I keep the angle is to do a few very light scrubbing passes at the original angle and then elevate the spine a little and do a few more light passes at the microbevel angle.

I haven't really seen where they help or hinder, but it is faster than polishing the entire bevel to a higher finish. It also requires less QC and observation to make sure the edge is burr free compared to single bevel. Coming from many years of single bevel, I don't necessarily stand behind either strategy, but sharpening for others this is how I go.

Normally I wind up maintaining on a hard strop, so coming back to it isn't really an issue. This is how I recommend folk maintain ones I've sharpened for them as well. Also, my micro is normally about 30° or lower, so folks with Sharpmakers can just use that setting to touch up the edge.

 

[maximus83]

So, an update to this thread and what I've been trying and learning around stropping lately.

• HeavyHanded has convinced me that stone stropping (backhoning on a polishing grade stone with very light edge trailing strokes) does work, but is not the best maintenance strategy. The reasons are not primarily about which approach is most convenient or removes the least metal. The real reason is that backhoning on a stone is far less forgiving in response to typical human error and variability. The slightest waver or wobble in your backhoning stroke on a stone is going to grind a bad spot into your edge. The same human error on a traditional strop is still going to impact you, but not nearly as much. That is the real reason, IMHO, to strop in some traditional method: it's a way to maintain your edge with a significantly reduced risk of messing it up.
• As for preferred stropping methods, I have narrowed down to ideal/home-stropping methods (when I have all the gear at hand), and improvised stropping methods. For the improvised, I just use any of the many methods and materials often discussed here on BF.
• After more experimenting, I've finally narrowed down to these 2 preferred home-stropping methods that get the best results I've seen to date:
  • The HeavyHanded method. Wrap computer paper around my Norton Crystolon, add cbn compound.
  • The @Jason B. method (he suggested it to me). Basswood block, sanded, add cbn compound. I also use the plain side of the block for non-compound quick stropping at home.

I honestly can't decide which of these 2 methods I like better. They both work, quite well. Both are simple to setup, use, and maintain. In some cases, I THINK maybe the computer paper approach gets faster results--I noted this on an M390 blade I sharpened recently. One thing I'm not as fond of about the paper approach, is that I keep struggling with the paper: getting it wrapped tight around the stone, and KEEPING it that way. Then, it wears out quickly, so I go thru a lot of re-wrapping paper and re-applying compound. On the basswood block, it works well but seems to work more slowly. Also, when it gets loaded with metal, I find that I've already had to re-sand the surface a couple of times to clean it up and then re-apply compound. If I don't, it gets to working even slower. So, both approaches require some maintenance of the strop.

Couple questions for the forum on maintaining the strop:

• On the basswood, would it work better/faster, and perhaps also last LONGER between reconditioning, if I used a coarser grit of sandpaper to rough up the surface more before applying compound? Or is it better to keep it pretty smooth like I have it now?
• In general, how often to reapply compound? Should I just do it every 10 to 15 stroppings, and resand the surface (or refresh the paper) while I'm at it?

Some pics. This week, I stropped a Kershaw Link in M390 using the paper+stone approach, it worked fantastic, turning an ok factory edge into a laser, without even going to a stone. This evening, I stropped a Buck Selkirk using the basswood. It worked great as well. In both cases I used the CBN 1 micron compound you see pictured. This stuff seems to work great on everything from soft steels to super steels.

 

[Obsessed with Edges]

I've not yet seen any need to re-sand my basswood strops at all. When they get loaded up, I just wipe them down with a microfiber towel (best) or a paper towel (usually good enough), and apply some more compound. If they're really heavily loaded with swarf, a little WD-40 or isopropyl alcohol on the microfiber towel helps to loosen & lift it away.

I used to use balsa blocks with compound. I sanded them periodically, but only because balsa's very soft and easily prone to denting, furrowing, cutting, nicking; so, the surface needs to be re-flattened & smoothed out periodically (a hand plane works great for that, BTW). If not for that, I'd have treated them in the same manner as the basswood.

Reapply compound as you find you actually need to do it. In my own uses, I'm certain I haven't needed to do this every 10-15 stroppings, or anywhere near that frequently. Pay more attention to how the strop is working & polishing your edges over time. When you notice it's getting slower or ineffective in producing the same improvement in results, then it's time to clean it up a bit, and/or apply some more compound. Same applies, if you also notice a lot of dirty stuff coming off the surface and clinging to your edges as you strop.


David

 

[David Martin]

HH, making sure I understand what your saying... Backhoning after sharpening for final burr removal should be done on
a softer stone which the grit will break free and tumble along. This helps in cutting the burr away. Since, I have no water
stones, this could be accomplished on sandpaper with a cardboard backing? DM

 

[HeavyHanded]

HH, making sure I understand what your saying... Backhoning after sharpening for final burr removal should be done on
a softer stone which the grit will break free and tumble along. This helps in cutting the burr away. Since, I have no water
stones, this could be accomplished on sandpaper with a cardboard backing? DM

That would depend on a bunch of factors. Certainly if backhoning, some wet/dry will work a lot closer to a waterstone than most other stone compositions.

In my use I find it best to eliminate the burr as close to 100% before doing any backhoning. I look at it more for a final edge finish than for removing the burr. But after that, yes on waterstones and wet/dry I always finish with some trailing passes.

 

[David Martin]

Thank you. I was considering it for maintenance work on a edge that has developed burrs from use. DM

 

[HeavyHanded]

It might work well in that role. Usage burring is not the same as sharpening burrs in my opinion. Usage ones tend to be a lot tougher and less liable to flop around.

 

[David Martin]

Exactly. I'm going after these and wanting to Not have to return it to a stone and do edge leading strokes. DM

 

[maximus83]

I've not yet seen any need to re-sand my basswood strops at all. When they get loaded up, I just wipe them down with a microfiber towel (best) or a paper towel (usually good enough), and apply some more compound. If they're really heavily loaded with swarf, a little WD-40 or isopropyl alcohol on the microfiber towel helps to loosen & lift it away.

I used to use balsa blocks with compound. I sanded them periodically, but only because balsa's very soft and easily prone to denting, furrowing, cutting, nicking; so, the surface needs to be re-flattened & smoothed out periodically (a hand plane works great for that, BTW). If not for that, I'd have treated them in the same manner as the basswood.

Reapply compound as you find you actually need to do it. In my own uses, I'm certain I haven't needed to do this every 10-15 stroppings, or anywhere near that frequently. Pay more attention to how the strop is working & polishing your edges over time. When you notice it's getting slower or ineffective in producing the same improvement in results, then it's time to clean it up a bit, and/or apply some more compound. Same applies, if you also notice a lot of dirty stuff coming off the surface and clinging to your edges as you strop.


David

Good to know, thanks. I'll try the tip with a bit of WD40 or something to clean the surface when loaded.

 

[maximus83]

One more Q came to mind about the CBN compound I'm using to strop. The CBN itself works great on all knife steels I've tried from simple carbon, to 420HC, to D2, flavors of Sandvik, tool steel, and powder/super steels. But what different characteristics would you expect between say 1 micron and 3 micron CBN compound? Is there a compelling reason to use one grit level over the other, for general purpose sharpening where I just want durable, toothy, good-performing utility edges and don't care about cosmetics? Almost wondering if 3 micron is the better way to go for general purpose sharpening.

 

[HeavyHanded]

For toothy EDU and ability to recondition some damage 9 or 12 would be an even better choice. Most black compounds are about 20 micron and are a popular choice for edu strop maintenance.

 

[maximus83]

For toothy EDU and ability to recondition some damage 9 or 12 would be an even better choice. Most black compounds are about 20 micron and are a popular choice for edu strop maintenance.

Are you aware of CBN paste abrasives in that grit range that would be worth considering? Ideally, I'd like to find a CBN compound since it'll work for all the steels I have.

 

[JJ_Colt45]

I agree the CBN for a knife going up to a coarser as HeavyHanded said gives a better EDC edge ... if you go with a fine CBN it will polish and its great for woodworking tools to push cut but takes the tooth out for better daily knife use.

And I leave the wood smooth seems to wear in after a few uses and actually works faster for me that way.

I had trouble at first with getting the burr removed and just a very light pull of the blade edge over the wood removed the burr and a few more trailing passes really brought the edge to where I wanted.

 

[Obsessed with Edges]

One more Q came to mind about the CBN compound I'm using to strop. The CBN itself works great on all knife steels I've tried from simple carbon, to 420HC, to D2, flavors of Sandvik, tool steel, and powder/super steels. But what different characteristics would you expect between say 1 micron and 3 micron CBN compound? Is there a compelling reason to use one grit level over the other, for general purpose sharpening where I just want durable, toothy, good-performing utility edges and don't care about cosmetics? Almost wondering if 3 micron is the better way to go for general purpose sharpening.

I know with DMT's diamond paste at 3 micron, it produces a very fast uptick in visible polish (on basswood), following something like DMT's EF/EEF hones. If you're looking for more tooth in your edges, you might consider something at/above 10 micron, as suggested by HH above. OR, produce more of that tooth on your hones (any one of Coarse/Fine/EF, by preference), and then very lightly follow with something like 1 micron compound, just to clean up the edge, leaving more of the stone's toothy finish intact.


David

 

[maximus83]

Makes sense on the coarser compound option. I can find a variety of 10 micron pastes that should work on pc paper or my wood block in diamond, and in SiC. CBN, not so much, I don't see a lot of coarser grit compounds available yet. I guess the CBN thing doesn't matter, assuming that SiC or diamond compounds should should handle all steels as well as CBN.

Any reason to choose diamond compounds over SiC ones for general purpose stropping, at this point?

For example, check out these SiC lapping compounds for automotive or from Brownells for firearms use. Seems like I'd want something in the 800 to 1200 grit range.

https://goodson.com/products/lapping-compound?variant=33471741702
https://www.brownells.com/gunsmith-...licon-carbide-abrasive-compound-prod1142.aspx

ETA: Ok, Bark River has some CBN emulsion compounds in larger micron sizes. Spendy though, $40 for 2oz 16 micron. I'm really interested in just trying the above SiC lapping compound or something similar, unless folks think this is a bad idea and will get significantly reduced results vs a diamond or CBN paste.

http://www.dlttrading.com/cbn-compound