When stropping isn't enough....

[7x57mm@gmail.com]

Curious to learn from those in the know how you would handle an edge that is starting to deteriorate. If a knife's edge start to show "glint" spots on the apex and bare leather stropping no longer corrects the issue, would you use a 3-4K stone to realign the edge or go to a ceramic honing rod first? Steels in question: W#2, likely B#2 in the future (the Anryu still responds to a leather strop like a champ) and SV30.

[d_rap]

Glints can be a tiny roll, or some micro flattening/ genuine dulling of the edge. At that point it's academic. Once I can't bring it back to near-perfect with a strop personally I usually drop to 1K or sometimes lower. But try a 3 or 4 for a couple minutes and see if you can get it back and remove the glints under good light and cut magazine paper like a dream. If a couple minutes on a 3 or 4 K doesn't do it, drop lower.

Once I can see visible imperfections, even small, under good light, I don't use my ceramic rod; I go to a stone touch up and drop as needed because glints suggest the need to remove metal. And by the way one of the downsides of a ceramic rod is it's incredibly easy to just bend a wire, or burr, back and forth and back and forth with it.

(Todd with the big microscope at the science of sharp will show you that even ceramic rods remove metal but that's for another thread.)

[ken123]

You should think of sharpening with stones and stropping as being on a continuum. Thus you can use coarser compounds or finer stones - your choice. You should carefully consider the strop you are using and the grit of the compound employed typically from 80 microns to 0.003 microns. You might consider starting with 8 microns or 2k. I would avoid steels as they are inherently less precise tools.
Ken

[taz575]

Get some compounds for a strop to remove steel if you need to touch up. Bare leather won't remove a lot of steel, but a strop with compound will keep you going for a long time before needing to go to a stone. I use the Bark River compounds Black and green on a strop and it touches up everything I have from AEB-L, 52100, 1095 to CPM S30V, S35VN, CruWear, Elmax, M390, etc. The higher end steels take a little longer, or I switch to a strop with CBN compounds (a little coarser) for the main work and then switch back to the BR strop to refine.

[mikeltee]

I'm happy to know you realize that you need to take the easiest step in order to repair your edge. Many people just use a normal progression on every edge and waste a lot of metal, stone and time.

[Jeff B]

Many people just use a normal progression on every edge and waste a lot of metal, stone and time.

The biggest myth repeated constantly in the world of sharpening.
To get a knife sharp your are bringing the edge to an apex. It doesn't matter if you do it with 3 minutes on a 1k stone or 3 strokes on a 320 grit stone. You have to remove the same amount of metal to get to an apex.

[d_rap]

Many people just use a normal progression on every edge and waste a lot of metal, stone and time.

The biggest myth repeated constantly in the world of sharpening.
To get a knife sharp your are bringing the edge to an apex. It doesn't matter if you do it with 3 minutes on a 1k stone or 3 strokes on a 320 grit stone. You have to remove the same amount of metal to get to an apex.

Just to say, I really think this kind of debate is productive and healthy, and speaking personally, in addition to hands-on practice it is how I learn. If anything, our forum needs more spirited disagreement where we actually engage one another's points.

I agree with Jeff, an apex is an apex. Now if you take his argument past a reasonable point (a 320 versus a 1K) and alter his example to, let's just say an 80 grit stone, well someone could object that at a certain point of coarseness you are going to create scratches and tear out that are unnecessary. And of course everyone knows even a 320 will leave deeper scratches than a 1K, although Jeff's point that it's basically the same amount of metal removed if you stop just as you attain an apex is correct. But it's probably fair to say that at some level that as you go lower the grinding will possibly be a bit more impactful, even if it's several strokes compared to 50. I interpret Jeff to be saying that using a 320 and a couple of quick well made strokes (assuming a good sharpener) is fine and in many cases better. And I really agree with that. Too many sharpeners will spend too much time on too high a grit stone when a lower grit stone will make quick work of the task and, yes, might leave less room for error and maybe be less impactful. And let's be honest, for a home cook with a collection of knives, these knives will last most of us a lifetime, even if we do sharpen frequently.

For me, it's what I suggested above: drop down as low as you need to to make reasonably quick work of apexing. Don't spend 5-10 minutes with a 4K when a 1K would do the work in 30 seconds, and the less time you spend, even if the scratches are a bit deeper, the less room for error in angle etc. As a sharpener gains experience he or she will get a feel and knowledge of how low they need to go to apex efficiently. No one would say go to a 320 if an 800 or 1K will bring you to a perfect burr in 30 seconds.

Finally, back to the OP's question and strops: sure, it's a continuum as Ken says, but it depends what strops you have and how you use them. I do have some coarser compound that can do some real sharpening on strops, but usually what I mean by stropping is going to my roos with 1 micron diamond paste and then .25 micron paste, and perhaps bare leather after that. So it depends. I do think most people mean something like that by "stropping," final edge correcting micro-finishing, so the fact that you can hypothetically set strops up like stones to sharpen might not really be answering the question someone is asking.

[FisherMAn1298]

Well said d_rap, you stole my thunder! Jeff B. also. Get some coarse grit spray/emulsion on a good roo or nanocloth strop and then if you want to really make it sharp go to .5-.003 as Ken says. That way you can keep that edge sharp a hell of alot longer before having to go back to the stones. Also, if I do have to go back, I agree with reaching back to my nubatame 1k and slowly running strokes til you feel your edge come back. It doesn't take much on that baby! Then go up the ladder at your preference, cutting paper all the well to evaluate your edge. I don't use a bare strop, the .125 emulsion works too well for me, that way it's one nano strop session after use and back to a great edge!Been using Ken's.10 pdp emulsion. Going to .0025 on a new nano cloth strop. That's my final round of a sharpening session as well as a touch up after every use of the knife.

[David_R]

Well said d_rap, you stole my thunder! Jeff B. also. Get some coarse grit spray/emulsion on a good roo or nanocloth strop and then if you want to really make it sharp go to .5-.003 as Ken says. That way you can keep that edge sharp a hell of alot longer before having to go back to the stones. Also, if I do have to go back, I agree with reaching back to my nubatame 1k and slowly running strokes til you feel your edge come back. It doesn't take much on that baby! Then go up the ladder at your preference, cutting paper all the well to evaluate your edge. I don't use a bare strop, the .125 emulsion works too well for me, that way it's one nano strop session after use and back to a great edge!Been using Ken's.10 pdp emulsion. Going to .0025 on a new nano cloth strop. That's my final round of a sharpening session as well as a touch up after every use of the knife.

Also agree with d_rap. The only thing I'll add is that strops are refining the edge, not creating the edge. I've done cut testing after stropping and the edge retention goes down after dulling and re-stroping of the same edge. So you get a sharp edge back, but it's not the same as edge sharpened on a stone.

Re the quote above, does going to < 0.5 microns on a strop really increase edge retention? I haven't see data on this. In my limited testing I don't see a big increase in edge retention after ~1K stone. This can vary based on the steel and what is being cut, of course. But all things being equal, I see edge retention start to flatten out after ~1K, maybe a little less.

Fyi, Science of Sharp on what a strop does: https://scienceofsharp.com/2014/08/13/w ... opping-do/

[FisherMAn1298]

I don't strop to increase edge retention, except when it's my initial sharpening where I do a complete progression from creating the edge at lower grits to finishing at 10k. Then I strop to bring the edge to as good as I can get it.I'm just trying to bring edge back to close to where it was. Your edge is created as you say in the coarse stone arena 150,220,500, then your 1k. The 2k is a small part of that but it also begins the refining and cleaning up the scratches going forward to the higher grits don't you think? I strop to give me that keen edge I lost from using the knife, never expect it to lengthen the retention of it for any period of time.
What do you think of an opinion of a novice, highly committed to the fun of all this newbie sharpener of 9 months. when I look for absolute truths and spot on answers I bow to the great Ken Schwartz, whom I respectfully refer to as The Master Of the1k. Funny, he refers to himself as a mud Salesman!! I love that, makes me laugh every time. Great post, love when someone adds to the thought process, making me think. that's what this is all about, and humor! Give me more humor!!!!
I've read the Scienc Of Sharp and it's got amazing info. However, it's he's talking about straight razors coated with some substance. It talke about abrasion where the scratch pattern is cleaned up. I don't strop bare, I always use emulsions at low micron leverls, either cbn or pdp diamond. that's what gives you a better edge in my opinion. i find the proof in the paper cutting as well as food cutting. A nanocloth strop with .1 pdp emulsion gives that edge a litle more of a keen edge. I feel it cutting paper, I hear it doing same and I feel and see it cutting food. Thanks for your thoughts David_R they are welcome and appreciated.

[David_R]

I don't strop to increase edge retention, except when it's my initial sharpening where I do a complete progression from creating the edge at lower grits to finishing at 10k. Then I strop to bring the edge to as good as I can get it.I'm just trying to bring edge back to close to where it was. Your edge is created as you say in the coarse stone arena 150,220,500, then your 1k. The 2k is a small part of that but it also begins the refining and cleaning up the scratches going forward to the higher grits don't you think? I strop to give me that keen edge I lost from using the knife, never expect it to lengthen the retention of it for any period of time.
What do you think of an opinion of a novice, highly committed to the fun of all this newbie sharpener of 9 months. when I look for absolute truths and spot on answers I bow to the great Ken Schwartz, whom I respectfully refer to as The Master Of the1k. Funny, he refers to himself as a mud Salesman!! I love that, makes me laugh every time. Great post, love when someone adds to the thought process, making me think. that's what this is all about, and humor! Give me more humor!!!!
I've read the Scienc Of Sharp and it's got amazing info. However, it's he's talking about straight razors coated with some substance. It talke about abrasion where the scratch pattern is cleaned up. I don't strop bare, I always use emulsions at low micron leverls, either cbn or pdp diamond. that's what gives you a better edge in my opinion. i find the proof in the paper cutting as well as food cutting. A nanocloth strop with .1 pdp emulsion gives that edge a litle more of a keen edge. I feel it cutting paper, I hear it doing same and I feel and see it cutting food. Thanks for your thoughts David_R they are welcome and appreciated.

Good reply - thanks for your thoughts. "Better edge" is in the hands of the user, I think. For most of my knives I don't see the benefit of going over 1K or 2K + a 1 micron strop. There could be a benefit to a more polished edge, but so far it eludes me in real world cutting.

[FisherMAn1298]

Honestly, this is a great issue for discussion where you can have a great time agreeing or disagreeing. I think going higher than 2k has its benefits but if I wasn't going higher than that by putting more time in on those lower stones we can get a great edge to work with that will last according to our steel's capabilities. Not to mention how amazing that .1(I much prefer .1 over 1 ) micron emulsion on a good nanocloth strop can do for your edge.I just enjoy it so much that I'm addicted to chasing the "best" edge you can get. It's fun to see how your edge feels and changes at each grit level. A 3k diamond plate is so different from any stone and the Naniwa snow white 8k feels and cuts amazingly and leaves your steel absolutely glowing as it cuts through paper so cleanly with a very soft sound, almost a whisper. I really enjoy those moments. It's really about all that, the enjoyment. It's all just a very pleasant hobby that i've learned to love in a very short time. Try that Naniwa 8k snow white if you know someone that owns it. Let me know what you think of how the blade feels on the stone, the feedback, how different it cuts paper afterward. I'd like to hear your opinion. I just switched my first stone in my progression from a 500 grit shapton glass to a 150 grit nubatame platinum. I thought my edge would be rougher but it was more precise. It cut a much more consistent pattern, mainly because of the consistency of the abrasive in the stone. The Nubatames are tremendously consistent in their grit. Let me know what stones you use in your progression please and thanks again for the excellent discourse.

[David_R]

Very interesting. I'll try that Naniwa 8K. I'm sure somebody near me has one.

I try to use the same stones for most of my knives. This is mainly to get my process and feel down. I can go 2-3 weeks without sharpening, so I'm trying to keep the muscle memory going. I sharpen high carbide steels fairly often (S35VN, K390, M390, S90, others) so really needed diamonds. I dislike surface mounted diamond plates. I currently use diamond matrix stones for most of my sharpening. They cut well and finish well. And they get the job done fairly quickly for any steel. I only have these up to 4K. The stones I really want are vitrified diamond or CBN. Maybe some day.

I had Shapton glass stones up to 16K. I rarely used them. They didn't do what I wanted on super steels really weren't any better than Naniwa stones for me on the other steels. For my kitchen knives I if I'm not using the diamond stones I'll use a Naniwa Pro 400 and 800. Sometimes the Naniwa 2K or the Green Brick after the 800. I keep trying to like the green brick but am still not sure about it. I been using a King Neo 800 recently. Not the best stone out there, but surprisingly good.

I prefer wood strops to leather, but use both. More leather on kitchen knives and wood on others. Always 1m diamond compound or smaller.

The "best" edge for me means that I like how it cuts and it's sharp enough. I'm usually at 12 or 13 degrees per side for my kitchen knives. I prefer a little toothiness on the edge, which is probably obvious. For kitchen knives I consider them sharp enough when I can cleanly cut a loosely held paper towel.