How To Maintain an edge on super steel knives

[HeavyHanded]

^So HH, do you think then that the application of Todd's findings from straight razors to knife sharpening are either "small" at best, or "unproven" at worst? Been looking into that a bit lately, as I observe some small improved performance from stropping a well sharpened blade, but the difference is definitely small and certainly does not prove that the micro-convexity thing is the cause.

You have to assume there is convexity proportional to the amount of material deflection. If that deflection is very slight, as with a waterstone, hardwood strop, frosted glass, the edge will actually fold away from the pressure rather than grind into a convex, based on the amount of pressure, approach angle and grind rate. So somewhere in the mix is a bunch of variables that have the edge deflect, grind into a micro, convex from the curve of the strop material. You have to spell out the variables before talking about effects.

If you're talking about an average leather strop I'd say for sure there is plenty of microconvexing. There's even going to be some off of lapping film.

 

[maximus83]

So, this won't resolve anything, just a few more observations from additional sharpening I did this afternoon. Kept working with Elmax chisel grind I posted about, here, and some back-and-forth with HH.

Now I've tried several different approaches with this Elmax steel, including SiC stones, diamonds from XC thru EEF, strops with CBN compound, and a clean leather strop. Here's the sharpening approach I landed on that--after profiling on the DMT XC--gives you the most bang for buck in terms of results for fewest amount of steps, while still getting great sharpness.

• DMT C
• DMT EF (lightly strop the flat side to deburr, plus about 10 light finishing strokes on the edge itself)
• Strop: wood block with 4 micron cbn (strop both sides about 10 laps per side)
• Optional: clean leather strop to finish. Not necessary and normally won't do this. But as an optional value-add after the hard strop, it noticeably improved the keenness a bit as seen in how easily the blade slices newsprint.

The green steps, in addition to being a reasonable finishing process for this Elmax blade and possibly other super steels, also seem like a legit maintenance process. As discussed above in thread, possibly one could substitute the DMT F plate (600 mesh) during maintenance in place of the EF, which would maintain slightly better toothiness at the expense of slightly more metal removal. I was also able to do pretty well omitting the stropping step entirely and just finishing after EF, although the strop made a difference in sharpness with less than 5 minutes of effort, so it seems worth it to me.

 

[David Martin]

Ok, if I'm reading your process right: You went from X coarse, coarse, EF and into some stropping stages on various, grit progression and bases. With a note about the fine. While I don't have any experience with Elmax and have only read it's a difficult steel to force a complete
sharpening on. I would think spending enough time at each grit progression should show the better results toward the end grits.
For me stropping stubborn steels gives slower results, even with slurry. It's in the stone work that I notice the better results. DM

 

[Uncle Timbo]

I tend to be a tad old school. As far as whether to use a strop or not, let's look at the old barbers. What did they charge their strops with? Bare horsehide?

 

[Obsessed with Edges]

Ok, if I'm reading your process right: You went from X coarse, coarse, EF and into some stropping stages on various, grit progression and bases. With a note about the fine. While I don't have any experience with Elmax and have only read it's a difficult steel to force a complete
sharpening on. I would think spending enough time at each grit progression should show the better results toward the end grits.
For me stropping stubborn steels gives slower results, even with slurry. It's in the stone work that I notice the better results. DM

This.^

More and more, that's what I'm learning too. It's why I've become less dependant on stropping as a whole, save for a few quick & light swipes on paper over the stone, or bare leather, or on my jeans afterward, to strip away the last loosely-attached, weak remnants of burrs.

If I approach each grit step as if it's the only grit I'm finishing on (whether in a progression or not), the results are always better and a whole lot easier by the finishing stages, than if I were treating early & mid-progression steps as 'just enough to move to the next step' and then relying on the last stage of honing and stropping to get it all the way 'done'.

I became more motivated to work from that perspective after I'd run out of 1-micron diamond paste and didn't really want to spend the money for some more.

I still do strop with compound, at times. But as I mentioned earlier, it's usually only with the goal of adding polish to the bevels for specific uses (kitchen use, chisels for woodworking, etc), if my hones aren't quite enough to accomplish that on their own.

 

[maximus83]

Ok, if I'm reading your process right: You went from X coarse, coarse, EF and into some stropping stages on various, grit progression and bases. With a note about the fine. While I don't have any experience with Elmax and have only read it's a difficult steel to force a complete
sharpening on. I would think spending enough time at each grit progression should show the better results toward the end grits.
For me stropping stubborn steels gives slower results, even with slurry. It's in the stone work that I notice the better results. DM

David, yes that's pretty much what I did. I found the Elmax slightly more difficult to sharpen than M390 (as in, slower to get equal level of sharpness), but not bad. I did essentially what Obsessed mentioned above, each grit I got the blade to a state of completeness (deburred, passing basic sharpness tests) before moving on to the next. At the end with the EF, blade was already cceptably sharp including shaving arm hair. But the quick effort to strop on THIS blade, paid off, it noticeably bumped up the performance in sharpening tests. Now it was popping arm hair, for instance. Whether that's worth it or necessary is obviously up to the individual; for sure I don't always strop. But if I could spend 5 minutes of stropping on my folders and field blades and get that extra bump in sharpness, I'd probably keep doing it. I'll probably try this progress on a few others blades, test after the EF plate, test again after the CBN storp, and see if it similarly appears to pay off doing the quick stropping step.

 

[maximus83]

If I approach each grit step as if it's the only grit I'm finishing on (whether in a progression or not), the results are always better and a whole lot easier by the finishing stages, than if I were treating early & mid-progression steps as 'just enough to move to the next step' and then relying on the last stage of honing and stropping to get it all the way 'done'.

Yes agree with you David especially on this, and that's the type of process I usually follow and did here. It's a bit more time consuming, but I get best results when I try to treat each sharpening stage as if it's the last one, getting the blade as sharp as I can get it on that grit. OK I don't go QUITE that far on the XC, since I know I'll go to the C after that, but from C on up, that's what I do. Even in spite of that, I found yesterday that the CBN stropping still made a noticeable (but not massive) improvement in sharpness. It was VERY noticeable though. Whether you need that level of sharpness in an EDU knife, whether it's worth the extra CBN compound and minutes invested, and whether the typical non-knife-knerd would care or notice the difference in real world usage, is up for grabs. For me, it's sort of mixed. I'll probably do this process on my favorite folders and fixed blades, but not on everything. The compound is expensive, and it's nice to be able to sharpen more quickly and, as Wowbagger mentioned, with just less hassle and steps.

 

[Mr.SATism]

I know this might be a ‘no duh’ moment, but I do find that if I strop with my lowest grit before I sharpen, it gives me an easier time sharpening. Now I’m not saying this is going to help with a “knife across brick” situation, but it is more of taking “just working” edge to a “tissue paper” type of sharp

 

[maximus83]

Related item is, even though we agree as above, that the foundational and most important work is all on your stones--especially the coarse stones--there are also a number of folks who've been doing for a while what I did here, basically adding an abrasive in the 3 to 6 micron range as a value-add refinement step with super steels. So even though the beginning process of your sharpening is the most important, how you finish can make a difference too. Last time I talked to @bluntcut, he was using a diamond plate in this 3K to 4K range. Pretty sure @Jason B. uses a UF ceramic which would fall in this range, both to refine and maintain edges. HeavyHanded has his own compound in that range (4K JIS), which when used to strop on the Washboard system, accomplishes the same goal.

The common theme is that regardless of how folks use this in their sharpening process, some are finding that adding an abrasive in this medium-high grit micron range as a refinement step can add some value with these steels. This was my first time trying this approach with Elmax, and first time using this new 4 micron CBN from Bark River, but it definitely made a difference. No vested interested in saying that, not selling anything, don't work for Bark River, and personally, if I have any sharpening bias at all it's striving for greater simplicity and reduced steps. But it was super clear in this case, adding a 4 micron abrasive helped. I'm not sure that stropping was what made the difference, more likely it was just the abrasive--the size, and the fact it is CBN. I assume if I had used a 4k diamond plate to refine, I could've gotten similar results.

Based on what these others guys are doing, and what I saw in this test, I'm going to keep experimenting with this idea of using something 3 to 6 micron to refine/maintain super steels. With my variety of blades in S30/S35, M390, 20Cv, Elmax, and a few others, the maintenance routine could be something like: DMT F or EF, followed by strop on this 4 micron CBN, OR by work on another abrasive in this same micron range. I'll keep trying this Bark River 4 micron for a while. Another option could be HH's 4K compound, which is cost-effective and has a mix of diamonds + SiC. Could be the DMT 'medium' 6 micron plate they've come out with recently in this range, that way would give the benefit of an 'all stone' solution without stropping.

 

[maximus83]

Ok David Martin , the testing continues, you'll like this one. In the interest of going minimalist, tried to see how FEW steps I could go to get to the level of sharpness I wanted. So I did a bevel reset on the DMT XC, completely overground the scratch pattern so it would be a fresh start. For sharpening: DMT C > 3 light backhoning strokes on DMT C to deburr the flat side > strop both sides on the 4 micron CBN.

That is the most minimal progression I can do that gets the Elmax chisel grind to the level I'd want. The stropping was required to get that result, but still that's not bad with only 2 sharpening steps. It's not QUITE as refined as the above progression, but it'll still pop hair off my arm and do all the newsprint and receipt slicing tricks, so this is solid for an EDU.

So now it's back to the maintenance question: if you want to keep your coarse scratch pattern, what do you maintain with in order to minimize aggressive metal removal? Light strokes on the coarse followed by strop? Or back to the idea of using DMT F + strop for maintenance?

ETA: Freshly popped arm hairs on the flat side, and a push-cut on Rizla, no starting cut. A little jag there at the beginning because I didn't use a starter cut which the test allows. Surprised this blade could pull this off with only a 2-step DMT C + 4 micron strop.

Latest look at the edge, it's reflecting light kinda bad, but gives an idea of the coarse finish:

 

[David Martin]

I'll wait and see what is said. DM

 

[David Martin]

"if I want to keep my coarse scratch pattern,". Yes I would take it back to the coarse and back hone it to remove the burr. If I could do it all on that grit or stone. Sometimes I can't quite get all of them removed on that. So, I'll take it to the fine for just that area. You can them strop if you like and it will become more refined. I try to just maintain on the stone, unless I'm away from my stone. In those cases I'll strop on my leather boot top adding some sort of grit to H2o as the carrier agent. i.e. ashes, very fine clay, ect. what ever is available. DM

 

[maximus83]

David, makes sense on using the coarse, or perhaps the coarse supplemented by the F for maintenance.

Hoping to learn more about the possibilities of that 3 to 6 micron range, for a finish grit in regular sharpening or in maintenance. I've been favorably impressed the 4 mic cbn on one blade, will need to try others.