What is a "keen" edge?

J

jeepnjg

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Sep 13, 2014
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I'm under the assumption that people viewing this thread are fairly knowledgeable on sharpening different types of steel and may be able to help me out.

I would consider myself average/capable and consistent in my sharpening abilities. My hand sharpening has gotten pretty decent over the last couple months, and I'm usually very happy with the sharpness of the knives I work on. Having said that, I just got a couple of Boker stockman/traditional style knives. The blades on the one I just tried sharpening were ground very rough and were embarrassingly dull. I went through my usual process (Norton coarse, Norton Fine, Dan's Hard Arkansas, Spyderco UF Ceramic, Stropman Strop with white and green compound). I used a marker to check my angles and raised a burr on both sides of the bevel (a couple of times actually just to be REALLY sure I had apexed the edge). The end result was...disappointing. The edges (3 on a stockman) would barely cut paper (it tore the paper really) and didn't even feel all that great cutting cardboard.

I've had great success on 8Cr13Mov, AUS 8A, VG10, S30V, and different flavors of 1095 (Wife: How many knives does one person need? Me: Um...More?). Arm-hair shaving sharp is my usual standard for those knives, but this Boker steel is somehow different (or at least that's what I'm telling myself). As I'm learning about Bokers, if the blade or handle doesn't specifically state Solingen as its place of manufacture, then the knife is one of their "budget" line, and this knife falls into that "budget" category.

Sorry for the long build up, but here is my question: Are some budget steels just not able to be sharpened as sharp as other moderate or advanced steels? I've read things like, "S30V takes a keener edge then XXX steel." Is this Boker steel just at the opposite end of that spectrum? I don't even know what type of steel it is. How sharp could you get, for example, Buck's 420J steel? Will it shave arm hair? I've seen a guy on youtube sharpen a spoon and shave with it! Shouldn't any steel be able to shave arm hair and cut paper? Or does this knife only get as sharp as it gets and no further? Thoughts? Thanks in advance!
 
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I treat steels like that much like I'd treat Victorinox SAK blades (my mantra for those is: LESS is MORE). More often than not, these steels are fairly 'soft' on the hones, and it takes very little to make a big change, for good or bad. A medium or fine hone, maybe like your Norton Fine, followed immediately by your strop with white, then green compound, is probably all it needs. It's very easy to go too far on these steels, either with very coarse or very fine abrasives. The Norton Fine stone should be able to remove as much metal as needed for re-setting a bevel, and the white compound on a firm strop should refine it as much as needed, stripping away burrs and perhaps even refining the scratch pattern left by the Norton stone. So long as technique is good (maintaining angle, good use of very light pressure), it takes very little to get these blades sharp again. Over-use of any of the other tools, like the hard Arkansas, Spyderco ceramic, or the green compound on the leather strop, may be counter-productive, taking some of the bite out of the edge. These all can be used to good effect, if your touch is very good and light, and if you have a good feel for the steel. But, it still takes checking the edge very frequently, every couple or three passes, to make sure you don't go too far.

The tearing of the paper during test-cutting might be an indicator of burrs remaining on the edge. If your 'white' compound is like mine, it should be handy for cleaning those up; works much better on a very firm strop, with little/no chance for rounding off the apex. That can happen quickly with white rouge AlOx compounds, which are very aggressive (very fast polisher); it'll round off the apex quickly, if the strop has any give or conformability under pressure.


David
 
Great input. Thank you very much!

By the third blade, I was becoming very pragmatic. I would sharpen on a grit until I got wire edges, do several light, burr-focused passes, and attempt to cut cardboard. But you are absolutely right. I wasn't completely deburring until the end. That's when I use the "stick push" method I learned from another BF member. I think his screen name is Bluntcut. This is his technique: https://www.youtube.com/watch?v=l2ynSDYEUYI&list=UUlYJZk9uax68As0B5wSYmLw. It's worked on VG10 very well!

But now I want to try stopping on the norton india fine and just focus on deburring really well. The other piece (possibly?) is this was my first use of the Stropman strop. I was using a green compound Knives Plus strop for the longest time before then. Maybe I should go back to that strop just to reduce the variables in play.

Actually, that's another great question. How (if at all) should I modify my technique going from a knives plus green compound strop to a Stropman white and green strop. Anyone else make that switch? Was there a learning curve involved?
 
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Changing sharpening mediums often throughout a progression like that can present problems. Different medias abrade differently , as a result it can be hard to completely remove scratches from one media to the next.

Many of the new bokers that I have seen have been quite thick , and the result is a bevel that is extremely steep. An extremely steep bevel combined with soft stropman strops and mystery compounds could have potentially rounded off the very edge of the edge , especially likely if you had a burr earlier on and the knife performed better prior to stropping.

So lets do some diagnostics. Start over , right from scratch (shouldn't take you long now) , go through your progression like normal. Do burr removal after each stone , on that stone. To do this do some extremely light alternating edge leading strokes. After your final stone see how the knife performs. If you go to your strops and the edge performs worse afterwords...

Heres a video I did on burr that talks about burr removal.
[video=youtube;j032eLxxhzc]https://www.youtube.com/watch?v=j032eLxxhzc&list=UURBNk3WxBpQFIrtqG-pnuzw[/video]
 
A "keen" edge to me is if the glint is gone and it will catch your skin. Sometimes you can definitely go to far as stated above by obsessed and sadden.
 
Sharpening a Boker slipjoint
I use DMT stones
I knock off the shoulders with a course stone
Burr with a fine
burr with an extra fine
a couple of passes with a strop with white compound
The final extra fine and strop is minimal

This is a keen edge

On a Boker slipjoint you can only get a keen edge as anything more than that is lost too quickly
 
Thanks everyone for your great input. Last night I started with the suggestion from Obsessed with Edges. I had another Boker to sharpen. It's the beer barrel stockman. I'll try to post a pic later. I did its first blade on my Norton india fine stone only. I laid the blade back to knock off the shoulder like neeman suggested. I actually do that with just about all the knives I hand sharpen. (I don't think I've ever gotten a factory grind angle I've been happy with. Well, maybe a mora, but I digress.) I was able to profile the bevel just fine on the fine side and raised a wire edge with no issue. I did the stick-push technique like I mentioned earlier in the thread. I actually had a more difficult time than usual working the wire edge off the apex. This was probably due to the fact I'm used to deburring off the Spyderco UF Ceramic stone, which leaves a substantially smaller burr build up. Then I went to the white and green compounds on the stropman strop. At first it was just OK. I found out later that way more stropping was needed to get the edge where it would start shaving hair.

Then I got curious.

On the second blade, I did the same thing on the Norton fine stone with a few light deburring passes. Then I went to the Arkansas hard stone, did the stick-push thing for the wire edge, and stropped on both compounds. The result? It was definitely not worth the effort to sharpen that particular steel on a more fine stone. To me, that totally validated what Obsessed with Edges was saying about possibly overworking the steel. I stropped the fool out of that thing while watching TV, but it just never got anywhere near where I wanted it. I actually put that blade back on the Norton fine stone, deburred it again, and did some quality stropping. Now the second blade's edge will shave hair a little. No where near my VG10 or S30V, but it does shave with pressure on my arm. (Maybe that's the definition of a difference of "keen-ness" or edge quality?)

By this time, I knew I would just do the third and final blade only on the India fine stone and really focus on deburring. It turned out to be the sharpest of the three blades on the stockman. I also got to know the Stropman strop a little better, and I really like it. My next step will be to go back to the original "budget" Boker, and take the same steps to see how it turns out.
 
jeepnjg said:
Great input. Thank you very much!

By the third blade, I was becoming very pragmatic. I would sharpen on a grit until I got wire edges, do several light, burr-focused passes, and attempt to cut cardboard. But you are absolutely right. I wasn't completely deburring until the end. That's when I use the "stick push" method I learned from another BF member. I think his screen name is Bluntcut. This is his technique: https://www.youtube.com/watch?v=l2ynSDYEUYI&list=UUlYJZk9uax68As0B5wSYmLw. It's worked on VG10 very well!

But now I want to try stopping on the norton india fine and just focus on deburring really well. The other piece (possibly?) is this was my first use of the Stropman strop. I was using a green compound Knives Plus strop for the longest time before then. Maybe I should go back to that strop just to reduce the variables in play.

Actually, that's another great question. How (if at all) should I modify my technique going from a knives plus green compound strop to a Stropman white and green strop. Anyone else make that switch? Was there a learning curve involved?
Click to expand...

Focusing on de-burring on the stones is always a good thing; the better one gets at doing that, the easier the refining steps will be. That'll also reduce the amount of work needed on the strops, in the end. With stropping, if you can't accomplish most everything needed in the first few passes (< 10 or so), you probably need to do some more refining on the stones first, before stropping. With this knife, you might also experiment using just a piece of plain paper over your stone, for stropping; no compound, just the paper. With simpler steels like this, sometimes that's all that's needed to clean up the burrs; I've started using this method with my Victorinox blades (very similar to the stainless in your Boker), and it works pretty well, leaving some very nice hair-popping 'bite' in the edge.

Main thing to watch for, in using the white strop (assuming it's an aluminum oxide 'white rouge'), is that it'll be a lot more aggressive in removing metal, than the green by itself. I mentioned earlier, when using the white, you'll want to frequently check the edge every 2 or 3 passes, because it's condition will change fast with white AlOx compound, based on what I've seen with the compound I've used. More so, with relatively soft & low-wear steels such as on these knives.


David
 
Here's that eye candy I promised!
IMG_20141023_092233949_zpsfdd38f11.jpg
 
^Nice-looking knife! :thumbup:

I see you're making some good progress, based on your update in post #8 (I was replying to an earlier post of yours, just as you were updating us in that one). Sounds like de-burring on the India Fine stone, and minimizing overworking on following steps, is the main difference-maker here; that'll always keep you on the right track. :thumbup:


David
 
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