New to knife sharpening - need help

L

LeCouteau

Joined
Mar 11, 2012
Messages
7
First post here. Hi.

I have been working on knife sharpening but I can't get any sharp (sharp enough to go through paper but not sharp enough that i'm scared of the edge). I have ruled out angle (I use a guide), I use DMT stones (a blue, red, and green set), and I know all about raising a burr then honing it off.

The steel of the knives i've been using are 420HC (specifically on a SAK) and 440 (not the most premium steels out there but people have told me I should be able to get them razor sharp easily). The only answers I can think of are:

1. I think i'm raising a burr but i'm not (the burr feels like a wire on the side of the edge, correct?)
2. the knives I have been using all have bad heat treatments
3. something wrong with the way I stroke the knife against the stone

Help. It's driving me crazy!
 
Both of those steels are pretty soft (not much abrasion resistance), so using very, very light pressure is key on the diamond hones. I wouldn't even bother using the blue hone (coarse). The fine (red) and EF (green) should handle those easily. It's possible the burr is forming, but the diamond will scrub it off very quickly, if you're not watching for it very closely. When you can see that you're very close to apexing the edge, check for the burr after each stroke. I can't emphasize strongly enough, use very light pressure. A little too heavy pressure is always counter-productive on diamond hones.

It also never hurts to use a good magnifier and bright light to closely inspect the edge for the burr. Make sure you get the burr with the first hone; don't move to the next until you do. And then, very, very light pressure again with that one, to carefully remove the burr.
 
Some burrs on less wear resistant steels that are mauable are harder for me to remove. Have you considered any stropping on the back side of a leather belt (thrift/second hand store/yardsale belt with buffing compound rubbed on it) or a piece of cardboard loaded with mag wheel polish? Again, very light pressure (not the full weight of the blade sometimes) will actually work better than heavy pressure because the flexible stropping material can round over your edge while rebounding from your pressure.
 
I tried going light on the stone and finally got the knife to shave some arm hair, albeit it seemed to shave only at around a 45 degree angle. I lightly felt the edge and it still felt pretty blunt though.
 
I think you're probably getting there. It may just take some more time & practice.

Check to see how it slices paper. I don't rely too much on shaving sharpness alone. A burr or wire edge on a blade will often shave, but it will also fold over and fail when cutting other things, even paper at times. And shaving hair is highly variable too. My arm hair is very fine, and sometimes doesn't shave easily either, in spite of how well my edge might be doing everything else. As for the 'feel' of the edge, that doesn't tell me much either, when I do it. An edge can still be extremely sharp, but if it's not very 'toothy', it may not necessarily feel so sharp (until it cuts you ;)). The 'teeth' on a coarser edge are often more responsible for the perceived 'feel' of sharpness.

Stropping the edge will almost always affect shaving sharpness, one way or the other. If the edge is shaving at all, strop it a bit and see how/if that changes. If it improves, fine. If, on the other hand, it goes away, then a thin burr or wire edge was probably responsible for the shaving sharpness, but not stable or strong enough to stand up to much else. Even then, if it's not shaving anymore, check to see how it cuts everything else. An edge doesn't need to be shaving-sharp in order to perform well at other real-world cutting tasks (paper, cardboard, plastic, food, etc.).

My favorite 'reliability' test for an edge is repeatedly slicing phone book paper. If the edge can slice cleanly, from heel-to-tip, and repeatedly through phone book paper, I've found that to be a good indicator of the edge's overall condition. I like the phone book paper, because it will snag easily on even tiny burrs or wires on the edge, or slip over a dull/blunt edge without being cut. If the edge is cutting it reliably and consistently, that tells me it's good.
 
I do most of my sharpening on sandpaper and polishing cloth so I hone my edges. I use newsprint to check sharpness. The paper has a grain to it. If my blade will cut the 4 corners off of a sheet of newsprint at 45 degrees, I consider it very sharp. The smoother and quieter it cuts the edges off the paper; the sharper, or perhaps finer, the edge. These are the knives I like to show off. These edges will also shave the hair off of my arm with little resistance. The blades that do this best for me now are high carbon Moras with HRc @ 59-60.
When I was using a sharpening aid I could almost get to this point with my Buck 440c. Make sure your stones are wet. You need the water to draw the heat away from the very fine edge. Hone very softly and not to fast towards the end. I haven't been able to get the edge on my Victorinox Huntsman this sharp. I usually tear the paper when I am cutting at 45 degrees to the grain with this blade.
 
I'll add this, which in retrospect, I should've added to my earlier posts.

I have found a fine/EF flat ceramic hone to be the most useful for putting a shaving-sharp finishing edge on the softish blades of Victorinox knives. The steel in these polishes up real easily, which also lends itself to taking very fine edges easily. So long as it's done carefully, again with light pressure, these blades respond very well to this treatment. I specified a flat hone, because using round rods or the corners of triangular rods (ala Sharpmaker) can easily roll or blunt the edge on these, if too much pressure is used.

Edit:
BTW, 420HC also responds well to this. Light pressure will also minimize issues of wire edges, which can be a persistent troublemaker with this steel.
 
:mad:

Still no luck, guys. I swear i'm getting a burr, but my problem seems to be on burr removal. I have tried stropping (using jeans, I don't have a dedicated strop) but no luck there either. Even if you still had a big burr, shouldn't it be noticeably sharp?

Any more ideas on what's going wrong?
 
LeCouteau said:
:mad:

Still no luck, guys. I swear i'm getting a burr, but my problem seems to be on burr removal. I have tried stropping (using jeans, I don't have a dedicated strop) but no luck there either. Even if you still had a big burr, shouldn't it be noticeably sharp?

Any more ideas on what's going wrong?
Click to expand...

A really big burr should at least feel somewhat sharp or jagged/toothy. If you're not feeling it at all, I'd bet it's not there. You might want to use a needle tip or a sharp toothpick, to slowly slide down the side of the bevel to the edge. If a burr is there, the tip of the needle or toothpick should stop against it, on one side of the blade or the other.

If you do have a very large burr, stropping on jeans probably won't remove it anyway. That works with very fine edges (like razors), with very tiny & thin burrs. A bigger, thicker burr wouldn't likely be fazed by it. On the other hand, if the burr is very big, it'll snag a bunch of fibers from the denim of your jeans. You'll see a whole bunch of 'lint' collect on the upper side of the blade, assuming the burr is angled to the downward side, after stropping on the denim. That's often how I detect a burr on an edge; just a few passes on the jeans, and see how much the fibers accumulate on the blade, and on which side. You'll see at least some on both sides, but the burr angled to one side will create a larger accumulation on the side opposite it.
 
On the coarse stone, you definitely should feel the burr when you slide your fingers from the spine to the edge (On the opposite side of where you sharpened last).
To remove these big burrs, I usually pull the blade over the edge of a wooden cutting board, then one or two light passes per side. You can see the removed metal in the cut on the board (it is all black). This should make a big difference in sharpness, otherwise there was no burr.
When moving to the finer stones you can do the same, but it takes much less pressure for everything once you had that initial burr.

What I noticed is, that with the soft steel of SAKs the edge doesn't feel as sharp as with other knives. Getting it to shave arm hair/cut newspaper is no problem, it just doesn't bite as much as other steels when I sharpen them exactly the same way.

Don't worry, you'll get there with practice.
 
Well I can get my knives now to push-cut through paper and cardboard relatively easily, and there doesn't appear to be any glints on the edge (indicative of dullness). Is this the sharpest I can get 420HC and 440 with the DMT stones and no strop? I realize those steels can't get a spooky sharp edge compared to steels like 1095 but I want to be sure of my sharpening skills before moving on to more expensive knives.
 
LeCouteau said:
Well I can get my knives now to push-cut through paper and cardboard relatively easily, and there doesn't appear to be any glints on the edge (indicative of dullness). Is this the sharpest I can get 420HC and 440 with the DMT stones and no strop? I realize those steels can't get a spooky sharp edge compared to steels like 1095 but I want to be sure of my sharpening skills before moving on to more expensive knives.
Click to expand...

:thumbup:
Sounds like you're making good progress. And you'd be surprised how sharp 420HC and 440A/C can get (push-cutting, shaving, hair-whittling). Every little bit of good technique that you can 'dial in' with more practice, will help to make further improvements in your edges. Once you've figured out the fundamentals, like raising the burr and then refining the apex, so much of what's left comes down to developing the feel for it, and training the muscle memory of the hands. You'll get more consistent with angle control and proper use of pressure, and you'll continue to see improvement from that. Keep in mind, these two steels are relatively soft, with little abrasion-resistance. Some of the more expensive knives, with presumably more exotic super steels, will take more time, using the same set of fundamental skills. So if you do move on to something else, just make sure to be patient with the process.

Keep doing what you've been doing so far, and keep a close eye on everything that changes on your edge while you're working. It's all about repetition and practice. You'll get there.
 
First of all, DMT stones are excellent, so that's not the problem. Blue, Red, and Green is everything you need. The blue stones cut very quickly to establish a new bevel on even a very dull knife, and the Red and Green will get you an excellent working edge.

I haven't watched you sharpen, so I have no idea what is going on, but if I had to guess, I'd say it's either your angle is off, or you are not taking enough time with each step. Sharpening is an art, but it is not rocket science. It worries me a little bit that you said "I know all about raising a burr" and then "I think i'm raising a burr but i'm not" in the same post...

Keep your angle steady (and know what the angle is... most people can't eyeball a 20 degree angle without a lot of practice first), and remember to lift the handle correctly when you turn to sharpen toward the tip through the curve of the belly (this keeps the same uniform angle on the edge itself). Practice it a bit and you will see what it feels/looks like.

Uhm... and keep light pressure on those stones. The DMT diamonds cut fast, and they cut best with little pressure. Other than that, develop a sense of when to move on to the next stones. Basically, you want to stay on blue until you've created the new edge you want. Then you move to red. You stay on red until you've completely smoothed over the rough edge caused by the blue stones. Then finally move on to green, and do the same thing: stay on it until you've smoothed over the edge caused by the red stones.

ESPECIALLY on the green stones, use a light touch. :D good luck
 
So after almost daily practice for like 2 weeks now I still am not any closer than I was before

My problem is highly likely to be on burr removal/polishing. I can raise a big 'ole burr but can't seem to polish it away.

Any more tips? I have tried

cutting into wood
stropping
alternating swipes on the stone
 
LeCouteau said:
So after almost daily practice for like 2 weeks now I still am not any closer than I was before

My problem is highly likely to be on burr removal/polishing. I can raise a big 'ole burr but can't seem to polish it away.

Any more tips? I have tried

cutting into wood
stropping
alternating swipes on the stone
Click to expand...

Don't raise 'em so BIG. ;)

I'm joshing you, but that's the important take on this. It's good that you're raising the burr. The key, which comes with practice, is to watch closely for when the burr is beginning to form, and then take it very, very slow and light, so you can complete the burr along the full length of the the edge, without making it too big. If you see a small burr just beginning to form in one section of the edge, focus on other sections that don't yet have the burr. That way, while you're forming a burr on sections that need it, you won't be continually enlarging the burr on sections that already have it. Small, delicate burrs are much easier to remove than the big ones.
 
good news guys

I can now get my knife shaving sharp on a medium arkansas.

I guess my problem was trying to shoot for "scary sharp" as a beginner to sharpening (still can't get to that level).
 
LeCouteau said:
good news guys

I can now get my knife shaving sharp on a medium arkansas.

I guess my problem was trying to shoot for "scary sharp" as a beginner to sharpening (still can't get to that level).
Click to expand...

Congrats! :thumbup:

It's all about making any progress, however big or small it may seem. I've always approached it with the intent of leaving the edge at least a tiny bit better than when I started, and hopefully learning something from it. If I attain that, and I understand why it's better now than before, then it's been a good day. :)

Keep at it, and you'll keep improving. I think you'll also notice, along the way, your definition for 'scary sharp' will always be changing. The bar keeps getting raised, each time you see improvement. Gives you something new to shoot for. ;)
 
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