Help a sharpening moron learn something!

[laynlow]

Hello all, I have lurked for awhile, read the sharpening FAQ, and search for helpful posts.

Here is my problem. I bought a new Kershaw Scallion yesterday. Well, after feeling that awesome factory edge, I decided I needed to get my other knives into shape. I bought a Lansky Deluxe Kit (all I could find locally), and gave it a shot.

I cannot get the thing to give me a sharp edge. Not even close. I believe it is my own doing, not the kit, but it is frustrating none the less.

When I progress through the stones, I use a Sharpie in between to see how I am progressing. Problem is, under magnification (about 30X) I can see the marker along the very edge. From the top of the bevel down to this line, the marker is gone, and the edge looks OK. Now it may be that I am re-profiling the edge of the knife. I am using the 20 degree hole. It just seems as much time as I have spent, I should have completed the profile by now. I have removed plenty of material from the blade.

Also, I have not been able to raise a burr (I think). When raising a burr, is it an obvious ridge on the opposite side or something slight that you must develop a feel for?

Any help/ideas appreciated.

 

[Buzzbait]

Keep on going with the coarse hone on a single side, until you get the burr. The burr will be quite noticeable if you run your finger along the edge bevel. You have to get that burr. It sounds like you're close, but close doesn't milk the cow.

Then use the coarse hone on the other side, to roll the burr to the other side. Then you can start working your way up the finer hones, using the same process to gradually shrink the burr down to nothing.

You often have to do a full reprofile the first time you sharpen a knife. If you keep using the Lansky in the future, and at the same angle, future touch-ups will be quick and easy.

 

[laynlow]

I guess I just needed a little encouragement. You were exactly right, I was close. I went back to the coarse and went to town until I got the burr. It was for real, just took time. By the time I was done, I could not detect a difference in my new factory Kershaw and my practice Swiss Army.

Thanks again!

 

[calyth]

What's a good angle that is good for a utility knife?
I go conservative and usually stick with the edge bevel from the factory (with some exceptions, ie my M16), but I'd like to have the opinions of others.
BTW I do have a lansky set, that's the reason why I'm asking.

 

[Buzzbait]

That's a tough question, actually. The problem is that the Lansky angle designations are ambiguous at best. If you sharpen a narrow blade at the 40 degree setting, you’ll get a different actual angle than if you sharpened a wide blade at the 40 degree setting. Does that make any sense, or am I rambling again?

With that said, I usually sharpen my medium and large size knives at 40 degrees, and my smaller folders and slipjoints at 30 degrees. Whether that’s right or not, I’ll leave up to the experts.

 

[calyth]

Yeah it makes sense.
Afterall I was stuck with calculus last semester.
What happens is that the high of the rod doesn't change, while the horizontal length away from the edge to the actual angle guide varies to blade depth. Narrower blades would make the "marked" angle higher while wider blades would make the marked angle lower...
It struck me that I forgot to mention I didn't exactly have the lansky system, but the gatco (that's what I can get my hands on without resorting to ordering from the US, which last time the tax guys here ripped me off on a $22US order) system instead. I think they half that angle.
If they do half that angle, then you would suggest me sharpen narrow blades at the 15 slot while wider blades at the 20, right?

 

[Sergiusz Mitin]

It’s just me, but I try to sharpen all my knives to 40 degrees totally at the edge. The back bevel could be sharpened between 30 and 20 degrees depending on blade grind.
I vary the proportion between edge sharpness and toughness changing the ratio between the main edge and back bevel wideness.
Wider back bevel and narrower edge will be sharper but weaker.
Narrower back bevel and wider edge will display more strength but worse cutting performance.
Just think what tasks you are reserving for certain knife...

 

[calyth]

More than likely tough use, even though I'd like to have a razor sharp edge on it.
Thanks for the tips!

 

[VampyreWolf]

Depends on steel quality and use...

I sharpen most knives to 40, but have 2 spydies at 30(Calypso jr lt, and SS Dragonfly). I can sharpen to 40 byhand, as I have for 13yrs. Just was given a knife and a stone at age 5, told any problems to ask... cut myself a couple times in the first few yrs(ok, many times), but learned how to sharpen!

My 'daily use' knives get 30, my beater(Spydie Delica, frn, ats-55) is 40. My 4" fixed(Muela skinner) is 40, but my CRKT BearClaw is 20(took some guessing the first few times).

Try a steep angle and if it rolls or chips, back off...

Taught my friend how to sharpen this weekend. Got him a stone and gave lessons for his birthday gift. The Black Marker trick works, as does holding your finger about mid-blade on the spine. If your finger hits the stone, it's too narrow.

 

[JohnW]

When you're thinking about what kind of angle to use for sharpening, part of the answer will depend on what kind of system you have. But <em>most</em> important is to understand how you want to use the knife.

A lot of modern steels will support a rather acute angle, like 15-18. But this is only wise if you don't plan on hitting anything hard with it. Also, there is the question of sharpening for a smooth edge, or a slightly rough edge. All of these details are part of your decision making process.

Many people have one or two knives that they plan to use on everything. For this purpose (EDC), a smooth 20 degree angle is a good choice, because it's strong and will last. For people who mostly cut boxes open, though, 18 degrees with a roughed micro-bevel might make your job easier. If you cut food mainly, 15 degrees smooth is better.

My advice is to play around. Unless this is a really expensive custom knife, try different angles, different styles (flat vs. convex), and different textures. Some people even sharpen different parts of the blade differently, in order to fine-tune their blade's utility.

But when it comes down to it, this is your guide: whatever you cut should yield easily to the blade, without nicking it, and without wearing the edge down too fast. The more acute the angle, the easaier it will cut; the smoother the edge, the worse it will slice. Etc. There are many factors, and only testing different options out will tell you what's "best" for a given use.

As for the person who saw that the marker wasn't being worn from the edge: you are definitely reprofiling, since you're grinding at an angle that's more acute than what the knife came with. Because regrinding takes off a fair bit of steel, it will go slower the closer you get to the edge. Just be patient, and keep going. Using a coarser stone will make the work go faster. When the marker is finally all gone, you should be able to feel a "catch" against the skin of your thumb, if you slide it 'toward and away from' the edge (as though you were rubbing dust off the edge). When that happens, you can now do the same on the other side, and then proceed to a finer grit.