Used knives with worn blades

[eveled]

Almost every used knife I’ve ever sharpened have a worn spot just ahead of the choil. No matter the blades shape What causes this? From cutting in the same place constantly? From poor sharpening seems more likely. But how? This picture of a KaBar Loom Fixer is my latest example. You can see were the stone is contacting near the choil and near the tip. In between is dished so badly it doesn’t even touch the stone.

It is strangely satisfying to sharpen these blades and watching the progress as the two contact points get closer and closer until they touch. Especially on straight edges like wharncliffs and coping blades.

[FRJ]

You just have to sharpen some decency back into them, eveled.
The old blades love that.

[kootenay joe]

I have noticed that it is usually the edge near the tang that gets worn down more with sharpening. I think it has to do with sharpening technique but i don't know how.
I hope a sharpening expert chimes in here.
kj

[KnifeSlinger#81]

Try using a narrow stone and focus just in the dished out area and once it's about even with the rest of the edge switch back to a wider stone. That way you will even out your edge without making a super wide bevel. It would also help to cut a better sharpening choil in, often times the factory choil is not very good or even nonexistent.

Sometimes these kinds of things are at the mercy of the blade grind or the factory edge grind. The best way to fix it and get down to a small bevel is to grind down the main grind.

[kootenay joe]

Paul, i don't understand this: "focus just in the dished out area and once it's about even with the rest of the edge"
If you are sharpening the dished out area will that not increase the 'dish' and make it further from the rest of the edge ?
I think i am not understanding your words correctly ?
kj

[eveled]

I have no problem fixing the problem and agree a sharpening choil is needed. My questions are how they get so bad in the first place? And why are so many of them like that?

[FRJ]

I think some folks just want to get a cutting edge back on their blade and they may not appreciate some proper techniques
that make a nice even edge on their blade. That is perfectly fine given it's their knife. They may not have good stones and
use coarser stones which can remove a lot of edge. It's important to know when to go to a finer grit if you can.

[eveled]

Good points. The more I think about it. They are probably using a pull through sharpener or steel. So the edge doesn’t stay straight.

[Mumbleypeg]

I’ve noticed the same, and also the tips on sheepsfoot blades are often rounded. I have a couple of EDCs that I bought used that have that problem. Both the OP knife and rounded sheepfoot tips are caused by improper sharpening. Pull-through sharpeners are especially prone to those results.

Ken

[FRJ]

rounded sheepfoot tips are caused by improper sharpening. Ken

..... and cutting cardboard over concrete ...........

[Mumbleypeg]

rounded sheepfoot tips are caused by improper sharpening. Ken

..... and cutting cardboard over concrete ...........

No doubt true. That’l do it!

Ken

[KnifeSlinger#81]

Paul, i don't understand this: "focus just in the dished out area and once it's about even with the rest of the edge"
If you are sharpening the dished out area will that not increase the 'dish' and make it further from the rest of the edge ?
I think i am not understanding your words correctly ?
kj

It looks to me like the dished out area is where the grind is at a different and more steep angle where it got wobbly during a previous sharpening. What I'm suggesting, if done correctly, would even out the angle of the edge without making the rest of the edge too wide of a bevel. Once it's close a regular stone can be used and the whole edge can be sharpened to a consistent angle without the middle being a narrow bevel and the heel and tip being really wide. It's difficult to explain, being a very visual thing I'm talking about and I'm also no wordsmith.

I'm very picky about the way my edges look and I try to keep a fairly narrow and straight bevel with no waviness. A smaller bevel is also easier to sharpen. I do a lot of sharpening and constantly try to improve and sometimes experiment with different methods and stones. What I'm suggesting is something I have found to help with this kind of situation when the knife is not cooperating.

Good points. The more I think about it. They are probably using a pull through sharpener or steel. So the edge doesn’t stay straight.

It could be that, but often times I have seen edges that won't stay straight because of the factory edge being very inconsistent in its angle and when you sharpen it the edge gets wavy and also it can sometimes be because of a wavy blade grind. It bugs the heck out of me when a blade has a sweeping grind (shown below) because it makes the heel a really wide bevel while the rest of the bevel is more narrow. Looks terrible.

[eveled]

Thanks knifeslinger.

That drawing is what I call the hour glass. (Too myself until now) Some knives have short hour glasses and some tall ones. Now I know regular and sweeping grinds. The sweeping grind lifts the blade off the stone so that the only contact point is mid blade at the other edge of the stone.

It drives me crazy. My OCD kicks in and I have to fix it. Add a very small sharpening choil and focus on the blade just ahead of the Riccaso. Once I fix it then I can sharpen it to my liking. If you don’t fix it you’ll end up with a recurve blade eventually and I despise those.

I just got a Buck skinning knife that not only has a sweeping grind but also a curved grind. Even though it has a massive sharpening choil it is difficult to sharpen. Not mine but one like it. I just made a new thread about that one.

971D0A67-1D38-4939-97B3-9537504061F2.jpeg (24.51 KiB) Viewed 4201 times

[KnifeSlinger#81]

I can't express how much I hate sweeping grinds, they are terrible.