Ever had a knife you just can't Sharpen?


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rcmodel
October 14, 2014, 10:49 PM
I have had this Kershaw Leek D2 composite for a little over a year.

http://www.knifecenter.com/item/KS1660CB/Kershaw-Ken-Onion-Leek-Assisted-3-inch-Composite-D2-Plain-Blade-Stainless-Steel-Handles

It was shaving sharp when new a little over a year ago.
But a small chip broke out of the edge near the point the first time I used it to snap-cut a 1/8"" green vine a week or two later.

So I had to sharpen that out with a bench stone.
And it has never been truly shaving sharp since.

(Yes, I know how to sharpen knives.)

Since then?
* I have used Spyderco Sharp sticks.
* A diamond steel.
* Re-profiled it to 17 degree per side with diamond Lansky jig & diamond & stone hones which took over a hour tonight.
* Then I tried a Arkansas Ouachita bench stone.
* And a Norton Fine Crystalon bench stone that will put a shaving edge on a carbide lathe bit!
* Finally stropped on a grey cardboard sheet for 15 minutes tonight.

* It still has no shaving edge, and won't hook into a thumb nail half the time.

I'm wondering now if they over-cooked the D2 goodness out of it welding the two steels together to make the wavy gravy blade?

Or is all D2 impossible to raise a wire edge on one side then the other while sharpening and making it hair popping sharp?

My buddy's cheap Walmart Leek can be sharpened arm hair shaving, stick to your thumb-nail sharp in about 2 minutes when I sharpen it for him every couple of months!

So, what's wrong with mine?

rc

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hso
October 14, 2014, 11:30 PM
welding the two steels together to make the wavy gravy blade?

They didn't weld them together. They're brazed and the line is the copper used in the process.

Send it to me and I'll take a whack at it.

jmr40
October 14, 2014, 11:31 PM
I have a Benchmade with D-2 that I cannot sharpen either. Of course I never claimed to be an expert at the craft. I tend to do better with some of the less exptic softer steels.

BigBore45
October 14, 2014, 11:34 PM
d-2 is hard and suppose to chip out, you can get it "shaving sharp" with a course ceramic and 17.5 degrees is to shallow causing it to micro chip. try about 22-25 degrees.

BigBore45
October 14, 2014, 11:38 PM
also once you get it there i suggest getting a leather belt and touching it up and not letting it get dull, as any high carbon blade is hard to get back once it goes dull.

rcmodel
October 15, 2014, 12:26 AM
They didn't weld them together.
They're brazed and the line is the copper used in the process.
Send it to me and I'll take a whack at it. Well, maybe so.
But brazing is welding in my old welding book.

No matter what you want to call it, a copper brazed joint didn't just stick itself together at D2 temper & draw temps!

Copper melts at 1,984F.
So they had to get the D2 somewhat over that to stick them together.

But, D2 is forged at about the same temp.
Then air hardened at about 1,850.
Then drawn at 750 or so.

So, I still wonder if somewhere in the process, they didn't burn it up, or over-harden it?

It's not like I don't know how to sharpen a knife, or don't have the equipment to do it HSO..
I have been successfully doing it for 60 years of my 70 years.

Just not this one!

And even if you can sharpen it?
I can't very well send it back to you every 2-weeks when it needs sharpening again!

It gets dull riding around in my pocket and opening the junk mail ep's everyday.
Except it quickly get too dull to open paper ep's in less then a week without grabbing and bunching up the paper.

I gave up on it for yard work, as it mostly won't cut green plants or bailer twine a day after I sharpen it again!

I'm probably going to send it back to Kershaw and ask them to replace the blade with something else.

In the meantime, my old Benchmade Mini-AFCK AST-34 steel is back in my pants again.

It"s been months since it needed sharpening.
And it just shaved hair off my arm when I tried it again tonight.

rc

reddrumtoo
October 15, 2014, 02:45 AM
reminds me of a Buck skinnerI had many years ago , just never could get a good edge on . Finally gave it away . I also had a schrade Uncle Henry trapper that sharpened easily [ vanadium steel ] get it shaving sharp ,put it in your pocket & the next day that shaving edge was gone . I guess it just rusted off in my pocket . No high humidity or anything . This was back when schrade was well thought of & american made . I guess everyone has lemons once in a while.

rcmodel
October 15, 2014, 03:16 AM
PS BigBore45.

I have already tried a steeper 25 degree edge about 6 months ago.

That was worse!

The original edge appeared to be belt or diamond wheel cut at about 25 degree's.
It had just enough 'tooth' on it to cut well for a couple of weeks of light use.

But like I said, a chunk of factory edge chipped out, two weeks out of the box, snap-cutting a small green & growing vine in the yard.

That rat there just ain't right!

rc

Zeke/PA
October 15, 2014, 08:43 AM
"it gets dull riding around in my pocket"?
That doesn't sound like a typical D2 blade at all.
Nor does a "chipped" blade.
My guess is that either poor heat treat treatment and/or poor quality control are the culprit(s). The "brazing" after heat treat certainly didn't help.
A D-2 blade of course is harder to sharpen than most but the edge retention is usually second to none.

Zeke/PA
October 15, 2014, 09:01 AM
RC,
I googled Kershaw and found that the Leek knives are made from a CMP D-2. Further, I found that the CMP steel is first powdered than re-smelted to achieve better carbide distribution.
It's quite possible that the research and eventual use of this material didn't favor the End User.

hso
October 15, 2014, 10:56 AM
Ohhh, I know you know how to sharpen. I just want to get my hands on it and see what it's doing.

MikeJackmin
October 15, 2014, 01:13 PM
I have the same knife in my front pocket right now.

I am pretty good at sharpening and this knife is my least favorite to deal with - no fault of the steel, it's just something about the geometry makes it hard to hold still and maintain a consistent angle. My impression is that the thin blade is very unforgiving of even tiny errors like that.

I use an edgepro and if I use the greatest care with it, if will take a razor edge. No way I could do it with my old lansky.

Get a magnifying glass and take a good look at that edge, see it it is as true as you think.

That said, it's quite possible for any knife maker to put out a bad batch. These folks have good customer service, perhaps you could send it in and see if they can sharpen it for you.

HoosierQ
October 15, 2014, 01:16 PM
Gerber LMF. I know, geometry right? The thing is supposed to be a sharp pry bar anyway. Problem is I have an ESEE 5, which is the same thing. Terrible geometry for anything but prying but it takes a great edge even if you can't do much with it. I think it's faulty steel.

I can get anything else sharp but this LMF with its mystery steel at its mystery hardness defies all my efforts. Also a Glock field knife. Terrible steel.

The Glock is a little too narrow and the Gerber is way too heavy. But by and large I really like the design of those knives. The sheaths are outstanding. The handles very good. But the mystery steel defies a good edge.-

MikeJackmin
October 15, 2014, 05:20 PM
http://www.ffmmov.com/kk2.jpg

Of course, not every batch of steel is the same.

JRH6856
October 15, 2014, 05:41 PM
I had a mexican switchblade stilletto when I was a kid. Wouldn't take or hold an edge for anything. ;)

The blades on those things are so soft, I think you could cut right through them with hot butter.

mboe794
October 15, 2014, 05:55 PM
I used the Lansky five stone system (20 slot I think) followed by a few pasted strops, to get my buddy's composite leek sharp. Maybe not quite as sharp as some of my knives with VG10 and other similar steels, but it had no problems shaving arm hair.

Valkman
October 15, 2014, 08:24 PM
I'm sure my Wicked Edge will sharpen it up, send it to me! I've never had a problem yet with any blade although one I made took three hours to get the bevels straight. Sharpening them on a grinder was not the best idea!

T.R.
October 19, 2014, 07:17 AM
I have an older folder than looks sort of like a Buck 110 but made in Pakistan with inferior stainless steel. It will NOT hold an edge for long. I should toss it into a recycling bin.

TR

Deltaboy
October 19, 2014, 04:18 PM
I had a S&W knife I could not get sharp for the life of me. I ran it by my local hardware store and they returned it the next day shaving sharp for $3 bucks.

Zeke/PA
October 19, 2014, 04:45 PM
I have a similar specimen which I save for use by folks who want to "borrow" a knife.

bodam
October 20, 2014, 09:37 AM
Every knife that I own is one that I can't sharpen. I suck at it.

bikerdoc
October 20, 2014, 09:47 AM
Bodam, there are are alot of old threads on sharpening. I used to stink at it. With knowledge and practice I learned to get blades scary sharp. Not saying it was easy but sure was rewarding.

bodam
October 20, 2014, 10:42 AM
I'm thinking of trying the sharpmaker for the new blades. That's where I am struggling. With a knife with an existing bevel, I can match it by hand and get it nice and sharp.

But these new knifes that I am making, I can't seem to get the sharp bevel correct.

C.R.
October 20, 2014, 11:00 AM
i use a Lanskey knife sharpener and after I am done I have an old leather belt that is covered with jewelers rouge I strop the knives on that to get the final edge. Give that a try a wide belt with rouge on it finishes a blade off beautyfully

Valkman
October 21, 2014, 01:09 AM
But these new knifes that I am making, I can't seem to get the sharp bevel correct.

Are you putting some kind of edge on it with the grinder now? Because I used to try and use my Sharpmaker and it's not very good at knives with no edge at all - it can't remove a lot of material. I gave up and just used the grinder for the final edge, but now I know the bevel angles were all over the place. If I did it over again I'd put an edge on with the grinder, as little as possible, and then use a guided system on it like the Wicked Edge, Edge Pro or one of the others.

rcmodel
October 21, 2014, 02:02 AM
I made this roller jig for sharpening Bear broadhead arrows years ago.
And it worked so good I was afraid of my arrows after I sharpened them!

They would shave the hair off a frog, and he wouldn't even jump out of the barber chair, or ask for a hot towel first!

The wheels are too big for knife blade angles.
And the clamp angle that butted against the broad head ferrel doesn't have a reference point on a knife blade spine.

But the idea is sound.
And a caveman could sharpen a knife to scary sharp if it was refined a little for use with knives.

204220

204221


I keep telling myself, Self, make new wheels for proper knife edge angle, and change the clamp for knife blades.

But, Nooooooo!

rc

bodam
October 21, 2014, 08:36 AM
Are you putting some kind of edge on it with the grinder now? Because I used to try and use my Sharpmaker and it's not very good at knives with no edge at all - it can't remove a lot of material. I gave up and just used the grinder for the final edge, but now I know the bevel angles were all over the place. If I did it over again I'd put an edge on with the grinder, as little as possible, and then use a guided system on it like the Wicked Edge, Edge Pro or one of the others.


Yes, I'm putting a sharp bevel, but it's still not getting where I want it.

My plan was to start it on the belt sander at 400 and finish on a sharp maker.

Once I get the money for one anyways.

Sav .250
October 21, 2014, 09:30 AM
That`s why when you buy quality.................you don`t have that
problem. :)

bodam
October 21, 2014, 09:43 AM
what problem?

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