Knife Refuses To Get Sharp, What To Do?

A

A_Blade_Afficionado

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Jan 20, 2009
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I'm using a SM. I've tried to sharpie technique, I'm hitting the edge. I used sandpaper and reprofiled it to 30 and then went to work on the 40 setting hoping to get somewhere. Nope, knife still refuses to cut paper. I've spent 3 hours going round and round with the knife and it won't get sharp. It will catch paper but not cut it. It sounds extremely dull when using the SM if you know what I mean and after 3 hours it's still the exact same.

Any ideas on what to do? If not I'll toss it in the collection and never bothering EDCing it becuase I refuse to carry a knife that can't even cut paper. I'm trying to like this knife but the more I work on it the more I start to hate it. I want to like it, but right now I'm struggling to.
 
I understand the frustration you are experiencing. May I ask, what steel are you sharpening and are you creating a burr after each grit?
 
Sorry. It's a 551 Grip in 154CM. I've used this method on Sg2 and it was razor sharp in under 20 minutes... So I'm wondering if the steel is bad or my technique is? But I figured if it could work on a super steel it could work on an average steel.
It's really starting to aggravate me.
How do I work up a burr? I figured the way the SM works I wouldn't need to bother doing that but I'm open to any suggestion at this point.
 
The problem with the sharpmaker is generally that one does not know if he/she has created a burr yet and therefore doesn't know if the knife is sharp. I doubt the HT was off and 154cm takes a good edge. Super steels usally have more vanadium and carbon and in my experience, make it much easier to get the knife sharp.

I would reccommend going back to a lower grit paper and while using very light pressure make about 20 strokes and check for a burr. If there is a burr, go to the other side, if not do 5 stroke increments until a burr is reached. Raise a burr on the other side and then go to a higher grit, repeat. With a trained eye, a burr is readily visible; you are looking for a "wire" or something that almost looks like aluminum foil on the very edge. You can test for a burr by placing the edge on your thumb nail, spine facing away from you and pulling. If it catches your nail, you have a burr.

Once you finish forming and honing the edge and you are on the polishing step, I would recommend making one swipe per side VERY lightly for about 20 strokes then strop the same way.

Good luck, I know this can be frustrating.
 
I use to have the same problem with tough steel like that. What I did was I went to Harbor freight and bought a $40.00 1X42 belt sander and then bought some 220 and 400 grit belts from Pop's knife supply and sharpen with it. Use it with the belt slack and practice on a cheap knife first but once you get the hang of it you will never go back. Keep the blade cool and use light pressure and give it a couple quick passes on a ceramic stick when done and it will be really sharp. Go to youtube there is a professional knife maker that has posted a video showing how to do it that is where I got the idea from.
Afer all custom knife makers usually sharpen with their belt grinder and it is how it was sharpened from the factory.
 
Get yourself a DMT Aligner kit, seriously. They are not that expensive and I just used mine to get my mini grip shaving sharp, literally.
 
You've probably got a burr that's just flopping back and forth. My SE Caly 3 is doing that, and it's pissing me the hell off... I have to do each serration individually (DMT Diafold), then give a swipe of the sharpmaker on the other side only to see that the burr has flopped back to the face side. I really want to break something.

With a PE, you can try cutting into some wood to break the burr off. Then continue at your bevel setting doing one pass per side in order to not create another burr. If you had diamond stones, I would recommend giving a pass on each side at a higher angle with a very fine stone. This would take off the burr and leave you with a small microbevel which you could get rid of by continuing with your coarser stone at your regular bevel setting. This trick doesn't work as well with ceramic in my experience; they're not aggressive enough compared to diamond.

Good luck.
 
A_Blade_Afficionado said:
Sorry. It's a 551 Grip in 154CM. I've used this method on Sg2 and it was razor sharp in under 20 minutes... So I'm wondering if the steel is bad or my technique is? But I figured if it could work on a super steel it could work on an average steel.
It's really starting to aggravate me.
How do I work up a burr? I figured the way the SM works I wouldn't need to bother doing that but I'm open to any suggestion at this point.
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154cm has a very high vanadium content.
Meaning ceramics won't sharpen it as effectively as lets say diamond.
You can either spend an extremely long amount of time with ceramics, spend a lot less time with a belt sander, or go with diamonds.
I would get an aligner kit or go free hand. Some steels have such a high vanadium content (S90V) that Carbondum stones can barely touch the steel.
If you think you do have a burr run the edge lightly along a piece of wood (as said).

If all else fails give me the knife I need my first benchmade (that use to be spyderco, but my tenacious came in!) ;)
 
nickE10mm said:
154CM has no vanadium in it....
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This.

table_blade_steels.gif
 
Ok. I finally got it paper cutting sharp. I think it was the burr flopping back and forth and I'd never had that problem before so it was a new one to overcome. It did look like aluminum foil so I'm assuming that was the burr.
It's still nowhere near as sharp as I'd like it but I'm going to continue to work on it today and see what happens.
Why it left that factory with a 50* inclusive bevel is beyond me... Just made it a big pain to fix.
 
If you can't get it where you want it you could send it back to Benchmade. Of coarse they sharpen by hand and might get rid of all your work. If you want you can also send it to me and I will match the angle you put on it with my Edge pro and sharpen it and strop it if you want. Let me know.
 
I just took my BM Griptilian downstairs for a quick tune (as it already popped hairs like a lawnmower). I simply did 20-25 SM strokes on the white flats and then about 40 strokes on various stropping stations and it will now whittle long strands of hanging hair. Ahhhh!!
 
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I've been able to get the end half of the blade very sharp but the base half by the handle just won't get sharp. I have a CE H2O Grip on the way so I think I'll carry that instead. I like the PE but I'm tired of monkeying with it at this point. I'll worry about the PE one once I get a set of paper wheels.
I just can't seem to get a consistent burr on the half of the blade closest to the handle. It can saw through paper but just won't take the edge the end half will.
 
If you are having burr trouble, I'd recommend cutting into the Medium flats at 90 degrees (yes, 90) to remove any burred/weakened metal from all the flopping around. Get a nice visible flat (0.001 inches or so) on the edge and start over with alternating strokes. This has worked for me on burr prone steels to the point that I cut off a burr and put on an edge that would whittle hair on a RADA Cutlery paring knife with a coarse waterstone. 800 grit is coarse for waterstones. It cut just as fast as my 90 grit Norton Coarse India.
 
me2 said:
If you are having burr trouble, I'd recommend cutting into the Medium flats at 90 degrees (yes, 90) to remove any burred/weakened metal from all the flopping around. Get a nice visible flat (0.001 inches or so) on the edge and start over with alternating strokes. This has worked for me on burr prone steels to the point that I cut off a burr and put on an edge that would whittle hair on a RADA Cutlery paring knife with a coarse waterstone. 800 grit is coarse for waterstones. It cut just as fast as my 90 grit Norton Coarse India.
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Okay. I will try that. I was thinking about that at first but it seemed like a quick way to ruin a few hours of work so I didn't want to.
I'll give that a shot and tell you how it works out.
 
I have a DMT double-sided Diafold coarse/x-coarse for really dull or improperly ground knives that I use with my SM. The SM is great for so many things, but it is too fine for fixing those things.

I suck at hand sharpening, but I can at least get the bevel roughly in shape for the SM to work.
 
A_Blade_Afficionado said:
Okay. I will try that. I was thinking about that at first but it seemed like a quick way to ruin a few hours of work so I didn't want to.
I'll give that a shot and tell you how it works out.
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Use the weight of the blade or less. If you put any pressure at all, then you're going to have a hell of a time getting an edge formed again.
 
I had a similar problem with my mini grip in D2. I think the way the thumbstuds are designed, it prevents you from being able to grind that part of the blade as quickly. I was raising a burr in the middle, but nada near the back or on the tip. I had to go to sandpaper and keep raising on one side, then raise it on the other, until the burr traveled enough.

Of course, after I did that, when I switched to ceramics to raise the burr/polish the edge, it never really got super scary sharp, and this is with a 12-15 degree inclusive bevel. I moved to the sharpmaker after making sure there was no burr on either side, and did alternating strokes on all the stones at 30-degrees inclusive, to put a small microbevel on, and sure enough it was like a razor.

I think the burr was not really being honed when I used the ceramics to raise it, and ended up just folding over or fracturing. Now i'll use the burr to make sure i've formed the bevel all the way to the edge, and then do alternating strokes on the ceramics to polish it. Seems to work better for me.
 
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