BM Dark Star impossible to sharpen...

[TheKnifeDude]

Ok I'll make this short. I bought a BM Darkstar and my local knife store. It did not come sharp. It would not cut paper cleanly and did not shave at all. So I got the sharpmaker and checked it was sharpened at 40 degrees. I did 40 passes on each step and it was not sharper at all. So then I started over at 100 passes per step. It was only slightly better. The steel is ATS-34 at 59-61. Iv'e sharpened my other BM in 154-CM and easily got it to a level of sharpness that made arm hair fly with the slightest touch. It should be similar to this knife. I than started over and did 150 passer per step, it was than better but still a long way from shaving. I called the store I bought it from and told them it didn't come sharp, they said they would sharpen it for free. I dropped it off came back the next day it it was only slightly better, it still didn't shave. But cut paper better. I am really quite frustrated now, do you guys think this knife might be over hardened? Or am I doing something wrong? I dont have any trouble doing my other knives with similar steel. Any help appreciated...

 

[underaged!]

Do the sharpie trick:

Before you take it to the Sharpmaker, color the edge of the blade with a sharpie. I just realized sharpie, for sharpening, haha.

Hit the stones a bit, and check to see if you're catching the very edge, if there is color at the very edge, then I guess you just have to spend more time on it.


Another thing you may look for is how the burr raises, if the burr develops significantly during you normal routine, you may want to depart from that. After identifying that you have a crazy burr, just work to cut if off (stroking the stones that is).

 

[Shmackey]

The Sharpmaker stones won't care if your blade is hardened to 59 or 64. Most likely explanation is that you're not consistently hitting the edge (like previous poster said).

While you're doing all this work, might as well take the blade down to 30 degrees instead of 40 and then put a 40 finishing bevel on it. Future sharpening will be much easier and it will cut better too. Just have to put in the time up front.

 

[fulloflead]

Hit the stones a bit, and check to see if you're catching the very edge, if there is color at the very edge, then I guess you just have to spend more time on it.

A LOT of time if the angle is different. The Sharpmaker is NOT very good at removing a lot of material - even the diamond stones only work if you're pretty close.

You can tuck a magazine or something under one end of the Sharpmaker base to tilt it a little to get the right angle. Obviously, you can only do one side at a time that way, but it works good.

.

 

[marcangel]

Why don't you send it back to Benchmade since it's covered under the "Lifesharp" program? Send them a note that it WASN'T sharp to begin with, and I would venture they'll fix it up. BM takes sharp VERY seriously.

 

[QuietOned]

Close enough to 300 passes and it's not sharp!!! The Sharpmaker can't be contacting the edge fully. The angle you're sharpening at isn't what the blade bevel is set at. You're sharpening at 20 degrees and the edge is at 40 degrees or something like that. (that is probably an exageration but is an example)

Use the blade colouring technique with a marker. If you are contacting the full edge then you are having edge control problems and not being consistent.

1. Use a coarser stones until you achieve a burr all the length on one side.
2. Do the other side the same until you flip the burr to the other side.
3. Switch to a finer stone and repeat.
4. Switch to a finer stone and repeat
5. Switch to a finer stone and repeat
6. Strop

 

[Walking Man]

Why don't you send it back to Benchmade since it's covered under the "Lifesharp" program? Send them a note that it WASN'T sharp to begin with, and I would venture they'll fix it up. BM takes sharp VERY seriously.

What he said. ^