Can't get this knife sharp...

[Dave568]

I semi-recently purchased a Becker BK-7. When it came from the factory, it was shaving sharp... not quite Spyderco NIB sharp, but pretty close. I used it a couple times for some pretty heavy outdoor work, and the edges became a bit duller. They were still sharp, almost shaving sharp, but I decided to give it a touchup on the Sharpmaker. At first I sharpened it at 30 degrees, which is what it came with from the factory. After the standard 20 passes on each of the 4 steps, it was significantly less sharp than before I began. I tried again, and the results were no better. So I gave it about 50 passes on the gray corners, and then tried sharpening it at 40 degrees, trying 20 passes on all 4 steps. However, the results were even worse than before. It will just barely cut paper, and has a very tough time with cardboard.

I'm not sure why this is happening... maybe it is because of the blade material, or perhaps because of the length, but I don't have this trouble with my other knives. To reassure myself, I went ahead and sharpened my Delica, and I got it hair-popping sharp in a matter of minutes. Does anyone have any suggestions as to what I should try next?

[Senate]

do you know the magic marker trick?
bascially you color the edge of the knife with a black marker and you sharpen it as usual, the marker will be removed where the edge really touches the stones, quite a surprise sometimes...

[Dave568]

Is that magic marker trick alright to use on non-stainless blades? Will the marker have any sort of ill effect on the blade if the sharpening doesn't remove it all? Thanks

[Zwaplat]

Is that magic marker trick alright to use on non-stainless blades? Will the marker have any sort of ill effect on the blade if the sharpening doesn't remove it all? Thanks

Of course not. Once you're done sharpening, you can even wipe off the remaining marker with some aceton or ether.

[Dave568]

Alright, I guess I'll go give that a shot now to see what is going on... Thanks.

[ront]

I just use alcohal to remove the marker.

Ron

[DAYWALKER]

*UGH*!!! That's why I mostly freehand nowadays...

Do try that marker trick...I have heard only good things about it, and it should help.

God bless and prayers sent

[dsvirsky]

My suggestion would be to sharpen freehand. 0170-6 sharpens pretty easily. Odds are the bevels on the BK-7 are greater than 40 degrees inclusive and you're not hitting the edge with the Sharpmaker.

[Dave568]

From reading Cliff Stamp's review from Bladeforums, I found out the edge is 30 degrees +/- 1 degree. So this would mean that sharpening at 40 degrees definitely would hit the edge, right? Anyway, I gave it another shot, and I guess it is a little bit sharper. It will push cut paper now in most spots on the blade. It still needs a lot of work, but maybe I just need to keep working at it.

[WORKER#9]

From reading Cliff Stamp's review from Bladeforums, I found out the edge is 30 degrees +/- 1 degree. So this would mean that sharpening at 40 degrees definitely would hit the edge, right? Anyway, I gave it another shot, and I guess it is a little bit sharper. It will push cut paper now in most spots on the blade. It still needs a lot of work, but maybe I just need to keep working at it.

I will say that after shapening countless knives with the Sharpmaker, I won't even use it without Diamond stones. The diamonds get you to a good edge real quick and the other stones are good for final touch up. On big knives or work knives I Just use the Diamonds and the Brown, I don't even use the fine ones.