Recommendation? Did I take of to much material from my Osborne? New to the Lansky Diamond Sharpener.

C

Casio_AlarmChronograph

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Oct 8, 2022
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Hello Everyone,

I’m new to sharpening so I decided to start with the Lansky Diamond sharpner. I wanted to put a 30 degree edge on my BM 945, so I started with the coarsest stone but I didn’t know how long to go, so I did many passes and a lot of metal dust came off. I’m now worried I took off far too much metal, since there was quite a lot of metal dust. The knife also doesn’t feel very sharp, it cuts paper but only next to where I’m holding the sheet. Am I doing sth. wrong?

Here are some pictures
https://imgur.com/a/XlBgEsE

Thank you all in Advance!

Greetings
Casio_AlarmChronograph
 
Really, you only took away too much if the profile of the blade was significantly altered. Otherwise it's more of a chronic issue, where over time you take off more than you need and end up sharpening the blade into a sliver. Usually doesn't happen for a long time if ever.

A good way to start is to sharpen one side of the blade until you can feel a burr on the other side. Then flip the knife over and do the same thing, sharpen until you feel a burr. That's an impossible to miss sign that you've actually ground away the previous edge completely. Once that happens you can do 10 swipes per side, then 8, then 6, then 4, then 3, then 2, then single strokes. That will slowly grind away/break off the burr leaving you with a relatively clean edge. You can also mark the edge with sharpie and inspect with magnification, or you can look for the scratch pattern (you will usually see a fresh bevel with fresh scratches and then a sliver of old edge that shrinks as you keep grinding in the new one). If you've actually established a new edge it should shave easily regardless of how coarse the grit, that's true for the 325 grit diamond stone I reprofile with (if I strop afterwards it will start to catch/whittle beard hairs).

Edit: Wasn't clear enough that this is just an outline of what I do, the specifics of # of strokes and such isn't very important
 
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Need to make sure you're producing a burr - when you see it, that's when you know you've gone far enough with the coarse stone. Verify the burr from both sides. In other words, when the burr appears along the full length of the cutting edge and is leaning away from the side being sharpened, flip the blade to sharpen from the other side until you notice the burr is then leaning the other way (away from the side being sharpened).

In working toward that objective, it's OK to grind from each side, in equal measure for a little bit at a time, to keep the edge symmetrical. But when it gets close to apexing and you're wondering if you've gone far enough, that's the time to work one side until you know the burr is there. Then flip it and work from the other side to verify the burr has 'flipped' in the other direction, as described above.

Don't worry too much about taking away too much metal. Your edge as shown in the pics looks pretty good. It's likely just not apexed yet (burr hasn't formed along the edge's full length). And if so, just take it further and look for that burr to form. Those Benchmade blades have been known to be pretty thick at the edge, needing a lot of work to reprofile them at times.
 
I’ve found with the lansky extra course stone, especially new, all that dust and debris is actually the stone not metal. Every extra course lansky stone I’ve ever used does this. The thick media is not bonded very well.
 
cudgee said:
Don't use the course stones though.
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I was tempted to say that myself. With the Lansky in particular, I tended to avoid the coarsest diamond hones (XC, Coarse) for apexing purposes. They're useful for hogging off steel in the early going. But for apexing and forming a burr, I heavily favored the medium diamond hone (orange holder) for that, which left a fine, thin edge with a lot of toothy bite and also produced a much more easily-seen burr. The very coarse hones tend to leave a very rough apex and it's sometimes difficult to detect signs of a burr in that rough edge. Not to mention, the very coarse hones will often just rip the burr away as it forms and it becomes much harder to know when the edge is as thin as it can be, as indicated by an obvious burr.
 
Thanks for the advice! Is it an issue that I didn't position the clamp right in the center? It's quite hard to get a good grip on the blade so I just put it somewhere it held well.
 
Casio_AlarmChronograph said:
Thanks for the advice! Is it an issue that I didn't position the clamp right in the center? It's quite hard to get a good grip on the blade so I just put it somewhere it held well.
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At blade lengths of 4 inches or less, it usually won't make an obvious difference (visually) where the clamp is placed. It's much more important to put the clamp where it'll maintain a good grip and won't slip - the results of the clamp slipping during sharpening would be much more ugly. I can't see any obvious variation in the bevel width in your pics - so I wouldn't worry about it.

Some blades with big changes in steel thickness near the edge can create uneven-looking bevels as the bevel width changes according to the thickness of the steel behind the edge. So, in cases like that, sometimes repositioning the clamp is a way to minimize that, for certain portions of the edge. I've generally never worried too much about that - as long as the clamp isn't slipping or moving, it'll all still be very sharp & clean when it's done.
 
The other issue you're going to run into is that the Lansky has only a few fixed angles to choose. So it's going to be difficult to match the factory edge angle. If your new sharpening angle is a little more acute than the original, you're actually going to end up reprofiling your knife. So you'll see more steel come off the first time. Every time you sharpen after that, it should take off a lot less steel.
 
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