Reprofiling m390 at 15dps, taking forever

[Mo2]

Don't form a bur or apex with the 50 grit. It's too coarse. It will just rip your edge up and will reduce the edge retention most likely. Just use it to set the angle. Use the 140 to form the apex and bur.

I'd also suggest using cheaper junk knives first and wear those stones in. At least three or 4 knives. Then tape up the blade on your good knives. Use something to act as a lube between the stones and blade. When Cleaning off the blade don't wipe it because your going to scratch it with the swarf.
Also I'd probably go 17 deg though 15 isn't too bad for just slicing.

 

[Alberta Ed]

Light strokes on diamond hones are sufficient; you're pressing a very small area onto the hone (think:walking on a golf green in high heels). I found my nice new DMT x-coarse 3x8 bench hone cuts very fast with only light pressure.

 

[Lapedog]

Anyone know how am I getting these little scratches on the blade? Any recommendation to remove them?

Yes, you are getting little scratches because it is a new stone and as you are grinding little diamonds and diamond dust are breaking off the stone. This often happens with new stones.

Try mixing water with a little dish soap and wetting your stones with the mixture. This will cause the diamonds dust to get caught to the stones or knife as a slurry which you can dab off the knife. It will also make the diamond stones easier to use.

As it is without that wetness the diamond dust is just blowing around and some is getting on the blade as you wipe it away.

 

[trailhunter]

Yes, you are getting little scratches because it is a new stone and as you are grinding little diamonds and diamond dust are breaking off the stone. This often happens with new stones.

Try mixing water with a little dish soap and wetting your stones with the mixture. This will cause the diamonds dust to get caught to the stones or knife as a slurry which you can dab off the knife. It will also make the diamond stones easier to use.

As it is without that wetness the diamond dust is just blowing around and some is getting on the blade as you wipe it away.

I still don't know how I got such long scratches, I did use honing oil. What a mystery, I'll be on the lookout next time

 

[NORTHWEST_KNIFE_GUY]

I still don't know how I got such long scratches, I did use honing oil. What a mystery, I'll be on the lookout next time

Only thing I can think of is that you inadvertently pushed the stone holder to far in a few times while sharpening and rode the heel / bottom portion of the stone past the bevel. With the diamond stones it wouldn't take much to make those scratches. When sharpening do you ever take break and rest / set the stone on the blade while the rod is still in the eyelet?

 

[Obsessed with Edges]

Only thing I can think of is that you inadvertently pushed the stone holder to far in a few times while sharpening and rode the heel / bottom portion of the stone past the bevel. With the diamond stones it wouldn't take much to make those scratches. When sharpening do you ever take break and rest / set the stone on the blade while the rod is still in the eyelet?

That's how it happens. The clue is in how uniformly dead-straight the scratches are (they're guided scratches), all running perpendicular to the edge. Random loose diamond particles being wiped off the blade can scratch it, but it wouldn't leave such uniformly uni-directional scratches.

I used to do this all too frequently in using my Lansky guided sharpener with diamond hones. A trailing corner of the hone is dragging past the bevel. The lightest, brushing contact is all it needs with diamond, which is about 10X as hard as the matrix steel of the blade. Cuts it like it was butter, and you won't even feel the incidental contact. Really have to concentrate to stop the hone before it overtravels the shoulders of the bevels, and lift it away before resetting for the next pass. Or an alternative, rig some sort of mechanical stop on the guide rod, so the trailing corners of the hone can't go that far in the first place and will be stopped short of the bevels' shoulders.

 

[cbwx34]

Nothing to do with the scratches... but how did you determine how the knife was positioned in the clamp? The tip area looks 'way wider' than the heel area.

(Would have something to do with why it was "taking forever").

 

[trailhunter]

Nothing to do with the scratches... but how did you determine how the knife was positioned in the clamp? The tip area looks 'way wider' than the heel area.

(Would have something to do with why it was "taking forever").

Seems to be the case for my knives. I always see this happening with my sharpening. Is this because the angle changes? That was my theory anyway.

 

[NORTHWEST_KNIFE_GUY]

Seems to be the case for my knives. I always see this happening with my sharpening. Is this because the angle changes? That was my theory anyway.

Next time try this, using a sharpie draw a straight line from the heel to the tip of the knife and square your clamp off with the straight line. Try to get the gap on either side even and place it into the clamp a little over a 1/3 of the way in. I use this method for medium size folders and the bevel comes out even tip to heel. Also, if you try to match the factory angle of the knife you're sharpening this will save you a lot of time. When you set your angle much lower you're gonna be scrubbing the steel off much longer especially with something like M390. I normally take a sharpie after it's mounted in the jaws and mark the bevel, then take a finer stone and make some light scrubbing passes to see if I'm close to the current angle and adjust accordingly. Then once I have the angle close I go to a coarser stone if needed and start sharpening.

 

[Wowbagger]

Only thing I can think of is that you inadvertently pushed the stone holder to far in a few times while sharpening and rode the heel / bottom portion of the stone past the bevel

That's possible with this sharpener ?
The Edge Pro stops before you can run off the edge in either direction.
One could put a stop collar, or even a wadded up rubber band, on the rod to give a reminder of where to stop in each direction.

 

[Blues]

That's possible with this sharpener ?
The Edge Pro stops before you can run off the edge in either direction.
One could put a stop collar, or even a wadded up rubber band, on the rod to give a reminder of where to stop in each direction.

Not that some of us, I'm not saying who, (okay,me), haven't scratched up a blade or two on the Apex...and lived to tell the tale. I hate taping blades. Though I suppose there are times I'll bite the bullet if'n I have to.

 

[Wowbagger]

. . . scratched up a blade or two on the Apex... I hate taping blades.

Put it this way. I almost bought some blue painter's tape recently; put it in the shopping cart save for later.
I offered to my boss to sharpen his Swiss Army knife up real pretty for him . . . kind of a celebratory gesture when business picked up again.

I planned to tape his; I never tape mine.

He avoided me at the end of the day (when I would have said "So do you want me to take that knife home and sharpen it "). He did this for several days until I got the message.

A week or two later he has holding one of my knives that I kind of roped him into checking out . . . as I have done now and agin in the past. He did enjoy waving the Ti Lite six !

In this latest one I was kind of showing him how I test the edge on my finger nail and he told me to take it back because really sharp things freaks him out.

ROGER WILCO = sharpening ain't gonna happen.
I'm screwed right ?
That's alright . . . I was already screwed.
I didn't buy the tape.
The best I do is wipe the face of the Edge Pro deck between grits. I have white masking tape on it. I hate how the glue from it can jump onto the stone ever so often.

 

[Blues]

The best I do is wipe the face of the Edge Pro deck between grits. I have white masking tape on it. I hate how the glue from it can jump onto the stone ever so often.

I put that clear mailing / packaging tape on the deck now based upon a video I saw online. It's nice and slick, and non-absorbent. (You can also use it for blades should you ever choose to. I haven't as yet.)

 

[cbwx34]

Seems to be the case for my knives. I always see this happening with my sharpening. Is this because the angle changes? That was my theory anyway.

It is because the angle changes... but it's happening because you're not setting the belly/tip area in the right place. (Centering the blade is not the answer).

Like Northwest Kinfe Guy said, get a Sharpie, mark the bevel of a blade, and practice moving the knife so that the Sharpie is removed consistently along the entire length. I don't believe the "draw a line heel to tip...etc," is actually correct, (more of a coincidence when it works)... but maybe a good starting point to see how the Sharpie is removed along the entire blade. Knives should be set based on the belly/tip area... as has been talked about many times before. (here's an example).. the angle doesn't change along the straight portion of the blade.

I also think it might be the actual reason you started seeing scratches along the straight portion... it got apexed early, and some of the larger diamonds were starting to contact the above the bevel. (Notice you don't see scratches in the belly/tip area... I'm guessing that you were trying to apex that part and quit when it did). My guess anyway...

 

[trailhunter]

What angle are you sharpening at? I'm sure others can offer some suggestions on how to remove the scratches but I think it might be kinda tough.

For the record, Northwest_knife_guy found this and as it may be the reason for my scratches and anyone else who gets these dreaded scratches as well