Trouble learning how to sharpen

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gnius

Joined
Jul 1, 2008
Messages
413
After spending hours today, trying to get my Leek sharpened with the DMT guided system, I am so frustrated...

This was my 4rd or 5th time trying to learn how to sharpen properly, and yet I still cannot get the knife to push-cut paper when I am done.

What am I doing wrong?
 
Some things to check for:

Are you removing a burr, or getting one at all? When learning to sharpen it's good to make sure you raise a burr, then work to eliminate it.

Are you grinding the shoulders or creating a microbevel? If the angle is off either can happen. You can visually inspect the knife, or if your eyes aren't that good rub sharpie marker on the edge bevel and then see where you're grinding.

Also, what grit are you finishing at? Low grit edges can shave and push cut paper, but it's not as easy to do when you're beginning.
 
The main problem people have with these fixtures is that they fail to grind the bevels to one of the set angles. Put the coarse stone in and grind until you turn a burr in each direction. Then you can start sharpening.
 
Thanks for your responses. To be honest, I have trouble detecting the burr. I know you're supposed to feel it with your fingertips, but I really don't, regardless of how long I grind, even when I see that I have removed metal, and even when grinding with the coarse stone will take the sharpie marker off the entire width of the bevel.

Is there something I am missing here?

P.S. I finally managed to get my Leek sharp enough to shave, by doing 20/side, 10/side, 5/side sequences with the DMT blue (coarse), red (medium) and green (fine) stones, followed by a brush against the DMT extra fine 9-micron steel, at the same angle.

Still not as sharp as my Kershaws come from the factory though... and I am sure that this kind of kit should get the knife at least as sharp as the factory (with skilled use, of course).
 
Try doing it the other way, less strokes with the coarse and more with the fine. To check for a burr drag the edge on the top of your finger nail in a stropping motion, if there is a burr it will scrap the nail surface. just be sure you are checking for the burr at the same angle as sharpening.
 
you should be able to feel a burr with the tips of your fingers. You can also see it. One the side of the burr there will be a little more reflection of light at the very edge. Even with fairly coarse stones you can shave hair off your arm after you have raised a burr and have carefully removed it. If you don't raise a burr you may not be sharpening at the very edge so all that work has not done anything to actually sharpen the edge.
 
Take a sharpie and mark the edge bevel on both sides. Give it a pass or two, you'll see real quick if you're not making it to the edge.
 
knifenut1013 said:
Try doing it the other way, less strokes with the coarse and more with the fine. To check for a burr drag the edge on the top of your finger nail in a stropping motion, if there is a burr it will scrap the nail surface. just be sure you are checking for the burr at the same angle as sharpening.
Click to expand...
You misunderstood me. What I did was to do 20, 10, 5 strokes per side with EACH of the stones. However, if you think I need to do more than that with the fine one, I can try that as well.

Thanks.
 
gnius said:
You misunderstood me. What I did was to do 20, 10, 5 strokes per side with EACH of the stones. However, if you think I need to do more than that with the fine one, I can try that as well.

Thanks.
Click to expand...


Most of the time the fine stones taker longer simply because they are removing less metal. 35 total strokes per side may not be enough, after I have set the bevel with my coarse stone each finner stone usually gets around 50-100+ strokes per side depending on type of steel and hardness.
 
It sounds like your sharpening bevels are smooth enough and come to a clean apex along the edge. So how can you get the edge any sharper?

First off you can sharpen to a lower angle. I would sharpen to 8 to 10 degrees per side (16 to 20 degree included angle) then I would do just a few light strokes at around 12 to 15 degrees per side. All of the last few strokes would be done alternating one stroke on the left side then one stroke on the right side.

Secondly you can use a finer abrasive for your finishing step. I like to strop with 1 micron then .5 micron diamond abrasive for my last step.

You could be comparing apples to oranges in sharpness. It is harder to get an ultra-fine low angle edge on a 440A alloy blade than a 13C27 alloy one. This is more noticeable when you try for shaving type sharpness.
 
I'd add: finish with a good leather strop.

It'll clean up the edge and bring you to your goal of being able to push cut - depending on the steel type as indicated by Jeff Clark.
D2, for instance is just not going to take an edge like, say, AUS8 or VG-10.
 
use japanese water stones as they give a very good edge. (better than factory ground edges)
 
Ive never heard of a burr until I came to this forum. Now I cant stop sharpening knives. My cutlery will now slice newsprint. I have to be careful when shaving hair off my arms as to not take off a flap of skin.
Heres my system. I use a diamond stone attached to ceramic rods with rubber bands. I work one side till I feel the burr then the other. Finally remove the diamond stone and finish with the ceramic rods which are at the exact angle. Its fast and it works. I have this forum to thank.

2008-05-29.jpg
 
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