I can't get an even sharpness throughout the edge

[poonchasta]

I have a Spyderco Sharpmaker, and I'm fairly new at the concept of knife sharpening. What I have noticed when I sharpen my knives is that I can get them fairly sharp, but I have trouble getting the entire edge to be at the same sharpness. I found this out by trying to slice paper at an angle. For most of the edge, I can slice the paper effortlessly, but then I will get to a certain part of the edge, like the very middle or like an inch from the tip, and the paper will rip instead of slice. Can anyone give me some advice on how to improve my technique and get an even sharpness throughout the entire blade? Thanks in advance.

 

[eyeeatingfish]

Maybe you are switching the angle of the blade on part of the pass unknowingly?

There may also be one section of the knife which is more damaged than the rest. This means that while the other sections get really sharp the damaged section will not have been fully sharpened yet. You may need to do a little bit more work on just the one unsharp section.

 

[krazichinaman]

Sounds like to me that you might have a nick in the blade that you cant see. Have you tried the sharpie method to see if you are sharpening the entire edge?

 

[mikeymoto]

Do what Chinese Man said. Use the marker to make sure your sharpening is hitting the edge all along the blade.

Also, spend the money on a quality 20x (or more) loupe (a small but high quality magnifying glass) so you can inspect your edge. You will learn a lot from it. I know I have!

I have found that many knives come from the manufacturer with uneven grinds along the length of the edge. That means you may need to spend more time at a given portion of the bevel before you are actually sharpening all the way to the edge. The loupe will make those spots obvious, if you can't find them by inspecting the edge with the help of light reflecting off it from above.

 

[Cliff Stamp]

I have found that many knives come from the manufacturer with uneven grinds along the length of the edge. That means you may need to spend more time at a given portion of the bevel before you are actually sharpening all the way to the edge.

That is exactly the right problem and solution in the majority of the cases.

-Cliff