Sharpening related questions from a newbie - Ken Onion with Grinder

[Gadgetguy2005]

Hello all,

I am a brand new Ken Onion + Grinder user.

I have tried sharpening a "junk" knife and I have some questions.

I have used the X65 belt to get a good burr, then I used the X22 about 10 times (did not get a burr I could clearly feel) then I used the X4 to finish.

The edge looks good (to my untrained eye) but the knife is really not sharp. What did I do wrong here?

Thank you for any pointers.

 

[Gadgetguy2005]

Update: I have read numerous posts here - but did not find the answer...

Not sure if that matters: I am using 25 degrees angle for sharpening

 

[l1ranger]

i dont know about the Ken onions - but I would try going back to the coarse belt. burrs on both sides, and remove burrs on both sides with very light pressure - then check for sharpness. if you aren't sharp coming off the coarse belt - no manner of finer grits will help.

after that, repeat with each finer grit belt that you want to use.

 

[cbwx34]

Hello all,

I am a brand new Ken Onion + Grinder user.

I have tried sharpening a "junk" knife and I have some questions.

I have used the X65 belt to get a good burr, then I used the X22 about 10 times (did not get a burr I could clearly feel) then I used the X4 to finish.

The edge looks good (to my untrained eye) but the knife is really not sharp. What did I do wrong here?

Thank you for any pointers.

Update: I have read numerous posts here - but did not find the answer...

Not sure if that matters: I am using 25 degrees angle for sharpening

25° (which is "per side", if that's what you have the sharpener set at), is a pretty high angle for most knives... so when you say the knife is "really not sharp"... how do you define sharpness? A knife at that high an angle may not "pass" some of the sharpness tests. (Also depends on the knife itself).

Too much pressure can be one issue... the more pressure the more convex = higher angle... so, combined with the high angle setting, it can keep the edge from getting sharp. One suggestion I have if starting out (and for most knives anyway) is to set the upper rollers in the "closer together" position... this prevents too much convex, and allows you to better see the contact between the edge and the belt... then, just enough pressure to make contact with the belt... don't "push down" on the blade.

Only worry about getting a burr on the first belt. Every belt after that is just refining the edge. So after the first belt and raising the burr on both sides, make alternating passes to clean up the edge... then on subsequent belts I use alternating passes to further clean up and refine the edge. The burr tells you you've reached the apex... once there, all the other belts will be at the apex, so alternating passes will refine the edge.

l1ranger has a good point also... you may want to try using just the X65 belt, create a burr, then alternating passes to remove it, then strop (or whatever you do to clean up the edge), then test for sharpness. You should at a minimum have an edge that will slice decently thru paper at that level. Practice until you can achieve that before moving on to other belts.

 

[JacksonKnives]

When I was learning with a belt grinder, I definitely used too much pressure.

The convex is a cool feature, but it's easy to overdo, especially if you're already using the angle guide to set a robust edge.

 

[hectorsn]

That's odd. Once I get a burr all the way through the blade on the coarse belt, I always get a burr on the next belt and much sooner.

And once I get a burr on the x65 belt, it's sharp. Will shave hairs although rather painfully.

 

[bgentry]

I've noticed several times with the WSKO that the angle seems to "change" when I'm sharpening freehand. I think what is happening is this:

When I'm using the lower grit belts, I'm probably pressing harder, which causes the edge to be slightly more convex as the belt "wraps around" the blade from the pressure. Then when I switch to a higher grit belt and use less pressure, the belt is actually not touching the edge as it is slightly convex and not straight up and down.

In these cases, I've found that *slightly* increasing my edge angle has fixed the problem right away.

Good luck.

Brian.

 

[cbwx34]

That's odd. Once I get a burr all the way through the blade on the coarse belt, I always get a burr on the next belt and much sooner.

And once I get a burr on the x65 belt, it's sharp. Will shave hairs although rather painfully.

I don't think that's "odd"... you will get a burr on subsequent grits, in fact, if everything is lined up properly, it should pop up right away, so you're correct on both counts. (If you're responding to my earlier post, my point was you don't need to specifically try to create one big enough to see or feel... just concentrate on refining the edge). Thanks for the clarification.

 

[Gadgetguy2005]

Hello all, thank you for the various comments. I was super busy the last few days - so just got to sharpening now.

I followed your suggestions: changed the angle to 15, moved the two rollers to the close position to reduce the apex and used the x65 belt followed by the 12000 grit one to remove the bur. And.... ..... the knife is now cutting paper VERY nicely!!!

Now it is time to learn how to sharpen that the edge is perfect from the end to the beginning etc

But since I see I CAN do it I can start learning how to do it well.

I probably (certainly) will have more questions as I learn - but for now you all helped me tremendously. Thank you all!