Sharpening on 2x72

colu41

colu41

Joined
Dec 24, 2014
Messages
1,598
After tossing my Lansky system to the side, because it was extremely time consuming. I decided to take a day and teach myself on the grinder. Eventually I got it down pretty good.

My procedure:
Create the edge with 120g
I then jump to 800g, and hit it on the buffer.

Now this is my problem. After a quick buff to knock the bur down, it cuts paper like butter, and also shaves hair, but I can literally run my finger up and down the blade without a mark. Feels extremely smooth & almost like its dull, like it has no ability to slice anything. Is there a problem with the grit I'm using?
I use pink scratchless compound on the buffer. That claims its 2000g. I've actually tried going down to my 1000g white compound and doesn't work as well. Any tips would be great!
 
You are buffing to much and taking all the tooth out of the edge

Literally just lightly pass the edge knocking off the burr. I use Green compound.
 
AVigil said:
You are buffing to much and taking all the tooth out of the edge

Literally just lightly pass the edge knocking off the burr. I use Green compound.
Click to expand...

Makes sense.. What type of buff wheel do you use?

Just by chance, is this you? https://www.youtube.com/watch?v=ySWaAqVaRek

I found this video here, and I dont remember if it was you, or maybe you just posted it? Anyways, this is where I learned it! Thanks
 
No that is Lon Humphries

Watch that video, he knows what he is talking about

I use a sewn wheel, not the loose one
 
AVigil said:
No that is Lon Humphries

Watch that video, he knows what he is talking about

I use a sewn wheel, not the loose one
Click to expand...

Ahh. Ok. I'll have to pick up another wheel and use my green compound and try it out. Thanks again.
 
I create the edge with 120g edge leading
Then I jump to 400, edge trailing and form a little burr

^this is done slow and wet with a tightly controlled angle, not by hand

I stone this tiny burr off on a fine oil stone in four off-hand swipes. Because it isn't burned soft, it comes off as glitter. It will shave hair aggressively.

I strop on a loaded leather strop a couple passes. It is now fiendishly sharp

For this to work well you have to control the angle and keep things wet, otherwise the very apex of the edge isn't hard and won't take a crisp edge.

I understand the appeal of buffing the edge because it's fast easy and gives the appearance of a good sharp edge, but really it's not very good.
 
I use the buffer to knock of the burr not to polish the edge. You can do the same thing with a strop.
 
Work to thin the edge to where there is little if any burr along the edge. Raise one on the grinder and remove it on the grinder. Buffing I don't believe is the best way to finish an edge. I don't strop I ERU.

Using a controlled angle is key for me as well. It takes much less work and produces a better edge consistently.
 
colu41 said:
and hit it on the buffer.

Now this is my problem. After a quick buff to knock the bur down,
Click to expand...

i think the buffer gives you a rounded edge
that's my opinion and experience, and admit I don't have much :-)

I use Tormek PA-70 Honing Compound on leather
or hone by hand on a 6000 grit stone.
 
Thanks guys. I'll look into maybe finishing the edge on or stone or maybe just strop.
 
I use a belt grinder to do the initial sharpening on a newly made knife then use a Lansky to give the bevels a specific angle as a lot of my customers prefer a particular angle.
 
Wheelz87 said:
What type of fixture are you using to hold that angle?
Click to expand...

A simple parallelogram hung from the ceiling. I measure the angle with a bubble level protractor and set the angle on the platen. The parallelogram just keeps the blade perpendicular to the ground.


edit to add: https://www.youtube.com/watch?v=u0Iu_EEyEIU

Doing a really good job getting a knife good and truly sharp with known repeatable geometry is so simple I don't understand why people make it so hard on themselves *shrug*
 
Last edited:
Nathan the Machinist said:
A simple parallelogram hung from the ceiling. I measure the angle with a bubble level protractor and set the angle on the platen. The parallelogram just keeps the blade perpendicular to the ground.


edit to add: https://www.youtube.com/watch?v=u0Iu_EEyEIU

Doing a really good job getting a knife good and truly sharp with known repeatable geometry is so simple I don't understand why people make it so hard on themselves *shrug*
Click to expand...

Love the parallelogram! Wonder if instead of using bolts you could use some sort of rare earth magnet so you could do blades after they had the scales on?
 
Nathan the Machinist said:
I create the edge with 120g edge leading
Then I jump to 400, edge trailing and form a little burr

^this is done slow and wet with a tightly controlled angle, not by hand

I stone this tiny burr off on a fine oil stone in four off-hand swipes. Because it isn't burned soft, it comes off as glitter. It will shave hair aggressively.

I strop on a loaded leather strop a couple passes. It is now fiendishly sharp

For this to work well you have to control the angle and keep things wet, otherwise the very apex of the edge isn't hard and won't take a crisp edge.

I understand the appeal of buffing the edge because it's fast easy and gives the appearance of a good sharp edge, but really it's not very good.
Click to expand...
Hello guys,

My first post here on bladeforums, and jumping in with a question right away for Nathan.
You say to keep a constant angle you don't do it free hand, I'm wondering how I would follow the curve of the blade then, with a grinding jig.(assuming that's what you use).
Also I was wondering what you guys think about those little tool sharpening systems.(those small little boxes).

Cheers.
Thomas
 
razor-edge-knives said:
Love the parallelogram! Wonder if instead of using bolts you could use some sort of rare earth magnet so you could do blades after they had the scales on?
Click to expand...

I've tried it, doesn't work, it can slide around and it still tilts off. I've used a big neodymium magnet plus a drop of super glue to hold stuff but you have to be careful how much force you put on it. It's better to use a fixture that holds the blade if you're not using a hole in the tang.

I use a parallelogram because it's compatible with my process, but there are a bunch of different ways to skin that particular cat. What's important is maintaining some control over that angle so the grinding process is controlled. That and using coolant.

However a person goes about do it, it they find they're getting much of a burr they may have a problem with their process. Also, if a knife isn't burr free and shaving hair it's not ready to strop <--- that's a short cut that masks other problems and gives mediocre results.
 
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