BFK sharpening thoughts sought

dhwfd46

dhwfd46

Gold Member
Joined
Jan 30, 2007
Messages
68
So, I have a buddy who got his first BFK. The knife was advertised as factory sharp so he just stropped it with 1 micron diamond paste and brought it by yesterday. It won’t even slice printer paper.

Now, let me explain here, he has a pile of Shapton glass and knows how to use them. He also has a Kazak Pro Black with multiple sets of stones: CBN, Venev Orion diamonds, Naniwa Chosera, to name a few and he gets stuff hair whittling, stupid scary retarded sharp. Of course blade steel, edge geometry, and heat treat all come into play and for anyone who’s seen a Gritomatic grit chart, grit designations aren’t universal.

He’s a big collector whereas I use my stuff for it’s intended and often unintended uses. I’m living vicariously through helping lighten his wallet after instantly getting him hooked on D3V with the aid of Nate’s don’t do this dumb $hit at home videos. Anyway, he seeks any recommendations to restore his BFK to the factory delivered level of sharpness.

Thanks in advance,
Dave
 
I've never handled any Carothers knife that wasn't scary sharp from the factory. I use my BFK quite a bit and I just sharpen it on the Wicked Edge and finish at 600 grit.

I have no idea what's happening with your friend's knife, but that doesn't sound normal. Did he buy it from Carothers or second hand?
 
“It won’t even slice printer paper.”

This is either an exaggeration or he raised a burr and didn’t strop it away.

Let me explain. I own all kinds of sharpening implements, including a guided system (WE).
I suck at sharpening with every single one of them. And even though my sharpening skills are pathetic, I am able to easily produce an edge that will cleanly slice printer paper. Even my HDMC (1/4”+ obtuse blade made for knuckle draggers) that has been used to chop down a few 6-8” trees and remove all their limbs, can slice printer paper without being touched up.
So there is either a burr, or you guys are trying to slice the printer paper with the spine.
I’m sure this post was not helpful. I feel bad about that, but I really don’t have any other explanation.
 
dhwfd46 said:
So, I have a buddy who got his first BFK. The knife was advertised as factory sharp so he just stropped it with 1 micron diamond paste and brought it by yesterday. It won’t even slice printer paper.
Click to expand...

I'm interpreting this clause to mean the buddy purchased the knife on the secondary market. Reading a little deeper between the lines, I wonder if the seller said "factory sharp" when in fact what should have been said was "lightly used but never re-sharpened or honed." That might help explain why the edge is not quite so keen.

As for touching it up, I have good results with light passes on a medium or fine diamond plate, a few passes on a medium ceramic hone, followed by a few passes on a strop. Heck, the last time I worked on my FK3 I took enough light, alternating passes on a medium diamond plate to raise a burr, then straightened the burr via a few light passes on the edge of a glass table-top (too lazy to get up to fetch my ceramics). Edge came out toothy and sticky and it absolutely sailed through everything I wanted to cut.
 
Strops are not for sharpening

If the knife cannot already shave hair it's not ready to strop

Stop using strops to sharpen. You're just creating an obscenely obtuse, super smooth, microbevel that doesn't cut very well.

Learn how to use a stone.
 
Cap’n Smudge said:
“It won’t even slice printer paper.”

This is either an exaggeration or he raised a burr and didn’t strop it away.

Let me explain. I own all kinds of sharpening implements, including a guided system (WE).
I suck at sharpening with every single one of them. And even though my sharpening skills are pathetic, I am able to easily produce an edge that will cleanly slice printer paper. Even my HDMC (1/4”+ obtuse blade made for knuckle draggers) that has been used to chop down a few 6-8” trees and remove all their limbs, can slice printer paper without being touched up.
So there is either a burr, or you guys are trying to slice the printer paper with the spine.
I’m sure this post was not helpful. I feel bad about that, but I really don’t have any other explanation.
Click to expand...

SharpBits said:
Are you me??
Click to expand...

NO, I AM SPARTACUS
 
oldmanwilly said:
I'm interpreting this clause to mean the buddy purchased the knife on the secondary market. Reading a little deeper between the lines, I wonder if the seller said "factory sharp" when in fact what should have been said was "lightly used but never re-sharpened or honed." That might help explain why the edge is not quite so keen.

As for touching it up, I have good results with light passes on a medium or fine diamond plate, a few passes on a medium ceramic hone, followed by a few passes on a strop. Heck, the last time I worked on my FK3 I took enough light, alternating passes on a medium diamond plate to raise a burr, then straightened the burr via a few light passes on the edge of a glass table-top (too lazy to get up to fetch my ceramics). Edge came out toothy and sticky and it absolutely sailed through everything I wanted to cut.
Click to expand...
Just a note:
A burr, in reference to sharpening, is a very specific thing. You want to remove a burr, not straighten it.

The burr wrt sharpening is a very thin section at the very edge. You CAN straighten the burr (somewhat), and it will slice through material that’s not particularly hard/tough eg. Paper, body hair etc.), but an actual burr folds over easily.

People new to sharpening, then go, “Yeah, I can get it razor sharp, but it doesn’t stay sharp for very long”, potentially leading to an incorrect impression on a blade’s edge holding abilities.

This is what a strop is good at doing. Sharpen and develop a burr, use a strop to remove the burr and micropolish the very apex.
 
My bad! Clearly I didn’t iterate that the knife was purchased on the second hand market and I know you can’t sharpen with a strop. Also apologies to Nathanan, as I know nothing leaves there that isn’t sharp. My buddy just received a K20 today, again, second hand market, but he just called to say it has a laser beam edge. We both have BFKs coming from the last sale.
 
bluemax_1 said:
Just a note:
A burr, in reference to sharpening, is a very specific thing. You want to remove a burr, not straighten it.

The burr wrt sharpening is a very thin section at the very edge. You CAN straighten the burr (somewhat), and it will slice through material that’s not particularly hard/tough eg. Paper, body hair etc.), but an actual burr folds over easily.

People new to sharpening, then go, “Yeah, I can get it razor sharp, but it doesn’t stay sharp for very long”, potentially leading to an incorrect impression on a blade’s edge holding abilities.

This is what a strop is good at doing. Sharpen and develop a burr, use a strop to remove the burr and micropolish the very apex.
Click to expand...
You are certainly correct re the purpose of the strop, and I agree that the burr is a detail often overlooked by people new to sharpening.

However, sometimes a small, fine burr is an advantage, especially if you're slicing fibrous material (cordage, hair, hides, vegetable/plant matter) and meat. That's why butchers traditionally used a steel on their knives: a few quick swipes to straighten up the burr between cuts is often enough to keep a sharp edge working all day. This all assumes that the person properly sharpens first to thin and apex the edge.

That's what I was aiming for in my process described above. A crisp, toothy edge usually works better for my needs and I don't mind stopping every now and then to hone and refresh the edge.
 
oldmanwilly said:
You are certainly correct re the purpose of the strop, and I agree that the burr is a detail often overlooked by people new to sharpening.

However, sometimes a small, fine burr is an advantage, especially if you're slicing fibrous material (cordage, hair, hides, vegetable/plant matter) and meat. That's why butchers traditionally used a steel on their knives: a few quick swipes to straighten up the burr between cuts is often enough to keep a sharp edge working all day. This all assumes that the person properly sharpens first to thin and apex the edge.

That's what I was aiming for in my process described above. A crisp, toothy edge usually works better for my needs and I don't mind stopping every now and then to hone and refresh the edge.
Click to expand...
In this case, I think it’s a case of using the term differently.

The image in this link, is what I think of, when the term ‘burr’ is used.

https://support.wickededgeusa.com/portal/en/kb/articles/drawing-a-burr

A steel is for realigning the edge, not the burr. The burr is weak and flimsy, and rolls easily. It’s pretty much a tiny piece of metal foil along the edge (and the image exaggerates the length). The thin edge of that ‘foil’ can cut (just as the edge of paper can cause paper cuts), but it will roll very easily, and once it does, it doesn’t cut well at all anymore.
 
You must log in or register to reply here.
Back
Top