carbon fiber bladed knife and sharpening?

[jbmonkey]

can one sharpen a carbon fiber blade knife at home using stones, crock sticks, sand paper, belt sander, etc.? i have googled to death and found very little on this. i did gather that the dust/micro splinters is dangerous and proper breathing equipment, eye protection, handling equipment, etc. precautions should be taken. i also read it's a terrible setup for kitchen or food use knives as splinters break off and you'd end up eating them? other than that though.....i'm at a loss for finding reliable information.

if you can sharpen with normal sharpening devices and systems, is it really hard to do and take forever, or realtively easy?

which leads me to my next question....anyone know how many cuts one can make before carbon fiber goes dull? assuming of course it was sharp enough to cut paper and cardboard, and paracord, etc. from the get go. i ask this cause as far as i can tell, carbon fiber doesn't comes in different varieties and heat treats, etc. like steels do................... or does it come in different edge holding formats and formulas of the binders, etc?

ya'll who make/work with and/or own carbon fiber blades....educate away. feel free to go in depth........ i'm looking for schooling. as always thank you in advance.

 

[wnease]

Are you talking about a carbon fiber blade with a carbon fiber edge? That will have almost no ability to hold an edge, it's like trying to use a wire brush as an axe. The individual fibers are strong and have high elastic modulus, but at the geometries required to form a knife edge the fibers will easily break out of their matrix. Also they are rather the reverse of wear resistant. Plexiglass edges outperform cf edges in my experience.

As a hideout shank it's possible to sharpen it with sandpaper, preferably wet, and clean up while still wet as the dust floats forever when dry. Serrations can be done by wrapping the sandpaper over the appropriate shape block (you may have to make this block by sanding)

Have fun, it's cool stuff to work with!

 

[jbmonkey]

Are you talking about a carbon fiber blade with a carbon fiber edge?

yes, Sir. exactly right. like the boker plus made in china featherweight knife, for example.

That will have almost no ability to hold an edge, it's like trying to use a wire brush as an axe. The individual fibers are strong and have high elastic modulus, but at the geometries required to form a knife edge the fibers will easily break out of their matrix. Also they are rather the reverse of wear resistant. Plexiglass edges outperform cf edges in my experience.

i did see that to be the general consensus of what i could find out there on carbon fiber as a blade material. thanks for the detailed description. follow up question......maybe a few cuts on card board...before going dull and being able to cut nothing? meaning standard box cardboard, not the heavy dense extreme stuff?

As a hideout shank it's possible to sharpen it with sandpaper, preferably wet, and clean up while still wet as the dust floats forever when dry. Serrations can be done by wrapping the sandpaper over the appropriate shape block (you may have to make this block by sanding)

Have fun, it's cool stuff to work with!

good information, thank you Sir. appreciate the education. can i assume ceramic based sharpeners, and diamond stones are a no go on sharpening?

another question.... what would be a better non-steel material to use. you mentioned plexiglass....i'm not sure if to make a point or were you being serious as a much better material than carbon fiber. i seem to remember cold steel made a knife out of zytel or some other fiberglass plastic material and of course that lansky knife made of some kind of plastic/vinyl fiberglass/polymer or whatnot. thanks again for the info and follow up.

 

[CWL]

yes, Sir. exactly right. like the boker plus made in china featherweight knife, for example.

Um, that knife has carbon fiber scales but the blade is 440C.

Think of carbon fiber as sheets of silk, or kevlar. Like micarta or G-10, it won't even become rigid unless it is suspended in some other materials such as resin. You aren't going to get a usable "edge" on it unless you reinforce it with carbides or some other industrial cutting substance.

Might you be confusing carbon fiber for ceramic?

 

[jbmonkey]

Um, that knife has carbon fiber scales but the blade is 440C.

i think we are talking about two different models, which is easy to do since there is so many models out there anymore with similar names and such....but what i am talking about is this one...

http://www.boker.de/us/fixed-blade-knife/boker-plus/tactical-knife/02BO279.html

Think of carbon fiber as sheets of silk, or kevlar. Like micarta or G-10, it won't even become rigid unless it is suspended in some other materials such as resin. You aren't going to get a usable "edge" on it unless you reinforce it with carbides or some other industrial cutting substance.

good info thank you, Sir. more of exactly the kind of info i was looking for.

Might you be confusing carbon fiber for ceramic?

no Sir. i guess boker site could be wrong saying "blade material:carbon fiber" in the specs? anything is possible, but i've seen other custom blades out there made of carbon fiber. i mean the blade as well as the handle. the whole thing.

 

[fen]

PM CharlieMike. He's made some carbon fiber knives if I remember correctly.

 

[Obsessed with Edges]

I don't see that knife ever taking a real cutting edge, as is consistent with the product description quoted below (emphasis added in bold text). I think the 'emergency situations' it was designed for are probably the kind encountered in dark alleys, late at night. Might also be useful for some probing/prying type of tasks, and in situations requiring a non-magnetic blade.

"The neck knife Featherweight, designed by Doug Hartsook, is made completely of carbon fiber. Although such a blade can never replace a steel blade, this knife, weighing less than one ounce, is a reliable tool for emergency situations and will not burden you with a heavy weight. It is not intended to be an everyday tool for frequent use or for executing fine cutting tasks. Includes a Kydex sheath and ball chain. Blade length: 2 7/8". Overall length: 6". Weight: 0.4 oz.

 

[jbmonkey]

I don't see that knife ever taking a real cutting edge, as is consistent with the product description quoted below (emphasis added in bold text). I think the 'emergency situations' it was designed for are probably the kind encountered in dark alleys, late at night. Might also be useful for some probing/prying type of tasks, and in situations requiring a non-magnetic blade.

Thanks David. I had read the description. I'm trying to get more detailing. Looking for knowledge from those who have played with cf knives and made them, sharpened them, etc.

 

[jbmonkey]

PM CharlieMike. He's made some carbon fiber knives if I remember correctly.

Good idea. You are correct. Thanks.

 

[CWL]

i think we are talking about two different models, which is easy to do since there is so many models out there anymore with similar names and such....but what i am talking about is this one...

I stand corrected Sir!

But regarding carbon fiber as a cutting material, it isn't one. My earlier comparison of trying cut with a sheet of silk is still accurate. The CF needs to be imbedded with a polymer of some sort to give it rigidity and to add some "heft" to the material. The Custom knives made with CF blades I have seen all have some sort of carbides imbedded to the edge to allow it to cut. Without something to give it cutting friction (carbides), CF is just a fancy letter opener.

 

[jbmonkey]

I stand corrected Sir!

not at all. your post was still packed full of good information. i really appreciated it.

But regarding carbon fiber as a cutting material, it isn't one. My earlier comparison of trying cut with a sheet of silk is still accurate. The CF needs to be imbedded with a polymer of some sort to give it rigidity and to add some "heft" to the material. The Custom knives made with CF blades I have seen all have some sort of carbides imbedded to the edge to allow it to cut. Without something to give it cutting friction (carbides), CF is just a fancy letter opener.

this is interesting to me. the part in bold....let me make sure i am grasping on this correctly. so it would be the "binder" (calling it that for a lack of a better word) that would make or break a carbon fiber blade being able to cut or not cut at all? if i am on the right path.....as is a carbon fiber blade would be good for a few stabs at best. sharpening is possible, but just to make it a stabber again. so it's worthless as a tool for cutting, other than a few cuts before it breaks down? thanks in advance.....

 

[Charlie Mike]

I wouldn't use one for much else but strictly stabbing in SD.

 

[jbmonkey]

I wouldn't use one for much else but strictly stabbing in SD.

i'm glad you joined in Cm. i was actually gonna pm you and ask for your input to these questions. thanks for your input since you have a vast knowledge of working with this material. good for me to learn and for others who google the topic and come across this post.

sharpening cf blade? easy, waste of time, hard to do....any details you don't mind sharing would be greatly appreciated. at least it would be by me, not sure about the others, but that's their problem.

 

[Charlie Mike]

Very easy to sharpen... you could do it on a disposable emery board you'd use on your fingernails.

 

[2knifecrazy]

Well my question has been answered.

I just bought a Bastion folder that is totally carbon fiber (other than the liner lock) and it will not sharpen at all. I think I'm going to get rid of it on ebay. Nice looking knife and light as a feather but useless...