Carbon Fiber

Flashpoint

Flashpoint

Joined
Apr 3, 2004
Messages
2,172
I was thinking of removing the left side scales from my Shallot and replacing it with a carbon fiber on. More or less an attempt to ad texture for a better grip and just to be different.

Is carbon fiber strong enough to use as a stand alone scale?
 
YES. Carbon fiber is an advanced material with an extremely high strength-to-weight ratio. It can be stronger and more flexible than steel. Warren Thomas, for instance, makes BLADES out of it. (With an electonically welded edge of steel or carbide, etc.) It is preferred in aircraft and in racing bike frames over aluminum for its strength, flexibility, and lightness. There is a world class paraplegic athlete who runs on "blades" or lower leg prostheses made of carbon fiber. It was a subject of some debate in sports whether he should be allowed to compete in track with the normal runners because based on his performance it was thought the carbon fiber might be giving him an "unfair advantage!"
 
Great. Thanks for the info.

Any special technique to shaping it or will a sander work fine?
 
It shapes very easily. Even a scotch bright wheel will remove material very quickly. YOU MUST WEAR A DUST MASK (RESPIRATOR) THE DUST IS VERY VERY BAD FOR YOU. It also makes your skin itchy.
 
Like JT said, you need to keep the dust out of the air (vaccum).

It is very bad for you. If you've ever been in a shop that drills and grinds it, you'd notice most have dust collection systems that pull it straight outside.Some shops don't, but they aren't realizing their liability yet.

Use a respirator!

Makes a strong handle and can be used alone or with a liner.

Kelly
 
look for the local ricer car hang out and steal a hood! ok ok maybe not but alpha knife supply stocks it.
 
Thanks again for the info.

Most of the stuff I'm finding is too think for what I'm wanting do. How thin can this be sanded down? The thinnest I've seen is 5mm and I need it to be closer to 3mm. Will that weaken the scales too much doing that?

Also is G10 as strong as carbon fiber?
 
5mm = about a 1/4 inch, 3mm then is about 5/32 and yes you can sand it down that far w/out comprimising structual integrity. It will be backed b titanium/brass/SS right? no need to worry about that. No clue about G10 might want to google that question though.

Jason
 
It can be stronger and more flexible than steel
Click to expand...

While I have no doubt that bare carbon fiber cloth is much more flexible than steel, I have a hard time with the first part of that statement...

Certainly strength to weigh advantage means that an equivalent weight of steel and carbon fiber would put the strength advantage in the carbon fiber camp, however, strength by cross sectional area, or volume is radically variable among differing steels, and I would wager that most are stronger in this regard than CF.

I am not trying to split hairs, but this thought that some modern marvel is "stronger" than steel is the basis for the hollywood myths about super titanium mega swords of doom, and all of the rest of the garbage that goes with them. While it certainly can be said, in the right context that CF has a distinct strength advantage over steel when satisfying some engineering requirement (typically where weight is a more critical factor than space) the basic statement "it's stronger than steel" is the oft perpetuated legend that I find mildly irritating.

If it were "stronger than steel" why would blades need a grafted steel cutting edge?
 
Please check out the following, and bear with me; I apologize in advance for a long-winded post.
_________________________________________________________________
Comparison of Carbon Fiber and Steel Material
Standard Grade Carbon Fiber Tensile Strength (GPa) 3.5
Tensile Modulus (GPa) 230.0
Density (g/ccm) 1.75
Specific Strength (GPa) 2.00

High Tensile Steel
Tensile Strength (GPa) 1.3
Tensile Modulus (GPa) 210.0
Density (g/ccm) 7.87
Specific Strength (GPa) 0.17

The superior properties of carbon fiber to steel and other metals meant that the aerospace industry was an obvious market for composite materials.

"The author of this page has been active in carbon fibers since 1980. My name is Vince Kelly, I was born in Manchester England, my work in carbon fibers has taken me to 1986 in Scotland, from 1986 to 2000 in Germany. I am currently an international consultant in all aspects of carbon fiber technology. I am also a professional member of the Society for the Advancement of Material and Process Engineering SAMPE. Founded in 1944, SAMPE is an international not-for-profit professional Organization with approximately 5000 members worldwide. As the premier technical Society in the fields of advanced materials and process engineering technology, SAMPE is recognized for its strengths across numerous industries and markets. The Society holds annual conferences and exhibitions in the USA, Europe and Japan and publishes two widely recognized journals throughout the year. Professional and Student Chapters actively hold local meetings, regional workshops and seminars."
_________________________________________________________________
The above is an excerpt from this carbon fiber page:http://www.geocities.com/vpkelly.geo/

So you can see that there are definitely informed people out there stating that carbon fiber is stronger than steel. Believe me, the above was not the only reference I checked. However, there is a lot of debate out there on the subject.

It seems fairly clear that some types of carbon fiber can consistently rate higher than some types of steel in standard tests such as resistance to fatigue, (flexing) tensile strength, shear strength, etc.
However, carbon fiber's advantages are pound for pound, not dimensional. So a bar of a given steel will most likely be "stronger" than a bar of a given carbon fiber of the same size. Conversely, if you scaled up the dimensions of the carbon fiber bar until it weighed the same as the steel bar, the carbon fiber bar would likely be considerably stronger.

All of the statements above are variable as well, considering: A., the type of steel vs. type of CF in the comparison, and B., your definition of "strength." There are many different ways of defining, testing, and applying properties of strength.

As for why one would need a grafted steel cutting edge on a carbon fiber blade, edge holding is kind of a separate consideration from "strength" and is not a property I would expect carbon fiber to posess.

Pretty much what I'm trying to say is that I partly agree with Dan Zawacki on this subject. However, I want to take pains to point out my initial usage ..."CAN be stronger than steel"... and that I am aware of how complex an issue it really is.
 
Carbon fiber is more than strong enough for a knife scale at just about any thickness.
the cheapest place I've found it online for 1/8" and under is
http://www.protechcomposite.com/ser...sive)-cln-3.1mm-Carbon-Fiber-plate/Categories They have a 3.5" x 3.5" x .122" sample size for $7
For anything thicker than 1/8" www.alphaknifesupply.com/ is the best place to go. Pretty much the only place actually.

WEAR A RESPIRATOR! Carbon fiber is super bad for you!


G10 is almost as strong as carbon fiber. It would also be more than strong enough. Alpha Knife Supply is about the only place you can buy small pieces of g10 at a reasonable price.
 
CAN be stronger than steel"... and that I am aware of how complex an issue it really is.
Click to expand...

OK, That's all I was after...

Again, I don't mean to sound like I'm splitting hairs. That CAN in the front is the most important part.

The reason, I guess, that I'm so hyopersensitive about this right now is that I've gotten a lot of questions from old childhood buddy's and such that go basically like this:

DOOOD! you make knives now!?

ummm... yeah, I've made a few

DOOOOOOOD! Thats's so cool! Could you make me a knife out of unbreakable titanium?!

At this point, I have learned that the best was to respond is by saying something like "you couldn't afford it" or "I don't have the special equipment I would need" I have yet to successfully disillusion one of these guys.

And so the whole "stronger than steel" thing is an oversimiplification that sometimes feeds some VERY irritating stupidity.


Glad to see you did your research! I wish more of the folks in my home town could do the same!
 
Thanks again the help. It makes me more confident in going ahead with my project.

Maybe in a decade or so I can have "knife maker" under my name. ;)
 
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