# DIY fully carbon fiber knife building. :) Lots of pics!



## liveforphysics (Jun 4, 2010)

I bought some carbon fiber materials to make some fairly complex parts with, and sadly realized that I was badly lacking the skills needed to make complex things. 

So, I decided to try some simple things first to teach myself a bit, and trying a knife seemed like a simple and fun first try.


I know you knife building pro's are 10000x better than me, and I know my shapes I just eye-balled for the blade shapes and handles etc are nothing amazing. This was just an exercise in working with CF for me, rather than the quest for building the worlds most amazing knife.


So, I picked through some of the pics that turned out decent (all just done on my cell-phone cam :sigh.







The first set of pics is for the thick and long bladed knife I made, which turned out to be really over-kill on blade stregnth, and kinda silly how thick it was. The second set I went with 1/2 the blade thickeness, and it still feels so rigid that flex seems almost undetectable in it, and it slices veggies and things much better with the thinner blade section.  






I used my DIY CNC machine to rough-out the strip to become the blade from some 1/4" CF.

Then I ground it and wet sanded it into a shape I liked.





Then I measured up my hand vs the tang material I left, and decided how big to cut the scabs to laminate into being the handle. 







Then cut them out with my CNC.






Laid them all up to make sure I was happy with how thick it would be. I used 2x2 twill weave carbon for the blade and inside area of the handle, and then used a slick 1x1 checker board weave for the outside layers of the handle. I think the design contrast is pretty slick. 







I mixed up a batch of the special fancy-pants epoxy in the special ratios, and mixed it in the recomended way to avoid bubbles from getting mixed in, then coated both sides of each piece, stacked them all together on a big chunk of solid teflon, and applied weight with another big chunk of teflon.






Patiently waiting for the stack to cure well enough to go in the oven for final hardening...






Once it all cured, I started the filing and sanding process. Dry sanding the carbon was pretty bad, but wet sanding with fine grits, like 600-1000 worked very well. 







Hours and hours of sanding later.... and I had something I was proud of.


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## DaFABRICATA (Jun 4, 2010)

EXCELLENT JOB!!!

And the pics are amazing for a cell phone!

NICE WORK!! Keep it up!!


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## liveforphysics (Jun 4, 2010)

The next week, I started another knife, this time with the thinner blade, because the first knifes blade was just way stiffer and stronger than I could ever imagine it needing to be.







Then rough ground it.







Then cut out the handle laminations, laminated them, cooked in the oven at 300f over night, and this is what it looked like. 








Trimmed off the ugly with the bandsaw.







Then I started in for a few hours of file work...







Then, another few hours of wet sanding, and I had another knife I was proud of.  This one just feels damn good in the hand, and I got an edge good enough on it to slice tomatoes easily, and it seems to do a pretty good job around the kitchen.


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## ninemm (Jun 4, 2010)

Pretty cool knives! Nice craftsmanship. :thumbsup:


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## Chauncey Gardner (Jun 4, 2010)

They came out pretty nice

I'd like to make some CF scales for some of my knives & may pm you later.


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## Anto (Jun 4, 2010)

WOW

that's awesome


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## liveforphysics (Jun 4, 2010)

So, some neat things about CF is that it's never going to rust, or be bothered by saltwater or things left on the blade. 

It's so light, I can have it loose in a back pocket, and even jogging I don't even feel the thing. I haven't weighed them yet, but I think they are under 1oz per knife. They almost feel like holding air, yet they are extremely rigid. 

No metal means metal detectors won't make you give-up your knife, though these perticular ones are too big for EDC (at least to me). 

They look really cool just dry in normal room lighting, but in sunlight when wet, they are hard to even take your eyes off!  When I'm slicing up fruits/veggies at the kitchen sink with the sunlight comming in through the window, the knife is so distractingly awesome looking, I've actually cut my fingers from paying more attention to the knife than where I'm cutting. 



For people looking to make there own, it's pretty easy. I spent about $400 initially in materials to get the proper carbon fiber epoxy, a small roll of cloth, and some pre-glued carbon fiber strips. I've got enough materials left to make at least 4-5 more knives, so the materials cost is really not too bad, well under $100 a knife for all materials involved if you're going to make a few. 


I'm sure the knife making guru's could do the grinding and sanding in under a couple hours, and it would be all perfect. For me, it was the bulk of the time in making each knife. 

I estimate I've got about 10hrs of work from start to finish for each knife.


I hoped you liked seeing how it's made 

-Luke


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## liveforphysics (Jun 4, 2010)

Thank you for all the kind words guys.


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## csshih (Jun 4, 2010)

nice work!


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## liveforphysics (Jun 4, 2010)

For the people wondering how CF holds an edge, I can tell you it's nothing like good steel. 

I can cut soft things with them, like veggies and fruit and trim steaks and things with no issues, and the blade stays sharp. 

However, if you start trying to carve wood or hacking through cardboard boxes and things, the blade does lose it's edge very quickly, and hacking at harder things puts tiny little knicks in the blade that a good steel knife would have taken no damage at all from. 

It has it's ups and downs as a material. It would certainly make a poor machete, but it does seem to make a fine kitchen knife.


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## liveforphysics (Jun 5, 2010)

Well, I cut some thin Ti blade blanks to wrap in carbon fiber, but keep the cutting edge of the blade as exposed Titanium. 

But... then a guy at the EDC forums made an excellent suggestion! Use a piece of ceramic for the cutting edge insert! 

Now I'm shopping ceramic blanks, and trying to get the best material money can buy for the cutting edge strip. From what I've read, there are ceramics for knives that can be sharpened well beyond the capability of any steel knife, and hold an edge as much as 60 times longer! The weakness is of course the tendency to break the blade if used to pry or dropped on the tip etc. 

A ceramic cutting edge inset into an extremely rigid carbon fiber blade/handle should really help over come the weaknesses of the ceramic knife, while the ceramic cutting edge over comes the weakness of the carbon fiber knife. And it keeps the perfect chemical/salt/rust resistance, keeps it entirely non-metalic, will still be 1/8th the weight of a similar steel knife, and can be made sharper and hold an edge better than any steel.    I don't care if it costs me $200 for the damn insert, I now must build my vision of the most perfect knife ever!


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## A380 (Jun 5, 2010)

WOW!! Great work. They are really nice.
Just one safety note, CF dust is very dangerous if it get into your lungs. Better if you get a mask (if you don't use it) when you sand CF.


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## an0nymous (Jun 6, 2010)

Ok. Wow. Yer ceramic cutting project is completely cool. Looking forward to those pics.


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## RepProdigious (Jun 6, 2010)

liveforphysics said:


> Then I started in for a few hours of file work...



You were wearing proper safety-gear when doing this i hope? The dust and flint coming off CF is really really nasty and especially the fine dust doesn't get filtered out by regular masks.....

Apart from that; Nice job! Are those knives legal in your country?


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## liveforphysics (Jun 17, 2010)

Ok, here are some crude pics of my crude testing with laminating metals into the carbon fiber. I'm using Titanium here, but it's only to practice the process of getting the carbon/insert/edge layout laminated to meet my standards for stregnth and visual qualities rather than trying to make knives, so don't go making fun of my stupid triangle blade shapes. They are just test mules to cut apart and pry with and flex and see how things hold up.
You can see I refined the methods on knives 5 and 6 to grab the blade with CF rivot-like shapes. I counter-sunk the holes on both sides, so each little carbon plug has fibers running long-ways down the blade, and through the holes. The result here was a CF/Ti blade that I wad able to fold at about a 45deg off-axis in the vise before the carbon started to crack away from the titanium. You can see the plug shapes in the blade I cut-away as a sacrifice to see how well the plug-insert method filled in with carbon, and I was pleased.


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## liveforphysics (Jun 17, 2010)

BTW- That Ti blade in the last picture I sharpened enough to shave with, and when you mess up and cut yourself with it screwing around, it actually doesn't hurt. You're just surprized to see blood dripping from somewhere and wonder where you got knicked. lol


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## FNinjaP90 (Jun 17, 2010)

Very nice! Can't wait to see the carbon ceramic knife.

I made a lot of stuff during school with carbon, and I also made myself a spoon. Highest stiff:weight spoon ever.


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## liveforphysics (Jun 17, 2010)

Beautiful spoon!


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## RepProdigious (Jun 17, 2010)

Thats the nerdiest, hyper most tacticool and overdone spoon i have ever seen...
















I want one


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## FNinjaP90 (Jun 17, 2010)

I'm currently doing graduate research on microscopic void analysis on vacuum-assisted resin transfer molded carbon fiber laminates embedded with multi-walled carbon nanotubes.


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## Bullzeyebill (Jun 17, 2010)

What cell phone are you using for your pics?

Bill


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## liveforphysics (Jun 17, 2010)

Bullzeyebill said:


> What cell phone are you using for your pics?
> 
> Bill



I was using an HTC G1. But, I just picked up an HTC EVO 4G, which has an 8MP camera with mechanical focus abilities, and takes pics that you wouldn't know came from a cell phone.


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## csshih (Jun 17, 2010)

RepProdigious said:


> Thats the nerdiest, hyper most tacticool and overdone spoon i have ever seen...
> I want one



same...


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## nbp (Jun 18, 2010)

Those are phenomenal! If you made some small versions that could actually be pocketed, and at a reasonable price, I think you could sell them so easily. I'd be in for one. I don't know yet what I'd use it for, but I'd love one!:thumbsup:


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## fishinfool (Jun 18, 2010)

Awesome knives and :kewlpics:!


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## N10 (Jun 20, 2010)

COOL knives & AWESOME SPOON...!!!


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## ron Lauinger (Apr 20, 2011)

Awesome looking knifes,, What kind of finish did you use on these? did you bake them before or after putting on the edge?

thanks


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## rusky (Apr 24, 2011)

Cool, good job and nice knives man!


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## shao.fu.tzer (Apr 24, 2011)

Very cool... Reminds me of what Warren Thomas has been doing... You should do a run of neck knives... they'd sell crazy-like...


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## hig789 (Jun 8, 2011)

Wow that is amazing. I would love to have one with a ti insert for a kitchen knife. Nice job.


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## Joe LeDux (Jun 29, 2011)

I've been interested in making laminated blades out of carbon fiber and other exotic materials for about fifteen years. I finally decided to quit thinking about it and actually do it. Was inspired by the originator of this thread, and by some guy on Ebay who bills himself as a knifemaking pro and sells knives made solely of carbon fiber. He misrepresents the capabilities of (only) CF as a blade material, and his knives look like complete kaa kaa that could be made by anyone handy with a file, yet he must be selling them because I always see new ones put up for sale on Ebay for $100+(!). So, "If he can sell that crap...." I just had to get to work.


On the other hand, Warren Thomas sells his CF/Ti knives for between four and twelve times that much, but his knives certainly do NOT look like kaa kaa. I'd love to have one.


First thing I had to do was research: what materials to use and where to get them. I never seriously considered making blades solely out of carbon fiber, because of the poor edge-retention as pointed out by others. I thought about ceramic and still think it's a good idea, but I haven't been able to find the blade segments in a shape I can use and for a reasonable price. And yes I said segments. Ceramic is brittle, and stiff as it is CF is much more flexible than ceramic, so that could lead to a broken, possibly shattered cutting edge if you stress the knife too much. If your ceramic cutting edge is already pre-broken, in a manner of speaking, then you don't have to worry so much about it. I'd still love to try it out.


I also considered titanium for the cutting edge, like Warren Thomas and the poster above. I actually bought some so-called knife grade titanium (6ALV) and will use it for something sooner or later. But again, titanium is less than ideal for a cutting tool because it won't hold a cutting edge very long, at least as compared to steel. (As an aside, I'm also experimenting with laminating thick Ti with thin steel, but I can't get the two materials to stay stuck together. I think you have to etch the Ti first or something).


So I pretty much decided on steel for the cutting edge. It could be quite thin, since the only part of it I was interested in was the cutting edge anyway. Luckily, great material exists at a wonderful price: Sawzall blades. I bought some Diablo Liquid Metal blades and I'm currently working with making something from them (that's what I was trying to mate to the Ti). Stuff is harder than hell and a pain to grind or file, but that's exactly what I was looking for, hardness. Despite the hardness they're quite flexible because they're so thin. There's also the cachet of "Liquid Metal" steel, which is quite a buzzword (buzzterm?) in the knife field right now and could help if I ever decide to try to sell them. Like with all heat-treated blades care must be exercised not to overheat it while grinding because that will ruin the heat-treating and the hardness with it. Anyway, that's what my next laminated blade will be made with. 



But before I got a chance to mate it with CF I found something that was so perfect for what I was trying to do that I (temporarily) dropped everything and started over. Clauss is a company that makes hunting knives with replaceable edge inserts. I was just about drooling when I saw them. And they're dirt cheap too. So I grabbed some.


http://www.amazon.com/TigerSharp-Titanium-Bonded-Replacement-Blades/dp/B001S7OFM8

Note: These things are harder than the Sawzall blades. I tried to drill some holes in one to give the epoxy some grip, and the drill bit just skated over the surface. Heavy added pressure broke the blade. In other words, they're ideal for my purpose, so long as I don't try to drill them. I was able to file them though. Slowly, patiently. 



Epoxy: I wanted the strongest possible that I could afford. Of course there's aerospace industrial stuff that comes in buckets and drums and costs about a bazillion dollars and don't I wish I could afford some. But I finally settled on two, Aeropoxy and West Systems GFlex marine epoxy. The Aeropoxy looks like it's a little stronger, but I'm currently using GFlex solely because there's a West Marine store in my city.


Carbon fiber slabs: I looked all over and ended up buying a bunch from a guy on Ebay. Thought about buying the fabric and resin and laying it up myself, but properly made panels (like the ones I bought) are cured in an autoclave, which makes them much stronger than anything I could make on my own (who the heck has an autoclave--a big one--in their shop? Probably the same guy that has a DIY CNC mill.) Also had to consider the orientation of the fibers. Ideal I think would be 0 degrees (running parallel to the long axis of the blade, since that's where the greatest stiffness lies), and the least desirable a weave, though the weave does look nice. The stuff I bought was alternating layers of 0, 45, and 90 degrees with a final layer of weave on one side. These panels were not very uniform in thickness (by design not deficient quality control) and that has turned into a bigger pain in the old fundido than I thought it would be. As anyone who has worked with CF can tell you it's nasty stuff and the less grinding involved the better. In the future I'm going to buy CF in strips of uniform thickness, and orientation of 0 degree, from 1 to 2 inches wide depending on what I'm making. Good source here:


http://www.acp-composites.com/home.php?cat=253


If I decide I want the weave look for cosmetic purposes I'll just buy the thinnest shiny panels I can find and epoxy them on as a veneer.


So I got all my stuff together and went to work. I ended up with an incredibly stiff knife that will shave hair, and weighs next to nothing. I'll give some details of the process of creation of my first CF blade in a subsequent post. Unfortunately I did not take pictures during the making of my first "exotic" CF blade (CF dust is not what you want on your cellphone or camera, something you will be holding close to your face), but I'll be happy to put up pictures of the finished product if someone will only tell me how to do it.


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## Joe LeDux (Jun 30, 2011)

Here are a few pictures of the finished knife. I hope you will be gentle in your opinions of my final product. This is the first knife I've ever made in my life, out of any material.


http://www.flickr.com/photos/[email protected]/5883649196/in/photostream

http://www.flickr.com/photos/[email protected]/5883649210/in/photostream

http://www.flickr.com/photos/[email protected]/5883649214/in/photostream

Don't forget, like I said this knife will shave, and it weighs very little. I could tote twenty of them around without noticing the weight. I'd have no qualms using it in a defensive capacity, and I've had some training in that area. For its mass/weight, it's pretty damn wicked. On to the next one, and I promise to take pictures during the process.


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## riff42 (Jul 25, 2011)

Not to hijack and old thread, but I find this information close to my heart. I started making carbon fiber motorcycle parts 7 years ago, and for the last 5, I have been in the composite industry. Last 4 years I have been lucky enough to be in the top research center for composite materials in the world. I will make anything out of carbon fiber that I can. For the longest time, I had a ring that I made one day. 
However, I still have respect for the 6 micron fibers, and resins full of NASTY chemicals. I would NEVER EVER EVER get my food or drink near a composite part, unless it has been fully covered in an FDA approved resin (or plastic).....To see you making knives, and other utensils for human use is scary. I LOVE how you made the knife, it looks amazing. I might try it one day if I get bored. But would I cut anything I would eat later with it? God no. Think of the weird nasties in the epoxy that you are using. If any of the fibers chip/delaminate, they will be put into the food stuffs.
I am just here giving you a work of caution before you use any composite material near your food/body. If you are careful, you can coat/vacuum form a plastic sheet over a carbon fiber bowl. There is a line of safety there. But once that plastic layer gets cut.....watch out.
ps: again, love the work. As for inserting metal slabs for knife etch, sand the metal well (80-120grit) or sandblast them, so the resin can grab onto the metal, and not delaminate from the composite.


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## SgtGoldy (Oct 25, 2013)

I've never seen that done! Wish I had the skills to do something like it.


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