Virtual BBQ WIP Carbon-Fiber Take-down

[Knifemaker87]

This is a knife is recently finished but explored several new ways of doing things, at least for me.


I have been wanting to try a take down, and I love this style blade. I dont have any forging pictures as I made this billet up at the Fire and brimstone hammer-in in 2010. It is W2-15n20-1084 at about 100 layers, (or thereabouts) and the forging was done when I left my camera at work.

The blade has been forged, rough ground, heat treated then final ground, ready for hand finishing. It is about 3/16 thick at the widest, with a modest distal taper. It got a slight warp in the tip during the heat treat and I had to bend the blade almost 45 degrees before it would alter the curve in any way. It is a light flexible blade, which is a nice change from the heavy, stiff tool steel blades I normally make. It will handle more like a fighter than a chopper.

this was going to be a take-down knife so i needed some threads for the finial.

The finial nut would prove to be a PITA. This is the first iteration;

 

[Knifemaker87]

I got the guard design hammered out I think. I am going for a light, fluid look. Ti is strong enough to deflect pretty much anything even at that thickness.
Then I milled the slot with an 1/8th inch endmill on a manual Bridgeport mill, leaving about 0.005 on the side so I could file it in, and then rough profiled the guard.
With the slot milled I still had to fit the guard to the handle, so out came the files, and I snuck up on it

With the guard rough fit, it is time to make the handle. This will be a "dry run", in that I am going to test the procedure out with low quality resin as a proof of concept, so I can tweak my process before I make the final handle.

With composites, the name of the game is "preparation"- you have to have everything ready before you mix the first batch of resin.
First, since this will be a unidirectional handle I have to get a bunch of fiber ready. I just used a bunch of scrap material I saved and pulled it apart to get the fibers all in one direction.

As I pulled the fiber apart, I sorted it acording to length until I had more than I would need. Again, better to have more than you need than run out of fiber while you are all sticky and your resin clock is ticking.

I got everything ready to go. My carbon fiber was ready, the "mold" was set-up, I had the resin and all my spreading implements...and plenty of paper towels and acetone

I almost forgot to mention; you need some form of release agent so the resin wont stick to your blade or mold. I use at least 2 types, usually three. In this case I actually used four. The "mold" is covered with teflon tape, as is the part of the blade that isnt getting "molded". Then I wax all the parts with two layers of regular car wax. Then I used a dry mold release that comes in a spray can. Once that dried I put on a layer of poly vinyl alcohol (PVA) that is water soluble and dried to a film. Then, I wipe down the tang with a very, very light layer of grease.

Then I called for my handy shop assistant, as it is almost impossible to pick up and use a camera with resin in your hands. It is also almost impossible to pick up dry carbon fiber with sticky hands and it not turn into a huge nasty sticky mess... so I had my wife hand me the carbon fiber.

Now, mix the resin. I was using the cheapo stuff from Walmart or Lowes made by Elmers for "fiberglass repair"- this stuff sucks. It smells horrible, it is bluish green, (who decided on that?!) and it doesn't cure as well. But it is cheap, so it is what I am using. Normally I use West Systems epoxy resin, and it is what I will be using for the final handle.

Resin mixed, I brush a layer of resin on the first side of the mold. I lay a layer of fibers down and spread resin on it, making sure that I get resin into the corners and that the fibers are saturated. I repeat that process; layer of fiber, layer of resin till the first half of the mold is filled.

Then the other side, trying to get the same amount of carbon and resin on both sides, and enough that when the mold is pressed together it compresses the fibers and resin.

I set up the knife so that I could clamp it down and "suspend" the knife in the middle of the mold. However, when I clamped it, it moved the blade and so it is not centered. That is something I will change in the design on the second mold.

I put the blade in position and flipped the second half of the mold over top of it and clamped it down

Then you have to play the waiting game. As it was, I had to play longer than usual because it was slightly chilly and almost all resins are temperature sensitive. The colder they are, the slower they harden. So I went in, ate some dinner, played with the puppy, watched some TV and generally "chilled out" with my fantastic wife.

I let the resin cure for almost a day before popping it out of the mold and cleaning up the edges. when i did... it looked like this:

The blue resin was pretty apparent, as was the fact that the blade wasnt quite centered.. and I made the mold TOO LONG. So.. I took it to the bandsaw and cut it closer to size. The blade and nut released perfectly, and slid out of their custom made pockets. Concept success, process needs tweaking. I will be making the second handle later.

 

[Knifemaker87]

I have a couple ideas on how to do it better this next time. I am going to mix in some finer carbon for a little bit of contrast in the "grain", hopefully it will be as instructive as it is fun.

I am also glad you like the guard... I think it flows pretty well. The handle idea is also a good one, though a lot of it will depend on what it looks like when I am finished shaping it. I do have access to a sand blaster here at work. I absolutely LOVE Don Fogg's textured wenge, but didnt realize it was blasted.. I was going to go for a satin finish on the handle with the sand blasted anodized ti and a blued/satin blade. I think it should go together nicely.

I like reading the threads where it is more "compact", however I rarely have the self control to not post anything before it is almost done. As it stands, I will make the final handle, and do the fitting of the gaurd and spacers before doing the rough shaping/bending of the gaurd. The ricasso on the blade is finished, but the flats have to be polished and then it will be the final fitting and tweaking. I have to say the molded handle fits together like a glove and is rock solid. I am very excited about that.
[/B]


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I did get the second handle all made but without my shop assistant handy, (she was in washing the dishes and making cookies) I wasnt able to get any "in progress" pictures. However, the process is the same. I did have a different mold set-up however. I turned another Ti nut that was a good deal longer, and made a set of blocks to hold it in the center of the mold.

This time I used West Systems epoxy. It is pricy but it is also the best. Cleaner, less smelly, cures harder and is easier to work with. But it is like $50 a quart.

So, I made my new mold and cut some more fibers. I also wanted to point out that I covered the exposed threads on the tang with clay so the resin wouldn't get in them and "lock" the tang in place. I did the same thing on the first one.

I pulled the second, (and hopefully final) carbon handle out of the mold. The pin locator worked great in keeping the blade centered in the "billet". The longer nut allowed me to hold the tang while still allowing for enough of a space between the end of the billet and the actual handle, as the edges and ends of a lay-up are where the most flaws are. You need enough "buffer" on all sides to get a really good part.

 

[Knifemaker87]

While I was waiting to cut the handle out, (since I dont have a bandsaw in the garage yet) I started working on putting the foundation polish on the blade, starting with the clip. I am using a piece of corian to back my sandpaper as it is hard and stable, but wont scratch the blade like a file or steel blank.

When I am sanding bevels or clips, I use a sharpie to mark both sides. The best thing to use is lay-out dye, but most people dont have this... and a sharpie does the same thing. It allows you to see where you are sanding and makes sure you have your sanding implement flat to the clip/bevel and that you are staying off the transition line which keeps the lines crisp and clean.

This also allows you to check to make sure your clip bevels are the same on both sides by highlighting them in contrast to the blade. When I am sanding the flat of the blade I reverse the procedure and have the clip colored.

It is pretty humid in my area, and since I rarely have the time to polish a knife start to finish in one sitting, I need to protect the blade from rust, especially as the polish gets finer. I use a little axle grease and rub it on the blade. It wont evaporate or get sticky, and protects the blade very well.

I then cut out the handle to a rough shape and to check for major flaws. It looks good. There are some very small voids that will get filled with fiber and resin, but at this point, almost all the flaws you see will be ground away, so I will wait till I have the handle rough ground before I touch it up. The holes for the handle and the nut came out perfectly and there are no voids around them. it fits the blade like it was made for it... oh wait...

I rough cut the handle out on the bandsaw, and then fit it to the handle with the guard. I still have to cut out for the spacers, one of which I have decided should be damascus and the other being Ti, but I wanted to see if it tightened down. OOOOhhhhh boy, did it ever! The fit is like nothing I have ever seen. Even with it rough fit and the nut finger tight, I can hit the flat of the blade with my palm and there is no vibration at all. It sounds and feels like a single piece.

Then, because it is difficult to see sharpie on carbon fiber, I taped up the handle and used my pattern to get the handle a little close to the final profile.

Once I had it close.. I had to see what the final is going to look like so I put the pattern on top of the knife. I think it is going to be nice!

I also milled the slots in the spacers so I can file them in and then put in the locating pins.

My plan is to get the pieces to fit together perfectly, then tighten them all down and do the rough profiling on the spacers and guard so I can go in and get the profiling of the guard. I will bend the guard before I take all the material off to account for dings and warpage from the bending process.

 

[Knifemaker87]

I really do enjoy the carbon lay-ups. I think I will get much better at it with some practice.. and honestly... it takes out the drudgery of cutting out the tang hole; which i really dont like. Very good thought.



I got the spacers filed and on the blade... all snug and secure. They are going to need the locating pins still. I am going to be making another guard as I am not happy with a couple little dings on the fit of this guard. I will be making version 2 later.
Carbon handle, Ti spacer, Damascus spacer, Ti guard.

And after a little tweaking of the handle.. I have a tight fit with no gaps of any sort and a super secure blade.

I decided that I wanted to make a second guard for two reasons; I wasn't quite happy with the tolerance of the first guard, and I wanted a little extra length to play around with for the curved sections of the guard. So I cut out a piece of Ti on the saw and put it in the vice on the bridgeport to make everything flat and square.

Once I had the block square and to the right dimensions, I used the existing part to scribe the rough location of the slot onto the face.

Now, since I had the existing part, I took the dimensions from that and figured out what I needed to cut. I dont want to bore you experienced guys with this... but inquiring minds might want to know.

The slot I wanted to make was 1.075" long and .160" wide. To cut the slot exactly that size I needed to do some simple calculations. I am using a 1/8" endmill for this.

Length: this one is easy. Simply subtract the diameter of the tool from the length you need to cut, since the machine records length of travel from the CENTER of the tool, so;
1.075" (slot length) - 0.125" (tool diameter) = 0.95"

Width: I know how wide the slot should be and how wide the tool is, but I need to know how much to move the tool "off center" to cut the right amount of material off each side. Again... machine travel is from the center of the tool.

0.160" (Slot width) - 0.002" (how much I want to leave on each side so I can file it in) = 0.158"
then 0.158" (finished slot width) - 0.125" (tool diameter) = 0.033" (extra material total)
but we want to take it off each side to make sure the slot is centered, so;
0.033/ 2 = 0.0165" (amount of material to take of on each side of the 1/8" slot)

So, you find the center line for your block. There are a bunch of ways of doing this, but I use and edge finder most of the time

Once it is on center I line up the outside edge of the tool with the outside edge of my slot and set the machine to Y-axis to zero.

Milling a slot like this with a small diameter tool took about 0.03" of material off each pass. I usually leave 0.005" once each end of the slot is cut while I am roughing it out, and then go to the full length after I have cut all the way through the piece. This makes the sides and ends of the slot smoother and less likely to have the tool chatter or taper the slot.

Once you know what you need to do, you just have to make the passes and keep the tool cool and lubricated while it runs.

Another change to this guard is that I am taking Nick wheeler's advice and cutting a slight relief in the back of the guard to allow for better fitment. I am interested to see how it works!

I didnt like how the second guard fit and so I am touching up the geometry of the tang a bit and hopefully the 3rd time's the charm, should have an update for you later. I have had zero time to work on it since the last email. I got a big job in at work and I have been working overtime and weekends.

I got about 2 hours to work on the knife after putting in 12 at work. I spent the entire time fitting the guard. The other two fit fine... but I wanted it to fit GREAT so... that takes time. At the end of the night, I got it:thumbup:. It needs some final tweaking to get it perfect but it is almost there.

There was sharpie on the blade so there is a slight exaggeration of the "seam" and this is only the first fitting up to the shoulders.

Now that the guard is fit and everything is on I will drill the locating pins in the handle spacers and guard before doing the rough shaping. The blade will get finished, and then after the guard gets bent it will all go back together for the finish shaping. After that it is just anodizing and final polishing.

 

[Knifemaker87]

I got the dowel pins drill and set in the guard and spacers.

With the holes set I heated the parts to pop them apart, then cleaned them and re-assembled them with short pins. Then I assembled the knife and glued the two spacers to the handle. The pins are a nice tight slip-fit so I slid the spacers off along with the handle and used the spacers as a template to drill the holes in the handle. I used both spacers in order to get enough thickness to ensure I drill the holes straight.

It goes together with the pins, without gaps, and aligns perfectly every time.

Okay, so now it is time to get the guard roughed out. I used Nick Wheeler's trick for this, and made a half template that fits on the blade ricasso. I covered the guard in layout dye to show the scribed line a little better.

Then I used a scribe to mark along it for a symmetrical profile. I marked it once, but didn't quite like it so modified the template. I will cut to the inner of the two lines.

Just a cautionary warning about grinding Ti- not only is it really tough on tools and belts the sparks are NO JOKE. I wore my leather apron, (normally I don't bother) safety glasses, dust mask and a long sleeve shirt. These sparks will catch stuff on fire a lot easier than steel, so I clean up my work-space before I go at it. Also... I completely destroyed a brand new ceramic belt roughing this guard out.. and it took me close to an hour.. TI is tough to work with.

Once I got it close I re-blued the face and re-marked the profile as the heat from grinding discolors the dye.

I finished the shaping and proceeded to cut the profile of the guard. This is a step that it is easy to screw up all of my hard work and have to start over, so I take it slow and continually check to make sure I haven't gone too far. I also drew where I wanted to go with a sharpie and then scribed a more precise line.

After the profile was done, it was an easy task to cut the handle to match. It still needs a little tweaking and then I will be roughing out the guard to match the cross-section of the handle.

I made a piece of aluminum that matched the profile of the handle shape and put it against the guard. This serves two purposes; I dont want to accidentally roll the part and ruin any of the grind, and I'm using it as a template as I rough the shape of the guard in. Being able to disassemble the knife repeatedly is really nice.

I am going to do most of the handle work before I finish the blade as I dont have to worry about marring the finished surface. As all the mating surfaces are finished already, I can finish the blade last and not worry about ruining anything. So I roughed in the shape of the handle. Sadly I didn't get a picture of the roughed guard before I started the handl. I thought I did but i must have forgotten.

There are some slight voids in the handle, but they can easily be fixed as I can fill them with fiber and resin. Unlike wood, where you hit a void and it just looks like you filled it, I can fill any voids with the original material and there will be no break in the continuity of the look or finish of the handle.

I will get the handle very close to the finished shape before going over and filling any voids. Then I will bend the guard and start the finishing process.

 

[Knifemaker87]

I got the gaurd set up in the vice. Using some copper to protect the face, I am holding it deep enough in the jaws that it should eliminate any warpage of the mating surface. Plus i would have to get it hot and the larger cross-section keeps it from getting too hot.

So.. turn on the propane torch and get ready to do some bending! It only took about 3-4 heats to get the right bend. I used my drawing as a template.. and it is really, really close. This is why I left extra material on, because now I only have to get it as close as I can before removing the excess stock to reveal the smooth curve inside.

I did the same for the top, and them popped it on the blade to see how it looks. Pretty darn good, if you ask me. Especially after having it stick straight down for so long.

After then it was on to the laborious and tedious work of hand sanding... I still have the extra piece of aluminum on there that is the shape of the handle, so I don't round the back of the smallest spacer. This is what it looked like after I was finished with most of the roughing on the grinder.. and had moved to a drum on the dremel.

This is the kind of work that makes me love my pana-vise. This is after a couple hours of work with 120-280 grit paper on blocks, files, and dowels.

Popped it back on the blade with the handle. I am waiting to finish the handle transition till I am almost finished with the guard due to the soft nature of the carbon fiber.

And here is a small preview... I wanted to see what the contrast looks like. This is a light etch on the Damascus. It is just a linear pattern, and will be topographically etched when the time comes and colored to match the blade, while the Ti. will get anodized. i think it will make for a real pretty contrast.

I put another coat of resin on the handle and should be ready for finishing. should have an almost final fit and match of handle and guard very soon.

I am planning on doing a light etch, to bring out the contrast, then blue the blade before going over it lightly to polish the 15n20 a bit for higher contrast without a topographical etch. Then I will sharpen the edge. The blade is really light and fine and is almost sharp now at an almost zero edge. It is going to cut like a razor.

I did get the key done, and I will be honest.. I am REALLY excited about this- it is really trick! I think we are both going to be happy as a result of this knife.

I cut the finial off, and designed the "key holes" to fit around the thread as they are deeper than the threaded hole. the key is Ti as well and will be anodized to match. next time i will make the finial a little bigger and deeper.. but you live and learn. The keys are hardened steel dowel pins.

 

[Knifemaker87]

I got the guard cleaned up to 400 grit and ready for blasting- I didn't want there to be any scratches that showed through. Also notice how I made a cap and a plug so I wouldn't round any corners.

The sand blasting was done, and I threw it back on the handle just so you can see how it fit, and what the handle looks like now.. also to 400 grit. It will be getting a 2-part epoxy clear coat in just a few days, (once it warms up to above 60 degrees).

I got my anodizing setup working. The only glass container that is large enough, that I had, was a beer stein, (works for me!) but that will be changing for my next go-around. The setup is very simple- a variable voltage AC source converted to DC over a 4-way bridge, and then a ion-rich solution, (I used TSP cleaning powder in water) with the leads hooked up to an electrode and the part to be anodized. The color is dependent on the voltage. This will be set at about 10-15 volts for a bronze color.

Here is the guard ready for anodizing:

And the Ti spacer in the solution. The anodizing process takes about 30 seconds to a minute.

I need to make some Ti clamps, as the steel alligator clamp I was using pulls voltage away from the work piece, giving an uneven coloring. So these will get blasted again and the corners rubbed to a polish and then anodized again with Ti clamps. But I think this is a nice preview...

And I did the key just to see what it would look like on a polished surface... pretty cool to watch it change colors!

One or two steps closer to the final knife. I got the Ti parts re-blasted and the edges polished. Then I got them anodized to the proper color. Holding the part in the solution with a Ti hook I made really fixed the evenness of the anodizing. (thanks Chuck for the suggestion!)

The handle is finished and ready for the clear-coat and I also got the finial to the finished dimensions. It looks pretty sweet if you ask me. The picture makes it look like there is a slight gap around the finial, but it is an optical illusion.

I started polishing the blade and had to throw it together. All that is left on the knife is polishing, etching, and bluing the blade and clear coating the handle.

The leather for the final sheath will get here in the next day or so. While the total carbon wrap didnt work out so well, I am planning on doing a carbon fiber inlay in the sheath, and it will have the stud anodized. I think it should make a really pretty package.

Before I got to the final grits of polishing I etched my mark in the blade. This is the first time I have ever etched my name, so I didnt have time to get stencils made, however I used nail polish, (my wife doesnt use this color...) and got my mark in there pretty good. I am thinking about changing the mark to just be my last name.

And then there were days of sanding... lots and lots of sanding. I think this was 320 grit.

Eventually I got it to a clean 1500 grit and ready for etching.

It took about 3 tries at etching and bluing before I got it the way I wanted it, and I am pretty happy with it now. It still needs some final touch ups (primarily the plunges).

I also got the handle sealed with automotive 2-part epoxy clear that is UV protective so the resin in the handle wont yellow with age. I still have to cut and buff it. There is no way to show how intricate the carbon on the handle is. The fibers reflect on the light as you move it.

Now all that is left is the final touch up and assembly for the knife and making the sheath. Then it is going off to Coop for pictures.

 

[Knifemaker87]

I really dont have any new information for you on this post, however I do have pictures, D).

I sanded the handle to 2000 grit to make everything smooth and to get out some drips in the paint. Here it is cut and ready for buffing:

Here is the knife all assembled. This is a preview. I am still not quite happy with the blade; I think it will take at least one more cycle of bluing to get it where I want it, as I got some streaking on the last blueing. You can see it on the blade, but it gets better each time, and I want it to be perfect.

also..I wanted to point out how nice the gaurd fit is... I am very proud of that.
enjoy the picture! Sheath coming soon.

I am going to re-do the blade to make it more even, and I was wanting your input. The sheath will be snug and I am going to put a retaining strap on it so it wont fall out.



I started out by making a pattern. I traced the shape of the blade, designed the welt and the inlay, and transferred that to poster paper.

Then I cut out my pieces. The welt, the two sides and the inlay cover making sure that they were oriented the proper way. I am using 7-8oz leather.

Then, I laid up a sheet of twill carbon fiber for the inlay, and using my template, cut it to size.

So here is a rough preview of what the sheath should look like minus the tooling stitching and belt stud. There is lots more to come.

Okay... now for a happy post.

First off, the only thing i have missing in the specs is the balance point. which is very important. i will post that as soon as i can get the knife in my hands again.

OAL:17"
Blade: 10.25" blade 1.5" wide and 0.16" thick 150 layers of 1084 W2 and 15n20
Handle: Custom uni-directional carbon fiber
Fittings: Anodized Titanium, and damascus steel

I finished assembling and stitching the sheath.

I also refinished the blade. i got it smoother and am much happier with it. I also coated the blade with museum wax to prevent corrosion.

and i think the sheath and knife go together pretty well.

And now... my first YouTube video is fitting to be used for the first take down, first Ti fittings, first carbon fiber handle knife, first real sheath i have ever made.
http://youtu.be/Fz_Qn4TZLXA

thanks so much for looking
~Chris

 

[Knifemaker87]

Coop has delivered!

 

[tryppyr]

Gorgeous!

 

[silver_pilate]

Wow, I just blew my morning's productivity on this post. Great job, Chris! Absolutely awesome work.

--nathan

 

[panch0]

Wow, Nice Job!

 

[Tjolbi]

Excellent work and thanks for posting the full wip, always makes for an interesting read. :thumbup:

 

[HuntBomb]

Wow. I wouldn't let that knife out of my sight. Great job with the CF...looks really frustrating.
I love this type of take-down thread. Adds much more substance to the pictures.

 

[Hesparus]

Holy crap, dude.

- Chris

 

[mgysgthath]

Wow..

 

[Carl_First_Timer]

Just picked my jaw up off the floor.

 

[TILLER]

WOW! That is sweet!

 

[Patrice Lemée]

Great detailed and photographed WIP. Amazing knife!

Thanks for taking the time to share all this with us. I may "borrow" a few ideas.