The hillbilly carbon fiber fab edumacation session

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The hillbilly carbon fiber fab edumacation session
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Posted: Aug 18, 2011 at 23:23 Quote
downhiller900sl wrote:
mini-freerider wrote:
That's the plan, I'm using ti rails from my existing saddle.

Just a tip: when your are joining the rails with the seat, use a seatpost to have the rails level, and equally positioned axially and tilted. did i explain my self?
i think you did... but just in case, same idea in other words: use the seat-post as a jig, like when people weld frames

Posted: Aug 18, 2011 at 23:49 Quote
Jose-David-DH wrote:
downhiller900sl wrote:
mini-freerider wrote:
That's the plan, I'm using ti rails from my existing saddle.

Just a tip: when your are joining the rails with the seat, use a seatpost to have the rails level, and equally positioned axially and tilted. did i explain my self?
i think you did... but just in case, same idea in other words: use the seat-post as a jig, like when people weld frames
No podias haberlo dicho mejor jajajajajajaja

Posted: Oct 8, 2011 at 17:34 Quote
how much do you think the full carbon build cost on this site? also time commitment? just wondering

Posted: Jan 22, 2013 at 5:32 Quote
Hummeroid wrote:
Ok, back due to popular demand....I said I'd make a down 'n dirty tutorial of how to lay CF, at least for the layman, and I'm actually doing it.

Disclaimer- This is not meant for structural parts, I don't want one of you making a carbon tube and using it for a Lefty fork. I can do structural stuff but I won't be getting into that here. This is for making yourself a bashguard, fender, sex toy...whatever your little heart desires. It will be VERY strong, but once again, not AS strong as the way I usually do things.

BTW, all this can be done using fiberglass resin instead of epoxy, but it will not be AS strong. BUT, for a first attempt I highly recommend it because it is MUCH easier to work with. If you choose to do that, just pretend all the spots that say "epoxy" actually say "fiberglass resin".

FIRST- Gather all necessary materials. For you all, this:
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should be good.
Carbon cloth
SHARP knife
wax paper (or non porous material and some mold release)
epoxy (you can get the actual stuff meant for CF work, but for you guys, normal CLEAR drying epoxy should cut it, choose a longer drying time for show quality parts, or short drying time for hand sculpting things where you can't sit there for 3 hours or more waiting for it to ger hard enough to set down)
Monster can to mix epoxy in and make you nice and aggro for fab time
Sandpaper of varying grit
Metal scoop-ula or other mixing/scooping device, don't use spoons you'll eat with again!


Ok, now that you have you little pile o' CF goodies, figure out what you're gonna make! I made a classy mudflap. Once you figure that out, you determine how much cloth you will need. For something like a mudflap that doesn't need to be CRAZY strong, 2 layers thick is fine. Depending on the cloth, it is about .75mm per layer after its layed. SO, judge how much cloth you'll need and add a lot of trimming room, and cut the cloth to size. I like to leave it in one piece and fold it, as it frays less while working with it.
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Now, find a FLAT surface to work on. Don't use you Mom's antique desk even if it looks like it is perfect for it. The epoxy will find its way to the thing you work on, so make damn sure you can either scrape it off when done, cover it up, or leave it there because you don't care. I use sheets of glass when initially epox-ifying the carbon. Lay out the wax paper so its way bigger than the carbon, and set it out on the surface, all organized and neat-like. Make another sheet of wax paper the same size as the one below the carbon. You'll be glad you did, because things get nuts when the epoxy is mixed.

Ok, once you have your workplace set, READ the instructions for the epoxy! MOST mix at 50/50, but check to make sure. Just so you know, the shorter the set time, the stickier and harder to work with the stuff gets! The 5 minute stuff is probably as sticky as the sheets on a porn movie set. Make sure to have your clothes covered and have latex/nitrile gloves or you will have troubles with being stuck to everything you touch. Rinse out your Monster can, cut it in half, and dry it out really well. Mix up a bit of the epoxy. Its worth mixing more than you need, as its much easier to get the epoxy to all the places it needs to be that way. If you have too little and are using quick setting stuff, you will have a fun time trying to get the fibers fully saturated. Once you have scooped the epoxy onto the cloth, place the other wax paper sheet on top and work the epoxy into the fiber. I used a metal rolling pin I made. Just make sure you have the stuff EVERYWHERE, otherwise you will have sections that are rough, and don't get the nice 3-D look to them.

NOTE: The next part is optional, you can just try to roll all the air out with a round bar or rolling pin instead of sucking it out.

Now comes a part most of you can skip if you don't have equipment. Most "real" carbon fiber is made in molds, and cured under heat and vacuum, with pressure on it, to remove all the air bubbles. I luckily have a vacuum furnace, and it pulls vacuum down to near intergalactic levels. We're talking if I was in there, my blood would boil, and hopefully I would explode. This device is GREAT for getting the air out. So I throw my sheet of epoxy/carbon goo cloth in there and pump it down for a few minutes. I suppose you COULD use some sort of food-type vacuum packing device, but I wouldn't eat anything that was used in that thing again. This epoxy smells like monkey vomit, and probably tastes no better. THIS is my bubble removing tool v
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For those of you who did that bubble removing, props as you were most likely very resourceful. For those who didn't you can get it to look perfect without it if you roll it long enough. ANYWAY, now that the epoxy is starting to cure, you can shape it. I did all mine by hand, but be creative! I've made molds for it before, and you can definitely make more complex shapes with molds, but for single radius bends, you can use tubing, buckets, cans... anything to make that kind of shape. For multi radius shapes, PM me, as you need to me making a mold and using mold release instead of wax paper. If you use wax paper it WILL be all ripply and ugly. Continue shaping until the structure is HARD. Not firm, but hard. If its only firm, it can still sag from gravitational pull. If you're making flat sheet, get 2 sheets of glass, and sandwich it in between and feel free to put some weights on it. The harder you can press it the better, but once again, you're not making aerospace tubing, you're making a simple form that won't kill someone if it does crack. Its still VERY strong even with NO pressure placed on it.

Ok, now you wait. Throw anything you used that has epoxy goo on it into a container and use the acetone on them to clean it up. And wait some more. NOW you have a nice hard sheet of ugly crap sandwiched between some stuck together wax paper. Peel apart as much of the wax paper as possible. Do some trimming to remove the excess dried up epoxy. NOW, do some trimming! Trace out the thing you want to end up with onto it with a marker, and use a coping saw, band saw, or HEAVY pair of scissors to hack your shape out. Get some sandpaper out and sand it so it has a nice even finish on it, like this v Ok, my shop was a mess at the time, don't give me crap about it.
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After you've gotten it to the shape you want you're onto the aesthetics part of it.

If you have big spots where you didn't get epoxy to you have two choices. Either make some more epoxy and rub it in the really well, or use enamel/clearcoat to make it look like you didn't screw up. SO, sand the piece down to about 240 grit, and give it a good coat of clear, and another fairly quickly. After about four coats, let it dry really well (like hours here people!) and sand it down again. Repeat this process till all the blemishes have been leveled out with nice deep clearcoat.

If you did well and didn't have bare spots, sand it down, and give it clearcoat till it looks as deep as you want. If you used a nice weave, you can get it to look VERY 3-D if you end up with many coats of clear. On a good day, I only use about 2 coats of UV resistant clear just as a nice scratch resistant coating. With that, you end up with......
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I hope this helped those of you that wanted to do something like this project, like I said, its a VERY simplified way, but it will look just as good as mine. The way I did it just cost more and is marginally stronger. I'm sure I forgot something important, and I apologize for my ADD style of going off on tangents while writing instructions! Send me pics of your projects if you make something!

Humm

Great Post thanks! Video Tutorial for a mud guard would be ace Big Grin Big Grin Big Grin Big Grin Big Grin Big Grin Big Grin

Posted: Jan 22, 2013 at 20:40 Quote
thats better than a video tutorial would ever be

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