anybody have any experience? Ive learned about pre-pregged and raw sheets. how to make molds with fiberglass and filler using silicone spray as a releasing agent, how to lay the layers and roll the final layer without any extra epoxy and how to vacuum bag it. And when youre curing it i guess youre supposed to have it under a heater? Does anybody have any more input they can give me on it? I figured I’d try it if i have spare cash laying around for the materials. whats a good heat resistant epoxy/resin? how do you drill for bolts/ rivets in the cured product without damaging the fiber? any tips or tricks?
Jim(Jim P) is very good with small to medium parts and CF. Member here on the forums. I deal with carbon alot as well, btu mostly structural aero components. I’m also gearing up for full on body shells soon for the DSR and kit car chassis I’m developing here.
Prepeg carbon is typically found as structural weave, used for composite construction of chassis and loaded components. I use it for large aero. Also the resin used is heat cured and requires the use of an autoclave. Prepeg also has a limited shelf life and must be kept at specific temperatures and humidity, so I do not recommend it for stuff you’ll likely use CF on.
System 2000 epoxy resin is the stuff I use. A bit high on price but I’ve found nothing else I like working with. Proper and dedicated waxes/release agents are a must when doing composite mold work of substantial size(over 2sq ft). You’ll waste alot of money in composite and conssumables using anything other than that.
Most epoxies are not heat cured, although a light heat can speed up cure times once you’re ready. Be careful though, hot temps can affect the overal product with the epoxy! I use the S2000 120 minute resin. I’d rather have the cure time and be left waiting, then have it setup before I even get the part laid out in the mold.
You can drill cured CF with ease using a very sharp 135 degree split point drill bit at 2000 +RPM. Use no lubricant. Faster RPMS better, use light pressure on breakthrough to avoid delamination on backside when the bit punches through. WEAR a respirator, you DO NOT want to ingest or inhale carbon fibers/splinters in the dust that can be produced. Really bad shit can happen.
that was a lot of really good info. thank you. I pretty much figured I didnt want to touch the pre-preg stuff. I was going to try a couple small interior pieces first to start off very simple and if i found i liked it I was thinking i’d try to make a rear under diffuser. I was going to try to use plywood or plastic as a frame for the more rounded off fiberglass mold and then lay the carbon on top of that. maybe even keep the mold in case others want it. Does this sound like a sound method? What releasing agent would you recommend? Thanks for all that info. Super helpful!
molds need to be very rigid for repeatability, just keep that in mind. wood makes an excellent mold material, but must be finish and completely sealed, then typically gel coated. Plywood/chip board is not of much use unless you’re getting into stuff lich birch or oak ply, which is abusively expensive to use for molds.
For molds I’ll use to make multiple parts, I build from MDF and then fully seal and gel coat/polish prior to use. The larger the mold, the multitude of stiffness required for the part go up dramatically. For one off components, especially complicated chambered parts, a PU foam or polisocyanurate foam plug or mold(sealed of course) is ideal. Once cured, the mold PU can be dissolved leaving the bare carbon component.
If you’re going to make a mold that you plan to use for quite some time, go overbard on the structure and make it storng. And use a tooling gell coat for the final surface. It will be super hard and hold a polish for a long time. The cleaner and stronger the mold, the less prepwork there is in the final product. I use T186 from Fiberglast.
For release agent I use a pva style release film(liquid) with Partall wax. Never have any issue with that combo. There are cheaper one step type agents/waxes that work pretty good. Probably your best bet for small stuff as it take little experience to lay a proper even coat of the premixed stuff.
I like to spend more money on really good resins, epoxies, and prep products as when I do actualy make CF parts for custom race setups it’s usually using expensive 12k triax or 6K5hs weaves. Waste gets REALLY expensive with that product.
adam quick question and please dont take this the wrong way ,do you jerk off to popular mechanics and such ? dude you know way to much shit lolol
Jim is another good resource for CF info. He makes some really nice hand laid stuff. Good guy too. Drop him a message. He’ll answer if/when he’s not working on his SRT4 :lol
I’m really a fucking nerd in disguise. Playboy - RCE…Id’s graze Pb for a few minutes then toss it aside for RCE and read that cover to cover. My brain thinks tech shit and I’m typically that ype of person that get’s bore REALLY quick if discussion/talk/work is not somehow related to tech. My friends and family keep telling me I’m wasting my time in this business and could be making millions elsewhere. They’re probably right, but I love what I do and hate the thought of working for someone else so I just plug along.
Poupular mechanics is the kiddie version of Design.
lololol, your to fuckin much man
jims good, my carbon heat shield is nice, and now i know how to make shit myself instead of just over lay shit…yet i haven’t made anything by myself.
hahaha. eh sometimes im the same way though. im deff a nerd and I’m really trying to learn more about fabrication despite my limited resources and friends that do that kind of stuff. Thats a lot of really good info though thank you. I’ll probably go with a slightly cheaper resin/epoxy. Then again considering how much abuse a diffuser would take (rocks, exhaust heat, and occasionally scraping the asphalt when i drive through a pothole in the troylet) maybe i should use something that’ll hold up the first time. As for the mold the plywood was just going to be a frame for the fiberglass to sit on because the wood cant form the smooth curves i want but the fiberglass cant hold the rigidity i want. MDF sounds like a good route too though. Who is his Jim character? Thanks again guys.
Adam are you like Nick Cage in gone in 60 seconds
I can picture you riddling of random shit when your bout to bust ur nut
haha j/p
but yeah man its deff nice to have someone like you in the community…
None the less your well not at least from what I’ve seen a cocky d-bag about what you know
jim must pay you in sexual favors… cause no one else says that bout him
in for more info on c/f bits
Don’t even think about it!
We haz Skyline to build.
:ohnoes
it better be at cars 4 cancer when i get there… if not… theres gonna be trouble…
:lol I love my line of work too much to quit buddy. Skyline will have work done son!
Ohthankgod.
Scott: I should be there. I’ll stay as late as I can,but car shows for over 10hrs get quite boring.
I’m looking into getting into Fiberglass/CF work myself as soon as things move along with the new shop.
Keep checking in!
I’ve gotten quite proficient at using fiberglass for finish and strength. I need to take the dive into CF and mold making when my wallet allows it.
<— in desperate need of fiberglass and cf work. fiberglass stuff is actually for my personal safety