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Carbon Fiber
Posted: Wed Oct 13, 2004 3:09 pm
by 91legacyman
im just curiouse as to hard it is to lay carbon fiber if its not that hard i was gonna maybe buy a book on it to study how to lay and cure the epoxy and such i seen it done once it looked kinda easy but all they were doing was makeing something for a huge rocket engineif its not that hard i wanna make fenders,hood,trunk id wanna get the pieces from a pick and pull though i wouldnt use my own car
but if anyone has a good idea as to (how to) or direct me to the place were i can get a book i want to study this
thanks
(Oh how i love the CAPS, lol - DLC)
Posted: Wed Oct 13, 2004 6:42 pm
by evolutionmovement
It's similar to fiberglass, but without vacuum or heat the quality won't be very good. It also takes some experience to mix the right amount of resin and hardener to carbon cloth.
Steve
Posted: Wed Oct 13, 2004 7:16 pm
by professor
I would consider it a bit out of reach, unless your mechanical skills are really high, and you have a lot of time and money.
check out
www.fiberglast.com for some free tips and tutorials.
Getting a Class A surface requires the use of female molds, not male molds as junk body parts would be. Making a single part this way you end up with a mold for a single use, a very expensive proposition. I would guess $300-$500 for a single body panel in materials alone if you can't buy in quantities. Then you could make subsequent copies for perhaps half that.
I've done plenty of work with resins and carbon so I do know of what I speak. Here are a couple of my projects. The skatecar has a driver in it and is 7 feet long and weighs 18 pounds.
http://img.photobucket.com/albums/v340/ ... hAbecs.jpg
http://img.photobucket.com/albums/v340/ ... /bmj-1.jpg
I would be willing to help with questions and technical issues if you wanted to give it a try. I would advise starting small, it is a lot kinder to the wallet to screw up on a small scale while you learn.
Posted: Wed Oct 13, 2004 10:10 pm
by 91legacyman
i really wanna do this but im not doughting u just from what i seen the person i seen do it put it into a bag and vuccummed it and then put into a oven and it was carbon fiber when it was done it looked really nice what kinda resin would i need and hardner and where could i buy the carbon cloth +resin and hardener of course
Posted: Wed Oct 13, 2004 10:17 pm
by 91legacyman
im at the site that sells the materials i need but i need to know how wide the rolls of fiber u get ?
Posted: Wed Oct 13, 2004 10:22 pm
by evolutionmovement
McMaster-Carr sells the cloth, possibly the resin.
Steve
Posted: Wed Oct 13, 2004 11:15 pm
by 91legacyman
thats cool i found a site that sells carbon kevlar resin and hardener for a decent price
Posted: Wed Oct 13, 2004 11:21 pm
by 91legacyman
a question for professor
do you absolutly need a mold cause im gonna do like u said and expirient with little projects but like if i wanted to make a carbon fiber hood could i just lay the carbon cloth on the hood(hood detached of course) and just lay it like that or do i absolutly have to make a mold of my hood then lay the carbon cloth in?
Posted: Thu Oct 14, 2004 4:04 am
by bignose
i think if you re read his post, you'll see him say you need a female mold, using a hood to make a hood won't work.
Posted: Thu Oct 14, 2004 4:24 am
by 91legacyman
ok but still i can still use the hood to make a female mold right?
Posted: Thu Oct 14, 2004 4:31 am
by 91legacyman
ive read some tutorials on the resins and the hardeners it doesnt seem difficult i just need alittle info on making the molds
these are some ideas i had
like maybe take the skeleton out of the hood and that would then make it a female mold right
or do i have to make it out of some kinda ceramic mold
if u can give me an idea ill run with it and go from there
but the resins and hardeners arent to expensive just startin out and the fibers arent to bad either
thanks
Posted: Thu Oct 14, 2004 5:35 am
by dzx
It's definately worth a try. Good luck
Posted: Fri Oct 15, 2004 2:29 pm
by professor
Yes you would make a female mold using the hood as the male "buck". Then the thin, actual part would be made on the female mold. That gives it a very smooth surface finish even before painting. I would suggest working with air-dry vinyl-ester resin, forget about heat curing for now you don't have a 6 foot square oven anyways.
I buy cloth that is 50-60" wide which would work well for a hood. You'd want some very light random mat fiberglass down first for the surface (sometimes called angel hair), followed by 2-3 layers of the carbon, one layer laid at a 45 degree angle to the others. I'm guessing 15-20 pounds for a hood for an amatuer attempt (sorry not an insult just that it takes experinece to get the weight down). Those seven pound hoods you hear about require pre-preg resin and an autoclave to cure.
Note that the mold would be all fiberglass as it is much cheaper, and needs to be laid much heavier so you don't have distortion.
You need carnuba wax for mold release, fiberglass, carbon, brushes, rollers, a respirator, about 3 gallons of vinyl ester, some polyethylene mixing tubs for the resin, and a lot of balls.
An assistant for the lay-up would be nice as the pieces are large.
Buy a book, there are some good ones on
www.fiberglast.com
Thier prices are stupid-high though, I buy from JR Sweet.
Posted: Fri Oct 15, 2004 9:05 pm
by 91legacyman
ok i got the part with the making of the mold which would be fiberglass and useing the carnuba wax as a release got that
but the part with the layed 45 degree angel part kinda threw me off abit if u could explain alittle more about that i didnt understand what the purpose was of that
Posted: Fri Oct 15, 2004 9:07 pm
by 91legacyman
oh what would be the best hardener cuase some of them have time limits for curing maybe the 120 min one would be best for me
Posted: Sat Oct 16, 2004 3:22 am
by THAWA
I'm assuming the 45 deg bit is about how to lay down the fibers or whatever.
like this:
/ / / \ / /
or whatever
Posted: Sat Oct 16, 2004 9:47 pm
by skid542
I have done radio control airplanes for a fair number of years and have been working with composites since I was 13. Making your own composite panels is definately within reach if you have at least 300-400 dollars to invest in equipement and setup, get a good vacuum system, it makes a difference. Then it's a matter of just taking some time to learn the process on small pieces. Using a male mold you can still achieve an extremely nice finish. You just have to have that male mold perfect before you start applying your release agents and you have to your mylars right. We use male molds on airplanes that hit 200mph + so smooth finishes are definately possible. But as anyone will tell you, it takes some practice and patience. I would recommend you check out some of my RC aiplane sites and forums, heres a few good ones I know of -
www.rcgroups.com ,
www.charlesriverrc.org ,
http://www.cstsales.com . Those should get you started, you'll have to navigate a touch but it should be pretty clear. There is a wealth of knowledge and it has always personally surprised me how much technology doesn't cross over into other areas. Seriously, my Legacy when I get out of school will have full composite panels. It's just a time investment and the high cost of material. But I'll share a little secret most people don't know. If you want free cheap kevlar that's high weave, go to a junkyard and get some used deployed airbags (the clean ones) and just wash them in your washer to remove chemical residue and there you go. Cheap, highweave Kevlar. Anyrate that's just my two cents.
Lee
Posted: Sat Oct 16, 2004 9:53 pm
by skid542
Getting into the actual layup process is a little more complex to do it strong and light. However yes for the most part you want a 45 degree bias. A lot of times though and depending on where in the door it is you might want a 60/30. Laying up a door should be done in multiple layers with care to reinforce the areas where needed and use the right material where needed. Kevlar is strong but impact resistant. Fiberglass is slightly less strong per oz/ft^2, generally, but most flexible. Carbon is the strongest but also stiffest and can be prone to brittle fracture failure without indication. Charlesriverrc.org is a great place with tons of info. There is also a wealth of knowledge on the forums at RC groups, a few key names, Mark Drela, Ollie, Joe Wurts, Danny Maize.
Posted: Sun Oct 17, 2004 12:15 am
by 91legacyman
ok thanks i went to the mall last night and i custome ordered some books