How much does carbon fibre cost?

[Nate Notta]

Kinda sad to say, but we've never had a chance to use carbon fibre here for FSAE. We want to try a few things this month, so I want to get an idea of how much we should pay for it.

Correct me if I'm wrong - you buy carbon fibre as a cloth like fibreglass, and cut out the strips you need and epoxy them together in layers?

If that's right, can you give me a ballpark cost for the cloth? Like for 1 yard X 50" of cloth is it ~60$ USD?

Any advice about the basics would be appreciated.

[Tudor Miron]

Nate,
There are many different sources where you can get it for much less. Try this one www.carb.com (http://www.carb.com) as they are known for good prices.

Thanks...
Ted

PS: and may be this one http://www.discountcomposite.com/inven.html

[Nate Notta]

Thanks for those sites. Can you suggest a 'normal' carbon fibre for us, because the selection is killing me... I have no idea what type of CF to use.

You've got to choose a Style (130, 205, 282, what do these mean?), a Modulus (1, 3, or 12K, I think this is the strength?), and the Weave (Twain, Harness Satin, Twill ???)...

I am lost.

[Gumby]

What we use for our structural and body stuff is a 2x2 twill with a 5.7oz weight. and I believe it is a 3k modulus.

Hope this helps

[Tudor Miron]

Nate,
3k modulus is a good choice as it's usually list expensive. Not because it's worse but because it's production volume is much bigger. To know what you need for your application - best way is to ask supplier they are usually willing to advise.

Thanks...
Ted

I'm not a composite expert in any means - all this information I got while searching web. Read FAQ on www.car.com (http://www.car.com) site as a starter.

[James Waltman]

Nate,
You should check out Fiberlay (http://www.fiberlay.com)
These guys have been great to us and they are willing to do small orders.

3k is not a measure of modulus. 3k means that there are 3000 filaments per fiber. 1k means 1000 filaments per fiber. There are more but I think you can see the trend.

This is a pretty good resource for the terms used to describe carbon fiber.
http://www.carb.com/terminologyintro.html (They leave out that the fill is also known as the weft)

The weave can make a huge difference in how successful your layup is. The plain weave is easy to understand: a fiber goes over-under-over-under as it meets fibers running perpendicular. Plain weaves are very stable. That is – they maintain their fiber orientation as you manipulate them. This can be a problem if your mold has tight compound curves because the fiber won't distort much to conform. Plain weaves are not as strong because of the number of crimps as the fibers go over-under. The intersections also lead to "holes"� were resin can accumulate.

A 2x Twill is a different weave: the fiber goes over-over-under-under-over-over-under-under. Twill weaves are not quite as stable as plain weaves. They will distort more easily around your mold geometry (they are more drapeable). But, because it can distort it is more difficult to maintain fiber orientation on curves.

There are many other weave types - typically they trade off stability for drapeability (conformability).

Plain: over-under-over-under
http://shopping.netsuite.com/core/media/media.nl?id=30&c=332832&h=91b9827950559dad6a89

2x Twill: over-over-under-under-over-over-under-under
http://shopping.netsuite.com/core/media/media.nl?id=37&c=332832&h=e0d71c45d58f6a7ab4ef

4 Harness Satin: under-over-over-over-under-over-over-over
Pretty easy to work with
Also called "Crowfoot"�

5 Harness Satin: under-over-over-over-over-under-over-over-over-over
Even more drapeable than 4HS

8 Harness Satin: under-over-over-over-over-over-over-over-under-over-over-over-over-over-over-over
Super drapeable, Getting close to Unidirectional

Choosing the right resin can be harder than the right carbon.
What are you planning on making? Do you know how to do vacuum bags?

[Broderick]

That was a great rundown of Carbon Fiber James. Excellent work.

Ryan B.

[Cement Legs]

For more info, if you dont have enough already, check out fiberglast.com (note the t in fiberglast). They have several tutorials spread out through their website that talk about everything you see here along with; cloth and resin selection, mold prep, pre-preg, layup (directional weaving), as well as carry a full line of all of your carbon fiber, fiberglass and kevlar needs.

[Nate Notta]

Thanks guys, great info. We are most likely going to try a few things this year, most pressing being the carbon fibre seat/firewall.

I haven't begun to look into resin yet, or vacuum bagging.

[James Waltman]

Nate,
I forgot you started the Firewall seperate from seat (http://fsae.com/eve/forums?q=Y&a=tpc&s=763607348&f=125607348&m=25210205111&p=1) discussion.

I think any carbon fiber layup that doesn't have some form of consolidation is a waste of time and material. It doesn't always have to be a vacuum bag though.

[Nate Notta]

Yeah that was me last year, and I'm still working on it.
In September I got a tour of your facilities from Dr.Seal, and got to see all those awesome vehicles from that old post. You don't know how jealous I am of your machine shop equipment. We're getting our 1st Bridgeport set up presently.