Carbon fiber "quality"

I'm looking into a few projects working with carbon fiber, non-load bearing, primarily for weight reduction and cosmetics. I understand colored fiberglass is probably a better match for that criteria, but that's beside the point.

Primarily, I'm curious if there is a significant quality difference from stuff available on ebay and stuff from a reputable company. Price is sure different. Nothing is going to be structural until I feel comfortable working with the stuff, however, I don't want it to fall apart. I'm starting to think the epoxy/resin is where quality is needed but I've never played with this stuff.

Examples: 3k 2x2 weave 50" by 1 yard; $59

Vs.

3k 2x2 50" by 1 yard $25

Now really, I know you get what you pay for etc. but really... cost to play? I'm not making an F1 tub, planning on making a radio blank/cubby hole various trim pieces....

Thanks, Mike

I think the biggest difference will be made by you. Get the cheap stuff, make mistakes, and find out why its cheaper before buying expensive. If it works fine.. Win/win!

You might also check for supplies from someplace like Aircraft Spruce for a comparison of know quality to cost.
You are correct that the Epoxy is the most important part, with respect to structural parts. The difference in the prices listed is huge and you may not be getting what you think you are for the low price. However, since you are not making structural pieces, you will be hard pressed to beat the low price.
As another option to cut costs for cosmetic parts, you could do the majority of your layup with Glass and use the Carbon as a top layer (for looks).

West systems epoxy is the bees knees

http://www.solarcomposites.com <= good customer service, a lot of info and a lot of selection

Someone who works in my office building has a Civic with a carbon fiber hood. I've noticed it hasn't held up very well to UV rays and is looking pretty scabby, I assume that has to do with the quality of the resin that was used.

In reply to stuart in mn:

IIRC cf hoods have to be clearcoated with a good UV-resistant/UV-filtering paint. The cheapo ones aren't, with predictable results.

BoxheadTim wrote: In reply to stuart in mn: IIRC cf hoods have to be clearcoated with a good UV-resistant/UV-filtering paint. The cheapo ones aren't, with predictable results.

^^this - UV light is what will kill the resin, no matter what grade you use. Eventually UV will destroy it, and the layers of composite will delaminate. A good coat of UV filtering Clear, and youll be good for the better part of a decade. You can repair bad stuff with a good sanding, a wet coat of resin, and more UV clear. I have a buddy who makes some good coin buying up haggard bits of composite stuff off C-list, fixing it up for about $10-$20 worth of materials, and then sells them for about $80+ over what he bought em for...pays for some of his autocross costs that way.

So... don't be a poser and paint the damned CF?

Gotcha. ;)

Paint costs money. Less poser to just let your function flag fly and berkeley a bunch of form.

I <3 raw CF.

I've used uscomposites http://www.shopmaninc.com/ in the past with good results.

Wicks is mildly competitieve with them on price though.

For cheap Use the Silmar Surfboard resin $38/gallon is cheap for UV stabilized resin but it is Polyester so MEK and higher weight than epoxy. Also a bit less strong.

Honestly for Cheap parts I'd use S-glass. It's about 1/4 the cost of Carbon and strong and light enough for most of the stuff your wanting to do.

West Systems epoxy is my favorite but the US Composites epoxy is pretty decent. You will want to do a good clearcoat it avoid the UV degrading the look of CF. Most of the quality of CF will come from you. So be prepared to screw up a lot and the best way to learn is to play. You are going to want to do a vacuum bag and oven setup in my opinion. Getting the right material for the vacuum bag, preforated release film and bleeder breather. Also if you get into molds, make sure the side of the part that you want to look nicest is the side against the mold. Machinable wax makes a great mold material if you are doing a one off part.

turboswede wrote: So... don't be a poser and paint the damned CF? Gotcha. ;)

I have a CF hood for the Ti.. It will get painted before going on the car. I love the lightweight nature of CF... but not how it looks

turboswede wrote: So... don't be a poser and paint the damned CF? Gotcha. ;)

That's my plan for the Miata once the replacement steel hood gets replaced with a CF one for weight savings.

BoxheadTim wrote:

turboswede wrote: So... don't be a poser and paint the damned CF? Gotcha. ;)

That's my plan for the Miata once the replacement steel hood gets replaced with a CF one for weight savings.

Aren't Miata hoods aluminum?

^That's what I was about to say. Can't imagine there is anything to gain, except weight savings from your wallet.

I think what he meant to say is that he has a steel replacement hood on his Miata.

Aftermarket steel hoods exist.

Wouldn't the aluminum hood be the better option? Its pretty light as is. I'd go after other parts to make a Miata lighter. Fenders and such. The trunk is light too. I'm thinking about a project where I can make a CF radio shroud and instrument cluster shroud. Got a buddy who's really good with fiberglass to maybe give me a hand with it. I mean, he's REALLY good with it. I think it'd be a cool project considering there aren't any real CF things out there for a Miata interior.

From what I have heard the CF Miata hoods don't offer much weight reduction, if any.

The problem is that for interior bits that don't require the stiffness of CF there are plenty of lightweight and cheap materials that will out perform CF on pretty much any metric you choose to measure them by except for fashion.

ABS plastic has a specific gravity of 1.04

Carbon Fiber has a specific gravity of 1.8

So replacing a piece of ABS interior trim with CF would weigh more than the original plastic piece.

Carbon Fiber isn't some magical helium filled weight reduction serum. As trim pieces you are better off with OEM bits....and if you are going for for aesthetics then whatever the average joe can cook up in their garage isn't going to hold a candle to what a chinese factory with proper molds and vacuum systems can turn out.

Very good point. Carbon isnt always the answer, but it was a good idea, none the less. Saves money for other things. I really wouldnt see the point of a carbon hood on a Miata anyways or a carbon trunk for that matter. Carbon could look really good if done in the proper amounts on the interior of a Miata, but like ditchdigger stated above, it would add weight.

miataman86 wrote: Wouldn't the aluminum hood be the better option? Its pretty light as is. I'd go after other parts to make a Miata lighter. Fenders and such. The trunk is light too. I'm thinking about a project where I can make a CF radio shroud and instrument cluster shroud. Got a buddy who's really good with fiberglass to maybe give me a hand with it. I mean, he's REALLY good with it. I think it'd be a cool project considering there aren't any real CF things out there for a Miata interior.

I don't think you'd be able to make the fenders much lighter. Maybe by a couple ounces. I'd bet there' more weight to be lost in the hood than the fenders.

DILYSI Dave wrote:

BoxheadTim wrote:

turboswede wrote: So... don't be a poser and paint the damned CF? Gotcha. ;)

That's my plan for the Miata once the replacement steel hood gets replaced with a CF one for weight savings.

Aren't Miata hoods aluminum?

Mine's done a bit of offroading so the PO replaced the front fenders and the hood with aftermarket steel parts.

mad_machine wrote:

turboswede wrote: So... don't be a poser and paint the damned CF? Gotcha. ;)

I have a CF hood for the Ti.. It will get painted before going on the car. I love the lightweight nature of CF... but not how it looks

BTW, how light is that vs stock? and I'm assuming aerocatches are required?

Just trying to decide if 30-40lbs off the nose of the car is worth the money. And I would paint it.....

I don't think you'd save that much weight - I know an E36 stock hood w/o insulation is surprisingly light.

considering I got it at cost and the hoods on my both TIs are not in good shape (one is bent and one has pin dents from stuff left atop the engine by the PO) I am not too worried about the cost to weight ratio. Basically, somebody ordered it for an E36 Sedan, put down 150USD as a deposit.. and flaked. I got it for list price minus the 150 because the shop was getting out of the "tuner" business