I was wondering typically how think are fiberglass hoods and fender and also the thickness of carbon fiber. Also what's the weight difference between two identical hoods? Just seeing if carbon fiber is worth the money or not. These are for a drag truck so lite weight parts will be used. Most of you know i have a 91 GMC Sierra that i'm building a 6.0l 10-71 roots blower for. With the exception of a one piece front end no one makes fiberglass fenders or doors for this model. So i'm in the process of making the molds and going to make my own parts. Thanks

 

True Carbon Fiber parts are waaaay lighter. Way way lighter. Also much more expensive.

 

Is carbon fiber lighter because the parts don't need to be as thick as fiberglass to get the same strenght? I have a powder coating business on the side so i have the needed oven to bake the carbon fiber. Anyways the carbon fiber 3k 2x2 pattern woud cost me $215 for material and resin per fender which is 5.7oz/sq yard and .012" thick. Fiberglass would be $93 per fender which is 10oz/sq yard and .014" thick. but i'm not sure how thick i would need to go with fiberglass and carbon fiber. By looking at the weight of the two fabrics it looks like carbon fiber is just a little over half the weight of fiberglass at about the same thickness.

 

I should mention the fiberglass above is a weaved fabric. Stranded mat per fender would be $68 per fender which is 1.5 oz/sq yard and .045" thick. But i'm thinking this would take 3 layers to get 4.5 oz/sq yard.

 

ive only messed around with the both of them a little but from what i have the carbon fiber is stronger per unit of thickness then the fiberglass. im sure it has something to do with the resin also though. a lot of aftermarket carbon fiber things are backed with fiberglass for cost and just the look. also thin layers of carbon fiber you can see through if that makes any difference for you.

id watch with making doors if your going to use it on the street. even if you have a cage with door bars which i hope you would if your going to use anything but the original doors, if hit it tends to shatter a bit and could really cut you up.

 

The truck has a 8 pt bar currently and will be adding in a 14pt cage. It;s mostly going to be strip and occasional street use. The fenders wold be painted to match the truck so carbon fiber wouldn't be for looks on that. I'm thinking fiberglass is fine either way the weight savings over stock metal would be huge. As stock fenders are 24lbs and the hood is 58lbs. Haven't weighed the doors but they must be heavy. 1st mold for driver side fnder is molded. Just need to clean up and coat the inside and should be ready to try making a fender. haha

 

Post pics of the process or you will be permanently banned from the site.

 

Most would say c/f isn't worth the cost, but that's up to you as an end user. Some use it for it's functionality (great stength & / or lite weight) others for it's look. I like both.

C/f is pricey for 3 reasons: It's expensive as a raw material, labor intensive, & skilled to do it right / nasty to work around. And it used to be only 2 places in the world made it. That was supposed to change as it's use become more prevalent & so on. Military buys most of it, & for a L-O-N-G, L-o-n-g time there was a huge shortage for that reason. Military gets it 1st.

Part thickness depends on where it's used & the stresses placed upon it. I would say c/f is stronger than glass cost it doesn't need to be as thick, but I've forgotten a little.
As far as oven. The lightest, strongest c/f is autoclave. It evenly distributes resin thereby contributing to that trait (lightwt.). Next is bag it. Then there is the way most do glass, to just try to press resin best they can. It's a wee bit heavier cause a human just can't duplicate the pressure that the other processes do. But u work w/. what u have, cause most can't afford a $100k autoclave.

Yes, to keep costs down or too dupe a person, some use fiberglass on the lower layers. If someone is buying parts, they should ask to prevent any surprise, "I didn't know" 's. Some just want the c/f on top layer as that's what the eye sees. If u want all c/f thruout, u can use blems on the lower layers & only the "nicer" cosmetic on top layers. But u just want functional, so maybe u don't even need the pretty stuff & blems are fine all along.

As MikeGyver said, pics or you will be permanently banned from the site.

I'd like to know how much doors weigh when u get to that point, please.
schino's point was, be careful on if it shatters if things get ugly. Visualize, if you've ever gotten c/f under your finger nail, think of it like a paper cut, but w/. strands of steel. Ouch!
Also, what did u use on that fender, c/f or fiberglass?

 

Well the 1st mold i made didn't turn out to my liking so i sent it to the trash. I'm now working on second mold and both are made of fiberglass. Once i get a good mold i will take pictures and post for sure with all details. I should have kept the 1st mold as it was something to work with but had alot of pitting on the body line. I went and bought 5 yards of pure 2x2 twill 3k carbon fiber which should be enough for a fender if not two fenders. I'll have to wait and see until i actually start the process of making a fender. I also bought some uni-directional 12K carbon fiber. My thought is to use the 2x2 twill for the outer layer and then use the 12k uni-directional for added layers for stenght and support. I'm out on the road for work so it's killing me not to be able to work on this but i will post pictures through the entire process.

 

Also i will be using an System 2000 epoxy 3:1 ratio resin for the c/f production.