Hi, I need extensive help with the fabrication of Carbon Fiber hoods for 1995 honda civics. I have no experience in CF however been doing work with fiberglass for a while.
If anyone can help regarding hood fabrication by either layup of vaccum bagging.

Also I need some tech. support regarding how many plies to use, the type of epoxy, resin and surface coats, and

lastly I need some help with the re-inforcements that go under the hoods.. Can that be made of CF as well or do companies normally use metal from the OEM hood.

Any help, pictures, write ups or links would be really appreciated.

Thanks

MD

 

Thats a lot of work when you can just go buy a VIS hood for 500.

 

You should really start with smaller parts first. Doing a hood is a TON of material if you don't have the experience to ensure it won't be a catastrophic outcome.

Also know, that just the materials and making of the appropriate molds will cost several times more than the purchase of a new hood. Even if you use the crudest methods, which will not likely yield a high quality product, the investment will be substantial.

My suggestion is to do some research, buy some material, and start/think on a smaller scale.

I've done alot of carbon fiber work making various custom parts, overlays and such. I even embarked on such a task as your proposing years ago when I first started with cf, and I definitely bit off more than I could chew back then....lol. I learned really quickly to go smaller.

If your looking to make something for yourself, and have the satisfaction that you made it yourself....ehhh...yeah it could be done. It's gonna cost more though than just buying a hood, it's gonna take three times the effort to make it presentable, and it's gonna be a job.

I've used West Systems resin for the mostpart. Some people don't like it, some people complain about it....I've had good good experiences with it. The guy I learned alot from, as far as carbon fiber is concerned, worked with composites in Formula 1 professionally, so if West System was good enough for him, then it's good enough for me.

That's all I'll give you for now. You have alot of reading and searching to do in order to find your own answers. If you google West System, I'm sure you'll find plenty of sites to read and learn from

 

I couldn't agree more with several of your points RC. A hood was my first project and it turned out badly even though I had done some reading. I would certainly steer you away from building a hood your first time out. While carbon work is different from glass work there are many similarities. Besides the obvious material property differences between cf and glass the main difference is you usually want to see the carbon fiber. I guess what I'm getting at is the questions you are asking tell me you may not be so familiar with glass work. That's not meant as an insult but I'm just saying you are just talking about switching reinfocement materials, many of the processes are interchangeable. I have no answers for you until I know what your goals are. Are you doing this to start producing andselling your own type of hood? Do you have a ceiling on your costs per hood? Is this just a personal project? Is this a race hood or street only, the constructions differences and layup will vary a lot depending on the end goals. As far as resin choice there are thousands of resins out there, each with a specofic purpose. Choosing a type or even a brand is premature unless the end goal is known. West System is used a lot for sure and I like some of their resins but they tend to specialize in Epoxies. One thing you will notice right away is epoxies are 2-3 times more costly than ester based resins but they certainly offer some desireable properties like increased stiffness etc. You just need to decide if the extra cost is worthwhile in your case. Composites are like anything you can get as specific as you want to get the desired result.

 

RC and CRX12, thanks a lot guys, I really appreciate your input.

I am doing this for making my own hood and selling it off in the local market. I have quite a lot of fiberglass material lying around from which molds can be made. But I agree with you guys as I am a little scared about doing such a big part for starters. I haven't yet ordered any material but I am talking to a couple of suppliers in China and Korea.

The major parts like hoods, trucks, roofs etc. would be for street racers. The rest of the jobs I am looking into are mainly going tobe overlays which I presume are alot easier to deal with.

I have been reading alot and trying to get my answers. Google hasn't been of best assistance but forums like these which I just came across a few days back seem to be the best places for help. (Thanks again to people like yourselves).

To begin with I was going to order 10meters of CF and then go ahead with making a sample. Yesterday one of my suppliers told me that a hood takes 6 plies which really gave me a shock as the material cost of going above my estimated selling price for the local market.

So then I am rethinking my prospects and considering going for smaller parts only.

If you guys can give me some leads to techniques for producing CF parts for street racing. I have about 15 to 20 customers who are hard core racers and would do anything to reduce weight.. So for applications like racing how many plies of CF should be used and would those "reduced number of plies" be sufficient or would I have to use a couple of plies of kevlar fabric?

I know I'm asking for a lot.. but this will really be a major help before I invest into this deeply.

Just if you're wondering, I'm not stubborn about this, if doing hoods and bigger parts turns out of my league I'm just gona go with overlays and try and earn some extra bucks..

Also guide me with what weave is more preffered in the racing "world".. I'm going for 200g/sqm 3K fabric and the supplier is giving me an option between the twill weave and the plain weave.. What is more appreciated in the market? there's only a 50cents difference in price.

Thanks

 

6 ply!!!!!! Dude, I've been to car shows and seen the sun through peoples raised hoods...hahaha. There are many companies which use 3k x 3k twill, one layer with a fiberglass backing.

It really all comes down to what you want in terms of strength, lightness, and ending appearance. For a hood, which has very little complexity, 12k x 12k twill weave carbon fiber is going to give you the most attractive ending product. It has very little to no spacing between the weave, it's quite strong, and the factor of being twill weave allows you to still get it around the minor shapes and curves of a hood.

If your really serious about trying to make the hood then you really need to come to terms with how much money your willing to spend to even make an attempt. Your going to be doing a "wet layup" method in order to produce this hood, and finishing the product with no air pockets or little bubbles where the carbon meets the mold is going to be difficult without vacuum.

In order to do vacuum bagging, your going to get yourself into alot more cost, once again, just to make an effort. Vacuum bagging, in my opinion, will give you the best shot at maybe making a finished and descent part of that size. I am sure wet layup can be done, but "for sale in the local market" is just not possible in my opinion. Your not going to be able to create repeatable results.

I'm sure you've heard of the saying "you have to learn to crawl before you can walk", well having no experience with carbon fiber and attempting to sale large scale complex product right off the bat is like trying to run a triathalon before learning to crawl. Your chance of success is about .1%.

Mold making is not all that difficult, but once again for a large scale part like a hood....it aint' so easy. Your mold has to be STRONG....and essentially perfect because it's well...your mold! When you lay that much resin with catylist inside your mold, that heat generated is going to want to distort the hell out of it. Your mold needs to be made with thick fiberglass matting, then reinforced with a wooden structure. This will be the bare minimum to maybe even possibly having it hold up. If your going to be vacuum bagging, there are going to be additional steps you want to take when making your mold....this is all just far far beyond the scope of this thread though. Your really gonna need to do alot of research.

I purchased several books off of Amazon when I started in order to familiarize myself with some things. You may want to look into that option, or your local library. Obviously online has alot of resources, but it's mostly going to be simple how-to's, and maybe a couple of descent learning sources, but it's going to leave you with questions unanswered, and books will help with that.

This is where I purchased by carbon fiber in bulk. They'll let you buy pretty small quantities though, if that's what you want.

http://carb.com/

Check this thread out from a little while back...this will give you a perspective on what it takes to truly put out a professionally made hood. Your talking massive autoclave, expensive molds, HUGE investments.

https://honda-tech.com/zerothread?id=1872097

I say for starters, just so you get a feel for what it's like to do a carbon "part". Get a piece of glass, or lexan from Home Depot. Once you have all your resin, polish/wax so the part releases when it's cured, acetone, rags, scissors, carbon fiber, basically all your minimal supplies, try making just a flat panel.

Clean the glass, polish/wax it so it doesn't grab the finished part, then use the piece of glass as if it were a mold. Pour some resin on your glass, coating the area your going to lay some fiber, lay your fiber in, add some resin and saturate the fiber, squeegie off the excess. During this time look beneath the glass...this will allow you what a mold won't....to see the bubbles....hopefully you have none.

If all goes well you should leave yourself with a flat panel that is nice and even. It'll give you a starting idea of what you'll be facing I think.

Overlays are WAY easier, and much more f*ck up friendly. They are just a bunch of work. Overlays, one off parts constructed over foam, simple molds...that's where you should stay as a DIY guy in my opinion. Without major tooling and money...I think hoods just are out of the realm.

By the time you get to the point of turning out a hood that's quality, your going to have to charge your friends 1000 bucks a hood to probably just make it worth your time and investment you've made. That's just a random guess....but it makes my point that, this isn't going to be the big money win for you.



Modified by RC000E at 9:25 AM 6/21/2007

 

Man.... You have no clue how thankful I am for all the help you're giving.. Thanks a bunch!

You've answered many of my initial questions in the last two posts. I think I'll take your word for it and go with smaller parts first. Like I mentioned before, I have a full set up for fiberglass and I have a good CNC machining center with me so making molds is no problem. However I'll just be using OEM parts to make tough and reusable fiberglass molds (for the small parts) and give them a shot with CF. I'll also try out overlays on a few parts and see how that works out. Then I can start doing whatever I feel I can produce better results with.

From what you mentioned about the plies... PHEW that was a relief man... I mean seriously, the guy who told me 6 plies had me really really confused as well. If its just one ply with kevlar or fiberglass backing maybe I'll still give it a shot but I will definitely work out my costs before I just throw in a big fiberglass mold.

I think I'll jsut go with 3kx3k twill and do some overlays as well as some fabrication of little parts and try and sell them with the locals, I think that'll earn me better bucks.

With my initial purchase of the the 3k x 3k twill I'll call for a little quantity of 12k twill as well and then experiment a little with that as well.

Thank again for all your help... Anything sources or helpful sites/pages/articles you can forward will be appreciated.. I'll keep you updated and will share the results of my first few trials.

Regards... Emdee