Making Carbon fiber panels, parts, etc....

[Guest ON3GO]

Hey everybody.

after reading this page on making your own carbon fiber parts and panels i desided to try it it.

http://www.bryanf.com/info/carbonf1.htm

thing is i dont know anything about it, as in i dont know what Toe size means.

what width i should get, oz's etc.

i plan to make my own center dash panel, because im taking out the Heater controls and etc and gonna make my own panel just like alot of ppl do here but im stuffing it with gauges, my sterio units, and what else ill be running in the Z.

i also want to make my own door panels, kick plates, and a few other panels. I would also like to make some stuff for under the hood but ill just take it one step at a time.

i found these sites: http://www.uscomposites.com and the other ones that was listed on that 1st site i posted.

anybody have any ideas for me?

 

mike

[HS1370]

ON3GO

 

Try a book called "Competition Car Composites" by Simon McBeath.

 

It will get you started.

 

Scott

[Z_Dust]

I would recoment that you go and talk to your local custom car audio shop. Usually these guys can whip up some pretty cool stuff using fiberglass and/or carbon fiber. I had a guy locally to build a custom low profile fiberglass midrange speaker "box" that replaces the kick pannels using same mounting bolt pattern.

 

Good luck

[Guest Zachb55]

whoa, look at all those different kids of carbon fabrics!!! uggh, i wonder which one would look the best, it seems so confusing. i would love to learn all about it though, ill have to check on those books and see what i can learn. i would love to be able to make my own panels... post pics if you do it so i can get a visual idea of what it takes.

 

-Zach

[Guest ON3GO]

ya im gonna check out the books too and im gonna start ordering some stuff soon, ill post pic of what i do and do a write up.

 

mike

[zguy95135]

believe it or not there was a good article on doing cf stuff in Car Craft

[rc's240z]

From a guy that used to do a lot of custom fiberglass for car stereo stuff, it is pretty easy to do, patience is the key.

 

There are a few tricks that i can suggest based on what you are looking at to fabricate, especialy if you are looking at making compound curves and such. Flat panels are fairly straight forward.

 

Carbon fiber is tough because you want to see the weave under clear resin, When working with compound curves it can be very difficult to work with and have look good. Air bubbles are the single most difficult thing to deal with when working with any mat material.

 

I hope this helps.

[Moridin]

This is what I've gathered for info so far.

 

You have single-directional (uni-directional) and cross weave (bi-directional). As I understand it, the uni-directional makes for good painted panels, because it doesn't make for waviness in the paint. The bi-directional is good for clear resins, as it looks good in a diagonal patern, but it's also stronger. The opposing weave gives it strength all over. If you really want some good strong panels, then a hybrid carbon-kevlar weave is the way to go. Problem is the color. It's usually has a gold component, because of the Kevlar.

 

Resins are extremely important, because they help to dictate the properties of the final product. There are way too many out there to really explain them all. Best is to visit TAP Plastics or other store that deals with composites and fiberglass, and have them explain things to you. It really helps.

[Nismo280zEd]

I've worked with fiberglass for over 6 years now, and i was wondering, since you've worked with carbonfiber, it is pretty much the same procedures? lay the cloth... apply resin.. wait till harden? does it use the same resins? or are they special?

thanx

-Ed

[Moridin]

As far as I know, its the same procedure. Getting the finish the way you want it is a little more difficult though. If you can create some sort of autoclave for the piece you want to make, than you can get that awesome finish that you see on all the nice parts. I actually haven't worked with carbon all that much, but I'm sure some of the other people on the board have more information to give out.

[240jz]

I have some experiance with carbonfiber parts... A little, I'm a suspension guy not a composites guy. But anyway there are two main types of carbon lay up. There is wet layup. This is pretty normal, you have your carbon cloth, you lay it on your mold and you apply your resin. You then put a cotton fiber backing over the part (reverse side) and seal it in a vacuum bag and pull a vacuum. If your mold is good you can get a pretty nice surface after you finish it. Alernatively you can use an autoclave. The outher type is pre-preg. It is impregnated with the resin when you purcase it. I have not worked with it much. But I know you must keep it refrigerate it and it is sometimes easier to make strong parts. These are just from my minimal experiance making CF pullrods. I'm shure I will be learning a bit more as we are constructing a CF monococue this year. Hope this helps a little.

[Nismo280zEd]

I've never used a vacum bag before... is it essential? or just used to create an even look?

-Ed

[Moridin]

Not essential, but it helps for strength and looks I think. Keeps the finish even and smooth.

[Nismo280zEd]

well i don't have any space for a vacumn bag... but if it's only for looks... then i think i'm gonna start playing

[Guest xero]

the only thing that I know about carbon fiber that haven't been talked about are:

 

1) a vacuum bag is only used with pre-preg carbon fiber, because it needs pressure against the half dried resin, and it also needs heat, so for a large DIY piece, pre-preg is out, but smaller pieces can be done, my dad did some in our oven when he was making parts for his R/C gliders.

 

2) a Fiberglass resin can be used, but only in non-structural areas, like places where you want to make, say, a gage panel in the dash, or a speaker box or something like that, something that isn't going to see any or little stress. If it is going to see stress, like a hood or a fender, it must have structural resin, which from what I've seen for carbon fiber, is a black resin that dries clear. This is how most carbon fiber hoods are made, even then, though, they make a fiberglass reinforcement piece just in case, to help rigidity.

 

3) teh way you achieve a nice finish, like on manufactured carbon fiber hoods, is to have a perfect mold. One way you can do it is to take your stock hood, cover it in mold release, then make a fiberglass mold from it. However, when you're done, there will still be imperfections that will be transfered over to the carbon fiber piece. Your mold must be sanded and thoroughly inspected for imperfections. It must be clean, dry, and free of all dust and dirt, 'cause you can't sand on the finished product, it will scratch your surface and will be dull. Also, I don't know the effects of mold release on a painted hood, it might strip the paint. Also, your plug part needs to be smooth and clean too, no rust spots or oxidation in the paint.

[Nismo280zEd]

so... as long as i use dry matting or non pregnated matting and the structural resins I'll be alright.

cool.

[240Z Turbo]

I should have jumped in long ago. For starters, the tow(not toe) size relates to the grouping of the individual fiber strands(cross-section). Each tow is made up of hundreds-thousands of individual fiber strands. So, if you have a woven fabric, the tow is the fiber bundle that is woven with the other fiber bundles. Some tows can be round, some can be very flat, some are very big and some are very small. Carbon is good for forming(depending on the fabric architecture) because its intra-ply and inter-ply frictions are usually lower than that of glass fiber, even more so when resin is added. Flat tow's will require less force to create fabric shear and will give a much smoother surface finish. So, for small complex parts you can use a 10-12oz plain weave carbon fiber. For structural parts you will want to use a heavier fiber. The plain weave fibers typically give a much cleaner surface finish over knitted(non-crimp) fibers when using hand layup and the lighter, smaller weaves, <12 oz also give much better surface quality. This is because the weave surface is more fine as opposed to a heavier fiber with a more course mesh. The fiber volume fraction will also dictate the part finish. Excess resin will fill in the imperfections of the mesh surface creating a real glossy look. However, you must realize the strength of a composite part is the sum of its components and their interactions. Resin itself is very brittle and fiber itself has no rigidity, but combine them together and you have a very strong part. Knowing that resin is brittle, reducing the resin content within your part will increase the strength of your part. If you can achieve >60% fiber volume you will have a very strong part.

Vacuum bagging, diaphragm forming, VaRTM are all methods to achieve nice parts, but require more skill and knowledge over hand layup. BTW, I am defending my dissertation November 10th with my research being in composites manufacturing.

I guess that will make me Dr. 240Z Turbo

[240Z Turbo]

the only thing that I know about carbon fiber that haven't been talked about are:

 

1) a vacuum bag is only used with pre-preg carbon fiber

 

2) a Fiberglass resin can be used' date=' but only in non-structural areas, like places where you want to make, say, a gage panel in the dash, or a speaker box or something like that, something that isn't going to see any or little stress.

[/quote']

 

1) not true, vacuum bagging is used for various composite mfg processes. Prepreg materials are used in vacuum bagging applications and also double diaphragm forming processes. To the point, you can vacuum bag fiber that has been hand layed with resin. You typically apply a perforated teflon/nylon sheet over the resin soaked fiber and then a permeable layer ontop of that. Finally, you lay your bagging material and pull vacuum. The excess resin is drawn through the perforations into the permeable layer. You must vary the vacuum pressure as too much pressure will squeeze out too much resin giving alot of print-through. FYI, vacuum bagging prepreg is the desired method for aerospace applications.

 

2) polyester resins don't have much of the desired mechanical properties and are not widely used in highly structural loaded parts. However, boat hulls utilize polyester resins. Typically epoxy based resins are more durable and impact resistant. Vinyl-ester based epoxy resins are fairly cheap and work very well in semi structural parts. Remember, for aerospace and other structural applications, the fiber-resin systems are qualified in very expensive, time consuming tests. It may cost 1million dollars or more to qualify a fiber-resin system for man-critical applications.

[Guest xero]

thanks for the clarification,

[Nismo280zEd]

Thanks for all the info!