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Carbon Fibre Hood?

Posted By: 604 Hemi GTX

Carbon Fibre Hood? - 08/08/16 04:39 PM

Just wondering if anyone here has got a carbon fibre hood on there ride?
If you do who did you get it from?
I'm in the market for a carbon fibre hood for my 70 Plymouth GTX

Thanks for any and all info
Kevin
Posted By: MR_P_BODY

Re: Carbon Fibre Hood? - 08/08/16 05:12 PM

I have one on my P-Body.... but I made it... no one
makes anything for my ride
wave
Posted By: jcc

Re: Carbon Fibre Hood? - 08/08/16 05:57 PM

Almost in every case, any typical fiberglass existing hood mold will also be fine for a carbon hood/part. The issue is, if one can find an existing mold, although making one is only a matter of time/effort/money. You need to ask, costs per part are not that much greater, more supply/demand pricing. They are anaziningly pretty stiff.

I'm in the early stages of doing a CF replacement/redesign radiator support on one of my cars, we'll see. grin twocents
Posted By: Monte_Smith

Re: Carbon Fibre Hood? - 08/08/16 06:31 PM

You have to be careful when you order carbon parts. The material costs twice as much, but weighs the same as fiberglass. The ONLY way the carbon hood is lighter, is because there is less of it, because of strength. BUT and here is the tricky part........to lay up the super light weight, super thin carbon stuff, you have to be able to pull a vacuum on the mold to do it correctly and few can do that. Also the "carbon" parts you get from some companies not only weigh the same as glass, they are also not really carbon. They will be glass, with the final layer carbon, to give it the "look".

So if you are looking for a true, super light carbon hood for a 70 GTX, probably not going to find such a thing. If you just want the "look" buy a glass one and have a carbon wrap put on it
Posted By: 604 Hemi GTX

Re: Carbon Fibre Hood? - 08/08/16 06:35 PM

Ok so I'm probably better off sticking with Fiberglass then.
Who do you guys recommend for a quality glass hood?

Kevin
Posted By: fullmetaljacket

Re: Carbon Fibre Hood? - 08/08/16 06:41 PM

Dip it and take off an honest 15 or so pounds and keep the steel look while you're at it.
There's a guy in Detroit that is an ace on the stuff.
Posted By: Monte_Smith

Re: Carbon Fibre Hood? - 08/08/16 07:23 PM

Originally Posted By 542GTX
Ok so I'm probably better off sticking with Fiberglass then.
Who do you guys recommend for a quality glass hood?

Kevin
Glasstek is probably your best choice
Posted By: MR_P_BODY

Re: Carbon Fibre Hood? - 08/08/16 07:36 PM

When you do the vac on CF there is other stuff that
has to be applied so when its vac down it sucks up all
the extra reson ... I had to build a big bag to vac it
but I screwed up and didnt have my stiffeners on it when
I vac it down so I added them after but didnt vac them...
I could have gone with 2 layers of CF but I put 3 layers
on it.. if done right 2 is plenty... my hood weighs 6#..
my fiberglass one was 17# but that was with the scoop
wave
Posted By: Monte_Smith

Re: Carbon Fibre Hood? - 08/08/16 07:47 PM

To give an idea of what NICE carbon fiber weighs. Customer with a Pro-Mod 63 Vette. The nose on those is pretty big. His entire nose and hood, with a 6" cowl and a titanium tree, weighed 11 pounds. Entire carbon bodies from 5 star bodies can weigh as little as 40 pounds
Posted By: MR_P_BODY

Re: Carbon Fibre Hood? - 08/08/16 08:09 PM

Originally Posted By Monte_Smith
To give an idea of what NICE carbon fiber weighs. Customer with a Pro-Mod 63 Vette. The nose on those is pretty big. His entire nose and hood, with a 6" cowl and a titanium tree, weighed 11 pounds. Entire carbon bodies from 5 star bodies can weigh as little as 40 pounds


Yeah I was listening to yesterdays BS when they were
in the rain delay.. and they said about 60# for a funny
car body... I still thought that was light... I've always
noticed that they always have the big guy open the body
after the burn out... but I think thats for height
wave
Posted By: mack

Re: Carbon Fibre Hood? - 08/08/16 08:36 PM

My DP Challenger came with a CF hood... About two years ago the scoop came off and it wasn't the hood or the scoop it was the lament that was used to attach.. Anyway, I remember the hood being as heavy as the scoop. I didn't weigh either but they felt the same.. That was close enough for me.. I do know that Mike Pustalny (SP) has CF and Glass hoods for the DP's that want to put them on springs and a hood latch like a normal car and get rid of the 12 fasteners.. He might have an outlet for other CF hoods... Might be worth a call... All he can say is no...
Posted By: jcc

Re: Carbon Fibre Hood? - 08/08/16 09:35 PM

Originally Posted By 542GTX
Ok so I'm probably better off sticking with Fiberglass then.
Kevin


I for the life of me can't see how that conclusion could be drawn from the prior replies to you making it.

The material costs are indeed higher, the CF, which has already been mentioned, but you need a lot less thickness with CF for equal stiffness, and the extra epoxy cost. There is no gel coat normally with CF. However the actual material costs are only a fraction of the total delivered price, and CF is way worth it weight wise, and does a better jib of retaining its shape in use, then FG/resins. Vacuum bagging any composite part is always preferred, but seldom done with FG. I would not toss the towel in so fast.
Posted By: 604 Hemi GTX

Re: Carbon Fibre Hood? - 08/08/16 09:58 PM

I've got the whole front clip acid dipped and I need the clearance for the intake

Kevin
Posted By: Monte_Smith

Re: Carbon Fibre Hood? - 08/08/16 10:03 PM

About anyone who lays up glass hoods, can and will do carbon......however, as I mentioned earlier, if they are not doing it right, you lose little to no weight and pay twice as much. And the companies who generally do the really nice, light weight race carbon are likely not to have a hood mold for a 70 Plymouth
Posted By: MR_P_BODY

Re: Carbon Fibre Hood? - 08/08/16 10:30 PM

One thing you will see in fiberglass is that it moves
in heat(sun light).. this doesnt happen with CF.. I
made my first hood in fiberglass.. it would sag in the
sunlight after a few hours... that was the reason I changed
over to CF... the hood I have on my Rampage is from AAR in
Florida.. nice piece... BUT it still moves in the heat.. I
might take a mold off of it and build it in CF.. I'll see within
a year.. if it continues to move like it has been I will pull
a mold if I can get it back to the proper shape
EDIT
You would be far better off going with CF... if you can
find a shop that has the mold for your hood and your willing
to pay the price.... way lighter, way stronger, doesnt move
in the heat.... make some calls.... a few questions will
tell you if its all cf or over fg... cf has a weight and
the reson after vac is almost nothing... just ask the weight
of the cloth they will use and if they will vac it down...
they dont vac fg
wave
Posted By: rebel

Re: Carbon Fibre Hood? - 08/08/16 10:40 PM

i modified my Kevlar front clip with carbon when i changed the front edge but this is a one off.

Attached picture 522045_10150839270345011_584320010_12201592_387220397_n.jpg
Posted By: 604 Hemi GTX

Re: Carbon Fibre Hood? - 08/08/16 11:18 PM

I'm not saying I don't want cf but if it's going to be 3 or 4 the price of fg and they can't do the cf procedures properly.
I'm way further ahead buying a fg hood, so besides cloth thickness and if they vac cf parts what else should I ask?

Thanks
Kevin
Posted By: rebel

Re: Carbon Fibre Hood? - 08/09/16 02:08 AM

If you know someone with a mold, ask if they can do Kevlar. That front clip I posted can be held above my head with just 1 hand. It is so light. If I could tape both my doors n bootlid to it I could still lift it with 1 hand. If you know any boat builders, they could possibly help you.
Posted By: MR_P_BODY

Re: Carbon Fibre Hood? - 08/09/16 03:30 AM

Originally Posted By 542GTX
I'm not saying I don't want cf but if it's going to be 3 or 4 the price of fg and they can't do the cf procedures properly.
I'm way further ahead buying a fg hood, so besides cloth thickness and if they vac cf parts what else should I ask?

Thanks
Kevin


Really nothing other than number of layers and support
ribs.. 2 layers is fine if it has good supports and
location of them.... and of course price
wave
Posted By: jcc

Re: Carbon Fibre Hood? - 08/09/16 03:38 AM

I would only suggest Kelvar if one felt part was going to be abused in use, and separating from the car would be a bad thing after contact. In the case of a hood that could be good or bad. Kevlar is not as strong as CF, just a lot harder to separate after failure, where Cf will mainly shatter when it fails. A single layer of Kevlar with the CF is not a bad compromise, I do it often. twocents

edited
Posted By: AndyF

Re: Carbon Fibre Hood? - 08/09/16 04:25 AM

A '70 GTX hood isn't much more complicated than a barn door so it should be fairly easy to build in CF. Any CF guy worth his salt can build you a hood but it might cost a ton to do a one-off.

I have no idea if someone is already making them, Google might find them if they exist.
Posted By: dart440_72

Re: Carbon Fibre Hood? - 08/09/16 04:33 AM

Originally Posted By 542GTX
Just wondering if anyone here has got a carbon fibre hood on there ride?
If you do who did you get it from?
I'm in the market for a carbon fibre hood for my 70 Plymouth GTX

Thanks for any and all info
Kevin



I ordered a hood from Unlimited products with a scoop on it. They offer carbon hood/hood scoops.
Unlimited Products http://www.up22.com/index.htm
Posted By: David_in_St_Croi

Re: Carbon Fibre Hood? - 08/10/16 02:15 AM

As Andy F said, a 70 GTX is not that hard to make. I made a mould for our 70 RR as the bonnet is rusty and with the tunnel ram it is now lift off. Lifting off the steel bonnet is getting old very quickly but life as it often does has thrown a spanner in the schedule.
The big thing with carbon is not so much the strength but the stiffness. The modulus of elasticity of carbon fibre is about 5 times that of glass, particularly when you are looking at unis. My plan is a light carbon cloth on either side of a 19mm nomex core. The bonnet is basically square so a 0/90 laminate works well as the stresses and required stiffness are similar in both directions. The core will give the thickness required for stiffness while keeping the weight. As I have a vacuum pump it is no problem getting both high fibre volume laminates and good core bonding. Around the perimeter and the hole for the carbies there will be some extra lamination. At the bonnet pin locations a G-10 compression tube and local build up will be utilized. For the mould I used polyester as it is cheap, for the part epoxy will be used of course.

Basically, once it is off the car, wax it like crazy and level it. Turns out I should have used some PVA in addition as will be seen later.


Then start lam inating. I put a layer of mat down then I believe 3 layers of 24 oz/yd^2 roving plus mat. Ugly but only planning on one part out of it:



Once it is cured need to put a grid on the backside that is nice and level. This grid does two things. It stiffens the mould and when placed on sawhorses and leveled with shims it ensures the part is not warped. The use of a scribe makes short work of marking the braces.



Perfect fit not required, actually a loose fit is in ways better. Easier to level and the tabbing will not create as much of a hard spot.



Transfer height to forward grid cross piece:

The wedge in former picture sets the level to level and it is sitting on the forward cross piece by that height. Set the scribe to that height and mark the forward cross piece:



Double check level fore and aft and athwarthsips:


Grid tabbed in place:



Wedging mould off of bonnet:



Even with the wax it pulled some of the paint. Poor quality paint job and I should have used PVA on top of the wax but I am sure the paint will come out easily.



Clean up the sharp edges and you are done, with the mould at least.

Or order one from the suppliers mentioned.

I know an excellent composite builder in Bristol, Rhode Island who could do a beautiful bonnet for you. You would need to ship the metal one for him to make a mould.
Posted By: jcc

Re: Carbon Fibre Hood? - 08/10/16 03:01 AM

I surprised you used no gel coat on the mold, even for a one off. work

The no pva, tsk grin
Posted By: David_in_St_Croi

Re: Carbon Fibre Hood? - 08/10/16 03:43 AM

Originally Posted By jcc
I surprised you used no gel coat on the mold, even for a one off. work

The no pva, tsk grin


Yes, I know on the PVA blush I think if I had used better wax would have been ok. After all, would have just waxed the mould next step so any residue is not an issue.

As far as gel coat, the mould was expensive enough (island prices). The layer of straight mat I put against the surface was resin rich and I worked it with a bubble popper roller, as I did with the subsequent layers. It should be fine for 1, at most 2 parts (all the core I have). The important thing is it is airtight and that is where the rolling out comes into play, along with wetting the material out on the bench, then transferring to the plug, rather than attempting to wet out in place. I am not expecting a straight to clear coat part, it is getting painted. We don't have the mild sun you have in Florida smile , it eats clear coats here (and subsequently the resin underneath as it is also UV sensitive).

For a mould that will see multiple uses, go straight to a tooling surface like Duratec, rather than run of the mill gel coat. It is the orange stuff in the picture. It will polish up to a nice gloss surface. That part is half of an ama for a 36 foot trimaran which will see considerable sea loads. As you can see carbon correctly engineered gives a stiff and light part. This is the shop in Bristol I mentioned.

Posted By: astjp2

Re: Carbon Fibre Hood? - 08/10/16 03:54 AM

Carbon is one of the stiffest fibers you can get as a consumer. When carbon is layered over a glass shell, it becomes a box beam type structure. Also 100% of the stress/strain in a multi fabric structure will be taken by the stiffest fiber (carbon) until that fails then it transfers the load to the next stiffest fiber until that fails..

Vacuum bagging is one primary way to improve the resin to fiber ratio, too much resin, it is heavier than necessary, too little and not enough bonding of the fibers.

Many epoxy resins use heat to accelerate the curing time but IR and UV light can damage the fibers so don't try to cure a part in the sun...I used a heat gun in an old refrigerator to get the temperature up to 140*f and it accelerated my west systems epoxy from 24 hours down to about 4.

Originally Posted By Monte_Smith
You have to be careful when you order carbon parts. The material costs twice as much, but weighs the same as fiberglass. The ONLY way the carbon hood is lighter, is because there is less of it, because of strength. BUT and here is the tricky part........to lay up the super light weight, super thin carbon stuff, you have to be able to pull a vacuum on the mold to do it correctly and few can do that. Also the "carbon" parts you get from some companies not only weigh the same as glass, they are also not really carbon. They will be glass, with the final layer carbon, to give it the "look".

So if you are looking for a true, super light carbon hood for a 70 GTX, probably not going to find such a thing. If you just want the "look" buy a glass one and have a carbon wrap put on it
Posted By: jcc

Re: Carbon Fibre Hood? - 08/10/16 03:41 PM

Neber heard of IR damaging fibers, I assume Kelvar is the most fragile, can't imagine CF would be delicate.

And about busting Davids chops grinon no use of Gel on his mold, I understand the island price concern, and sounds like you mitigated its non use. The issue is, to those here in the states also making a one off, if your mold has any/slightest imperfections, you will live with that or fix it later in the final piece, and a hood is the most visible part on a car, or close to the drivers door in visibility.The GEl coat in a mold, mainly provides as David mentioned, ability to polish the gel without a break thru into fibers concern, and mainly, IMO reduces shadow "print thru" of the first layers of fibers, be they roven, fabric, or mat onto the molds surface, not an ideal cosmetic result. twocents
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