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Cf Bonnet Going Soft When Hot.

msports180

By msports180,
in Exterior & Interior Styling

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msports180 Mentor

msports180

Posted
Posted

Hi guys,

I bought a Project Mu CF vented Z tune style bonnet for my R34, drove it the other day on a 35deg day and when i pulled up the bonnet had a weird smell to it (like the smell of body filler) and was really soft, like i could distort its shape with one finger and when i popped the bonnet the hole thing flexed.

Is this normal for a CF and Fibreglass bonnet?

Im just worried about it cooling down and hardening in a deformed shape.

Cheer's!

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Carbon 34 Grand Master

Carbon 34

Posted
Posted

Hi guys,

I bought a Project Mu CF vented Z tune style bonnet for my R34, drove it the other day on a 35deg day and when i pulled up the bonnet had a weird smell to it (like the smell of body filler) and was really soft, like i could distort its shape with one finger and when i popped the bonnet the hole thing flexed.

Is this normal for a CF and Fibreglass bonnet?

Im just worried about it cooling down and hardening in a deformed shape.

Cheer's!

Sounds like the epoxy mix was wrong or its a knock off

Carbon epoxy should be able to handle damn near direct flame !!!

It should never go flimsy or its defective bond

There is epoxy on the market used to make it super shiny but fails and goes soft above 80-90c

Maybe thats it

Fiberglass doesnt go flimsy either unless its near flame( different epoxy used )

Japan doesnt get hot as hell like oz so dont expect it to have UV stable epoxy , japan isnt cutting edge in compostes but the fit is normally way better from QC

PewPew Proficient

PewPew

Posted
Posted

I bought a Project Mu CF vented Z tune style bonnet for my R34, drove it the other day on a 35deg day and when i pulled up the bonnet had a weird smell to it (like the smell of body filler) and was really soft, like i could distort its shape with one finger and when i popped the bonnet the hole thing flexed.

Project Mu as in... the brake company? AFAIK they don't do bonnets so it's probably a fiberglass copy with a layer of carbon for cosmetics.

Noy Experienced

Noy

Posted
Posted

What do people expect for $700? Project Mu would not be Epoxy

At best Vinylester but I'd be guessing Polyester, Considering the low Tg of polyester this would be normal.

A carbon bonnet in direct sunlight can get to around 135 degrees C so even a poorly made vinylester bonnet would soften.

Project Mu bonnets are Gelcoat finish also, 1 layer of carbon and backed with general chop strand mat.

When you think about it vacuum infused 200gm 3k carbon is around 4 layers per millimetre, so even 3mm carbon laminates have flex and a bonnet is around 2sq metres. Do the maths 12 layers of carbon x 2sqm = 24sqm of just carbon alone @ $40/sq/m - $960 just in carbon for a 3mm thickness. Just for a bonnet skin!

So back to Neil, I see your car is black so either way if you had it carbon or painted you will end up with the same outcome.

I think you just need to get use to it or go back to your metal bonnet if your worried.

Noy

Carbon 34 Grand Master

Carbon 34

Posted
Posted

It's not vinyl ester !!!

they would have used pre preg carbon sheet and vacuum autoclaved it , with that in mind autoclaving is 150c or more

Most run of the mill pre preg. Is good for 300c !!

and carbon itself is unaffected by that little bit of heat , epoxy failures yes but not carbon

now chopper strand mat is weaker but stil not affected by 150c , corvette is made that way since 53 !! and they don't go floppy ??

I have a large hunk of 3k tow 2 layers thickcarbon with west systems epoxy and you can beat the hell out of it hot or cold with a ball peen hammer not a mark ( this sits in the sun for the past 3 years now!! )

but the same epoxy with a sandwich of Kevlar and carbon baked , failed at 250c ( delaminated )

during some epoxy trials for a strut bar of pure composites no metal

it's a bad mix ( cured wrong ) IMO

msports180 Mentor

msports180

Posted
  • Author
Posted

Thanks for the replys guys.

It was Mu's Secret sorry: http://www.musecret.com.au/category37_1.htm

I have emailed them but as of yet no reply, i took it for another spin the other day, when its hot u can indent the underside with your finger nails...

  • 1 month later...
Noy Experienced

Noy

Posted
Posted

How did you go with this Neil?

Did Project Mu come back with a response?

Prepreg :no: fkn LOL, you are well out of touch with the market if you think these are made with dry carbon.

+ factor in the cost of running an Autoclave.. unless someone in the world has learnt how to run an autoclave from a hamster wheel.

Also the statement about 300c prepregs is way off..

300c you would be looking into Phenolic's or BMI's and these make the $80-$100/sm prepregs look cheap.

Noy

Carbon 34 Grand Master

Carbon 34

Posted
Posted

How did you go with this Neil?

Did Project Mu come back with a response?

Prepreg :no: fkn LOL, you are well out of touch with the market if you think these are made with dry carbon.

+ factor in the cost of running an Autoclave.. unless someone in the world has learnt how to run an autoclave from a hamster wheel.

Also the statement about 300c prepregs is way off..

300c you would be looking into Phenolic's or BMI's and these make the $80-$100/sm prepregs look cheap.

Noy

I use it all the time mate

Worked in aerospace at lockheed on shuttle/rocket parts as well , I do know a bit

Even exotics like zylon !! Used on the deep space probes

Spunky Munky Grand Master

Spunky Munky

Posted
Posted

This begs the question; has there been a general decline in people rocking CF bonnets as I see many people actually wanting to go back to the stock metal one. Is this true and why?

Carbon 34 Grand Master

Carbon 34

Posted
Posted

Defectable in carbon ?

funny pretty soon all cars will have carbon parts , more every year and not just exotics

Slam some kevlar in the mix the thing would be stonger then hell and not crack on impact

my body kit is layered in it , its abrasion resitant as well for parking blocks and spoon drain rubs

666DAN Grand Master

666DAN

Posted
Posted

It's not vinyl ester !!!

Yeah vinyl ester and carbon gives a weak bonnet, epoxy is the win....but as mentioned it depends on the type of epoxy formulation; to be honest you're not going to see too many aromatic amine-cured, BMI-Novolac hybrid bonnets getting around in consumer circles.

On an unrelated note, I've got a part I made at work which is silicon carbide bound by a BMI-Novolac hybrid . It got the nickname "the indestructable disc" after many attempts by the lab guys to do it harm. Fantastic paper-weight!

Spunky Munky Grand Master

Spunky Munky

Posted
Posted

666DAN, aren't you the guy famous on here for selling LED dash lights? I bought a set off you almost 3 years ago and it's still running strong.

So you're a CF pro now are you? Why not start making your own bonnets?

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