Yellowing Carbon Fiber

[RufMD]

Originally Posted by porschemeister

I am also very interested what the outcome will be. I am in the market for a GT and have looked at several GT's owned by friends and the yellowing really disturbs me....

I am not a concours guy, but love to drive my cars and thought oh well a little yellowing no big deal, but seeing it in person it sucks really bad

Especially when you have carbon which looks normal right next to the yellowing stuff. The brace in the back is the worst.

How will this effect the market for these cars??? I think we are currently only seeing the tip of the iceberg and lots of owners are looking "the other way" right now because the car has so much to offer otherwise.

I guess time will tell.

In time, it will be called patina....

[Jarez Mifkin]

I was looking a GT yesterday that has 1600 miles on it, never driven in rain, is garaged in a heated/cooled garage and say that the brace in the back of it is yellowing slightly. The fender liner next to it is still perfect...

[Bill S.]

Originally Posted by jmorris3

I was looking a GT yesterday that has 1600 miles on it, never driven in rain, is garaged in a heated/cooled garage and say that the brace in the back of it is yellowing slightly. The fender liner next to it is still perfect...

Does the CGT use two different types of materials? That is, for the structural parts, I think Porsche uses carbon-fiber-reinforced-plastic (CFP). The other parts may use a different composition. Is it the plastic in the CFP that breaks down in the UV rays? If so, it may be a much more serious problem than just cosmetic.

The fact that the yellowing is occuring after only a few years is disturbing. That implies there is a finite life to these pieces from UV rays and possibly even mechanical stresses. Porsche should have a public announcement that clearly states what's happening here and what this means to CGT owners. If they don't, I suspect it may be a bigger issue than just yellowing.

BTW, I agree that carbon street cars are overkill. We've already seen lighter street cars with less exotic materials, including new cars coming from Porsche. Remember that the CGT is built off an existing racing design, not a street design. I doubt Porsche would ever again make a street car in carbon.

The only possible advantage I see in a carbon street car is the strength of the tub providing increased safety for the driver and occupant. However, a much less expensive roll cage does that also.

Current sport cars are too big, and much effort is spent making these big cars lighter. GM initiated the smaller sport car with the Z06. Ferrari will likely be the lead in the next generation of smaller sport cars. In 10 years, I predict the current sport cars will look way too big.

[porschemeister]

I looked at a 1997 911 GT1 yesterday and ALL the carbon fiber pieces (doors, part of the rear frame which is wrapped around tubes) is just fine. No yellowing whatsoever...go figure a car 10 years old

[autosea]

MY company Autosea Enterprises is composite based boat building. I am fully insured to work on Porsche CGT. See previous posts on this yellowing thread.
Its not rocket science.
Colin Taylor
Autosea Enterprises
206.612.0444

[pcar964]

Originally Posted by autosea

MY company Autosea Enterprises is composite based boat building. I am fully insured to work on Porsche CGT. See previous posts on this yellowing thread.
Its not rocket science.
Colin Taylor
Autosea Enterprises
206.612.0444

No, but it is carbon science

[oc997]

Yellowing is merely a function of the pre-preg resin embedded in the carbon fiber changing colors from UV rays. It is mostly a cosmetic issue and does not compromise the structural integrity of the carbon parts. The carbon fiber itself is very much intact and undisturbed.

A industry tip for the owners would be to have a good painter lightly mist a black ghosting on the carbon parts and go over this with 1-2 layers of a high quality clear from PPG or Sikkens. This should eliminate the yellowing look of carbon and bring it more black.

Regards,

[RufMD]

Lots of hyperbole here....fact is, the CGT market is stronger than ever with many buyers looking for cars, despite this issue being breathlessly bantied around.

[PogueMoHone]

Originally Posted by RufMD

Lots of hyperbole here....fact is, the CGT market is stronger than ever with many buyers looking for cars, despite this issue being breathlessly bantied around.

I think you are onto something here.

So many opinions and so few cars.

The OP never did follow up on his promise to produce the purported communication from Porsche (IIRC).

His efforts at driving the CGT are plastered all over Youtube and might lead one to the conclusion that the car had a hard life, and he is now tired of it.

I wonder if there were modifications (ecu, etc.) to that car and that there might be more to the incident than we know.

It is amazing to watch how people grab the "negative" as fact, all because of something they want to believe.

The yellowing issue is a lot of bullshit. No material (man made or natural) will ever withstand the impact of UV or mother nature (or heat), but that doesn't make it a problem.

There is always someone looking for deep pockets.

I will follow this "purported" lawsuit with great interest...but I won't hold my breath waiting for it to happen, and I wouldn't make any decisions (or conclusions) based upon the claims.

Anybody want to buy a bridge?

[PCH]

Originally Posted by VRAlexander

My CGT has been turning Yellow for the past eight months!! I have brought this up to Porsche and they are not willing to stand behind their product...they are pointing fingers are the carbon manufacturer...It is so bad on my car that the rear engine sub-frame has turned yellow/orange as well... I am very dissapointed with PCNA!!!

I spoke with my service manager and he said that if Porsche was to warranty mine, they would have to warranty everyone's and thus would result in a HUGE monetary loss for them! As a result, I am selling my CGT and not picking up my GT3rs......Porsche has lost a repeat customer...

Alex, you have a PM

[jury_ca]

Ever considered what it's like from Porsche's perspective?

You have a single supplier for the CF trim. It seems like the supplier's product failed to meet the spec in terms of cosmetic-appearance after a period of use. The issue is not a manufacturing defect but a design defect (i.e. the process and materials used to create the cf trim). That is why the problem is consistent across a number of cars. If you replace the cf trim on the customer's cars the problem will resurface with the new cf trim, so that is not a satisfactory option. Only option is to determine the root-cause of the problem, correct it, undergo a bunch of tests once again to ensure it meets all other specs. Manufacture a new batch (for a vehicle no longer in production). Oh, and since it's your supplier's fault, ask them to cover the cost of all of this.

You can see why the supplier might be dragging its feet. Porsche literally have their hands tied behind their back on this one.

[cr207]

i believe it was mentioned that this uv gloss costs something like $1000 a gallon.

[Tipo815]

Originally Posted by oc997

Yellowing is merely a function of the pre-preg resin embedded in the carbon fiber changing colors from UV rays. It is mostly a cosmetic issue and does not compromise the structural integrity of the carbon parts. The carbon fiber itself is very much intact and undisturbed.

A industry tip for the owners would be to have a good painter lightly mist a black ghosting on the carbon parts and go over this with 1-2 layers of a high quality clear from PPG or Sikkens. This should eliminate the yellowing look of carbon and bring it more black.

Regards,

After 14 pages of posts I was thinking the same thing. I bet a good painter could premix some blend of black and clear and lightly mist the yellow pieces to reduce the "yellowing." The only problem might be the need to mist everything (good and bad pieces) so it blends properly. Not a proper solution by any means but probably the most economical one versus the alternative!

[jimhuber]

Originally Posted by VRAlexander

Thanks guys....Its good to be here...

I have escalated the CGT issue all the way to Porsche AG and they flew out some people that spent two days with the car at the dealer...they took over 100 photos and then flew back out. That was over 6 weeks ago and now all they can do is point the finger at the carbon manufacturer.. If this was a 20K car, that would be one thing...however this is a $500,000.00 car and they treat their customers like this??? Not even a phone call or thorough follow up??? Thats BS! PCNA has been very good to me for years and years and they stand behind me 100%...Its Porsche AG that is making the call on this one.... I can understand (to some extent) their position, however this is BS...I was planning on picking up my GT3rs next week and had an order in on a new GT-2 as well as expressed interest in obtaining the CGT replacement when they released it....I am done with Porsche...this is very dissapointing..

On the other hand, you would think that they learned...my 996 turbo had a similar problem with the carbon and they where happy to replace it...several times ?????? Go figure ????

IMHO you give up to easy. You need a bulldog with that type of car and others. I do not know what you do but I am sure it is more important than fighting with Porsche. Good luck.

Jim Huber

[shustermeister]

Originally Posted by cr207

i believe it was mentioned that this uv gloss costs something like $1000 a gallon.

Both AutoWeek and Car And Driver reported the cost of the UV inhibitor at $60,000 per gallon!!