Painting a Carbon Fiber Roof

Long story short, the gel coat on my roof has failed in a number of spots despite periodic detailing and protection. The roof is stripped and awaiting next steps - clear coat or paint. Local shops do not want to attempt clear coating and are pushing me to paint to match the body color or jet black for contrast. Cost is not really the issue, just looking to do it right.

I am disappointed in BMW craftsmanship on their carbon fiber roofs. If it were on an E92 generation issue in certain climates, that is one thing. But, this issue is appearing on F generation cars as well. Even in cars without failure of the gel coat, yellowing is still an issue.

Clear coat it or take it to different shop

That's kinda telling me they don't know what to do with it.

mvestor wrote

Long story short, the gel coat on my roof has failed in a number of spots despite periodic detailing and protection. The roof is stripped and awaiting next steps - clear coat or paint. Local shops do not want to attempt clear coating and are pushing me to paint to match the body color or jet black for contrast. Cost is not really the issue, just looking to do it right.

I am disappointed in BMW craftsmanship on their carbon fiber roofs. If it were on an E92 generation issue in certain climates, that is one thing. But, this issue is appearing on F generation cars as well. Even in cars without failure of the gel coat, yellowing is still an issue.

Can I ask which state you live in, and is the car parked outdoors under hot sun?

Florida. Garage kept since I purchased in 2013.

Definitely UV related in my case.

If the shop doesn't know what they are doing, find another one.

Clearing the roof is easy. Sand down starting with 400 grit, then hit it with an 800 grit pass then full clear. 3 layers. Polish out and it will last for years to come.

Any bodyshop that says they can't do it is a joke and should not be working with cars from the get go.

I see posts/comments like this every once and awhile.

Long term and I mean like years and year term, I don't think E9X M3s were meant to live out in the sun.

Drive in the sun? Sure. Parked out 24.7, I don't think so. I am fortunate to have a garage and my office has a parking pad I park under. Car only sees sun on the commute or parked at Cars & Coffee for 2 hours.

That gel coat has a shelf life. Some shorter than others.

I live in Central FL and had some rocks chips into the carbon roof which where repaired and re cleared. Looks amazing and only cost 500.00 prob like 6 or seven lays of clear

I would try and find a high-end boat repair shop for a second opinion

Please please - for everyone on this forum's sake - do not paint over the carbon roof. That shop just doesn't know what they're doing or doesn't want to deal with it.

This thread may be helpful, too: Carbon Fiber Roof Saved! dreadful gel-coat fix https://www.m3post.com/forums/showthread.php?t=1406986

You need to find a place that has experience with carbon fibre repair. Look for Ferrari-approved body shops, for example. It will cost you more than typical paint work, but this is the nature of exotic materials.

Problem solved...CF Wrap. Look for an update on the shark fin wrap today 4/12.

https://www.m3post.com/forums/showthread.php?t=1697557

Shop in the background is Euromotive in Florida. They could probably refer you to a good local paint shop.

Also post in the Regional Forums for the Southeast and Florida.

Cheers

Do it right. Use a bristle disk with a good angled grinder attachment. Then clear coat it.

It will come out like new if you use the correct hand tools.

Cheers -

Find a better shop, I got mine re-cleared and it looks brand new. They took the windshield off and replaced all the trim too

phantasticphan wrote

Find a better shop, I got mine re-cleared and it looks brand new. They took the windshield off and replaced all the trim too

I would love to find a shop in the greater Houston area that can do this. These types of boutique car shops seems to exist only in California and Florida

GM

phantasticphan wrote

Find a better shop, I got mine re-cleared and it looks brand new. They took the windshield off and replaced all the trim too

Where did you get it done? I have few rock chips and it’s been bugging me for a while lol

TheRussski wrote

phantasticphan wrote

Find a better shop, I got mine re-cleared and it looks brand new. They took the windshield off and replaced all the trim too

Where did you get it done? I have few rock chips and it’s been bugging me for a while lol

2m autowerks off Miramar rd

phantasticphan wrote

2m autowerks off Miramar rd

Thank you!

There is no gel coat on these roofs. Gel coat is used mainly in boats and molds and for products that need color and will not be painted. My belief is that BMW didn't prep them properly. You can't prime carbon that will be exposed unless there is a clear primer that I'm unaware of. Carbon is super slippery and requires a mechanical bond post cure opposed to a chemical. Therefore prep is a must. Carbon is also super forgiving from a sanding aspect. Meaning you can use more abrasive grits of sandpaper and not have sand scratches show through the clear as the same paper would if it was painted. Carbon is tricky in that it soaks up the clear coat. I made a carbon fiber skateboard several years ago and used a stupid expensive clear coat on it. Luckily I pounded the clear on because every couple years I have to wet sand and buff because the carbon started to "soak up" the clear and you can see the weave in the clear coat.

Carbon with epoxy has to be cleared with a quality clear or you will have yellowing from UV exposure. So when you see those Chinese carbon parts with a yellow tint they either skipped the clear or used a crappy one.

These are reasons why some shops don't want to touch it. You may think that these shops are inexperienced or don't know what they're doing but I'd say the opposite. It's actually pretty smart of them to pass on these jobs. From a time and money aspect it would be a quick job for them but they wouldn't make to much money either and the chances of you coming back in a year or two claiming warranty are pretty high. They don't know how it was prepped or what clear was used and in order for them to do it right they're have to sand off all of the existing clear. Doing so would provide the best results and ensure that there clear and the BMW clear would be used in conjunction and potentially cause adverse affects.

Sorry I'm an ex aviation composites engineer and a nerd.

Like everyone else as suggested - find a different shop. There's a shop down here in Doral that detailed a carbon roof restore on Instagram for an E92 M3 (sun damage) that came out looking like new. Lots of sanding and layers of clear were used but he got it.

CHE///MIST3 wrote

phantasticphan wrote

Find a better shop, I got mine re-cleared and it looks brand new. They took the windshield off and replaced all the trim too

I would love to find a shop in the greater Houston area that can do this. These types of boutique car shops seems to exist only in California and Florida

GM

If you're not familiar with them already, contact ABR Houston. I had my PPI done there - positive experience. They're super familiar with these cars. They likely don't do this type of work but might be able to point you in the right direction locally.