Carbon Fiber Roof Saved! dreadful gel-coat fix

[E92friendly]

I AM HERE TO HELP WITH ANY QUESTIONS FOR THOSE IN CONSIDERATION OF THEIR OWN EFFORTS!


So I myself have done countless hours of research trying to figure out who else saved their carbon fiber roof from the peeling gel-coat. The most i found was one guy with an M6 made a video talking about his roof and ended up painting it the same color as the car. Well folks, that does not satisfy me. I purchased the car for the car and its performance and aesthetics. Painting over the looks of the carbon the same color of the car would be nothing but an utter disappointment. So here I am now writing up on this experience and hoping i give a deep insight on my experience on recovering the roof without sacrifice. I am also conducting this write up to help give people the relief that they to can also salvage their roof from the horrifying gel-coat that becomes weaker over time from outside sittings. Not only have i taken plenty of pictures but i also made some video footage of my process for them DIY guys. I want to make this write up simple and fast because no one wants to read forever. haha.




Lets begin



remove the antenna cover, it is double back taped so you can get some sort of strong thin plastic to removed it cutting through the tape. once removed, use a T25 or T30 torque socket and pop the antenna off. I suggest taking a picture of the wiring plugs to ensure its plugged back into the same slots.

Peel from the beginning center of the roof

Work your way around until entire center is peeled

in my experience the 4 corners begin to become a challenge. that is because the roof is a dome shape which the sun beats directly in the center.

any hard areas to work i used a brand new clean razor blade.

you cannot cut directly with the blade you must take your time and do a teeter-totter motion to slice through the gel-coat. be sure to keep the blade in a very sharp angle to prevent slicing into the roof. it may happen that's okay just cannot cut so deep more than likely you will not see it after re-cleared.

where the antenna is located try your best to remove as much clear as possible but keep in mind the antenna will cover the area so it is okay if there is a hard line inside within the cover itself no one nor you, will see it.

as for the edges, use the blade in a sharp angle to carefully cut through the clear, it was relatively easy for me cut down as much as possible, keep in mind also here the roof moldings will hide any hard lines in there too.

it is an option for the enthusiast to have both front and back glass removed for painting but is not needed. they can pull back the strip and mask off the seal.

mask off the hole where your antenna was with good tape and rinse down your roof cleaning it up as well as you can with water, also enjoy it with water on your roof as it simulates clear coat looking clean.

The next morning i drove to my shop where i work and parked my car inside the other building till my lunch break and dropped the car off at my buddies shop down the way for him to do the job.

5-7 coats of clear is recommended, every 2 coats sanding is recommended. the final coat you will still see the weave pattern in the clear coat as it settles in. my buddy did 7 coats as he told me. i left it alone at that if i want to i could sand it down and buff polish to give it a flat final finish. but the weave pattern in the coat does not bother me i dont really notice unless i take a good look at it.

As safety reasons i highly suggest gloves and a respirator at most to avoid inhaling and getting all the resin all over your hands. do at your own risk.

[0-60Motorsports]

Excellent work on rescuing the CF roof.

[Blindside_137]

Very nice. Looks brand new.

Should be very helpful for others. I know I have seen at least one post or two about guys who had their carbon roof start to fade or peel.

[///M Power-Belgium]

Good job , CF roof looks really good !

Think I saw a dent in your car ?

[E92friendly]

Originally Posted by ///M Power-Belgium

Good job , CF roof looks really good !

Think I saw a dent in your car ?

Haha! Yes thanks for pointing that out the first owner put a bike rack on the car. It's okay i will repair that to on a later day the hood also has a ding.

[vincE92M3]

Nice work!

[deansbimmer]

Great work!

Most will recommend painting the roof body color because removing the clear from bare carbon is very difficult. It is very easy to use a sander and go past the clear and into the weave which will ruin the weave's visual effect. Clever of you to use a razor to shave off the 'dead' clear. Sounds like the conditions were just right to allow it. Most shops wouldn't hassle with that method.

[E92friendly]

Originally Posted by deansbimmer

Great work!

Most will recommend painting the roof body color because removing the clear from bare carbon is very difficult. It is very easy to use a sander and go past the clear and into the weave which will ruin the weave's visual effect. Clever of you to use a razor to shave off the 'dead' clear. Sounds like the conditions were just right to allow it. Most shops wouldn't hassle with that method.

Well hopefully I did not miss lead anyone because I only used the razor blade for the edges and the four corner areas of the roof but mostly 90% from the center and out words easily peeled off with a thin hard plastic scraper a used from work also keep in mind I am an autobody technician so I was confidently able to do this project. But I feel that anyone can do this since no true bodywork is needed other than time and effort and patience to peel off the existing gelcoat

[vincE92M3]

Was your car parked outdoors in the sun for most its life?

[E92friendly]

Originally Posted by vincE92M3

Was your car parked outdoors in the sun for most its life?

Yes that is why It happened.

[JRob23]

Looks good. I'm curious if that dent would be difficult to pull/pop given its position on the car.

[E92friendly]

Originally Posted by JRob23

Looks good. I'm curious if that dent would be difficult to pull/pop given its position on the car.

As a body tech yes I can pop most of it out with a dent puller, however I will still need to fill the little bit left in with putty or glaze and block it smooth.

[6ixSpd]

Great work salvaging your roof! Always good to see people trying new ways to fix these issues.

[E92friendly]

Originally Posted by 6ixSpd

Great work salvaging your roof! Always good to see people trying new ways to fix these issues.

I had also posted a thread of a repair salvaged front carbon lip as well.

[M3MPH1S]

So once you peeled off the damaged layer did you sand the bottom most exposed layer before you started painting? Or was it already sufficiently clear?

[Dr. Dre]

I use to work for Mitsubishi Motors NA. The carbon fiber rear wing coating would start to fade and peel. One of the body shops in San Jose was able to fix them. The guy would use a razor blade and strip it by hand (amazing) and refinish it. They looked pretty much factory.

It was so good that we sent finished samples back to Japan.

[Crash n burn3]

Where are your videos?

[MachinesWithSouls]

Could you wet sand it instead of taking a razor to it?

[m3jala]

Awesome

[MikePe92]

Hi all, new to the forum. I have a 2011 M3 Coupe with the CF roof and just started having the same issue. I had a small chip and moisture got underneath the clear so now there's a bubble about 3 inches in diameter.
Can anyone recommend a body/paint shop in the Los Angeles/Orange County area that can do this repair?

The body shop I use for some of my other cars has never done this with carbon fiber and said that his guys would normally sand down the spot, feather it out and respray the clear coat.

Thanks, Mike

[BayE30]

5-7 coats of clear with sanding in between would cost a fortune for the consumer. almost better value to replace with a new roof... for insiders it makes sense, but otherwise probably not.

[MikePe92]

I'm in the auto industry so I can get insider rates. The issue I'm running into is that a lot of the shops that I use haven't done anything like this (and generally don't work on CF). Is this process something that any competent body shop should be able to do if I show them this link?