E92 Carbon Fiber Roof - Restoration Success Story

[mvestor]

Late last year, my detailer noticed a spot near the middle of my carbon fiber roof that looked as though something had found its way underneath the gel coat. I knew immediately that something had hit the roof and caused the integrity of the gel coat to fail. Flash forward several months and the spot got worse until eventually I had enough and began removing the gel coat in sheets to prepare the roof for either replacement or refinishing.



My local BMW dealer would not touch the roof, nor would their certified shop. I quickly found out what a pain this process would be and fortunately had the garage space and alternative transportation to figure out the best next steps. With the Coronavirus mess I had enough time to call around found a shop in Central Florida (closer than I expected) that specializes in restorations - they actually have done some paint work for Revology Cars. Carbon fiber was somewhat new to them, specifically how to remove the residual gel coat (yellowing) and the most efficient products to replicate the OEM look, but hopefully last longer than OEM. Needless to say, I gave them the go ahead to research, experiment and do what needed to be done. At the very worst, the roof could be painted to match the body if restoration was not successful.

Enter PPG. The shop has a good relationship with PPG and some of their personnel involved with their racing division. By some miracle, an employee had a similar experience to mine with an F80 M3 and shared the process he went through. I wanted to share with everyone some process photos that shows the roof after a chemical treatment to remove the gel coat residue and the final product after 5 coats of clear coat with intermittent sanding and preparation.







There is still a little bit of buttoning up to do to finish the job before putting the car up for sale, but I wanted to share this with the group - restoration can be done! As to what started the mess, I can only speculate that an acorn or piece of debris poked a hole in the already weakened gel coat and the rest was history. It is not if your roof will have an issue, it is when (at least that is my opinion). I am happy to share anything I can, so please feel free to reach out.

[dlsq]

Nice job!

[MechEngineer408]

Very nice

[PYE46M3]

Interesting! Glad everything came out ok!

Do you think it’s a good idea to cover the roof with XPEL to protect it from rock chips etc damaging the gel coat ?

[SYT_Shadow]

Originally Posted by PYE46M3

Interesting! Glad everything came out ok!

Do you think it’s a good idea to cover the roof with XPEL to protect it from rock chips etc damaging the gel coat ?

it is, for sure

[njdrive]

Looks good!! What was cost for the repair?

[mvestor]

Originally Posted by njdrive

Looks good!! What was cost for the repair?

Right under $1,000. I've seen it can be done cheaper; however.

[SoCalRPM]

Looks good! Would love any more details like what chemical was used to remove the gel coat residue, etc?

Get PPF after all that work for an added later of protection

[njdrive]

Originally Posted by mvestor

Right under $1,000. I've seen it can be done cheaper; however.

Thank you. Based on the quality of cars they work on I'm sure you got quality work.

[mvestor]

I appreciate the feedback. My main objective here is to share with the group that all is not lost - restoration can happen and there is no need to panic about a resolution.

As for the chemical they used to clean the roof, they did not disclose other than PPG recommended it. I will have to ask.

[crowtrobot]

Cool thread, thanks for sharing! Good to know it can be done for somewhat reasonable money.

[TX]

Man I must say that is absolutely amazing work. I grew up around boats doing small fiberglass and gelcoat patching and I can say whoever did that work is a real pro. You did well finding them.

[NeverL8]

Looks brand new! I had couple rock chips in my roof and I could see the moisture spots under the gel becoming bigger and bigger...so I wrapped it in gloss black vinyl (don’t care for cf look) and will have it redone before I sell the car in 20 years lol

Great alternative to replacing the whole roof for $5k+

[SRB_Mpower]

Can you please send me (or post) the shop info. I still haven't fixed my CF roof. Thanks!

[Mercinman]

Hey man, sent you a PM. Just wanted to post some pictures here. The first is of the roof after the shop re cleared it. You can see an overall yellowing and even some wavy discoloration at the rear edge next to molding. It was still there after reclear! Hoping I can find out more to get this crap fixed!

[Bubbles]

Originally Posted by Mercinman

Hey man, sent you a PM. Just wanted to post some pictures here. The first is of the roof after the shop re cleared it. You can see an overall yellowing and even some wavy discoloration at the rear edge next to molding. It was still there after reclear! Hoping I can find out more to get this crap fixed!

It looks like the some of the gel coat wasn’t removed all around the edges and near the rear.


OP, car looks great.

[MisterClutch888]

AWESOME. CF roof is definitely the most sexiest part of the E92.

[Biginboca]

I recently bought a roof from a wrecked e92m3 to swap into my non M e92. It had a few chips in the clear coat and I was able to repair them myself. It’s not hard just sand the the chips until the edges are smooth, then fill with clear coat or gel coat, and then wet sand to flush with the rest of the gel coat. My roof came out flawless...









It’s pretty much no different than repairing paint chips. Sand chip edges smooth, then fill the chip with paint (clear coat or gel coat in this case), and then wet sand after it’s dry. It actually surprised me how easy it was and I have never done any paint repair before.

[Mercinman]

Originally Posted by Bubbles

It looks like the some of the gel coat wasn’t removed all around the edges and near the rear.


OP, car looks great.

I wasn't very clear, the bottom picture shows the wavy discoloration around the edge and overall roof yellowing before being recleared. The top picture is after a shop sanded and recleared it. Roof is still badly yellowed and rear has the wavy discoloration. Not sure if the shop just didn't sand my roof down enough or what?

[1SloeEm3]

Originally Posted by Mercinman

I wasn't very clear, the bottom picture shows the wavy discoloration around the edge and overall roof yellowing before being recleared. The top picture is after a shop sanded and recleared it. Roof is still badly yellowed and rear has the wavy discoloration. Not sure if the shop just didn't sand my roof down enough or what?

The shop that did it didn’t know what they were doing . They didn’t prep it right. All the yellow is in the gel coat. I don’t think you can fix it anymore since they just cleared it .

[Mercinman]

Originally Posted by E92Em3

The shop that did it didn’t know what they were doing . They didn’t prep it right. All the yellow is in the gel coat. I don’t think you can fix it anymore since they just cleared it .

How would them clearing it prevent it from being fixed now? Shouldn't it just be able to be sanded down again past new clear etc.

[PYE46M3]

Originally Posted by Mercinman

How would them clearing it prevent it from being fixed now? Shouldn't it just be able to be sanded down again past new clear etc.

no because they will never know when to stop sanding.. they can sand right into the CF.

is the car at the shop? did you pay them yet? I wouldn't take her home until its fixed.