Carbon Roof Clear Coat Fix

[kwatkins12]

Hey Everyone- I have a few small areas of the carbon roof that have small chips or areas of missing clear coat. Has anyone used a product like this clear coat in a bottle to brush on the roof? Any other suggestions before fully committing to having the roof re-cleared?

https://www.automotivetouchup.com/st...clearcoat.aspx

[sarge153]

that could work but you need to remove all the flaked clear to start. Wet sanding would help

[BigFatRaccoon]

Edit: I stand corrected, looks like the oxidation is only in the clear so that's good

You could get the touchup as a bandaid solution but depending on the age of the car, it might be best to reclear, especially the 2015/16 cars that have seen some sun parked outside.

Talked to a euro body shop about it, they said they'd sand down to 600, smooth it all out and shoot a few coats of 2k UV resistant clear coat back on it. Contrary to what some say, it's not a gel but just a normal automotive clear coat.

The issue with these carbon roofs is once they become 9-10 years olds, it shifts the carbon from that nice factory dark gray color to a gross greenish/yellowish tint. Once that happens, refinishing won't "darken" it back to OEM as much, moreso just give it that refreshed protection it needs against the elements, UV, etc. Clear coat is clear and will only accentuate whatever color the carbon has become. Only way to "slow" this process is to park in the garage when possible, as to have the roof avoid the sun entirely, it's quite a shame really.

If you want to see how good/bad your roof is, a quick and free way to check is to open one of your foldable roof rail slots and peek into it. That will show you what your roof looked like from factory, as that part sees 0 sun being covered 100% of the time by the foldable flap.

I'd budget $500-1000 for this job depending on the shop, quality, and your relationship with them.

[M3SQRD]

Originally Posted by BigFatRaccoon

You could get the touchup as a bandaid solution but depending on the age of the car, it might be best to reclear, especially the 2015/16 cars that have seen some sun parked outside.

Talked to a euro body shop about it, they said they'd sand down to 600, smooth it all out and shoot a few coats of 2k UV resistant clear coat back on it. Contrary to what some say, it's not a gel but just a normal automotive clear coat.

The issue with these carbon roofs is once they become 9-10 years olds, it shifts the carbon from that nice factory dark gray color to a gross greenish/yellowish tint. Once that happens, refinishing won't "darken" it back to OEM as much, moreso just give it that refreshed protection it needs against the elements, UV, etc. Clear coat is clear and will only accentuate whatever color the carbon has become. Only way to "slow" this process is to park in the garage when possible, as to have the roof avoid the sun entirely, it's quite a shame really.

If you want to see how good/bad your roof is, a quick and free way to check is to open one of your foldable roof rail slots and peek into it. That will show you what your roof looked like from factory, as that part sees 0 sun being covered 100% of the time by the foldable flap.

I'd budget $500-1000 for this job depending on the shop, quality, and your relationship with them.

Removing the gel coat, wet sanding the CF and reapplying a new gel coat will bring the original CF color back. It’s the gel coat that yellows with time due to UV exposure. I have an ‘09 e92 M3 with a perfect looking 15+yo CF roof. My ‘12 e92 M3 (took delivery in Nov 2011) CF roof still looks perfect with the original gel coat with absolutely no yellowing. It’s been garaged its entire life and has only ~30k miles. My ‘16 f82 CF roof also still looks perfect.

[kwatkins12]

Originally Posted by BigFatRaccoon

Edit: I stand corrected, looks like the oxidation is only in the clear so that's good

You could get the touchup as a bandaid solution but depending on the age of the car, it might be best to reclear, especially the 2015/16 cars that have seen some sun parked outside.

Talked to a euro body shop about it, they said they'd sand down to 600, smooth it all out and shoot a few coats of 2k UV resistant clear coat back on it. Contrary to what some say, it's not a gel but just a normal automotive clear coat.

The issue with these carbon roofs is once they become 9-10 years olds, it shifts the carbon from that nice factory dark gray color to a gross greenish/yellowish tint. Once that happens, refinishing won't "darken" it back to OEM as much, moreso just give it that refreshed protection it needs against the elements, UV, etc. Clear coat is clear and will only accentuate whatever color the carbon has become. Only way to "slow" this process is to park in the garage when possible, as to have the roof avoid the sun entirely, it's quite a shame really.

If you want to see how good/bad your roof is, a quick and free way to check is to open one of your foldable roof rail slots and peek into it. That will show you what your roof looked like from factory, as that part sees 0 sun being covered 100% of the time by the foldable flap.

I'd budget $500-1000 for this job depending on the shop, quality, and your relationship with them.

Thanks for the advice, looking unit eh gel coat issue. If it’s truly gel I probably won’t mess with it and leave it up to a shop to fix I’ve called around a few places near me (SC) and received various answers. Some even telling me it’s not fixable or that they won’t touch it in fear of messing up the carbon.

[kwatkins12]

Originally Posted by M3SQRD

Removing the gel coat, wet sanding the CF and reapplying a new gel coat will bring the original CF color back. It’s the gel coat that yellows with time due to UV exposure. I have an ‘09 e92 M3 with a perfect looking 15+yo CF roof. My ‘12 e92 M3 (took delivery in Nov 2011) CF roof still looks perfect with the original gel coat with absolutely no yellowing. It’s been garaged its entire life and has only ~30k miles. My ‘16 f82 CF roof also still looks perfect.

Sounds like a bigger undertaking than I was initially thinking, not sure I’ll try a diy. Have you had to have any of the gel coats repaired from chips or the like on any of them? Mines a ‘15 and not a 10/10 exterior wise so I’m debating if the cost is worth it to fix the few small spots. I’ve been quoted around 2k.

[M3SQRD]

Originally Posted by kwatkins12

Sounds like a bigger undertaking than I was initially thinking, not sure I’ll try a diy. Have you had to have any of the gel coats repaired from chips or the like on any of them? Mines a ‘15 and not a 10/10 exterior wise so I’m debating if the cost is worth it to fix the few small spots. I’ve been quoted around 2k.

The ‘09 was used as a DD for 4.5 years so it was exposed to UV for several hours/day. It was just starting to turn yellow in 2019 but it was really noticeable when parked next to the ‘12. So I had a body shop that works on high-end McLarens, Ferraris, etc. redo the CF roof. Their work is flawless. You can’t tell it was redone.

I have no experience with small chip repairs on the CF roof. Has there been any local yellowing or delaminations under the gel coat? $2k sounds a little steep. Did they describe the process they’ll be using to perform the spot repairs? There’s no way to spot apply a gel coat so you’d have to use a clear coat only. I’d be concerned of localized delamination of the gel coat potentially occurring if significant water was absorbed in the areas with the chipped/damaged gel coat over time. The coefficient of moisture absorption/expansion are small for the gel coat and CF resin but non-zero. Sealing in the moisture in the gel coat by locally applying clear coat could over time cause small delaminations to form under the gel coat (moisture is now trapped in/under the gel coat by the spot applied clear coat). It has a low risk of actually happening.

[kwatkins12]

Originally Posted by M3SQRD

The ‘09 was used as a DD for 4.5 years so it was exposed to UV for several hours/day. It was just starting to turn yellow in 2019 but it was really noticeable when parked next to the ‘12. So I had a body shop that works on high-end McLarens, Ferraris, etc. redo the CF roof. Their work is flawless. You can’t tell it was redone.

I have no experience with small chip repairs on the CF roof. Has there been any local yellowing or delaminations under the gel coat? $2k sounds a little steep. Did they describe the process they’ll be using to perform the spot repairs? There’s no way to spot apply a gel coat so you’d have to use a clear coat only. I’d be concerned of localized delamination of the gel coat potentially occurring if significant water was absorbed in the areas with the chipped/damaged gel coat over time. The coefficient of moisture absorption/expansion are small for the gel coat and CF resin but non-zero. Sealing in the moisture in the gel coat by locally applying clear coat could over time cause small delaminations to form under the gel coat (moisture is now trapped in/under the gel coat by the spot applied clear coat). It has a low risk of actually happening.

There are areas on the roof I can tell it’s starting to yellow a bit but it wasn’t bothersome prior to the areas with peeling clear/gel. The 2k quote was to repair the entire roof not just the few spots. I am getting a few other opinions on pricing before making a decision on it. It sounds like the only real possibility to do this the right way is to completely redo the gel coat. Really appreciate the insight.

In the future any carbon roof will be getting PPF right away to prevent issues like this and hopefully some yellowing.

[M3SQRD]

Originally Posted by kwatkins12

There are areas on the roof I can tell it’s starting to yellow a bit but it wasn’t bothersome prior to the areas with peeling clear/gel. The 2k quote was to repair the entire roof not just the few spots. I am getting a few other opinions on pricing before making a decision on it. It sounds like the only real possibility to do this the right way is to completely redo the gel coat. Really appreciate the insight.

In the future any carbon roof will be getting PPF right away to prevent issues like this and hopefully some yellowing.

I’d recommend doing the entire roof if it’s starting to yellow. Once there’s UV damage, it’ll continue to worsen so get it addressed to ensure you’ll get it back to the original OEM look.

Good to know. $2k is in the right price range. Have they redone CF roofs before? Ask for pictures if they have. Any measurable hesitation in their response might suggest they don’t have any. Top shops might not have pictures, too, but they won’t hesitate telling you they don’t have any. They may also say they’ll ask a former client to bring their car by to show you. Basically, you’re looking for a shop you can trust.

Definitely get it ceramic coated before the PPF to add an additional layer of UV protection. You want this repair to be your first and your last!

[Jaizero]

Originally Posted by kwatkins12

Hey Everyone- I have a few small areas of the carbon roof that have small chips or areas of missing clear coat. Has anyone used a product like this clear coat in a bottle to brush on the roof? Any other suggestions before fully committing to having the roof re-cleared?

https://www.automotivetouchup.com/st...clearcoat.aspx

This is exactly what I used to fix a rock chip on my roof.

DON"T USE IT!

1k clear is not the correct fix here. There will be edges to the repair which will flake and peel eventually. The roof needs to either be replaced, or the existing clear needs to be stripped and reapplied.

I am shipping my car here for the repair this fall. There is nobody around me that will even touch the roof. I am in the midwest.

https://2mautowerks.com/service-pack...r-coat-repair/

[M3SQRD]

Originally Posted by Jaizero

This is exactly what I used to fix a rock chip on my roof.

DON"T USE IT!

1k clear is not the correct fix here. There will be edges to the repair which will flake and peel eventually. The roof needs to either be replaced, or the existing clear needs to be stripped and reapplied.

I am shipping my car here for the repair this fall. There is nobody around me that will even touch the roof. I am in the midwest.

https://2mautowerks.com/service-pack...r-coat-repair/

It’s odd that they say several layers of clear coat are applied. It should be a gel coat finished with clear coats. Here’s a video showing a gel coat being applied after removal of the factory gel coat, prep’ing of the CF and factory clear coat.

[kwatkins12]

Originally Posted by Jaizero

This is exactly what I used to fix a rock chip on my roof.

DON"T USE IT!

1k clear is not the correct fix here. There will be edges to the repair which will flake and peel eventually. The roof needs to either be replaced, or the existing clear needs to be stripped and reapplied.

I am shipping my car here for the repair this fall. There is nobody around me that will even touch the roof. I am in the midwest.

https://2mautowerks.com/service-package/bmw-carbon-fiber-roof-clear-coat-repair/

Thanks for the heads up on the 1k. I’m trying to find someone local or driving distance to fix the roof. To me it’s not worth 2k shipping each way and 2k for the repair, I would leave it how it is for now. I may also get a few trade in values and see how much the roof chips effect the value vs repair cost.

[Jaizero]

Originally Posted by M3SQRD

It’s odd that they say several layers of clear coat are applied. It should be a gel coat finished with clear coats. Here’s a video showing a gel coat being applied after removal of the factory gel coat, prep’ing of the CF and factory clear coat.

If I could figure out how they get it so clean and smooth before laying the gel coat I might consider trying this myself.

[M3SQRD]

Originally Posted by Jaizero

If I could figure out how they get it so clean and smooth before laying the gel coat I might consider trying this myself.

There’s a complete DIY on this forum or m3post (e9x M forum) in the DIY forum. The guy showed every step in extreme detail. I also look for it.

[hC1001]

Originally Posted by kwatkins12

Hey Everyone- I have a few small areas of the carbon roof that have small chips or areas of missing clear coat. Has anyone used a product like this clear coat in a bottle to brush on the roof? Any other suggestions before fully committing to having the roof re-cleared?

https://www.automotivetouchup.com/st...clearcoat.aspx

I did over a dozen rock chip repairs on my car. https://f80.bimmerpost.com/forums/sh....php?t=1709293

The repairs have held up well so far. I did half PPF on the front of the roof a couple months after the repairs. Main goal was to seal the CF. Its been 4 years since the repairs.