One Of Our Most Popular Carbon Fibre Repairs Currently Is In The Form Of Carbon Roofs Found On The BMW M3 / M4 Platform!

Sadly, carbon fibre does age, over time and the finish will degrade from a variety of different factors. One of the biggest reasons that carbon fails is due to bird droppings and acid rain along with general fallout.

We are starting to see an awful lot of carbon roofs failing to the point where it made sense to create a blog to discuss this. We have over the last few years been undertaking more and more carbon roof restorations to bring back a failed finished to a high lustre shine that looks like the day it did when it left the factory. The process however, can differ slightly depending on the extent of the damage. With a lot of modern day BMW M3’s and M4’s having carbon roofs as standard, these generally are the most common car we see in for carbon roof repairs.

To take a recent look at a repair we recently carried out (as below), the lacquer on the roof of this BMW M3 had failed which allowed water ingress under the lacquer (which then lifted and peeled). Once this happens you have a relatively short window to rectify before there is a potential of UV damaging the carbon (yellowing) along with water embedding into the fibre themselves which both are incredibly difficult and sometimes impossible to resolve. This roof had suffered from UV and weather staining on the carbon but as you will see from the end result, it has now mostly been rectified to the point even when looking for it, it’s difficult to see.

To start off with we stripped down the lacquer on the roof which since the lacquer had pretty much unbonded itself from the carbon, this was a fairly pain-free process. Sometimes more sanding is required but, in this case, sharp blades can lift the lacquer or air pressure. We tend to use a more manual approach as it negates any potential for a catastrophic problem from using high powered air pressure.

With the lacquer removed, we applied resin to seal in areas of the carbon that had been damaged to ensure the fibres are structurally sound and the roof was level. The entire roof needs to be prepped for lacquer which require a sanding procedure, if this is done incorrectly, the carbon can be damaged leaving an uneven weave and finish. Once the prep work is done, generally we layer 2-3 coats of lacquer to seal the entire roof in. Lacquering carbon is difficult to get a permanent bond and you can’t prime carbon in the same way you would bodywork which means it’s more delicate and needs more care than paintwork to preserve its finish.

This particular M3 had perished window seals so these were replaced at the same time. Technically the front screen doesn’t need to be removed but following BMW’s technical work instruction and procedure, it should be removed, this also has the added bonus of allowing the lacquer to penetrate further into the roof line.

Once back from lacquer, all that is required is a good flat and polish. We do also offer a ceramic coating option which can help protect from future damage. This customer took the opportunity to upgrade the level of finish and protection with a G-Techniq Ceramic coating.

If you would like to discuss a roof repair or any other carbon repair work for that matter, please do get in touch via our contact form to discuss further. Generally, carbon roof repairs and refurbishments start from £2,000+VAT. A fair amount cheaper than replacing the entire carbon roof for more than £4,500+VAT as I write this!

Thanks for reading and if you have a carbon roof that has failed or any other form of carbon repair required please do get in touch.