Maintaining your carbon fiber part's finish

It is a fact that not all carbon fiber is created equal. This disparity is evident in the quality of the finish you see when you compare low-priced carbon fiber components and those from established manufacturers like Seibon, Vorsteiner and Superleggera. As you may know, there is a wide variety of resins available to composite fabricators, and the quality of these resins play a large part in the resulting quality of a CF part. And after freeing the part from the mold and final trimming, the clear top coat that is applied to protect the resin and carbon fiber layers from the elements will also affect how the part looks.

Over time, hazing can occur on the surface finish of mediocre-quality parts and some intervention on the owner's part is required to keep the finish as close to the original look as possible when it was new. Another thing to watch out for is radiant heat discoloration from automotive components like exhaust manifolds, turbochargers or even just plain underhood temps. Radiant heat will cause carbon fiber to scorch/change color. Using insulating or reflective metal tape like that used by air conditioning techs will help prevent the discoloration that can cause your beautiful carbon fiber part to become an eyesore. This kind of eyesore will be most evident in the broad expanse of a CF composite hood, which normally does not have the underhood protective layer that OEM hoods come with.

With age and use, swirls will also become evident on the surface finish of a carbon hood or other component made from the same material. These minute cracks and imperfections are part of the oxidized resins that cause fading and hazing. Normally these can be restored to their former finish by a refinishing kit that contains paint removers and waxes. Since the swirls are in fact microscopic cracks, the abrasive paint remover will smooth over the ridges that you see as swirls. Of course, one has to be careful to stop at the point where the swirls are removed, otherwise you may expose the actual resins to the elements that can induce bigger cracks. Unlike removing scratches from paint, you will not have the telltale sign of your rag turning into the color of the car's paint, which would indicate that you're already going too far. For large surfaces like a hood, remember to work on small sections at a time.

If the surface finish on your carbon fibre part is too far gone and no amount of DIY care seems to make a difference, you can look into having a local paint shop adding a fresh layer of clear coat. This should restore the surface look and finish of the part to like new condition, unless it is the resin itself that has become discolored.