The Easy Way to Refinish Carbon Fiber
Who doesn't love carbon fiber? It's light, it's strong, it can be used in so many different applications. However, what many people don't realize is that carbon fiber takes an extra level of care to ensure longevity. So what happens if you have skipped out on some of the maintenance that carbon requires?
What happens when carbon fiber is not washed and waxed as often as it should be? Well, just like paint and headlights, carbon oxidizes. This means that the outer surface starts to degrade, picking up more debris and inclusions, and essentially starts to rot. This is almost exactly the same scenario that happens to headlights that have been exposed to the elements for a few years. This is because the resins used to make carbon fiber parts are just like plastic and react when exposed to UV light (sunlight).
Over time this oxidation destroys the clear coat on the carbon making it look dull, hazy, and chalky. At that point no amount of wax or polish is going to bring back the gloss or correct the problem.
The only real way to correct the problem is to remove the oxidation and contaminants, or in some cases the clear coat entirely. This gets the part back to the base gel/resin coat or to the carbon weave itself so that a fresh clear coat can be applied. This is the recommended process from Seibon Carbon and Meguiar's and can be done in your garage with a bit of patience and elbow grease.
The first step is to remove the part and survey the damage. If there are significant cracks or fissures in the clear and gel coats going down to the weave itself these are labor intensive to fix and a new part may be more cost effective in the long run. Hazy/chalkiness is superficial and can be wetsanded out before new clear is applied.
Assuming there is no structural damage and the part has been thoroughly washed, wipe the part down with a wax/grease remover. This is important otherwise you run the risk of embedding old wax into the gel coat or weave which will cause painting problems later.
Then begin the labor intensive task of removing the haze and oxidation by wetsanding the part with 400 grit sand paper (don't forget to put a drop of detergent in the water used for wetsanding). Wetsanding normal clear coat will leave white sanding residue, but sanding-off oxidation will leave a tan or brownish residue similar to wetsanding oxidized headlights.
If the sanding residue starts turning grey or black STOP IMMEDIATELY. This means you have started to sand the actual carbon weave. When the whole part is sanded, wipe it clean with acetone and then rubbing alcohol. The part should look like satin carbon fiber. If any hazy spots remain, sand those areas again.
After the part is sanded and clean, inspect it again for any structural damage, fissures in the clear coat, or any deep chips. If there are then the chips and fissures need to be filled first. They should be filled with a premium epoxy resin such as West Systems (105 resin and 207 special hardener). Mix the resin per the manufacturer's specifications. Apply it to the chips and fissures with a fine artist's brush and let it cure over night. Sand those areas smooth with 400 grit again and re-clean the part.
Once everything is smooth and repaired it is time to clear coat. A premium clear coat is recommended such as House of Kolor's Show Clear because of the high UV protection (think sunscreen for the carbon fiber). Mix and spray per the manufacturer's recommendations. Note that your local paint and body supplier might let you rent or borrow a quality spray gun such as Iwata or Sata. If it is a small part, you can order urethane clear coat in spray can form from www.automotivetouchup.com. It is highly recommended to spray out two wet coats, let cure, then spray 2 more wet coats. Wetsand with 600 or 800 grit prior to the second round of coats.
Once the part is cured, you can cut and buff to a show quality shine following Meguiar's instructions. Or if the clear layed out nice then you could leave it alone. That part all depends on the finish quality desired.
How to Maintain Carbon Fiber
Whether it is a new carbon part or a refinished/restored carbon part (after 60 days of curing), care and maintenance will extend the life of the part for years. The care process is simple really. Wash your vehicle regularly with a quality car wash like Meguiar's Gold Class or Ultimate Wash & Wax. Then polish it with an actual polish (before waxing) with something like Meguiar's Ultimate Polish or Show Glaze. The polish is important as it returns essential polymers to the clear coat, just like lotion returns moisture to your skin. Then lock it down with a good wax such as Meguiar's Ultimate Wax. Keeping the vehicle and especially the carbon parts waxed is absolutely crucial to extending the life of a vehicle's paint and the life of the carbon part.
For example, the 370Z shown has a one-off carbon roof, interior, front/rear trim, and Seibon Carbon front and rear lips. The roof is 9 years old, interior is 8, and the lips are 1.
Yet all of them still maintain an OEM level of gloss and luster with no visible forms of oxidation. This was achieved by staying up on maintaining good wash and wax habits. Carbon fiber is an expensive investment and it only makes sense to maintain it accordingly.