Polishing Carbon Fiber

Last Updated November 11, 2024

Carbon fiber trim on cars and motorcycles looks sleek, stealthy and above all, cool. Unfortunately, carbon fiber also scratches easily and is susceptible to clouding from oxidation. 

Polishing carbon fiber isn’t easy because it has a delicate gelcoat unlike the harder clear coat on car paint. So how do you properly polish carbon fiber to produce a beautiful shine? In this article, we’ll provide step-by-step instructions on how to polish carbon fiber safely to restore a glossy finish.

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Why Carbon Fiber Gets Cloudy and Scratched

The type of carbon fiber you find on cars and motorcycles is typically protected with a layer of gloss gelcoat.

Gelcoat is similar to the clear coat found on modern cars except it’s softer and more susceptible to scratches, which is why carbon fiber shows swirl marks easily.

Gelcoat is also susceptible to oxidation from the sun’s UV rays, which degrade the gelcoat and cause it to become cloudy, dulling the shine. 

The only way to repair this type of surface damage on a carbon fiber surface is to machine polish using a very light abrasive product. That being said, there are some important precautions you should take before polishing a carbon fiber gelcoat.

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IMPORTANT: Things to Know When Polishing Carbon Fiber

• Use a Gentle Polish: Carbon fiber gelcoat is soft. To avoid burning through the gelcoat, use a low aggression finishing polish or glaze when polishing carbon fiber. 
• Monitor Surface Heat While Polishing: Carbon fiber doesn’t dissipate heat as well as the body metal of a car, so it’s more susceptible to overheating while polishing. Try sticking with a DA free-spinning polisher on a medium speed and avoid holding the polisher in one spot for too long. 
• Don’t Try to Remove Deeper Scratches: While deeper scratches may not come out with gentle polishing, avoid using more aggressive methods like wet sanding to remove scratches. If the gelcoat is compromised and the raw carbon fiber is exposed you can’t just re-spray the material like automotive paint — it’s no longer usable.

Carbon fiber is more susceptible to overheating while polishing.

How to Polish Carbon Fiber

Tools and Materials You’ll Need

Here’s a list of what you’ll need for polishing carbon fiber:

Polishing:

• Dual-action (DA) free-spinning polisher 
• Soft foam finishing pads
• Fine or finishing polish/glaze
• Microfiber towels

Step-by-Step Polishing Instructions

Step 1: Clean the Surface

Before you start polishing, clean the surface thoroughly. Decontaminate with a clay bar if necessary.

Step 2: Mask Off Surrounding Areas

Use masking tape to protect the edges of the carbon fiber and any surrounding painted or plastic areas. This prevents staining adjacent areas with overspray while you polish.

Step 3: Start Polishing

• Attach a foam finishing pad to your polisher. 
• Apply two or three pea-sized drops to the pad.
• Start the polisher at a low speed and spread product over a small section (about 2 feet by 2 feet). 
• Increase to medium speed and make slow overlapping passes horizontally and vertically, keeping the polisher moving at all times. Don’t hold it in one spot, as this can cause heat buildup.
• Wipe off the polish residue with a microfiber towel and check your progress. Repeat if needed. Continue until all carbon fiber is polished.

Step 4: Apply Protection

Apply a ceramic coating to enhance shine, protect the carbon fiber against oxidation and make cleaning easier to avoid scratches from washing and drying. 

Applying protection to the carbon fiber after polishing should ensure you don’t have to polish the carbon fiber again anytime soon. Just be sure to clean the carbon fiber as needed and apply a ceramic coating topper spray every so often to reinforce the contaminant and UV resistant properties. 

Have any tips of your own for carbon fiber polishing? Share them below! Please feel free to also leave any questions about carbon fiber polishing as well — we’ll be sure to answer.