Carbon fiber is a strong, sturdy, lightweight, reinforced composite material that has the ability to replace steel. In modern-day, it’s used in specialized, high-performance components such as aircraft parts, racing car bodies, sailboat masts, bicycle frames, and other sports equipment.
It is also used in more mundane products such as computer cases, phone cases, and even eyeglass frames where lightweight along with higher strength is required.
One of the appealing qualities of carbon fiber is its smooth, sleek appearance, which can be further enhanced by painting. But remember, painting carbon fiber is different from painting your regular car parts because of the woven material, which tends to absorb the paint quickly.
Also, the paint will add weight to the carbon fiber part, which can be an issue, especially if you are using the parts on a race car or other performance vehicle.
In short, painting carbon fiber is possible, but there are a few things you need to know first. These are:
- You will need a particular type of good-quality paint designed to be used on carbon fiber parts.
- The painted carbon fiber can crack and damage fast if you use lower-quality paint.
- You must first prep the surface by lightly sanding it and then using a primer suitable for carbon fiber.
- When applying the paint on carbon fiber, the paint will get absorbed fast, so you will need to work in small sections and be quick.
Painting Over Carbon Fiber Parts – Step by Step
Painting carbon fiber isn’t difficult for people interested in DIY projects. But if you are a beginner, you must know a few key steps to get the best results.
Here’s a quick overview of the process and steps involved when you decide to paint over carbon fiber:
Step 1. Clean and sand the surface
The very first step is to clean the surface using mild soap and water.
Next, sand the surface of the carbon fiber to help give the primer paint a better grip. You don’t need to sand down to the bare carbon fiber; just create an evenly sanded rough surface.
To sand carbon fiber, use 500-grit sandpaper followed by wet sanding. Wet sanding will help in cleaning and removing any paint or clear coat layer that might already be present on the surface. If you do not remove that carefully, it will interfere with the paint adhesion.
After sanding, clean the surface nicely with a piece of cloth and let it dry thoroughly.
Step 2. Apply masking tapes
Next, apply masking tape to any areas you don’t want to be painted.
The tape you can use can be 3M Scotch-Blue, a multi-surface medium adhesion tape ideally designed for painted walls, trims, glass, metal, and plastic. It should also work on the carbon fiber material.
Step 3. Apply the primer
To prepare the carbon fiber hood for painting, apply at least two coats of primer or adhesion promoter and let it dry for approximately 30 minutes.
Rust-Oleum Brush on Automotive Filler Primer is a great product to use on surfaces including carbon fiber, fiberglass, metal, wood, etc. It can be found easily online or at your local automotive store. You can apply it using a paintbrush or a sprayer.
Keep in mind that carbon fiber absorbs paint quickly, so depending on the component you want to paint, you may require extra layers of primer. After it dries, use sandpaper to lightly smoothen the surface for better paint adhesion.
Step 4. Apply the paint in small sections
When painting carbon fiber, it’s important to choose the right type of paint. While any paint will work, some paints dry better and are more consistent than others.
So, if it’s an important project (like your car hood or other parts), I suggest using acrylic enamel paint on carbon fiber parts. It’s very durable and ideal for getting the best results.
Because rolling and brushing the carbon fiber might be tricky owing to its thickness, the best way to paint it quickly is with a spray can or an airbrush.
But if you are using a bristle paintbrush or a small nap roller, start with small sections and work quickly, as the paint will absorb fast.
Also, consider applying the lighter base shade first and then the darker shade on top. This will help you achieve a consistent finish and a chance to do touchups if necessary.
Step 5. Let the paint dry, and apply a clear coat
To protect the painted carbon fiber parts and give them a shiny finish, it is recommended to let the paint dry for 24 hours and then apply a clear coat. While applying a clear coat is optional, I suggest doing so for optimal results.
Two clear coat products that I recommend using are:
- SprayMax 2K Glamor High Gloss Aerosol Clear – good for achieving a glossy mirror finish
- Flitz Multi-Purpose Sealant – good for a matte finish on your car hood, along with getting UV protection
After the application, let the clear coat dry for about 24 hours, then remove all the masking tapes.
Challenges You May Face When Painting Over Carbon Fiber
Painting over carbon fiber can be challenging due to its uneven surface and texture, which can be especially difficult for novice painters using improper brush or roller techniques.
Applying too much paint at once can lead to a darker and less transparent appearance. So, it’s essential to be cautious during application to avoid damaging the surface.
Also, the fine structure and woven material of the parts can cut into the skin if not handled carefully. To prevent injury from sharp carbon fiber parts during painting, it is essential to wear gloves and clean your hands thoroughly afterward.
Why Does My Carbon Fiber Hood Look So Old – Can It Be Repaired?
Carbon fiber hood is susceptible to oxidation which is a gradual process that erodes the outer layer of the material when not maintained properly.
Neglecting this damage will eventually result in a loss of the carbon fiber’s glossy finish, causing it to appear dull and aged.
Also, when exposed to UV light, the resin binding the carbon fibers together will discolor. If not taken care of, this damage cannot be entirely fixed with polishing or waxing.
Fortunately, there are two types of repair (cosmetic and structural) that can help repair carbon fiber parts. Depending on the level of damage and repair done, the repaired part can last for quite a while.
Cosmetic repair only intervenes with the surface of the damaged area but doesn’t affect the structural integrity of the carbon fiber part, so this repair is easy relative to others. Here an automatic polishing machine makes the process easier, and no special tools are necessary.
On the other hand, intensive labor and skill are necessary when repairing carbon fiber structures. This is because the strands of carbon are woven together in a certain direction, meaning that the technician must pay attention to both the number of fibers and their orientation.
Furthermore, every layer of repaired carbon needs to replicate the original design exactly to maintain identical properties.
The bottom line
Painting over carbon fiber might be possible, but it’s difficult, especially for novices unsure how to use a good brush or roller to apply paint.
So, if you are new to painting, it’s good to use a spray paint can or airbrush as they will be easier to use on carbon fiber and help you achieve a more consistent finish.
Just remember to take your time, have patience, and practice on some smaller pieces before you tackle any bigger, more expensive, and more important project.
Jack Luis is a semi-retired painter who loved painting his clients’ ideas on their walls.
He had worked as a painter for over a decade serving customers in areas such as Charleston, Mount Pleasant, Beaufort, and Georgetown, SC (South Carolina). Today in his free time, he likes to read and write about the newer techniques implemented in his profession. You may read more about him here or get in touch with him here.