Google the phrase ‘how to paint carbon fiber’ and you will get an interesting set of results. For example, plenty of people have produced posts detailing how you can use spray paint to achieve the carbon fiber look without actually investing in carbon fiber. There aren’t a whole lot of articles on how to apply paint to a finished carbon fiber part.
So, can you actually paint a carbon fiber part? Yes, but it is time-consuming and rather exacting work. It is not as easy to do as painting aluminum, steel, or wood. Thus, fabricators have been working on different ways to color carbon fiber materials so as to completely avoid painting them at all.
Coloring the Fibers
One of the first methods for coloring carbon fiber was achieved through coloring the virgin fibers in early-stage production. When the fibers that become carbon fiber tow and woven fabrics are first produced, they are black. But it is possible to mix those fibers with colored glass fibers to create a carbon fiber tow in red, blue, or any other color.
It is believed that manufacturers can do something similar with other fiber additives. No one knows for sure though because manufacturers are reticent to reveal their secrets. Yet the fact remains that fibers can be colored before they are spun into the threads and yarns that eventually become carbon fiber fabric.
Adding a Powdered Dye
Another option is to add a flaky, powdered dye to the fibers as they are being spun into threads. This method doesn’t work as well as coloring with a glass fiber additive, but it does work well enough. You can achieve a variety of colors with powdered dyes. The downside is that you do not achieve the same lustrous appearance. In short, dyes are dull.
Painting Finished Parts
The advantage of additive fibers and powdered dyes is that you can color carbon fiber parts without hiding the weave pattern people love. For example, a navy-blue car body panel would show the same weave pattern underneath a shiny, lustrous finish that really makes it pop. But if you don’t care about seeing the weave pattern, carbon fiber parts can actually be painted.
According to the engineers at Salt Lake City’s Rock West Composites, the painting process begins with slightly scuffing the surface of the part in question. You would use a light grit sandpaper to slightly rough up the surface. This is the most critical part of the painting process.
Why? Because carbon fiber parts – like car body panels – are composite parts made by combining a carbon fiber fabric with an epoxy resin. Join those two ingredients and cure them in an autoclave and you produce a carbon fiber reinforced plastic. Roughing up the outer surface of a carbon fiber part involves actually damaging the resin.
If you sand too much resin away, you can reduce the integrity of the part. You can even sand all the way through to the first layer of fabric if you’re not careful. Therefore, you have to sand and scuff ever so lightly to prevent significant damage.
Sanding is followed by a thorough cleaning and at least one coat of epoxy primer. The primer will fill in any small imperfections to create a smooth surface. On top of that you can apply your paint and clear coat finish.
There are multiple ways to color carbon fiber parts. You can color them from within using fiber additives and powdered dyes. Or you can literally paint them the same way you paint aluminum or steel. And now you know.