Stripping and repainting a CF frame
 

My Felt has a few chips (one large one on rear chainstay where another cyclist ran into me) and I was thinking of getting it repainted, how do you go about stripping the old paint off? Or maybe you don't, and just fill the bits that are chipped and paint over the old paint? I was thinking of taking it to a car smash repair shop for the actual paint.

Calfee refinishes CF frames. Their pricing options include a complete strip down to the bare CF or just scuffing the old paint so the new paint sticks. So it looks like you can do either. I don't know how they do the strip...mechanical or chemical...?

A good way to strip carbon is to have it blasted with baking soda. I've never actually seen it done to a bike, but I've had it done on a racecar many times. It doesn't affect the carbon fabric or resin. You just get bare carbon with kind of a matte finish.

FYI: Use caution when stripping carbon. Back in Robotics club (I was a dork, leave me alone), we were told that carbon particles are terrible for your lungs + eyes (cancer causing things). And the dust itself could short out electrical components.

Don't know about bikes, but I do know about composite sailplanes (gliders)...the owners and the FAA are pretty fussy that refinishing to compromise the structure of these.

The old finish (gel coat) is removed mechanically. The call it grinding, but coarse sandpaper is what is used. The gelcoat is sprayed into the mold as the first step of construction, so the inside surface is rough. The grinding is only through the thin spots. As soon as the glass or carbon starts to show, no more finish is removed. Low spots are filled with bondo or microballoon/epoxy (lighter than bondo, but more effort to sand out flat). The aircraft is then sprayed with gelcoat (epoxy) and sanded out to a smooth finish.

In some cases, the aircraft will just be fine sanded, and painted with Imron paint. This results in a nice looking and durable finish, but adds more weight than the above process.


If the bike was ever polished with a product containing silicone oil, good luck...very difficult to remove enough not to cause finish problems.