hmmm... I know that NASA stopped painting the large orange external fuel tank on the space shuttle to save the weight of the paint (the first two shuttle launches it was white). From published NASA documents, they saved 1000lb (454kg) of weight by not putting a finish coat of paint on it, and since the tank is 27.6ft in diameter, and 153.8 ft long. Ideallizing it as a simple cylinder for ease of calculations, that means it had surface area of around 13330 sq ft (1238m^2). Therefore, the finish coat of paint can be estimated to weigh about 0.075 pounds per square foot (0.37 kilogram per square meter). You could probably double that weight to account for the primer layers, so call it 0.15 lb/ft^2 (0.74kg/m^2).

Anyway, I guess you might be able to save a few kilograms, which might be important for a race car, but it's really not a big difference compared to the 30+ lbs that can be saved just by switching from a steel panel to a composite one.


Peace be with you!