Not only have the coatings that protect and beautify cars evolved from natural products to synthetic ones, the method of applying them has changed from hand brushing to fully robotic methods.
Thanks to information we gleaned from the sheboyganchryslercenter.com site, we have put together nice article here that traces the history of automotive finishes.
In the early part of the 20th century, automobiles were painted completely by hand. The paints were natural-based (frequently linseed oil with natural pigments for color) and the painting process involved days of work. Needless to say, this was a serious bottleneck in the automotive manufacturing process.
In the 1920s, DuPont developed a greatly improved lacquer paint system. These paints were based on nitrocellulose, a natural substance, and were applied via spray guns. This speeded up vehicle assembly time a great deal. They weren’t perfect paints, though, because multiple coats were still needed and lengthy drying had to occur in between coats. Lacquers also have poor resistance to certain solvents, such as gasoline.
In the late 1930s, another major development in paint technology came with the introduction of enamel paints. Enamels were sprayed on vehicles via spray guns and then were baked in ovens. This speeded up the manufacturing process and produced a rock hard finish which was resistant to solvents. However, enamels oxidized in direct sunlight and this caused the colors to fade. The way to prevent this from happening was to apply a good coat of wax to your car in order to keep UV rays at bay.
In the late 1970s, a new type of finish, called “basecoat/clearcoat,” was developed. Basically this type of paint consisted of a pigmented enamel basecoat followed by an ultra-hard clear enamel top. It allowed a great deal more flexibility in the composition of the base coat (more colors and metallics) Although initially expensive, by the late 1980’s this paint system had become widespread.
While the basecoat/clearcoat paint system is far superior to the older single enamel paints in many respects, it has a few disadvantages. The clearcoat has a greater tendency to show marring when rubbed by foreign materials. It is important for car owners to realize that the days of waxing and buffing are gone for basecoat/clearcoated cars but you can still wax your car but you need a special non-abrasive formulation so the clearcoat isn’t eroded.
Article Source: Sheboygan Chrysler Center