History of Automotive Finishes

Starting with the large-scale production of the automobile, the driving force has been speed of application and drying time. From the inception of the assembly line, achieving the desired result faster was the primary goal. In the beginning, finishes were applied by brush as had been done in the carriage trade. Quality was mediocre at best and there were limited colors (dark earth tones) available. Durability was poor as colors were not light fast, some more prone to sun fade than others but, none with good color holdout. As the industry grew, the lack of a more durable, faster drying finish was a definite handicap. Nitrocellulose was developed in the 1920’s and greatly improved the application and drying problems. Closely related to guncotton used in smokeless powder, it was dangerous to produce. This explosive concoction of purified wood cellulose and acids was the base of the lacquer used through the fifties. Nitrocellulose finishes also ushered in the use of the spray application and a larger choice of
colors became available.

The next innovation was the development of alkyd resins in the 1930’s. These alkyd enamels were the beginning of the modern process of automotive finishing. At about this time, Ford developed the soybean based enamel which many feel was the best finish to that point and would probably rate pretty good even today. High gloss, durability and a good color palette were benefits of these developments.

After World War II, acrylic lacquer came on the scene with much faster drying time than the earlier enamels. This time it was the speed factor not durability that propelled the use of acrylic lacquer, primarily on GM cars, since durability did not match that of the enamels of the same period. Approximately a dozen years later the acrylic resins were used in enamels
improving resistance to ultra-violet damage. When the use of catalysts was introduced, performance was boosted 50% over lacquer.

In the 1980’s urethane became available, either in a single stage form or basecoat/clearcoat. These finishes are highly resistant to chemicals with almost an infinite range of colors. However, some feel these finishes, especially the clearcoat are not applicable to vintage vehicles, too far removed from original finish in both composition and patina, and there is always the possibility of delaminating. As we progress into the next century, more developments will occur with the primary emphasis on our environment.