DuPont Paint Information
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This page was last updated on June 25, 2016.
(DuPont is used here in its single-word version, instead of the more formal du Pont. The company's full name is E.I. du Pont de Nemours & Co.)
Dulux vs. Duco
DuPont Duco was a lacquer formula dating from 1923. It held its gloss better over time and stood up to regular washing better, and being a lacquer, took less time to dry. Duco was also more expensive.
Dulux was an enamel formula introduced in 1926. It took longer to dry (usually overnight), but was less expensive. Dulux enamel was more resilient and resistant to chipping, and was a better choice for locomotive and car running gear.
Many railroads, including D&RGW and UP, specified Duco lacquer for use on the carbodies of their diesel locomotives, but continued to specify Dulux enamel for use on locomotive running gear.
Aluminum paint color, sometimes known as bright aluminum, was used to simulate polished stainless steel. Depending on the needed durability, both Dulux Aluminum enamel and Duco Aluminum lacquer were used.
DuPont Paint Coatings History
Quoting directly from the DuPont heritage web page:
DuPont began producing nitrocellulose-based pyroxylin lacquers after acquiring the International Smokeless Powder and Solvents Company in 1905. The purchase of the Arlington Company ten years later (in 1915) deepened the company's involvement. Although they were quick drying and widely used on brass fixtures, conventional lacquers were too brittle for more demanding uses. By the 1920s, however, the automotive industry had become a huge potential market. Although mass production had vastly increased output, because conventional paints took up to two weeks to dry, finishing remained a bottleneck. In 1920 chemists working with film at DuPont's Redpath Laboratory in Parlin, New Jersey, produced a thick pyroxylin lacquer which was quick drying but durable and that could be colored. DuPont marketed it under the name Viscolac in 1921. Assisted by General Motors (GM) engineers, DuPont refined the product further and renamed it Duco. The success of Duco led to further experimentation with finishes and late in the 1920s, DuPont developed Dulux, an even more effective alkyd finish. Duco retained a niche market, however, and DuPont continued to produce it at Parlin until the late 1960s.
According to an article in the February 25, 1953 issue of The New York Times newspaper, after du Pont developed its new Duco-brand paint coating, Pierre S. du Pont, then president of General Motors, offered to buy exclusive rights to the brand from E. I. du Pont de Nemours & Co., whose president was Irenee du Pont, Pierre's brother, but GM's offer was turned down. The offer was made public during the anti-trust suit against du Pont, and was intended to show that GM and du Pont acted separately and independently from each other, even though the du Pont brothers were president of the two companies. Development of Duco began on July 4, 1920. Duco was developed while du Pont chemical engineers were working on developing a brand of movie film. A drum of thick nitrocellulose compound was left standing over a holiday weekend, and when the chemists returned, they found a liquid, or a laquer, that they thought might hold pigment, and make a good paint coating. (New York Times, February 25, 1953)
General Motors' use of DuPont paints stemmed from DuPont's purchase of 23 percent stock interest in GM in 1917-1919. In 1949, the U.S. government sued DuPont to break what it said was an illegal monopoly by DuPont of automotive finishes and fabrics. Here are several snippets of information from that court case relating to Duco, Dulux, and their use by GM:
Two products account for a high proportion of these finish sales to General Motors: "Duco," and "Dulux". However, Duco and Dulux did not come into commercial use until 1924 and 1931, respectively, and du Pont's position as a principal manufacturer of finishes was attained much earlier.
The invention and development of Duco in the early 1920's represented a significant technological advance. The gradual adoption of Duco by some of the General Motors' car divisions, viewed in conjunction with its proved superiority as an auto finish, illustrates the independent buying of each division and demonstrates that Duco made its way on its own merits. From the beginning, General Motors continued to look for competitive materials. Finally, the success of Duco has never been confined to the General Motors' car divisions. In 1924 and 1925, nearly all car manufacturers abandoned varnish for Duco. General Motors has continued to test paints on thousands of cars annually. Du Pont has retained its position as primary lacquer supplier to several General Motors' divisions because these divisions have felt that Duco best fits their needs.
The second largest item which General Motors buys from du Pont is Dulux, a synthetic enamel finish used on refrigerators and other appliances. Since its development, Dulux has been used exclusively by all the major manufacturers of refrigerators and other appliances - General Electric, Westinghouse, Crosley, and many others - except Frigidaire, which continues to finish parts of its refrigerators with porcelain.
Expressed in percentages, du Pont supplied 67% of General Motors' requirements for finishes in 1946 and 68% in 1947. In fabrics du Pont supplied 52.3% of requirements in 1946, and 38.5% in 1947. Because General Motors accounts for almost one-half of the automobile industry's annual sales, its requirements for automotive finishes and fabrics must represent approximately one-half of the relevant market for these materials.
The du Pont Company's commanding position as a General Motors supplier was not achieved until shortly after its purchase of a sizable block of General Motors stock in 1917. At that time its production for the automobile industry and its sales to General Motors were relatively insignificant. Before the first block of General Motors stock was acquired, du Pont was seeking markets for the artificial leather, celluloid, rubber-coated goods, and paints and varnishes in demand by automobile companies. More than just a profitable investment was contemplated. A major consideration was that an expanding General Motors would provide a substantial market needed by the burgeoning du Pont organization. Immediately after the acquisition, du Pont's influence growing out of it was brought to bear within General Motors to achieve primary for du Pont as General Motors' supplier of automotive fabrics and finishes. J. A. Haskell, du Pont's former sales manager and vice-president, became the General Motors vice-president in charge of the operations committee. Haskell frankly and openly set about gaining the maximum share of the General Motors market for du Pont.
The record does not show that the fabrics and finishes used in the manufacture of automobiles have peculiar characteristics differentiating them from the finishes and fabrics used in other industries. What evidence there is in the record affirmatively indicates the contrary. Duco was first marketed not to General Motors, but to the auto refinishing trade and to manufacturers of furniture, brush handles and pencils. In 1927, 44% of du Pont's sales of colored Duco, and 51.5% of its total sales, were to purchasers other than auto manufacturers. A substantial portion of du Pont's sales of Duco have continued to be for non automotive uses. Dulux has never been used in the manufacture of automobiles. It replaced Duco and other lacquers as a finish on refrigerators, washers, dryers, and other appliances, and continues to have wide use on metallic objects requiring a durable finish.
In 1947, when du Pont's sales of Duco and Dulux to General Motors totaled about $15,400,000, the total national market for paints and finishes was $1,248,000,000, of which about $552,000,000 was for varnishes, lacquers, enamels, japans, thinners and dopes, the kinds of finishes sold primarily to industrial users. There is no evidence in this record establishing that these industrial finishes are not competitive with Duco and Dulux. There is considerable evidence that many of them are. It is probable that du Pont's total sales of finishes to General Motors in 1947 constituted less than 3.5% of all sales of industrial finishes.
The largest single finish item which du Pont sells to General Motors is a low-viscosity nitrocellulose lacquer, discovered and patented by du Pont and for which its trademark is 'Duco'.
The invention and development of 'Duco' represented a truly significant advance in the art of paint making and in the production of automobiles; without 'Duco' mass production of automobiles would not have been possible.
In the federal case brought in 1949 that was decided by the U. S. Supreme Court in 1957 (U. S. v. DuPont (General Motors), 353 U. S. 586, 1957), the higher court overturned the lower court's decision, finding that an illegal monopoly did exist, and returned the case to the lower District court which had dismissed the suit, saying that a monopoly did not exist. DuPont and its shareholders delayed the lower court's remedy due to projected high taxes from the sale of such a large block of stock, suggesting instead that Dupont merely lose its voting rights. In 1961, the case returned to the Supreme Court, which found that only DuPont's sale of all of its stock in General Motors would satisfy the provisions of the Sherman Antitrust law.
DuPont sold its consumer paint business in 1983. The Dulux brand is now sold by ICI, a British company with a worldwide distribution network, with the ICI acronym denoting Imperial Chemicals Industries. The Dulux name was established in Canada and Great Britain in 1927 (one year after the brand was established in the U.S.) to market the new high quality decorative gloss paint based on new technology using alkyd resin. ICI Dulux is now a 100 percent acrylic paint with zero volatile organic compounds (or VOCs, which are environmentally harmful solvents).
Duco was DuPont's most successful coating. First produced for testing purposes in 1920, Duco was a durable lacquer that dried quickly--a boon to the emerging mass production industries. Marketed as Duco beginning in 1922, it was the standard finish on all General Motors cars within four years.
DuPont's Duco paint was a nitrocellulose lacquer that first brought color to automobiles when General Motors first used it in 1923. Using Duco lacquer revolutionized the automotive finish business by reducing finish time from two weeks to two days. It was thick and quick drying, which pleased car makers, but frustrating for consumers who couldn't apply it like the oil-based paints they were used to.
The following is from DuPont's Duco web page (no longer available):
Duco, a durable, quick-drying finish invented by DuPont, helped make the 1920s revolution in consumer goods mass production possible, becoming the standard finish on automobiles, hardware, appliances and toys. General Motors introduced Duco finish on its Oakland models in 1923 and it more than fulfilled expectations, reducing finish time from two weeks to two days and drastically cutting rejection rates.
DuPont began producing nitrocellulose-based pyroxylin lacquers after acquiring the International Smokeless Powder and Solvents Company in 1905. The purchase of the Arlington Company ten years later [in 1915] deepened the company's involvement. Although they were quick drying and widely used on brass fixtures, conventional lacquers were too brittle for more demanding uses. By the 1920s, however, the automotive industry had become a huge potential market. Although mass production [of automobiles] had vastly increased output, because conventional paints took up to two weeks to dry, finishing remained a bottleneck. In 1920 chemists working with film at DuPont's Redpath Laboratory in Parlin, New Jersey, produced a thick pyroxylin lacquer which was quick drying but durable and that could be colored. DuPont marketed it under the name Viscolac® in 1921. Assisted by General Motors engineers, DuPont refined the product further and renamed it Duco. The success of Duco led to further experimentation with finishes and late in the 1920s, DuPont developed Dulux, an even more effective alkyd finish. Duco retained a niche market, however, and DuPont continued to produce it at Parlin until the late 1960s.
The following is from DuPont's Dulux web page (no longer available):
DuPont has been using Dulux enamel in automotive coatings since 1926. Dulux actually owes its existence to a flaw in its more famous cousin, Duco. This nitrocellulose lacquer first brought color to automobiles when General Motors used it in 1923. It was thick and quick drying, which pleased car makers, but frustrating for consumers who couldn't apply it like the oil-based paints they were used to.
So DuPont researchers tried mixing synthetic alkyd resins with oil and found that the resulting enamel's drying time was slower than Duco but faster than that of traditional oil paint. Dulux alkyd resin, named in 1926, also had a pleasing high-gloss look. By the early 1930s it won over consumers under the label Dulux "Brush" Duco.
Dulux high-gloss enamels were also used widely in the 1930s on refrigerators and washing machines, outdoor signs, gasoline service stations and pumps, and railroad cars. Once tried as an undercoating for Duco auto paint, Dulux also found a niche as a low-cost alternative to Duco auto finishes. In 1954 some automobile manufacturers chose an improved Dulux alkyd enamel over Duco, and over DuPont's new water-based Lucite® acrylic lacquer. However, Lucite® soon pulled ahead in household sales, and after DuPont developed a new acrylic polymer in 1957, Lucite® also outshone Dulux in the appliance and industrial markets. DuPont sold its consumer paint business in 1983.
DuPont Dulux and Duco Colors
Most new stores aren't equipped to mix synthetic enamel since they've made a complete switch to acrylic paints. Also the old DuPont Dulux paint numbers are being replaced by DuPont Centari acrylic enamels. One way to convert Dulux to Centari numbers is to drop the prefix from the Dulux number. For example, a Dulux 93-57704 gray becomes a Centari 57704-A. (from Minneapolis-Moline.com, user forum)
DuPont Paint Codes
Information taken from sources for automotive colors has found that DuPont 202-xxxx and 246-xxxx color codes were Duco, and 93-xxxx color codes were Dulux, with Duco being a spray-only paint. Research during 2003 found that DuPont 88-xxxx is for brushable Dulux, and 234-xxxx is sprayable Dulux.