PAINTS Original Model T Ford paint colors are all but impossible to duplicate accurately today. The paints used in the very early cars were varnishes and had a relatively short life. This was also true of the later enamels and Pyroxylins, although they were a good bit better than the earlier varnishes.
The original early greens and blues were all but black, and could easily be taken as black. Consequently, original cars seen today no longer have the same color they had when they were new. Even today, batches of the same paint formula will vary in color, and it is certain the variations were even more pronounced more than sixty years ago.
The paints listed below are acceptable equivalents for the original colors. The numbers are current replacements for older Ditzler nitrocellulose lacquer numbers shown in previous lists. The DDL number is Acrylic Lacquer and the DAR number is Acrylic Enamel. There is not always a perfect match between the two types of paints so one should not mix the paint types unless slight differences are acceptable. Some of the Ditzler numbers are the same for either the lacquer or the enamel. The full number, of course, would be, say, DDL-71969 (lacquer) or DAR-71969 (enamel) for Brewster Green. We are told that Ditzler dealers can match DDL colors with DAR equivalents where there is no DAR number listed here; they have the formulas but they are not ready-made stock colors.
|72092A (Dupont #)
|81501A (Dupont #)
|Note: The original blue and green were almost black. Often the color cannot be detected except in bright sunlight, and even then seeing the “color” can be difficult. Surviving original cars substantiate this observation. Red and gray were only used prior to June 1909. Green was used from early 1909 (before June) through 1910. Blue was used from 1911 to early 1913. Black was the standard color from 1913 until the 1926 models.
|Use paints listed under Pyroxylin
|Use paints listed under Pyroxylin
|Rock Moss Green
|L4 E 317
|L4 G 311
|L4 Y 337V
|L4 Y 332
|L4 M 318
|L4 Y 303
|L4 B 320
|L4 B 325
|4190A (Dupont #)
|Note:Based on letters from the factory to the dealers at the time, the standard wire wheel color supplied on the cars by the factory was black. The color options were dealer-installed on an exchange basis.
|* Carmine and Champagne were used on the black closed cars during the “iron” era (1917-1926). The exact color is not known at the time of this writing.
PAINTING Exposed parts of Model T Fords were generally painted the body color. Early red cars, for example, had red fenders, aprons, hoods, running boards, axles, and wheels. The same is true of the Brewster Green and blue cars but here there is some question. Since these greens and blues were extremely dark, if not black, it is often difficult to determine if the parts were the body color or actually black paint. The consensus is that the above parts were originally the body color, not black.
Nuts, bolts, and small assemblies which could be seen easily, were also painted, even though such parts were installed after the painting process. Ford had people with paint and brush in hand to touch up such parts. While there may be exceptions, all exposed pieces were painted, and this includes the cotter keys in these pieces.
Engines, engine pans, and splash shields (at the side of the engine) may or may not have been painted. Again, the consensus is that many engines were not painted but that some were painted in a very thin black during the Model T era. Late 1926 and 1927 engines were painted Moleskin, at least at the main factory. Even here, though, there were exceptions. Engine pans follow the same pattern. The dust shields were probably painted body color in the early years, and black through 1927. Floor boards were generally not painted but may have been given a coat of linseed oil or similar.
Indeed, there are no hard and fast rules on what was and what was not painted on any Model T. There were too many variations.
ENGINE PAINTING 1927 In Walter T. Fishleigh’s files in Accession 94 at the Ford Archives there is a memo dated July 26, 1926 entitled: Finish For Model T Motors. It lists the finish to be put on each of the exposed parts of the motor. Black Pyroxlylin used on:
Black Graphite Paint used on:
Exhaust Manifold and Carburetor
Black Enamel used on:
Commutator Retainer Spring
Nickel Plate used on:
Cylinder Head Cap Screws
Spark Plug caps and Thumb Nuts
Spark Plug Wire Terminals
Coil Box Terminal Bolts and Nuts
Water Connection Cap Screws
Manifold Cap Screws
Bright Zinc Plate used on:
Cut Out Cover
Moleskin Pyroxylin used on:
Air Intake and Manifold
(signed) C. W. Avery
They were finished, just like all coaches were finished, and it took a long time to complete it.
-J. L. McCloud, Reminiscences, p.25
Most Model Ts were black. Not all, just most. The early 1909 models were red and gray, but in the middle of 1909 this gave way to a dark green. During December 1910 and January, 1911, the dark green in turn was changed to a dark, almost black, midnight blue. Finally, in late 1914 to early 1915 the blues were replaced with just plain black on the open cars. From this point until the introduction of the Improved Models which appeared in August 1925, black was the standard color. Roughly 11,500,000 cars were produced during this time period and even after the introduction of the Improved Models, many of whose bodies were painted in green and maroon, a substantial portion of the cars, and even whole cars, continued to be painted black.
Although there is little about the color of Model Ts to argue over, there is still a great deal to be said about the finish of a Model T. That is, what type of paint was used and how was it applied. Very few cars survive with their original finishes. Most have been repainted one or more times during their lives, usually with the improved paints and painting techniques that have been developed over the last 70 years. To help those of us who have never seen a brand new Model T understand what their original finishes looked like, this article will look into the different materials and the methods used to paint the various parts of a Model T black.
There is reason to believe that Model Ts painted with modern paints using modern application techniques may look somewhat differently than when those cars originally left the factory. For one thing, the materials used to paint cars today have very little in common with the materials that were used by the Ford Motor Company during the black era. Technological advances in the paint industry have made using the old paints impractical, while environmental concerns make their use undesirable. The methods of applying the paints have also changed. Paint spraying and powder coating techniques, technologies that are still evolving today, have replaced the Ford factory methods of dipping, brushing or flowing on the coats of paint.
In addition, this investigation of Model T paints and painting techniques provides the opportunity to examine two other issues. First, it will review one of the long-standing views regarding the reason why Ford standardized on the color black. Second, it will provide some insight into the reasons for the changes in Model T body construction that occurred in 1922 and again in 1925.
Since this investigation is likely to stir up some controversy over some long held opinions relating to the painting of Model Ts, it is appropriate to begin by describing the sources for the information on which the investigation and this article are based. Essentially the information comes from two sources: the Research Center at the Henry Ford Museum and Greenfield Village and several technical publications. The Research Center is the depository for many of the engineering documents relating to the production of the Model T. These documents, once a part of the archives of the Ford Motor Company, are found in five major accessions. Accession #1003 contains the Obsolete Materials Specifications sheets. Beginning about 1916, the Ford Motor Company began writing detailed specifications for the materials that were used in building Model Ts including the paints. These material specification sheets helped insure consistency in the materials supplied by Ford’s vendors and tended to promote price competition among the vendors. Today, the sheets tell us what the chemical composition of the paints was, who were the principle suppliers and, to a lesser extent, which components of the Model T were to be painted with a specific paint.
Accession #166 contains many of the process sheets for the Model T. The process sheet is an engineering document which describes how to produce or assemble a Model T part or assembly. Since painting a part or assembly is a part of the assembly process, the process sheet will frequently tell whether or not a part was painted and what it was painted with.
Accession #1701 is one of the largest in the Research Center’s collections. It includes microfilms of the drawings for nearly all the parts ever used (or considered for use) on a Model T. It also includes microfilms of the Record of Change cards or Releases for nearly every Model T part. These documents tell the story of how a Model T part changed over the years by specifying the date, nature and authority for the change and often includes what material the part was to be painted with.
Accession 125 contains the Ford Motor Company’s monthly Cost Books for the Model T. Beginning in late 1913 the Company began keeping highly detailed accounts of the costs of producing the Model T. The time period covered by these books extends from December 1913 to July 1926, with some gaps in between where the Cost Books for several months apparently have been lost. In addition to the cost of the complete car, these books list the cost of every part and every assembly operation. When a part or assembly was to be painted, these books will frequently identify the painting materials used on that piece of the Model T right down to the sandpaper and solvents.
Finally, Accession #65 contains several reminiscences by Model T era employees of the Ford Motor Company, one of whom was J. L. McCloud. The Ford Motor Company hired McCloud in 1915 as it’s first college-trained chemist. In the late teens and early twenties he was responsible for insuring that the paints used were consistent in quality and performance. In his Reminiscences, McCloud makes many comments about Model T paints and their application based on his first-hand experience.
In addition to the information found at the Research Center, several technical books and articles on paints were consulted. These sources include: Dick’s Encyclopedia of Practical Receipts and Processes. This book describes the methods of making Japan black and paints in general during the late 19th century. The 1925 standard reference work on paints and their applications was Maximilian Toch’s The Chemistry and Technology of Paints. The Ford Motor Company engineers frequently cited this book in its material specification as a source of information about paints. The Technology of Paints, Varnishes and Lacquers edited by Charles R. Martens describes the history and evolution of paints, the theory of film formation and descriptions of different types of paints. The DuPont Refinishing Handbook provides an excellent historical background on paints and includes a superb glossary on painting terms. Finally, the standard reference work on how the Model T was manufactured during 1914-1915 is Arnold and Faurote’s The Ford Methods and the Ford Shops. This book provides detailed descriptions and photographs of the various painting processes used in the Ford factory during the mid-teens to early 1920’s.
The scope of this article is limited to the paints and techniques used during the years from 1915 to 1925. There are a number of reasons for this limitation. First, it now appears that the black paint era of the Model T began later than has previously been thought. The Cost Books indicate clearly that through at least September 1914 Ford was still painting touring car bodies blue. The cost books indicate that different paints were used in October, November and early December 1914, but do not indicate exactly what color they were. No touring car bodies were painted and trimmed at the Ford factory from late December 1914 until very late in January 1915. Once touring car body painting resumed in 1915, the Cost Book’s descriptions of the paints match those used through the early 1920’s. Thus good evidence that black topcoats were being used on touring car bodies does not appear until early in 1915.
Second, good, reliable information on the composition of Model T paints and on what parts these paints were used on does not begin until 1915. The earliest material specification sheets for paints are dated 1916. The Cost Books indicate that virtually all of these 1916 paints were in use during February 1915. While there is evidence that many (though not all) of the materials and techniques described in this article were employed earlier, some as early as 1912, Ford factory paint documents dated before 1915 are scarce
Third, the reintroduction of colors to the Model T in mid-1925 and the use of pyroxlin paints beginning in mid-1926 defines an entirely different era in Model T production. Rightfully this should be the subject of a different article. Similarly, engine painting is a highly controversial yet important enough subject to warrant its own discussion at a later date.
THE PAINTS A paint is a fluid material which when spread thinly over a surface will form a solid, adhesive film over the surface. It serves two important purposes: protection and decoration. Without paint, objects made of iron or steel will soon start to rust and deteriorate. The paint protects the underlying surface from the effects of water and sunlight, extending its useful life. Paint also serves for decorating an object, making its appearance more pleasing and attractive. Paints have been used for thousands of years. For most of that time, the final user manufactured the paint, because shelf or storage life of the paints was short. Commercially prepared paints began to appear after 1865 when New England paint makers discovered that the addition of silicate of soda to linseed oil based paints dramatically extended the shelf life of the paint. This made the preparation and marketing of mixed paint in small packages feasible and marks the beginning of the commercial paint industry in America.
Paint is applied as a liquid, but to serve its dual purposes, it must be converted into a solid. This process is called film formation. For most paints, this process begins when the material is exposed to the air. Some modern paints, which are composed of two separate parts, are an exception to this. The two parts are mixed together immediately before application and once mixed the film formation process begins and continues even in the absence of air.
The paints available before the introduction of nitrocellulose lacquers in 1924 bear little resemblance to the materials purchased today in hardware and auto supply stores. Model Ts were painted with color varnishes, and while the term ‘enamel’ is frequently encountered, they are not enamels in the modern usage of the term. Color varnish paints were based on drying oils, such as linseed and china wood oils, that are derived from vegetable sources. When exposed to the air, these oils would capture and combine with oxygen, forming a dry, hard, resinous material.
By themselves, these oils take a very long time to dry. This is partly due to the initial formation of the film at the surface between the oil and the atmosphere. The film inhibits access of the paint below the surface to the oxygen needed for the conversion of the oils into the hard, resinous material. Long ago it was learned that by adding certain chemical metallic compounds to the oils, known as dryers, the conversion process could be sped up and enhanced. These compounds catalyze the drying process, increasing the rate of absorption of oxygen and promoting the drying of the lower layers of the oil. During the Model T era, various metallic compounds were used as dryers, including cobalt, lead, manganese, calcium, zinc and iron. Drying oils, while frequently having a brownish tint, are essentially transparent. As such, paints based on them would have little decorative purpose. However, other materials can be added to the oils and dryers, to give color to the paints. These materials are known as pigments, and they frequently do more than just give color to the paint. Depending on the shape of the pigment’s molecules, they may actually provide greater strength to the paint and adhesion to the surface, much the way steel rods and wire mesh are used to reinforce and strengthen concrete structures.
Paints need to be fairly fluid in order to be spread evenly across the surface, but once applied, they must stay put. That is, the viscosity of the paint must increase after it has been applied to reduce running and sagging. This can be achieved by adding rapidly evaporating solvents to the mixture. These solvents are known as thinners. They enhance the flow-out characteristics of the paint when first applied, but rapidly evaporate, reducing the viscosity and tendency of the paint to run during the drying process.
Temperature can also have an important effect on the drying of color varnish paints. Frequently, the painted object can be baked in an oven to reduce the drying time to one hour or less. The composition of the paint, in terms of its pigments, dryers and thinners must be adjusted for oven drying in order to prevent cracking or checking of the finish.
A large number of different paints were used on Model Ts during the black era. Over thirty different Ford Motor Company specifications for black paint have been identified. (See Appendix A for a list of these paints.) They vary in terms of their chemical composition, the amount of thinners used, the pigments used and in several other respects. For the purposes of discussion, all of these paints can be divided into two categories: oven drying paints and air drying paints. Oven drying paints were used on all-metal parts that could withstand the high temperatures of the baking ovens, such as fenders, hoods and similar parts. Air drying paints were used on dashes and bodies, where the wood contained in these parts would not withstand the high temperatures required to bake the oven drying paints.
The basic oven drying paint for the Model T was what historical sources call Japan Black. Why the term Japan Black was used to describe the paint is somewhat obscure. Before 1900 Japanning was known as a particular type of varnishing that was practiced by the Japanese. It was unique in that after the application of each coat of color varnish, the object was placed in an oven or stove and baked at as high a temperature as possible without damaging the object. To an extent, painting Model T fenders, hoods, and other all metal parts resembles Japanning in that after the film of paint was applied the part was baked for up to an hour at a temperature of about 400 degrees.
The term japan has second connotation in the painting industry. A particular combination of chemical compounds is known as Japan Dryers. When added to vegetable drying oils, as described previously, they reduce the time it takes for the paint to dry. Since Japan Dryers were used in making some Model T paints, this too may partly account for the use of the term.
Ford used two japan black paints. The First Coat Black Elastic Japan was given the factory specification number F-101 (M-101 after March 15, 1922) and F-102 (M-102 after March 15, 1922) was the factory specification number for Finish Coat Elastic Black Japan. Both paints were very similar in composition. They consisted of about 10% linseed oil and dryers (lead and iron dryers were popular in oven baked paints), 55% thinners (mineral spirits or petroleum naphtha), and 25 – 35% Asphaltum. F-101 also contained 1 – 3% carbon black as a pigment, while the finish coat, F-102 contained none.
The surprising and interesting element in these paints is the asphaltum or asphalt. Asphalts are dark film-forming compounds that were used in paints noted for their resistance to water and dampness. The Ford material specification sheets usually specify that the asphalt used was Gilsonite. This is a natural, hard, brittle resin that is mined in the western United States as well in other places around the world. It was used in the manufacture of many products during the 1920’s including paints, varnishes, oils, and shellacs. When compounded with other asphalts and rubber it was made into automobile tires, phonograph records, waterproofing and insulating materials. When used in paints Gilsonite must be melted at 270 – 400 degrees before it is added to the linseed oil and dryers. As a part of the paint, the Gilsonite is low in cost, acts as a hardening agent for the oils, and results in a high-gloss dark-colored surface. It also tends to increase the plasticity of the paint, making it less brittle, more flexible and able to withstand the vibration of fenders, hoods and shields without cracking or peeling.
There appear to be several good reasons for the choice of black as the color of the paint. First, black color varnish paints tended to be more durable than lighter colored paints. Authorities on paint in the 1920’s noted that black paint tended to last longer than paints with lighter colored pigments. Second, as mentioned above, the addition of Gilsonite improved the damp resisting properties and the final gloss of the paint, but also resulted in a very dark colored paint. The range of colors that asphaltum paints can have is quite limited. The dark color of the Gilsonite limits the color of the final paint to dark shades of maroon, blue, green or black. Cost may also have been a factor. The carbon black pigment used in these paints is probably the least expensive pigment available; almost any other pigment is more expensive than carbon black. One often cited reason for the use of Japan black on the Model T was that it allegedly dried faster than any other paint. However, there is no evidence in either the Ford engineering records or the contemporary literature on paint, to indicate that that was the case. The drying time of oven baking Japan black is no different from the drying time of other colored oven baking paints of the period. In short, Model Ts were not painted black because black dried faster. Black was chosen because it was cheap and it was very durable. In fact, both F-101 and F-102 (which later were redesignated as M-101 and M-102) worked so well that the Ford Motor Company continued to use these same paints to finish fenders, running boards and shields well into the V-8 era.
As mentioned above, the black elastic Japan paints were designed as oven drying paints. The specifications called for drying in an oven at 400 degrees for one hour. Not only did oven baking result in a fast drying time for the paint, it also helped to minimize the surface preparation of the metal part. All that was required was to wipe the part with turpentine to remove any oils or grease left on the part during the manufacturing process. Anything else would tend to become amalgamated with the oils and asphalt in the paint during the oven baking process. Thus the use of this paint was also cheap in the sense that very little labor was required for paint preparation. F-101 and F-102 were some of the most commonly used paints on a Model T. Some idea of the extent to which these paints were used can be found in Appendix C which lists all the parts on a 1924 touring car that the factory specified were to be painted with Black Elastic Japan paints.
Wood Model T parts were painted with an entirely different paint. Unlike fenders and hoods which could withstand oven baking temperatures of 400 to 450 degrees, wood dashes, wood wheels and even bodies, which had quite a bit of wood reinforcement in them until 1925, could not stand such high temperatures. So these parts were painted with multiple coats of air drying color varnish.
Air drying color varnishes differ from their oven drying counterparts in several respects. While they were still based on linseed oil, asphaltum was omitted and instead rosin was combined with the oil. Rosin is derived from the distillation of oleoresin from pine trees. When cold, the rosin is a brittle, solid material. The rosin must be heated before it can be combined with the drying oils to form the paint. The inclusion of rosin in the paint tends to retard gelling and results in a relatively quick drying varnish.
The oil and rosin gums in the air drying paints made up 44 – 60% of the paint. These paints frequently used lead and manganese as dryers, which constituted about 1 – 2% of the paint. Thinners were made from a combination of turpentine and petroleum naphtha and accounted for 39 – 52%. Carbon or lamp black was frequently used as pigments, making up from a trace to up to 33% of the paint. All of these paints required 24 hours to dry at a temperature of 80 degrees.
Application of the Paints Spray guns for the application paint were not developed until the early 1920s. Credit for their development belongs largely to the De Vilbiss Company. Prior to that time Model T parts were painted using brushing, dipping or flowing methods.
Many Model T parts were painted with a brush. One of the largest components that was brush painted was the front axle assembly. At the end of the front axle assembly line the last four operations consisted of 1) paint with F-105 First Coat Brushing Black Japan by two men; 2) bake in oven; 3) paint with F-106 Second Coat Brushing Black Japan by two more men; and 4) bake in oven. Brushing was also used to touch up spots between coats on the bodies and was used on the final assembly line to paint the nuts, bolts, washers and cotter pins used to assembly the chassis.
Dipping was another painting processes that was frequently used in the Ford factory during the Model T era. Fenders, hoods, running boards, running board shields, steering column tubes, coil boxes and windshields were all painted using the dipping process. The dipping of fenders in glossy black paint and baking them in special drying ovens was practiced in the Ford factory by 1912 and may have begun even earlier. In the teens automatic dip tanks were used so that the fenders were carried on a conveyor through the dip tank and then through an oven. In order to conserve factory floor space, the fenders were dip painted on the top floor of the Highland Park factory and the conveyor carried the fenders up to the roof where the baking ovens were located.
The rear axle assembly was one of the largest components of a Model T that was dip painted. As the individual component assemblies of the rear axle (rear axle housings, torque tube and radius rods) were completed they were individually painted. When the entire rear axle assembly was completed, it was painted a second time in a novel way. The axle assembly was hung on a conveyor and carried up over a tank filled with paint. At this point, a machine automatically placed caps over the ends of the axle, and the tank was raised six feet, completely immersing the rear axle in the paint, before returning to its original position. After painting, the axle was carried through a baking oven to dry.
Another interesting dip painting operation was the painting of wood wheels. The first coat applied was F-108 Black Wheel Surfacer. This paint was primarily made up of pigment (52-54%), with the oil, gum and metallic dryer representing 12-14% of the paint, and a thinner of mineral spirits which accounted for 32-34% of the paint. Unpainted wheels were mounted horizontally on a vertical spindle above a circular vat partially filled with paint. The vat was raised, immersing the wheel in the paint and then partway lowered. The wheel was then spun at 540 to 720 rpm for about a minute while still within the vat but above the surface level of the paint. After spinning the paint was considered to be dry enough that the wheel could be handled and it was placed in a drying room for the next 24 hours. The subsequent two coats of paint were applied in a similar manner. The second coat was F-159 Black Wheel Color Varnish. This was followed by F-404 Finish Coat on Wheels. F-404 could be described as a nearly clear topcoat varnish. It contained only enough pigment to give it a dark tint. This painting process resulted in wheels that were a deep, gloss black color.
A final example of using dipping to paint a Model T part was the crankcase. While dip painting the crankcase assembly may not in itself be remarkable, the paint that was used is. This paint was F-142 Black Slush Paint. It was probably the fastest air drying paint used in the Ford Motor Company, and it certainly was the simplest in composition. It was made from 50% Gilsonite and 50% petroleum spirits (paint thinner). Crankcases were dipped in this material and would air dry in an hour or less. Parts painted with F-142 would have appeared to be dense black in color, but probably not very glossy or shiny.
Painting Model T bodies was one of the most complex and time-consuming processes in the Ford factory. From a chronological standpoint, it was also one of the last painting operations to be undertaken by the Ford Motor Company. The Cost Book for December 1913 contains the interesting note We are using only about 5% of Touring Car Bodies purchased in the white which we trim and paint ourselves. We are trimming and painting none of the Torpedo Car Bodies. This indicates that the Ford Motor Company had just begun the painting and upholstering of bodies in its own factory, and that 95% or more of the bodies used on the Model T were still being delivered from the body supplier to the Ford Motor Company completely painted and upholstered. Ford continued to paint and trim only 5% of its touring car bodies through April 1914. Painting and trimming operations were expanded in to 10% of Ford’s total touring car body requirements in May 1914. Production of painted and trimmed bodies continued to rise so that by October 1914, Ford was trimming and painting 40% of its touring car body requirements. The point at which Ford was painting and trimming all of its touring car bodies is not known since the Cost Books no longer state this statistic after October 1914. Painting and trimming of torpedo (roadster) bodies in the Ford factories did not begin until September 1915. Through September 1914 the Cost books indicate that the final color coat on touring car bodies was F-115 Spraying Blue. The use of black color coats on touring car bodies does not appear until the February 1915 Cost Book.
From 1915 to 1922 bodies were painted with four coats of air drying color varnish. Bodies arrived at the painting department with the wood and steel bare of any finish. After a quick cleaning, the first coat of paint was applied. This was designated as F-111 Red Body Prime. This paint used a pigment that was a mixture of carbon or lamp black and Venetian Red (30% of which was iron), so it may have appeared more of a brown color than red. Arnold and Faurote reported that it was applied with an atomizer at 80 pounds air pressure as early as 1915. After inspection, the freshly painted body was stacked to dry for 24 hours. After drying, the body was sanded before its first coat of color.
The color coats were applied using a process called flow painting. J. L. McCloud in his Reminiscences described it this way:
Instead of being applied with a brush, a flood of paint was squirted on the automobile bodies out of these flow pipes. It was more or less run on… The paint was contained in an overhead tank … and it came down in a pipe and came out in the form of slow streams from a comb-like end on the pipe… That was held up alongside of the body and drawn along the body as the body moved along on a conveyor. In that way it was flooded with paint, and the paint ran off and was returned to the tank and reused in that way.
This first color coat, F-160, was composed of 4-9% oils and gums (including rosin), 50-52% thinner which was a combination of naphtha and turpentine, and 39-47% pigment. It wasn’t quite black. The black that was used was, in fact substantially fortified with a very dark blue, so as to make it a truer black instead of tending toward a yellowish black, which you would get unless you didn’t put the bluing in the color. The pigment was made up of Drop Black, Prussian Blue and Ultra Marine Blue. After the first coat was flowed on, the body was removed from the conveyor and stacked to dry for another 24 hours.
When the first color coat had dried, the body was returned to the conveyor and prepared for its second coat by mossing. This meant that it was rubbed with curled hair to remove any dust that had fallen on the paint while it was drying. Then a coat of F-162 Black Rubbing Color Varnish was flowed on. Then body was removed from the conveyor, stacked and allowed to dry for another 24 hours.
After the second coat of F-162 Black Rubbing varnish had dried, the bodies were again placed on a conveyor and the paint was rubbed down with pumice and water to a smooth surface. When this was completed the bodies were upholstered. After upholstering, the bodies were cleaned inside and out in preparation for the final coat of paint. For the final coat a clear body varnish, F-751, was used. This varnish was made up of 38-48% Naphtha and Turpentine thinners, 44% oils and dryers and 18% gums including rosin. It had no pigment. Like the previous coats, it was flowed on, and after painting any runs or sags were touched up by hand with a brush. After this final coat of varnish, the body was once again stacked for 24 hours to dry. McCloud said, It took days to really dry the paint finish on a Model T… The body plants had a lot of bodies in them at temperatures just slightly above room temperature. One of the reasons the Ford Motor Company built the four big six story buildings that border Manchester Avenue at its Highland Park plant in Detroit was to provide enough room for all the bodies to dry. By 1916 Ford production required 2000 bodies a day. Since each body required four coats of paint to finish, room may have been needed for as many as 8,000 bodies at a time.
Never-the-less, the final finish was quite good. McCloud also says that flow paintings …had the practical equivalent of dipping the automobile body. It was very successful. It gave a quite nice quality paint job… The process did have one problem.
The only trouble is that it tapers. The top of the panel, or whatever you’re painting, gets thin and the paint at the same time gets thick at the bottom. The big problem in making a flow-coat or dip-coat paint was to make one that will not taper too damn much.
The effect of tapering is quite evident in Model Ts that survive with their original paint jobs. Paint near the top of the bodies will show more deterioration than near the bottom because it was thinner at the top than at the bottom. In addition, paint on the body will generally be in poorer condition than that on the fenders and hood because the air drying black color varnishes are not as durable as the oven baking black Japan paint.
While touring and roadster bodies were completely painted using the flow method, closed car bodies used a combination of flow and brush. As late as 1922, the Ford production department required branches to flow paint bodies below the belt line molding, but apply the paint by brush above the belt line.
As the production of Model Ts continued to rise during the early 1920’s body painting was clearly becoming a bottleneck. It appears that the Ford engineers followed two strategies to speed up the painting of Model T bodies. The first of these strategies was to adopt faster drying paints. During 1922 a body baking paints was developed and employed. The painting of a newly assembled touring car body began by slushing a coat of M-142 (the same paint as used on crankcases) on the heel boards, toe board, sills and bottom of rear seat. The body was then dry sanded, blown out with air, and wiped off with a tack cloth before applying its first coat of paint, maroon primer M-161. After flowing on the primer the body was baked in an oven at 150 to 160 degrees for about three hours.
When the body emerged from the paint oven the upholstery was installed, the body was blown out again with air, and two covers were installed to keep the upholstery clean during the final painting operations. Two coats of color varnish were flowed on. Designated M-165, this paint was 3.25-3.75% carbon black pigment, 55-57% thinner made from petroleum spirits and turpentine, and 43-45% oils, resins and dryers. Cobalt resinate was used as the metallic drier. This black paint was designed to bake to a hard surface in 2-1/2 hours at a temperature of 150 to 169 degrees.
After two coats of M-165, the body was ready for its final coat of finishing varnish. In a manner similar to the air drying paints used in previous years, this final coat was a clear finishing varnish that was designated as M-403 Floco Finishing Varnish. It consisted of a naphtha-turpentine thinner, a trace of carbon black pigment, lead and manganese dryers, and a combination of linseed oil, china wood oil, #2 Kauri Gum and ester gum. Like M-165, M-403 would also force dry in 2-12 hours at 145 degrees.
While low bake enamels were one approach to eliminating the body-painting bottleneck, the Ford Motor Company also followed another. It was a well-known fact in the automobile industry during the early 1920’s that the Dodge Brothers Company was able to use black Japan varnishes on their automobile bodies because Dodge didn’t use much wood in them. The low wood content permitted Dodge to bake the paint on their bodies the way Ford baked the paint on Model T fenders. Ford decided to follow Dodge’s example. Beginning with the redesign of the touring and roadster bodies in 1922, the wood content Ford bodies began to decline. By the time the Improved Models were introduced in mid-1925, the structural wood content of the touring, roadster, coupe and tudor sedan bodies (with the exception of the top framing on the closed cars and the seat frames of all models – which would have been added after the body was painted) had completely disappeared. Thus like Dodge, these Model T bodies could be painted with Japan type oven drying paints.
New baking paints were developed for the new all steel bodies. Using the new paints, bodies could be finished with only two coats. Beginning in August 1925, touring and roadster bodies were painted with one coat of M-114 First Coat Low Bake Enamel and one coat of M-115 Finish Coat Low Bake Enamel. These paints were intended to bake to a dry film in one hour at a temperature of 350 degrees. M-114 consisted of 2% carbon black pigment, 36-38% drying oils, 9-11% resins, 2% metallic drier and 51-53% mineral spirits. M-115, the finish coat contained 8-10% asphaltum, 9-11% resins, 37-39% drying oils, 4% turpentine and 40% mineral spirits. The asphaltum gave this paint a jet-black color.
Like the paints used from 1914 to early 1922, the low bake enamels were applied to Model T bodies by flowing. In fact, flow painting of Model T bodies continued until 1926 and the introduction of pyroxylin (nitrocellulose lacquer) paints.
The Improved Ford Models introduced in August 1925 also reintroduced colors to the Ford line. Factory literature states that closed cars were available in either Channel Green (M-392) or Winsor Maroon (M-393). While the neither the material specifications or the formulas for either of these paints has as yet been located, General Letters from the factory indicated that these paints were also color varnishes. It is likely that they did contain asphaltum, which is probably why the new colors were limited to dark shades of green and maroon. The lighter colors such as M-635 Fawn Gray or M-634 Phoenix Brown did not become available until after Ford adopted the used of pyroxylin lacquers for open and closed car body painting in August 1926.
One final point about painting Model T’s. Factory records indicate that not every part on a Model T was painted. Some were left intentionally unpainted. In a letter to its assembly branches the Ford Motor Company wrote:
Effective immediately, all branches painting that part of steering post which is exposed under the hood, will discontinue same. Our reason for not desiring to paint this portion of the steering gear post is that when painted the quality of the steel used in these posts is not visible and the outstanding appearance of strength is covered up.
Apparently these instructions did not go over well with all the branches. Somewhat later the Stock Superintendent at the San Francisco assembly plant, H. J. Rudige, wrote to the Production Department at Highland Park concerning leaving the steering posts unpainted.
In checking over cars in the territory, we find that cars that have been out any length of time become very rusty and very dirty, and the quality of material does not show.
Due to this, do you not think it is advisable to white shellac or apply the white coat of Pyroxylin on the lover part of the steering column so as to keep this material in A1 condition at all times and also assuring the public just what is assembled in the steering post.
While Mr. Rudige’s memo has survived, complete with hand written notes from no less than five different executives in Ford’s Production Department (a clear example of passing the buck if ever there was one), the response to his request has been lost with time.
CONCLUSIONS There are four main conclusions to be drawn from this investigation. First, the paints used on Model Ts during the black era years of 1914 to 1925 were really color varnishes. These types of paint bear little resemblance to the modern automotive finishes used today when restoring a Model T.
Second, over 30 different types of black paint were used at the same time to paint Model Ts. The different types of paint vary according to the means of drying them (air versus oven drying) and were also formulated to satisfy the different means of applying the paint to the different parts.
Third, Model Ts during the black era were painted using the techniques of brushing, dipping or flowing the paint on. Paint spraying equipment for finishes did not come into widespread used in the Ford factories until 1926.
Fourth, the color black was chosen because it was cheap and it was durable. Black paints, especially those containing asphaltum, were noted for exhibiting better damp proofing properties than other colors during this period. The claim that black was chosen because it dried faster than any other color is not supported by the Ford engineering documents, the contemporary literature, nor by the first hand accounts of Ford Motor Company employees.
The Model T was a most practical car, and no doubt Henry Ford was convinced that black was simply the most practical color for the job.
List of the factory paints used by the Ford Motor Company: 1913 – 1925
Ford # Name Purpose Type F-101 First Coat Black Elastic Japan Prime coat on Fenders, hoods, etc. Oven F-102 Second Coat Black Elastic Japan Finish Coat on Fenders, hoods, etc. Oven F-105 First Coat Brushing Black Japan Front Axles Oven F-106 Second Coat Brushing Black Japan Front Axles Oven F-108 First Coat Black Wheel Surfacer Wheels Air F-111 Red Body Prime Bodies Air M-111 Quick Drying Black Touch Up General Purpose Repair Work Air M-114 First Coat Low Bake Enamel Touring and Roadster Bodies Force Dry M-115 Second Coat Low Bake Enamel Touring and Roadster Bodies Force Dry M-117 Carburetor Lacquer (Black) Carburetors Air M-121 Repair Enamel (Low Bake) Repair low bake enamel finishes Force Dry F-122 Radiator Black Radiators Air M-124 Empire Gray Metal Primer Touring and Roadster Bodies Force Dry M-125 Empire Gray Color Varnish Touring and Roadster Bodies Force Dry M-132 Black Asphaltum Wood Battery Boxes Air M-140 Black Graphite Paint (To withstand 600 degrees) Exhaust Pipes Air M-142 Black Wood Slushing Primer Crankcases and inside of bodies Air M-144 Black Dull Gloss (Fordtone) Truck cabs and bodies Force Dry M-151 High Gloss Black Lamp Enamel Lamps and accessories Oven F-152 Windshield Baking Japan Windshields, coil boxes, bow sockets Oven F-159 Black Wheel Color Varnish Second Coat on Wheels Air F-160 Second Coat Black Ground Second coat on bodies Air F-161 Maroon Primer First coat on bodies Air F-162 Black Color Rubbing Varnish Third and fourth coats on bodies. Air F-163 Black Touch Up Body Repair Work Air M-164 Black Brushing Color Varnish Touch Up Air M-165 Body Baking Enamel Touring and Roadster Bodies Force Dry F-178 Rear Radius Rod Black Dipping Radius Rods (Outside Manufacture) Air F-183 Sedan Sanding Surfacer Prime coat on wooden body parts Air F-189 Dash Oil Primer First coat on dash Air F-190 Dash Velvet Finishing Second & third coat on dash Air F-191 Instrument Board Satin Finish Enameling instrument boards Air M-195 Closed Body Wood Primer Primer coat on hard wood Air F-199 Gear Metal Primer Primer coat on chassis frames Oven F-402 Body Varnish Flowing Finish coat on bodies Air M-403 Floco Finishing Varnish Finish coat on bodies Force Dry F-404 Gear Varnish Finish coat on wheels Air
Enameled Parts on 1924 Touring Cars: The following parts were painted with M-101 and M-102 first and second coat Black Elastic Japan Paint:
Catalog # Description 1330-B Engine Pan, Right 1331-B Engine Pan, Left 2725-C Steering Connecting Rod 2771 Spindle Connecting Rod 2849 Spare Rim Carrier 2849-D Spare Rim Clamp 2914-B Gas Tank Support – Right 2915-B Gas Tank Support – Left 3076-B Crankcase front bearing and spring clip 3455 Hand Brake Lever 3634-J Steel Dash 3640-D Dash Bracket, Left 3641-D Dash Bracket, Right 3660-D Rear License and Tail Light Bracket 3664 Front License Bracket 3810 Front Spring Clip Bar 3833 Rear Spring Clip 3835 Rear Spring Clip Bar 3910 Starting Crank Assembly 3939 Outlet Connection Pipe 3947-C Radiator Shell 4050-C Hood >4052-B Hood Clip 4056-C Hood Block, Left 4057-C Hood Block, Right 4800-C Left Front Fender 4801-C Right Front Fender 4802 Right Rear Fender 4803 Left Rear Fender 4804-M Rear Fender Irons 4809 Front Fender Irons 4814-C Running Board Shield, Right 4815-C Running Board Shield, Left 4818-B Running Board Brackets 5014 Starting Switch 5047-C Battery to Switch Cable Support 5150-B Battery Bracket Assembly 5152 Battery Clamps 5159 Battery Box Cover and Door 6602-BRX Instrument Board 7135BRX Rear End Sill 7139BRX Rear Seat Right Hand Side Frame 7140BRX Rear Seat Left Hand Side Frame 7141BRX Rear Seat Center Frame 7143BX Tool Box Bottom 7148BX Rear Toe Board 7375X Front Heel Board 7411-BX Top Rest Irons 7837-X Windshield Bracket, Right 7838-X Windshield Bracket, Left 8027 Horn Switch Bracket 8349BX Rear Heel Board, Sill Covers, Top to Windshield Clamp
1925 First shown in factory photos dated December 12, 1924, the first pickup boxes did not have the Ford script on the rear door. The script was added in early 1925. Side panels had reinforcements to which the fender irons mounted. Factory List of Conversion Parts
Standard Runabout to Pickup Factory # # Reqd. Description td>T6203 1 Side panel assy, RH T6204 1 Side panel assy, LH T6206 1 Front panel assy T6174 1 Battery trap door T6157 2 Tail gate chain & bracket assy T6184 1 Tail gate assy T6171 2 Floor board retainer, long T6172 2 Floor board retainer, short T6167 1 Cross sill T6168 1 Rear floor board support T6207 1 Side panel support, rear assy T6175 1 Floor board, RH T6181 1 Floor board, LH T6176 1 Floor board, intermediate, RH T6180 1 Floor board, intermediate, LH T6179 1 Floor board, center T6173 1 Channel filler T6158 2 Rear fender iron T6182 2 Tail gate hinge bolt T6194 1 Tail lamp & license bracket support T6200 12 Floor board retainer bolt washer T6201 2 Rivet, panel support #1 to side panel and bracket T60 2 Nut, tail gate hinge bolt T341 4 Nut (5/16-18) Side sill to roadster sill bolt. 2 Tail gate hinge on sill to panel support 2 Cross sill to roadster end sill bolt 2 Tail lamp bracket bolt. T757 2 Cotter pin, tail gate hinge bolt (3/32 x 7/8) T925 4 Washer (5/16 i.d.) Side sill to roadster sill bolt 2 Tail lamp bracket bolt T1309 22 Nut (1/4-20) Floor board retainer bolt T1966 22 Washer (1/4 lock) Floor board retainer bolt T388 1 td> Rear spring assy (9-leaf, also used on Fordor sedan) T1971 4 Rivet, tail gate chain bracket bolt T4294 10 (1/4-20 x 2-1/4 carriage) Floor board retainer T5327 4 Bolt (5/16-18 x 1-3/4 small-head carriage) Tail lamp bracket to sill T5667 12 Bolt (1/4-20 X 1-3/8) Floor board retainer, rear T7014 2 Bolt (5/16-18 x 3) Tail gate hinge on sill to panel support T7111 2 Bolt (5/16-18 x 1-3/4) Cross sill to roadster end sill T7170 2 Rivet (1/4 x 3/8) Side sill to front panel 18 Rivet, panel support, rear  . 2 Rivet, front panel bracket to side panel 10 Rivet, panel support #1 to side and front >panel ^nbsp; 16 Rivet, rear floor board support to panel support T7254 4 Lock washer (5/16) Side sill to roadster sill bolt 2 Tail gate hinge on sill to panel support 2 Cross sill to roadster end sill bolt 4 Tail lamp bracket bolt T8120 4 Bolt (5/16-18 x 2-3/4) Side sill to roadster sill Note that while they specify the 9-leaf spring, they neglect to add the longer spring clip (T1737, part # 3833B).
1926-1927 Similar in style to the 1925, the side panels were embossed to match the rear fenders which were now mounted directly to the panels. Later (perhaps 1927) the bed was slightly altered and the front reinforcing post was moved forward a few inches, and the embossed molding changed to match. The vertical molding above the fender, which extended from the top molding to the bottom (curved) molding, now only went part way down from the top molding and did not connect to the curved molding. In addition, the floor boards (bottom of the box) were altered to accommodate the metal cover plate over the rear frame crossmember, new with the 1926 models.
1909 Winged Ford script on front. Brass Ford script, fastened horizontally (not on an angle as is often seen on restored cars), on the core on most cars. Filler was machined brass, rather low, soldered to the top. Cap had higher fins than usual type. No hole in side for lamp hoses.
General design differs from 1911 and later types in that there were fewer seams in the construction. Radiators were supplied by Briscoe from the beginning of production until about 2500, McCord beginning with about 2500, and Detroit Radiator beginning about 8500. Early production (but after 2500) used screws to mount the radiator, rather than studs. Paris radiators were shown on very early (pre-2500) invoices; may have been another brand. Some of the first (Briscoe or Paris?) radiators had separate shells, soldered to an inner core at the top.
1909-1910 The same as 1909. Standard Ford script used in addition to winged. Supplied by McCord and Detroit until about 17,000. Ford began making radiators beginning about 12,000, and supplied all after about 17,000. It may be the Ford brand that began the standard Ford script on the upper tank. Mounted with studs instead of screws. About mid-year, 1910, a number of modifications were made, including a higher filler neck and the addition of the support bar across the lower part of the radiator core.
1911-1912 Higher cast filler neck style which was introduced in summer of 1910. About January, 1911, a hole for the choke rod was added to the left front side trim piece. Beginning in about October, 1911, the drawings indicate holes for the rivets which now secured the filler neck to the top tank. Standard Ford script without Made in USA. Newer seamed construction, typical of all later brass radiators. Radiators now all made by Ford. The Ford on the radiator core was not used after late 1910. In mid-1912 holes were added in the sides for the gas lamp hose, with a soldered-in-place pipe from side to side for the headlamp gas. Made in USA under Ford script was added about April 16, 1912.
1912-1916 Spun-brass filler neck, riveted and soldered in place During 1914 the name plate on the back of the upper tank was eliminated and was replaced by embossing the design in the tank wall itself. In 1915 the gas tube for the lamps was eliminated. Filler cap had short fins. In 1915, too, the flanges of the side wall where they overlap the frame were made shorter. The embossing on the rear of the top tank was again changed and now indicated the month and year the radiator was manufactured.
1917-1919 Black metal shell over new radiator. Assembly mounted on pads on the frame. Filler neck and cap now nickel-plated. Water outlet hose increased in length to 3-1/2 (from 2-3/4).
1919-1923 Similar to 1917 but mounting holes larger for cushion spring mount. Outlet hose length increased to 4 for better fit.
1924 (Introduced about July 1923) Higher radiator. Outer shell now had a skirt at the bottom, over engine mount area.
1924-1926 Some flat tube radiators used during this period. Beginning in late 1925 an optional brass, nickel-plated, shell was offered. During 1926 three and four-row round tube radiators were used in addition to the standard five-row. The bottom skirt was secured to the engine mount/spring clip with a screw. Skirts used with the nickel shell had a nickel trim strip.
1927 Four and five-row, round-tube, radiators used. Nickel-plated-shell now standard.
Radiator Filling Flange Cap T-8714> This is the radiator cap used on the 1917 and later models. Prior radiator caps were of polished brass in a few variations in style. The earliest design had rather high and sharp fins. The fin design was modified in later 1909 and by about 1913 the fins were down to the standard size. 6/27/16 Adopted. It was made of stamped brass, nickel-plated and polished. 1/17/18 Redesigned from a brass stamping to a die-casting.This change to take effect a once. All caps and plugs on hand to be used up. 6/4/18 Redesigned and changed material from Die-casting alloy to S brass. Caps to be nickel plated and polished on the outside. This change makes the design of the cap the same as T-1103-B (the pre-1917 brass radiator cap), we have therefore specified the same size of stock that is being used for T-1103-B, also that these caps be made because the aluminum in the die cast cap corrodes too easily and is to take effect at once. Die cast caps to be used up. 8/20/26 A flange was added at the bottom of the cap where it contacts the radiator cap gasket. On a related note, I found in the Ford Motor Companies legal files correspondence indicating that the Bridgeport Brass Co. had filed suit about this time against Ford Motor because Bridgeport Brass claimed to have a patent on the stamped brass design of radiator cap. The court eventually threw out the suit.
EVOLUTION OF THE BRASS RADIATORS
By Trent Boggess
As we know, the brass radiator went through three major redesigns. The first radiator was designated as T-1100-A and was for use on the first 2500 cars. The documentation on this radiator is rather sketchy, but what I did find yesterday were the drawings for the first radiators—both of them—as in two different radiators. The drawings are dated February 26 and February 29, 1908. Both appear to be identical from a front view. The difference shows up in the side views. The February 26 drawing (which is labeled at T-1100 Type A) is three inches thick as measured across the top of the tank. The Feb. 29 drawing (type B) is four inches thick as measured across the tank.
Interestingly enough, very few of the parts on the assembly drawings have factory numbers. The filler neck, cap, hood holder and rivets, the water outlet and inlets do, but that’s it. This drawing reminds me of the discussion of the drawings of leather top straps a year ago. It shows lots of dimensions and basically appears to tell an outside vendor what size to build the radiator to, but leaves the details of its construction to the vendor.
The radiator was redesigned after the first 2500 cars. The new radiator carries the factory number T-1100-B. At this point, many more parts appear to have factory numbers on them. Also on August 13, 1909, a new part appears. It is T-1159 and it is called the Name Plate on Radiator (yes, HFMGV has the drawing). The new radiators have the same external dimensions as the older style, but the lower water connection has been redesigned for the thermo-syphon system.
During the summer of 1910 the radiator went through a third redesign, a much more extensive redesign than had occurred the previous year. The changes in the parts included a taller filler neck (T-1102-B), a new top tank front wall (T-1141-B) and top (T-1136-B), and new sides (T-1139-B and T-1140-B). Most of the redesigns have their first adoption dates of about 7/23/10, but one occurred three weeks earlier. The release for the radiator carcass (core) T-1133 indicates that the T-1126-B Radiator Support bar was added on 6/30/10. It would be interesting to know how many surviving 1910’s built in July 1910 actually have the support bar in their radiators.
The other parts of the T-1100-B radiator were, as stated above, redesigned later in the summer of 1910. The final assembly drawing for T-1100-B was not updated until October 1910. It is not clear whether the individual parts changed all at once in October 1910 or whether it occurred piecemeal during the months of August, September and October 1910. An important question whose answer still alludes us is when did the front wall with the winged Ford script change.
The T-1100-C radiator set the pattern for the remainder of the brass era production. However, individual differences occur over time. One of the first of these differences appears on the T-1145-B Radiator Front Side Piece RH. On January 4, 1911 the release notes Added a 5/32 punched hole for Carburetor Priming Rod on lower left hand side. A small, but significant change occurred in the radiator top T-1136-B. On October 10, 1911 the release indicates Added three 9/64 punched holes for Filler Flange Rivets. The releases for the filler flange tell us nothing about the addition of the rivets so this was indeed a find.
What is more on November 28, 1911 another note states: Moved rivet and soldering holes for filler flange, 30 (degrees) about center of hole for filling flange. This brings one of the rivet holes on center line of radiator, at the rear side of filling flange, making the other two rivet holes located symmetrically about the same center line. The Model T had symmetry, but not style.
In 1912 holes were added in the radiator for the gas lines. On June 13, 1912 a note on the release for T-1139-B Radiator Left Wall reads: Added .5 punched hole for gas lamp hose, the hole to be located 3.5 from front edge of plate, and 11 7/8 from top end. A few days later on June 17, 1912 a second note reads: In FL#316 we were advised of .5 holes for Gas Lamp Tubes, being punched in certain pieces. To do away with the sharp edges of metal which would soon cut the tubes, we have called for a 3/32 flange around the hole — the metal being flanged in the direction that will bring to the inside of walls, when same are assembled to radiator. To be sure that the latest print reaches everyone concerned, date has been corrected to read 6-17-12.
During 1914 the name plate on the back side of the Radiator top tank was changed. The releases indicate that the separate plate was made obsolete. While the releases for the rear wall of the top tank, T-1141, say nothing about it, the drawings for this part indicate that the plate was replaced by embossing the design of the plate in the rear wall of the tank itself.
Steve Coniff and Larry Smith have been giving original 1915-16 radiators a close look. They have noted what the factory documentation confirms. The flanges on the radiator side walls where it overlaps the frame changes significantly during 1915. Prior to 1915 the flanges were .75 long. During 1915 the flange was shorted to about half that length. I understand that Larry has named the later style the Mini Skirt Style and the earlier ones the Long Skirt Style. Here is what the releases have to say. On May 28, 1915 the releases state This flange was removed because it interferes with frame. This change is to take immediate effect. Flanges to be clipped off, on walls we have on hand. Then on June 26, 1915 the flange was modified again. Changed height of flange which projects over side of frame when radiator is on car, from 25/32 to 11/32 specifying rear corner to be rounded with 3/16 radius instead of square. This changes distance between the bottom of flange and the lower end of flange on rear edge of wall from 1-1/32 to 19/32.
Another subtle change occurred in November 1915. The embossed name plate in the rear wall of the radiator was replaced. According to the drawing a note shows that the numbers .5 high, representing the month and year the radiator was made, were to be stamped into the rear wall in the same location that the name plate had been located in.
Interestingly enough, the changes in the radiator side walls from the Long Skirt to the Mini Skirt styles is not incorporated into the radiator assembly drawing until January 1916, even though they had been made some six months earlier.
A final item. One question that frequently comes up is just how long were the brass radiators used in production? While I would not consider this a definitive answer, the releases indicate that the brass radiator and all of its parts were designated For Repairs Only on September 9, 1916.
RADIUS RODS See Front or Rear Axles
(Also see Driveshaft)
1909 Initial design of 1907 used pressed-steel brake backing plates. These were changed to cast iron in November 1908. It is not known if the pressed-steel type ever saw production. No-rivet style. Non-tapered axles. Babbitt axle (inner) and pinion bearings. Bronze bushings throughout the differential gear assembly. No wires to hold differential nuts in early axles (with the riveted-in-place ring gear). Instead they used slotted nuts which were peened down to lock them. Filler plug was slotted screw. Brake and radius rods had forged ends.
EARLY REAR AXLES HOUSINGS
Trent Boggess Several new drawings under several previously unknown factory symbol numbers will assist in our understanding of these parts. The new factory symbol numbers are T-171 Rear axle housing (56 Tread) showing construction and T-188 Assembly of Rear Axle—Centre (sic) Section. These are both very good drawings and they shed quite a bit of light on the differences between the axles used on the 1909-11 cars.
The first housings were T-1 (right) and T-2 (left). These are the so-called no-rivet housings. This design used the babbitt inner axle shaft bearing. The housing for this babbitt bearing carries the factory symbol number T-9A. It also uses the simple T-4 coupling reinforcement ring at the mouth of the housings where the driveshaft tube is attached to the rear axle. The drawings for T-4 show it as being literally a steel ring that was cut in half, one for each half of the rear axle housing. It appears that this axle was used from the start of Model T production until well into 1909.
The drawings indicate that there may have been two different no-rivet housings. The second one used a modified version of the inner bearing housing, T-9B, but I have not been able to determine how this housing differed from the T-9A.
In the later spring and early summer of 1909 another design appears. These housings carried the factory symbol numbers T-1C and T-2C. These designs use inner roller bearings instead of a babbitt bearings. The housing for holding the bearings is T-9C. The drawing calls for this bearing housing to be riveted to the pressed steel axle housings with six rivets. So this is the prototype six-rivet rear axle. I say prototype because it also is still using the original T-4 coupling ring between the two axle housing halves and the drawing is marked in pencil Not Used—Hold and Obsolete Aug-16-09 so it does not appear that this design was ever used in production. (Note: Other Ford documentation shows that the roller inner axle bearings were used after the first 12,000, and that the roller pinion bearing was used after the first 18,000. Therefore, this design may have been used for about 6,000 cars in 1910.)
The next six-rivet designs used in production were T-1D and T-2D. The drawings for these two housings differ from the C design in that the coupling ring has been changed from a machined steel ring to a drop forging with a skirt that extends down the side of each of the housings that is riveted to the housings and obviously provides considerable reinforcement. The new coupling ring carries the factory symbol number T-4C. (I think T-4B was never produced, but would have used the odd ball 13/32 inch threads for the driveshaft flange bolts). This is the six-rivet design that we all know so well. Actually, there were two versions of this, the D design and the E design. The difference between the two is the D still uses 3/8-inch threads in the T-4C coupling ring, while T-4E uses the odd ball 13/32-inch thread. The designs for these housings are dated November 2, 1909 and no doubt they appeared in production within a month or two after that. Also, the inner bearing housing carries the factory symbol number T-161, not T-9C so there was probably a difference here as well from the T-1 and 2C design. (Note: T-161 is the roller bearing sleeve which fits inside the T-9C bracket.)
Now for the interesting part. There were several different changes to the flanges where the two housing halves meet. The basic design appears to have remained unchanged through September 1910. On October 5, 1910 the Ford engineers decided that the joint between the mating flanges of the housings need to be reinforced. The first attempt at reinforcement took the form of brazing washers on the outside of both T-1 and T-2 where the coupling bolts attach the flanges together. Actually, they weren’t washers at the time they were brazed on—they were discs some .063 thick. They became washers when the holes were drilled for the coupling bolts through both the discs and the pressed steel housings themselves. The washers carried the factory symbol numbers T-126.
This lasted (on the drawings) about eight days. On October 13-14, 1910, the design was changed again. The T-126 washers were replaced with T-123-B reinforcement segments. These segments are little crescent shaped pieces of steel, 3/32 thick which were to be brazed to the outside of the housings at the flanges. They fit the contour of the housings at the flanges and provided a boss for the connecting bolts. The drawing indicates that ten of these segments were to be used for the two housings.
What happened to the T123-A you ask? I’m not sure. The drawing for T-123-A shows a Rear Axle housing flange that is in effect a full circle reinforcement. It looks as if this would have had to be brazed to the inside edge of the flanges where they meet. It was to be made of steel .063 thick. The drawing for it is dated August 17, 1910, but I can find no reference that it was ever used. I do know that the 123-B was used because those are on the housings I was hoping to use on the 1911 torpedo.
The T-123-B reinforcements were used for about two months (at least this is the time span between the changes in the drawings). Then on December 21, 1910, they were declared obsolete and it appears that the T-126 washers were re-instated! However, again this was a short-lived change before still another and more extensive change was made. In January 1911 the engineers modified both pressed steel housings so that they would be 1/8-inch shorter. The overlapping flange on the female half of the housing (T-2) was made 1/4-inch longer. And the T-126 washers were declared obsolete again on January 13, 1911 and replaced with T-123-C Rear Axle Housing Reinforcement. This reinforcement is half moon shaped, 1/8-inch thick, and four are required, two per axle housing. They were to be brazed to the inside edges of the axle housing flanges, which explains the shorter length of the housings. This was the final change in the six rivet housings for the balance of the time the six-rivet axles were used in production. The records seem to emphasize that the change in the length of the housings came on January 13, 1911not just in design but in production of the housings themselves.
While going through all these drawings I ran across an interesting experimental drawing— actually two of them. They were designated as T-1E Exp and T-2 Exp dated October 15, 1910. What they show is that Ford was considering going back to the NRS design rear axle. These two pieces were to be made of malleable iron and look like 1912 clam-shell halves except that like the NRS and 1915 and later housings they were to use straight tubes that were inserted into the castings and riveted in place. That is, they have the outside contour and shape of the clam-shell halves, but the construction is like that of the NRS and 1915-25 style rear axles. For some reason they did not choose to pursue that design at that time.
REAR AXLE HOUSINGS
Only the major parts of the rear axle assembly are listed here.
(Early) Part # Factory # Description 2501 1 Right 2502 2 Left 3/8 Drive shaft studs until about 12,000 (October 1909). Babbitt inner axle bearings. Smooth brake backing plates. Pressed-steel housing with no rivets and no reinforcements.
1910 Part # Factory # Description 2501 1B Right 2502 2B Left Similar to 1909. Reinforced brake backing plates. Slotted filler plug.
Six-rivet style. Non-tapered axles. Roller inner axle (after 12,000, October 1909) and pinion (after 18,000, March 1910 ) bearings. Later 1910 housings had reinforcing washers around the flange bolt holes, and still later, a ring brazed around center section. By 1911 two such rings were used, one on each half, inside the housing, making the center seam much thicker. Pinion bearing housing drilled for 3/8 studs. Brake backing plates changed from smooth to those with reinforcing ribs in drawing dated November 12, 1909.
1910-1911 Part # Factory # Description 2501 1B Right 2502 2B Left The brake backing plate was again revised in a drawing dated October 18, 1910. The 1910 style continued until July 13, 1911 when new 1912 rear axle (12-rivet, clamshell design with cast center section) appeared. Tapered axle shafts standard after early 1911 and appeared before the housing change in July. New housing used 13/32 studs for the driveshaft pinion bearing spool. Slotted filler plug.
1911-1912 Part # Factory # Description 2501-1/2 1E Right 2502-1/2 2E Left 1912 Same as late 1911 1912 axle. The newer 1913 axle appeared later in the year, perhaps as early as September (date unknown) but definitely by November. Slotted filler plug.
Part # Factory # Description 2501B 1E Right (Same as late 1911) 2502B 2E Left Note: The roller bearing sleeves used in the earlier axles differed from the later in that the locating dimple was about 3/4-inch from the end, while the later one had the dimple at about 1/2-inch. Whether both types were used, or just when the change was made is not certain, but is believed to have been in late 1911 or 1912.
1913-1914 Part # Factory # Description 2501D 2835B Right 2502D 2836B Left Introduced in about October 1912. Larger cast center section, similar in shape to later types, but with the axle tubes flared and riveted to the center section. In 1914 the forged-end radius rods were replaced with the less expensive split-end type. These were seamless and interchangeable from side to side. Brake shoes modified to use two springs instead of one; the second spring being across the mounting bolt side of the brake shoe. Hexagon filler plug now standard.
1915-1919 New standard design adopted about March 1915. Tubular axle housings inserted into center section. Early 1915 brake backing plates did not have reinforcing ribs (added in October 1915). Oil filler hole just below centerline. 1915-1916 Part # Factory # Description 2501E 2835C Right 2502E 2836C Left 1917-1919 Part # Factory # Description 2501 2835C Right 2502 2836C Left Same as 1916 except for part number change.
1919-1921 Similar to 1918 but now machined for a gasket between the two halves. Oil filler now 1-3/4 below the centerline. Driveshaft modified in 1920 to use new forged bearing sleeve. Outer oil seal cups larger in diameter due to machining change in the axle tubes. 4-1 gears became available in July 1919. At first these were a 48-tooth ring and a 12-tooth pinion but by January 1920 the 10-tooth pinion which could be used with the standard ring gear replaced the first type.
1919 Part # Factory # Description 2501 7635 Right 2502 7636 Left 1920-1923 Part # Factory # Description 2501 7635C Right (Same as 1919) 2502 7636C Left 1923-1925 Part # Factory # Description 2501 7635D Right 2502 7636D Left Beginning about 1922 the rear radius rods were of seamed construction. Lefts and rights were required so that the seam will be down for drainage. 1926-1927 Identical to 1925 except for larger brake backing plates. An oil seal was added at the outer axle bearings. Oil plug changed to type with recessed square hole instead of hex head during late 1926.
At least four brake backing plates were used. Some had riveted-on brake shoe retaining clips. Others had clips that were pressed from the backing plate, with and without a spot-welded cover over the pressed-in area on the outside surface. The earliest type (with the pressed clips) came with either smooth backing plates or with an embossed C shaped molding and an oil vent on the bottom half. The riveted type is believed to have appeared in calendar 1926, but those noted had the embossed bottom area and used the old hex-head filler screw.
During 1926 the radius rods were modified to eliminate the rearward nut at the universal joint. The nut was replaced with a forged-in collar which located the radius rod on the U-joint housing.
Part # Factory # Description 2501B 7635B Right 2502B 7636B Left
REAR AXLE SHAFTS
1909-1910 2503 48 Non-tapered Axle gear held with small woodruff key and a pin. 1910-1911 2505A 48B Non-tapered Axle gear held with large woodruff key and a collar. 1911-1917 2505D 2818 Tapered Axle gear held with large key and collar (2 pieces). The diameter of the axle shaft where the roller bearings fit is 1.062 – 1.063. The length is 31-3/64 – 31-5/64. The taper is 2-3/4 long and ground portion where the outer bearing fits is 5-1/4 and the ground area where the inner bearing and the gear are is 6-1/4 long. 1917-1927 2505 2828 Tapered Same as 1916 except for part number.
(Fiber, between axle shafts) 1909-1927 2506 39 1-1/32 diameter
AXLE BEARINGS 1909 2507 51 Babbitt inner bearings. 2508 97 Hyatt roller outer bearings 1910-1920 2508 97 Hyatt roller (Inner and outer) 1920-1927 2508 253 Hyatt roller (factory number change)
AXLE BEARING SLEEVES 1909-1911 2509 170 Right * 2509B 161 Left * Outer only in 1909. Locating dimple further from the end than later design. 1911-1927 2509 170 Right (Dimple nearer the end) 2509B 161 Left
REAR AXLE SEAL CAPS 1909-1919 2510 56 2-13/32 i.d. (Initial design caps were brass but were changed to pressed steel in a drawing dated March 11, 1909.) 1917-1927 2510-1/2 56B 2-7/16 i.d.
DIFFERENTIAL GEAR CASE 1909
(Early) —– 10 Left (For riveted ring gear) —– 11 Right 1909-1911 2512 10B Left (9/16 spider arms) 2513 11B Right Uses 2517 axle gear bushings. 1911-1913 2512B 10C Left 2513B 11C Right 5/8 spider arms, bushing for axle gears. 1913-1915 2512C 10D Left 2513C 11D Right >5/8 spider arms, no bushing. Uses 2514 stud. 1915-1927 2512C 84 Left, Final design. 2513C 81 Right, uses 2514B stud.
DIFFERENTIAL GEAR CASE STUD 1909-1915 2514 52 3/8 x 2-3/4 1915-1920 2514B 52B or 2865 3/8 x 2-1/4 1921-1927 2414C 52C Now a cap screw.
DIFFERENTIAL GEAR CASE BUSHING 1909-1913 2517 19 Bronze 1-9/16 I.D., 1-13/16 O.D.
(40 tooth) 1909 —– 12 Riveted to gear case. 1909-1927 2518 12B Threaded holes
(Axle gear, 24 teeth) 1909-1911 2520 13 Drilled for pin #2522 1911-1927 2520B 13B For key and collars.
DIFFERENTIAL GEAR THRUST WASHER 1909-1914 2523 32 3-1/16 dia. Fiber.
DIFFERENTIAL PINION GEAR
(3 used) 1909 2524 14 1909-1911 2524 14B 9/16 bushing. 1911-1914 2524B 14C 5/8 bushing. 1914-1927 2524C 14D No bushing.
DIFFERENTIAL GEAR SPIDER 1909 2526 15 1909-1911 2526 15B 9/16 arms, axle bushing. 1911-1914 2526B 15C 5/8 arms, axle bushing. 1914-1927 2526B 15D 5/8 arms, no bushing.
DIFFERENTIAL GEAR SPIDER BUSHING 1909-1914 2527 18 1-1/16 brass.
DIFFERENTIAL THRUST BEARING
(2 used) 1909-1915 2528 30 Bronze 1915-1927 2528 30 Babbitt
DIFFERENTIAL THRUST BEARING WASHER
(4 used) 1909-1927 2529 31 Steel, 3-3/4 diameter.
DIFFERENTIAL THRUST WASHER PIN 1909-1916 2530 17 13/32 long. 2531 37 7/32 long. 1917-1927 2531B 7640 Dual diameter pin, larger of which fits into housings.
DIFFERENTIAL OIL DRAIN PLUG 19O9-1912 2532 817 Screwdriver slot. 1913-1926 2532 817 3/4 x 24 Hex head. 1925-1927
(Late> 2532B 2824 1/2 Recessed square socket pipe plug. (The change to the pipe-plug was noted in a release dated late 1925 but many of the large-drum (’26-27) housings have the 15/16 hex screw.)
(Also see Driveshaft) 1909-1910 2533 153 Babbitt pinion bearing 1910 2582 74C Drilled for 3/8 studs. Used beginning at 18,000 1911-1914 2582 153D Drilled for 13/32 studs. 1914-1920 2582 153D One-piece type. 1920-1927 2582 153D Flange modified for new pinion bearing.
AXLE HOUSING EVOLUTION, 1907-1911 Date Factory # Comments 10/24/07 1A Adopted. Pressed steel 11/17/08 1C Adopted. Pressed steel No date 1D Adopted. Pressed steel 04/20/09 1D T9B driveshaft reinforcement ring changed to T9C which is heavier. T9B used on first 6000 cars. 07/14/09 1B Adopted. Pressed steel 08/04/09 1D Changed T9B to have two 5/8 holes instead of one 08/04/09 1D T9C changed to T9D, used after 15,000. T9D is the forged reinforcement around the driveshaft mounting area on the axle housings. 08/16/09 1C Obsoleted 09/10/09 1D Changed oil hole from 5/16 to 7/16 09/15/09 1B Lower oil hole in T9B eliminated. Upper hole changed from 5/16 to 7/16 09/17/09 1D Coupling ring T4B in place 01/11/10 1B Obsoleted 03/24/10 1D T9D changed to T9E 04/22/10 1E Adopted (1911 design). Same as 1D except for 13/32-18 studs instead of 3/8-24 04/25/10 1E Studs changed from 13/32-18 to 13/32-16 10/05/10 1D T126 washer used at flanges. T126 is #13 (.09375) steel 10/13/10 1D T123 flange replaces T126 washers 10/14/10 1E T123 flange replaces T126 washers. T123 was #16 (.065) sheet steel. 11/05/10 1G Adopted 12/21/10 1D Two T123B flanges replace T123. T123B was #13 (.09375) steel 01/07/11 T123C (#11, .125 Steel) replaces T123B. 02/11/11 1G Changed from 6 to 12 rivets 10/10/11 1E Obsoleted 10/24/11 1G Obsoleted The above relates to the early 6-rivet pressed steel axle housings. Apparently more than one design was being used at any given time if the dates are any indication.
T1 is the male housing. T2 is the female half on which similar modifications were made.
(Early production) Part # Factory # Description —– 1410 R/H (Linoleum covered) —– 1411 L/H Note: This board was made up of T1412 Rubber Matting; T1421, T1422, T1423, T1425, T1486, T1487 and T1488 Brass Trim pieces. (Factory numbers.) 1909-1910
(First 15,000 cars, January 1910) Part # Factory # Description 2941 1410B R/H and L/H Steel with uninterrupted ribs running length-wise. No Script. Painted body color. 1910 Part # Factory # Description 2941 1410C R/H and L/H Steel with interrupted ribs running lengthwise, beginning with 15,000 in January 1910. Painted body color. 1911-1912 Part # Factory # Description 4812 2530 R/H Blue 4813 2531 L/H Steel with typical diamond pattern. Ford script ran lengthwise. Made in USA added in later production 1912. Painted body color. 1911
Torpedo Runabout Part # Factory # Description 4846 2551 R/H Blue 4847 2552 L/H 1913-1921 Part # Factory # Description 4812 5418 R/H & L/H Ford script now ran across the board. 1913 to 1925 running boards were steel, similar to 1912 but script now ran across the width. Earlier boards had much sharper diamonds that later, apparently due to wear on the dies that pressed them. There were minor variations in the Ford script, the placement of holes, etc. during the years but the basic boards were identical. Painted black after 1912. 1918-1925 Part # Factory # Description TRUCK 1129 TT5418 R/H and L/H P/N changed to 4830 in 1920. 4830 TT5418 R/H and L/H 1922-1925 Part # Factory # Description 4812 5418 R/H 4813 5480 L/H Same as earlier boards but drilled differently. 1925-1927 TRUCK Part # Factory # Description 4830B TT5418 R/H. (21-29/32 long) 4830C TT5480 L/H 1926-1927 Part # Factory # Description 4813B 5418B R/H and L/H Wider board with much smaller diamonds. Ford script now much smaller and was imprinted along the outer edges of the boards.
© Bruce W. McCalley. Rev. February 9, 2007