REVISED AND UPDATED – The Ford soybean car: Scam or hoax? Only 72 years late, Mac’s Motor City Garage rips the lid off the controversy with this probing investigative report.

(An earlier version of this story appeared at Mac’s Motor City Garage on April 24, 2013.)

Long before he reinvented mass production with the Model T, Henry Ford spent his childhood on a farm in rural Michigan, and in middle age he became fascinated with the notion of merging farming with industry. Much of this effort focused on finding uses for the soybean in manufacturing, with some limited success. However, as with many of Ford’s projects, it can be difficult to separate the reality from the publicity surrounding it.

Henry Ford takes an ax to an experimental plastic deck lid on a production1941 Ford sedan, demonstrating its alleged dentproof properties.

The Ford soybean car of 1941 was so named because its body panels were said to be constructed from a soy-based plastic created in Ford’s soybean laboratory at Greenfield Village in Dearborn. (The building still exists. It’s the gray frame structure on your left as you pass through the Village front gate.) Though no formula survives, Lowell Overly, the Ford employee in charge of the project, said the body material was “soybean fiber in a phenolic resin with formaldehyde used in the impregnation.”

Plastics engineers today scoff at the claim, skeptical that the plastic contained any significant soy material at all. The body panels were more likely a conventional phenolic plastic similar to the stuff we know as Bakelite. Soy-based structural plastics have never proven out to this day.

During the Second World War, license plates in several states were manufactured using pressed soybeans, but the cardboard-like material was so flimsy that few survive. (Farmers also remember that barnyard animals found the plates delicious and would eat them right off the cars.) The soy-based material also brings to mind Duroplast, the cotton-fiber plastic used to make bodies for the East German Trabant automobile (1957-1991). In recent years, the proponents of hemp production have hijacked Ford’s soybean car experiment to advance their own agenda—with inadvertent comic effect. Makes you wonder what they’ve been smoking.

Ford soybean car chassis

But all that’s okay, because the so-called soybean car is interesting in so many other ways, starting with its architecture. Originally designed by Ford styling chief Bob Gregorie with assistance by John Najjar, the chassis and integrated body superstructure were constructed from thinwall steel tubing. The 14 molded body panels that made up the car’s skin were hung on this support structure, forming an extremely light, simple assembly. Lightweight plastic windows and a 136 CID Ford V8-60 hp drivetrain also helped to keep the weight down, reportedly under 2000 lbs.

Alas, the soybean car is no longer around for us to explore its mysteries. Gregorie had it destroyed, apparently not long after its two known public appearances in the summer of 1941. In the gallery below you’ll find the patent drawings and a selection of photographs.