Clark Foam, in operation 1961–2005, was a Californian manufacturer of surfboard blanks — foam slabs, reinforced with one or more wooden strips or "stringers" — cast in the rough shape of a surfboard and used by surfboard shapers to create finished surfboards.
The Company was founded in 1961 by Gordon "Grubby" Clark, a 1959 graduate of Claremont McKenna College who had worked as a glasser, applying and finishing the fiberglass surface of surfboards for surfboard pioneer Hobie Alter. Alter set up a separate operation in Laguna Canyon making polyurethane blanks and put Clark in charge of it. Around this time, the surfing-themed movie Gidget was released and surfing became more popular. Clark was soon manufacturing 250 blanks a week for Alter, and in 1961 set up his own company, Clark Foam.
For decades his company exercised a near-monopolistic control over the market. At the time of its 2005 closing Clark Foam provided about 90% of the United States supply and 60% of the world supply of surfboard blanks.
On December 5, 2005, Gordon Clark abruptly shut down Clark Foam, then worth about $40 million, and began destroying his molds and equipment, citing difficulties with government regulatory agencies over the chemicals and equipment he used and claims filed against him by former employees. Clark Foam used toluene diisocyanate in the manufacturing process, one of the last California manufacturers to do so, and the United States Environmental Protection Agency (EPA) had threatened to shut down the company in the past. In a seven-page fax, Clark cited several issues pending with the EPA as his reason for shutting down, although no known action was under way against him.
The abrupt closing of Clark Foam sent shockwaves through the industry and left surfboard shapers scrambling for new suppliers. Since Clark Foam closed, surfboard manufacturing has turned to new and innovative materials, such as carbon-fiber-reinforced polymer, hollow blanks, and new "flex" materials used by other various companies.