Duramold

Birch or poplar plies are impregnated with phenolic resin and laminated together in a mold under heat (280 °F, 138 °C) and pressure for use as a lightweight structural material.

[4] Over 17 varieties of Duramold were developed, using various combinations of types of wood in thin plies.

[citation needed] Virginius Clark developed Duramold for Fairchild Aircraft, working with George Meyercord of the Haskelite Corporation.

[7] Several aircraft used Duramold in parts of their structure, the largest manufactured with the process being the Hughes H-4 Hercules designed by Howard Hughes and Glenn Odekirk, which was built almost completely with Duramold including very large sections.

[5] The Duramold and Haskelite process was first developed in 1937, followed by Gene Vidal's Weldwood and later the Timm Aircraft Company's Aeromold process, which differs in that it is baked at a low 100 °F (38°C) at cutting and forming, and 180 °F (82°C) for fusing together sections after the resins are added.