Frame planning

I looked at the mechanical properties of the phenolic sheets. Phenolic is a fiber-reinforced resin laminate, available in sheets, tubes and rods. It is a thermosetting plastic, with good electrical properties. According to one manufacturer, linen phenolic type LE has a tensile strength of 13000 psi “lengthwise” and 9,000 psi “crosswise”. This compares to a tensile strength along the grain of 11,300 to 16,300 for “oak” in Mechanical Properties of Wood, by David W. Green, Jerrold E. Winandy, and David E. Kretschmann. The paper phenolic (XX type) has about half the fracture toughness of the LE plastic. Note that the tensile strength at yield for King Starboard™, a marine polymer sheet, is 4000 psi. The principal reason for using Starboard would be its low moisture absorption, about 1percent of the phenolic.