Following the thread about cork blanks, I contacted a cork producer (in Portugal) and got the following answer :>>> We’re manufacturer of expanded insulation cork>>> Standard density is 110/120 Kgs/m3 (can support 2/2.500kgs /m2)>>> Standard dimensions 1000 x 500mm>>> Thickness until 300mm The product’s density (110 kg/m3) seems interesting, somewhere halfway between polyurethane (80 kg/m3) and balsa (160 kg/m3). Dimensions (40" x 20" x 12") mean some scarfing would be required. Maybe I’ll give it a try this winter… Pierre
Tech. data about expansed cork Color : brown, almost black (as a matter of fact it’s called “black cork” in France ) Manufacturing process : grains are expansed at 300°C and glue themeselves without any glue needed. Grain size : 3/16 mm Dendity : +/- 120 Kgs/m3 Température where it can be used : from -160°C to + 105°C Max temp. : + 120°C Aging of material : none Resistance to flex : 2.6daN/cm2 Resistance to compression : breaking point at about 3Kgf/cm2 Panel resistance to tearing : breaking point at 0,5 bars Panel resistance to traction : 6 N/m2 (I have more tech data about resistance but I’m not sure about their meaning) Bending due to heat : none Bending : resist without deterioration to bending diameters of 60 times its thickness. Water content : 0,004g/cm3 Resistance to water vapor : 0,20g/m/h/m2 à 0,5 bar Won’t break apart if boiled Dimensions changes depending on temperature : none Dimensions changes depending on moisture level : 0,14 % Corrosive action : negative Odor : not durable, not toxic for food Resistant to solvants (such as acetone) Volatility at + 100° C : no gas release Fire resistant, burns slowly without toxic fumes