[Kari Lumppio]

Originally Posted by Graham Boak

The Spitfire propellers were made from resin-impregnated wood, effectively a new material, not just carved from a piece of a tree in the traditional manner.

AFAIK For it's wooden propellers Rotol used German manufacturing technique called Leichtholtz-Mantel. Patented by Gustav Schwartz Propellerwerk already before the war.

At least in German propeller blades resin-impregnated (under high pressure) wood was used only on the middle, the sides being made of lighter wood strips (spruce IIRC) glued together and carved. This helped in keeping the balance of the blade, the "spar" in the middle being heavier than the leading and trailing parts.

Regards,
Kari