I have a collection of hard woods which I have used in some of my projects. My favourites
being Purpleheart and Lignum Vitae which is used for ships’ propeller bushes and
bearings, since it has three times the life of bronze or steel as a result of its
natural self-lubricating qualities. Lignum has a specific gravity of 1.23 meaning
it sinks in water so no use for raft building.