How do you extract the oil from the fruit of the Tung tree?

Tung oil is made from pressed seeds from the nut of the tung tree. The tung tree, native to China, is named for its heart-shaped leaves because "tung" is Chinese for "heart." In the 14th century, Chinese merchants were noted for using tung oil to waterproof and protect wooden ships from the eroding powers of the sea. There are even mentions of tung oil appearing in the writings of Confucius in around 400 B. C. For these reasons, it is also sometimes referred to as "China wood oil.