VeloTrain wrote:" . . . and that Irish navigator who recreates pre-historical ships , Tim Severin , tried to build a junk the old way and sail it on the northern circle sailing route east to the states across the Pacific . The traditional hull treatment was supposed to be stuff called "Tung Oil" inside and out , but there was something wrong there for they only got about halfway and the shipworms had chomped her full of holes , so they had to be lifted off . Shame ."
Apparently the problem might have been that they used tung oil, but not the rest of the recipe. From the Wiki article on Junks: "For caulking the Chinese used a mix of ground lime with Tung oil together with chopped hemp from old fishing nets which set hard in 18 hours".
So in other words...The Chinese used some kind of concrete casing on their hulls???