What's So Great About Tung?

Perhaps you have heard that green designers often use tung oil as a substitute for more toxic wood finishes. Many woodworkers consider tung oil to be one of the best natural finishes for wood. But what is tung exactly? The oil is obtained from the seeds of a tropical tree, the tung tree (Aleurites fordii). The seeds found in the heart of the tung fruit (which is the size of a small apple) contain more than 50% tung oil, readily obtained when the seeds are heated, ground, and pressed. Tung oil was used to waterproof Chinese ships as long ago as the 14th century. The thin, transparent oil penetrates deep into wood pores, practically becoming part of the wood. It forms an almost permanent seal against moisture because it never loses its elasticity. Other unsaturated plant oils, such as castor oil and linseed oil, take longer to dry and leave an oily residue until they soak into the wood surface. You can read more about tung oil here. [by Justin Thomas]