Last month I wrote about the Royal Paulownia tree, which is known in China as the T'ung Tree. A good friend and customer, who is also a part time casket maker, e-mailed us with two logical questions: First, if a Chinese girl child doesn't marry, would the wood of the T'ung Tree, which had been planted at her birth, be saved for her casket rather than her wedding chest? Secondly, does Tung Oil come from the T'ung Tree?
I can't answer the first question although Lindy ventured that maybe the wedding chest got made anyway and the Chinese girl just kept hoping. As for the second question, I did a little research…
Tung Oil is pressed from the seeds of the Tung Tree (Aleurites of the Euphorbiaceae family) which is a different species from the Paulownia. It is a deciduous shade tree native to central and western China where seedlings have been planted for thousands of years. Although native to China, there are now Tung plantations in Argentina and in the southern U.S. from Florida to Eastern Texas. In the U.S. the trees live about 30 years. It grows up to 12 meters tall and spreads out to about the same distance. It has smooth bark and soft wood and its dark green heart-shaped leaves are 15 cm wide.
The leaves appear just after the flowers which grow in clusters and are whitish and "rose-throated". The seeds are spherical or pear-shaped, green to purple in maturity, and consist of a hard outer shell and a kernel from which the oil is obtained.
The trees usually begin bearing fruit the third year after planting, are in commercial production by the fourth or fifth year with maximum production at about ten to twelve years. The seeds drop during the fall and are left on the ground 3-4 weeks until hulls are dead and dry and moisture content has dropped from 60% to 30%.
Besides the well known Tung Oil that woodworkers use, the versatile product is also an ingredient for lacquers, varnishes, paints, linoleum, artificial leather, brake-linings, india ink, caulk, and mortar. During World War II it was even used by the Chinese for motor fuel. It tended to gum up engines, so they processed it to make it compatible with gasoline and the mixture worked fine.