The word Tung is an ancient Chinese term for heart. Today, the term also refers to the large, dark green, heart shaped leaves of the Tung tree. This is a fast growing, deciduous tree that reaches a height of about forty feet when mature. The life span of a Tung tree is about thirty years. Fruit bearing begins in the third year of tree growth.

The Tung fruit occurs in clusters, each of which bear four or five nuts. When the nuts are dried and pressed they yield about twenty percent oil. Under favorable conditions an acre of  Tung trees will produce about two tons of nuts and eight hundred pounds (one hundred gallons) of raw Tung Oil annually. Successful cultivation of Tung trees requires exact climatic conditions, including the proper ratio of warm and cool days. The major growing areas include China, Argentina, Paraguay, and parts of Africa.

The first record of Tung Oil appears in the writings of Confucius dated about 400 B.C. . Even then, the Chinese recognized the amazing qualities of Tung Oil. Throughout their history, the Chinese have used Tung Oil to waterproof the masts and sails of junks (boats), to finish furniture of royal families and according to legend, to seal the Great Wall! When Marco Polo returned from China, he brought tales of the wonderful "China Wood Oil". But Tung oil was unable to capture the attention of the West until this century.

In 1912, the American Ambassador to China shipped Tung trees to California, but they died due to lack of proper growing conditions. Successful Tung plantations were established in the Gulf Coast states during the 1930's because of the perfect growing conditions. The U. S. automobile industry began using Tung Oil to prevent rust and reduce friction on engine parts. Soon Tung Oil was used to coat the insides of cans, to insulate electric circuits, and to make high-quality paints. In 1969, hurricane Camille destroyed the Tung plantations of the Gulf states and stopped the domestic production of Tung Oil. Even though Tung Oil is now an imported commodity, it remains a vital part of American industry.

TUNG OIL VERSUS OTHER FINISHES

In recent years, those who appreciate the warm richness of beautiful wood have begun to realize what the ancient Chinese knew; when turned into a finishing product, Tung Oil is the finest natural wood finish in existence and has yet to be duplicated synthetically!

Man's ingenuity has created many synthetic finishes, including lacquer, shellac, and varnish all of which protect wood with a hard impervious layer. But these surface finishes prevent the development of patina, the lovely depth and tone that only natural aging can produce. Eventually synthetic finishes will break down and discolor, when that happens the entire surface must be removed by labor intensive stripping and sanding before another coat is applied.

Penetrating finishes formulated with linseed, soy or paraffin oils actually go into the wood and enhance its natural beauty, but these oils often dry incompletely and fail to form a hard and durable surface. Furthermore, they develop a gummy build-up when additional coats are applied. Linseed oil, the most commonly used penetrating finish, darkens and changes color with time and finally disintegrates.

A Polymerized Tung Oil finish is hard yet flexible, waterproof and impervious to alcohol and many food acids. Polymerized Tung oil as a penetrating oil allows wood to continue its aging process and to develop its patina. The wood's rich color and grain are enhanced by the natural ambering (coloring) of Polymerized Tung oil over time. Any sign of wear disappears when a thin "maintenance" coat of oil is rubbed in. The maintenance coats, rather than cause a build-up, actually improve the patina as they protect and preserve the wood. A floor, a piece of furniture, or any other wood object finished and maintained with Polymerized Tung Oil will never have to be stripped again. The finish will become more beautiful with time.

POLYMERIZATION AND FORMULATION

As Tung Oil dries and cures, the molecules join together in a tight complex formation. This process is the secret to Tung Oil's effectiveness as a finish. The cross linking of the oil's molecules makes the surface waterproof and impervious to many chemicals. The bonding also gives flexibility to the surface, making it capable of withstanding wear and tear.

Sutherland Welles Ltd.® uses a process called polymerization to intensify Tung Oil's natural cross- bonding tendency. Polymerization is essentially a cooking process that enhances the molecular structure of the oil and further improves the natural cross-bonding reaction of raw Tung Oil.

Many other manufacturers of Polymerized Tung Oil will claim they polymerize Tung Oil, but their "cook" is not as extensive as ours and requires formulation which includes additives such as varnishes and urethanes to improve the hardness, durability, and lustre of the finish. This adds to the toxicity of the finish and inhibits the penetration of the oil into the wood fibers as well as slowing the drying and curing time.

The polymerization process used by Sutherland Welles Ltd.® is very sophisticated and "cooks" the pure, raw Tung Oil to its "maximum thermal threshold." Controlling the "cooking" and the "cooling" is an expensive process that at its perfect point produces an oil that has maximum durability and a gorgeous sheen. If the process isn't well controlled the oil solidifies to the consistency of a rubber eraser and the entire batch is lost. The intricacy and therefore expense of the process is what leads most companies to formulate with modifiers. They believe they can achieve the same results with a cheaper process and formulation. In time, the varnishes and urethanes discolor and deteriorate and with it the finish.

Polymerization increases the viscosity of the oil making it difficult to work and reduces penetration into the wood. The Polymerized Tung Oil must be formulated with solvents to thin the oil to maximize its workability and penetration and driers to shorten the drying and curing time. Sutherland Welles Ltd.® has researched and implemented driers with the lowest toxicity available. We also use solvents that are "cleaner" reducing the environmental impact and minimizing a finisher's exposure to toxic fumes and chemicals.

We at Sutherland Welles Ltd.® are proud of our commitment to improve product performance while reducing its environmental impact both to the earth and to wood finishers using our products. We will continue to make changes in our formulations that achieve that goal!

THE LOC-LAMIN® WOOD FINISHING SYSTEM

The Sutherland Welles Ltd®  polymerization process and formulations are the core of what we call the Loc-Lamin® Finishing System . This system is based on the application of several thin coats of our Polymerized Tung Oil each fusing to previously applied coats. This creates a durable finish that bonds completely to the wood as if it were one solid coat. Microscopic examination of the finish shows a three-dimensional molecular locking of the finish into the wood fibers. The Loc-Lamin® System does not deteriorate over time. The molecular locking of the finish into the wood remains stable indefinitely eliminating the multiple layers from peeling apart.

The process begins by applying Polymerized Tung Oil Sealer to new or stripped wood. This thinner formulation penetrates deep into the wood pores. As it dries, the Polymerized Tung Oil molecules join together creating a tough, interlocking network. This hardened sealer acts as a base for the finish coats of Polymerized Tung Oil whether a finisher uses a penetrating or surface application. As the first finish layer dries, the Polymerized Tung Oil molecules bond with those already in the wood. Successive coats of thinly applied Polymerized Tung Oil will fuse with each other and are firmly locked into the wood.

Regardless of which Polymerized Tung Oil product is used, it is important that it be applied as multiple, thin coats rather than as one thick coat! Thin applications ensure that each layer dries and cures completely; this is essential for the Loc-Lamin® Wood Finishing System to perform.

The Loc-Lamin® Wood Finishing System also contributes to the ease of maintaining a Polymerized Tung Oil finish. Abrasions are sure to occur on any piece of wood over its lifetime. Temperature and humidity changes cause expansion and contraction of the wood eventually causing small cracks in the finish. When a piece of wood is routinely treated with Sutherland Welles Ltd.® Polymerized Tung Oil Wood Care product or periodically given a thin coat of Polymerized Tung Oil finish product, the Polymerized Tung Oil molecules in the fresh coat bond with those in the existing finish, forming a new, smooth uninterrupted surface. Sutherland Welles Ltd.® Penetrating Stains can be added to new finish coats to renew the color of the finish and help hide small scratch lines.

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Last modified: September 26, 2007