finish is very important so lots of research went into the finishing process. I
wanted to accomplish several things. First, I wanted the best possible
protection from the elements, second, it had to be easy to maintain and last
but not least I wanted a warm rich patina.
found the qualities I was looking for in Sutherland Welles Ltd Tung oil. Below
you can read all the important stuff about tung oil and if you want more visit http://www.sutherlandwelles.com/
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
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.
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.
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.
a penetrating oil finish, Polymerized Tung Oil allows the development of
patina, which is the lovely depth and tone of the wood color as it ages
naturally. Sutherland Welles Ltd.ģ Polymerized Tung Oil is a pure Polymerized
Tung Oil that creates a finish that is hard yet flexible, and impervious to
alcohol and food acids. Maintaining the finish is easy. Applied according to
directions, the surface never has to be sanded again! Recoating with a thin
layer of Polymerized Tung Oil on a periodic basis preserves the wood and
restores the lustre to its original sheen. The finish becomes more beautiful
with time! Other manufacturers claim to make a "polymerized" Tung oil
but their process is shortened to avoid "over cooking ' the batch,
solidifying it and ultimately ruining it. They compensate for an "under
cooked" polymerization process by adding varnishes to improve the
durability and additional chemical driers to promote faster curing. We achieve
all this with heat!
is a "cooking" process that changes the molecular structure of pure,
raw Tung Oil. Sutherland Welles Ltd's process takes the cook to its
"maximum thermal threshold" creating a three-dimensional molecular
locking that maximizes the bonding of the oil to the wood, increases
durability and enhances Tung Oil's natural sheen and allows the oil to cure in
a "reasonable" length of time (for most lustres the average curing
time is twenty-four hours to re-coat).
Tung Oil is thick like molasses, with a slow drying and curing time. After
polymerization, the oil is combined with solvents to allow the oil to penetrate
the wood and improve its workability. The addition of chemical driers shortens
the drying and curing time which completes the process of making Polymerized
Tung Oil a wood finishing product. Sutherland Welles Ltd.ģ formulates the entire line with
the "cleanest" solvents and the lowest toxic driers available. We are
committed to "clean and green" and finisher-friendly product
is probably no greater challenge in formulating a wood finish than those posed
by an exterior application. Many variables work in concert to destroy an
exterior finish; heat, water and especially light.
degree of protection of an exterior wood surface is a function of the type and
amount of coating applied to the surface initially, a regular maintenance
schedule, as well as the wood species itself. Some wood species weather better
than others, but in time all wood suffers degradation due to outdoor weathering
as do the coatings applied to protect them.
radiation sets into motion a process known as photo degradation. Photo
degradation begins when ultraviolet (UV) light causes damage to the polymers in
either the coating or the wood fibers. The initial insult is fairly minimal,
but with continued UV exposure and compounded by the second contributor to
coating failure, moisture, the process soon escalates with rapid and extensive
damage occurring to the coating and then to the wood substrate itself.
the best exterior wood finish begins with the essence of the coating.
Sutherland Welles Ltd.ģ Pure Polymerized Tung Oil is the perfect wood
preservative. It has been used for centuries to waterproof all types of
exterior woods. The ancient Chinese recognized the amazing qualities of Tung
Oil. Throughout history, the Chinese have used Tung Oil to waterproof the masts
and sails of junks and according to legend, to seal the Great Wall! During World
War II, Tung Oil was used by the military in the Pacific to coat engine parts
to prevent rusting . Tung Oil is resistant to many alkalis and acids as well.
After its resistance to water, Tung Oilís ability to remain flexible yet
durable makes it perfect for exterior applications where the continual
expansion and contraction of wood surfaces as they are exposed to moisture and
drying heat stress the integrity of the coating. Moreover, unlike linseed oil,
which darkens with age and exposure to UV light, Tung Oilís light amber color
is consistent throughout the life of the coating.
Tung Oil dries and cures, the molecules join together in a tight complex
formation. This process is the secret to Tung Oilís effectiveness as a finish.
The cross linking of the oilís 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.
Welles Ltd.‚ uses a process called polymerization to intensify Tung Oilís
natural cross- bonding tendency. Polymerization is a cooking process that
changes the molecular structure of the oil and further improves the natural
cross-bonding reaction of raw Tung Oil.
other manufacturers of Polymerized Tung Oil will claim they polymerize their
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.
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 isnít
well controlled the oil solidifies to the consistency of an erasure 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 wood.
Welles Ltd.‚ has researched and implemented driers with the lowest toxicity
available. We are now using solvents that are "cleaner" reducing the
environmental impact and minimizing a finisherís exposure to toxic chemicals.
FOR THE EXTERIOR APPLICATION
next step in producing a superior exterior finish is adding the best UV guards
and mildewcides available that help preserve the finish. Sutherland Welles
works closely with our chemical supplier to keep abreast of the latest research
developments in coating additives to maintain the highest coating performance
possible. At this point in time, we combine two UV additives. The first absorbs
UV radiation converting the absorbed UV radiation into harmless heat energy
that is then released across the coating. The second is a light stabilizer,
which neutralizes the effects of the by products of photo degradation known as
"free radicals" from continuing the chemical process of coating
breakdown. The third additive, a mildewcide or algaecide, prevents the
colonization of fungal growth on and into the coating surface. Fungal growth
produces discoloration, marring and eventually failure of the coating.
After the initial finishing schedule, the most important component to coating
longevity is a regular maintenance schedule. No coating lasts forever. The
maintenance schedule will be dictated by the degree of exposure the coating is
subjected to. Consistent exposure to bright sunshine, high moisture, or high
temperatures will require more frequent (annual maintenance). For other more
moderate exposures, the average coating life is about three years. The
flexibility of our Polymerized Tung Oil serves to reduce surface failure by
allowing the finish to move with the wood. The fractures in the finish tend to
be fine, microscopic lines, which minimize moisture invasion and are easily
filled when another coat of Exterior Polymerized Tung Oil is applied. Coat
after coat can be applied because of our Loc-Laminģ Finishing System that
insures adhesion from coat to coat all firmly bonded into the wood pores,
regardless of when it has been applied.