CHINA WOOD OIL

China wood oil provides a hard, transparent and non-yellowing coating.
China wood oil can be used on outdoor wood and indoor furniture.
China wood oil is suitable for all woods in contact with food when VOC-free.

CAS Number: 8001-20-5
EC Number: 232-272-3

TUNG OIL, chinawood, CHINA WOOD OIL, TUNG OIL PARAFORMALDEHYD, TUNGMEAL, Tungoel, Einecs 232-272-3, Tung oil [oil, misc.]

China wood oil is obtained from the seed kernel of tung (Aleurites fordii), a tree that grows in parts of China and South America. 
The oil content in the kernel varies from 40 to 60%.

The crude oil is mainly used. 
China wood oil is bright brown, opaque and with a characteristic odour.
China wood oil is an oil with the highest drying power, even greater than that of linseed oil. 

The main fatty acid is eleostearic (between 70 and 85%), with 3 unsaturations in combined positions. 
Eleostearic acid is only present in China wood oil.

China wood oil is mainly used in resins, varnishes, inks and generally in formulations where high film strength is required. 
When considering China wood oil use for coatings, China wood oil use is basically exterior.
China wood oil is one of the main components of teak oil together with linseed oil.

China wood oil or Tung oil is a drying oil obtained by pressing the seed from the nut of the tung tree (Vernicia fordii). 
China wood oil hardens upon exposure to air (through polymerization), and the resulting coating is transparent and has a deep, almost wet look. 

China wood oil is used mostly for finishing and protecting wood, after numerous coats, the finish can even look plastic-like. 
Related drying oils include linseed, safflower, poppy, and soybean oils.

Raw China wood oil tends to dry to a fine, wrinkled finish (the English name for this is gas checking).
This property was used to make wrinkle finishes, usually by adding excess cobalt drier. 
To prevent wrinkling, the oil is heated to gas-proof China wood oil (also known as "boiled").

'China wood oil' is often used by paint and varnish manufacturers as a generic name for any wood-finishing product that contains the real China wood oil or provides a finish that resembles the finish obtained with China wood oil.

China wood oil is a drying oil that’s extracted from the seed of the tung tree, which is native to China and a few other Asian countries. 
The oil has been used for centuries as a water-resistant finish for boats and other wooden objects, as well as to finish stone. 
China wood oil is an excellent alternative to other drying oils, such as walnut, linseed and soy.

On top of producing a beautiful and protective finish, China wood oil is also a popular choice for projects because China wood oil is versatile, easy to use, and environmentally friendly. 

There are many reasons why people love China wood oil for their projects, and one of the most popular is China wood oil flexible, durable, food safe, and protective waterproof finish that doesn’t mold, darken or go rancid. 
On a practical note, China wood oil also dries faster than other oils, making China wood oil easier and less time-consuming to apply. 
From an aesthetic standpoint, China wood oil also cures to a beautiful matte finish that adds depth to woodgrain, producing an antique-style finish on any surface.

Tung oil, also called wood oil, or china wood oil, pale-yellow, pungent drying oil obtained from the seeds of the tung tree. 
On long standing or on heating, China wood oil polymerizes to a hard, waterproof gel that is highly resistant to acids and alkalies. 

China wood oil is used in quick-drying varnishes and paints, as a waterproofing agent, and in making linoleum, oilcloth, and insulating compounds. 
China wood oil is produced chiefly in China from the tung tree.

Marco Polo is said to have brought a sample back to the western world from China.
Completely natural and renewable, pure China wood oil has gained recent popularity among the environmentally conscious.

Inherently resistant to disease and insects, tung trees require no fungicides or pesticides.
Tung nut byproducts can be used for mulch.
During World War II the Chinese figured out how to use China wood oil as motor fuel.

China wood oil is a small deciduous tree that grows up to 40 feet tall with smooth bark and a branchy head. 
China wood oil leaves are dark green and glossy with blades 3-13 inches wide. 

The tung tree has flowers that range in size from 1-3 inches in diameter with petals that are white tinged with red and yellow. 
Each nut or fruit contains 3-7 large seeds.

The tung tree’s official botanical name is Aleurites fordii. 
China wood oil thrives in moist, well-drained, slightly acidic soil. 

These hearty, fast growing trees mature to bear fruit in their third year and yield commercial quantities at four to five years of age. 
Maximum production occurs in the tenth to twelfth years of growth, with trees expected to be commercially productive for at least 20 years after optimum production has occurred.

In the Northern Hemisphere, tung tree nuts grow in clusters and fall to the ground from late September through November. 
The fruits are left for a few weeks to dry and cure. 

China wood oil is produced by harvesting these nuts and separating the nuts from their hard outer shells. 
Then the transparent oil is squeezed from the seeds inside.

Dried and pressed nuts yield about twenty percent oil. 
Under favorable conditions an acre of tung trees will produce about two tons of tung nuts and yield about 100 gallons of raw China wood oil annually.

China wood oil is made from pressed seeds from the nut of the tung tree. 
The tung tree, native to China, is named for China wood oil heart-shaped leaves because “tung” is Chinese for “heart.” 

In the 14th century, Chinese merchants were noted for using China wood oil to waterproof and protect wooden ships from the eroding powers of the sea. 
There are even mentions of China wood oil appearing in the writings of Confucius in around 400 B.C. 

For these reasons, China wood oil is also sometimes referred to as "Tung oil".

Pure China wood oil is considered a drying oil much like linseed, safflower, poppy and soybean oil and is known to have a slightly golden tint. 
China wood oil, which is actually a vegetable oil, is considered the best penetrating drying oil available due to China wood oil unique ability to wet the surface, allowing China wood oil to penetrate even the densest woods. 
Unlike linseed oil, China wood oil will not darken with age.

Originating from China and South America, China wood oil—an extract from tung-tree nuts—is a natural drying oil that coats your fine wood furnishings with a transparent, wet finish. 
China wood oil enhances the color of your wood, offers excellent protection and is eco-friendly.

While there are many advantages to using China wood oil, pure China wood oil takes two to three days to harden, and needs at least five coats. 
Oil/varnish blends and wiping varnishes are faster-drying, more practical options, but such terms rarely appear on labels. 

Penetrating China wood oil finishes come in three varieties: pure China wood oil, oil/varnish blends, and wiping varnish. 
They all share the benefits that China wood oil imparts to a finish—durability, water resistance, resilient hardness, and color stability—depending on how much of the oil they actually contain and what form China wood oil takes.

Pure China wood oil:
Pure China wood oil is easy to identify because China wood oil contains no solvents. 
That may be a good thing in terms of limiting your exposure to VOCs, but applying China wood oil is an exacting, drawn-out process.

You have to wait at least two to three days for each coat to harden. 
And China wood oil takes five to seven coats to get a protective film. 
Rushing the process, or applying too thick a coat, causes wrinkling, which has to be sanded off.

Regular reapplication is a must—”once a week for a month, once a month for a year, once a year ever after,” as the saying goes. 
The results can be gorgeous, as long as you have the necessary patience.

Uses of China wood oil:
China wood oil is used mostly for finishing and protecting wood, after numerous coats, the finish can even look plastic-like. 

The interior can be used for all woods (except floor).
China wood oil can also be used on wood that comes into contact with food.

Especially gun handles, wooden handle cutting tools, wooden products for hobby purposes are especially preferred.
As the number of layers increases, China wood oil brightness increases.

Wood Finishing:
China wood oil is very popular today because of two properties: first, China wood oil is a naturally derived substance. 
Second, after China wood oil cures (5 to 30 days, weather/temperature related), the result is a very hard and easily repaired finish, so China wood oil is used on boat decks and now on floors. 

The oil is often diluted with hydrocarbon thinner so China wood oil viscosity is very low and enables the oil to penetrate the finest grain woods. 
This thinning vehicle evaporates within 15 to 20 minutes. 

When applied in many fine/thinner coats over wood, China wood oil slowly cures to a matte/light satin look with slight golden tint. 
China wood oil resists water better than any other pure oil finish and does not darken noticeably with age. 

China wood oil is claimed to be less susceptible to mould than linseed oil.
China wood oil is considered safe to be used on sculptures made near waterways.

Heating China wood oil to about 500 °F (260 °C) in an oxygen-free environment will substantially increase the viscosity and film-forming quality of the product. 
Most polymerized China wood oils are sold mixed with mineral spirits to make them easier to work with.
Limonene and D-limonene are less toxic alternatives for mineral spirits.

Oil-paper umbrella:
The oil-paper umbrella is the traditional umbrella used in China, Japan, and other countries in the sinosphere, and was brought to Western countries through the Silk Road. 
China wood oil is the "oil" mentioned in the oil-paper umbrella, which is used to protect the paper from getting wet, and to make the umbrella waterproof.

The Many Uses of China wood oil:
Carpenters, woodworkers, crafters, and hobbyist alike all love China wood oil, and over the years they’ve used China wood oil as a beautiful and protective finish on a wide number of projects and surfaces. 
For instance, China wood oil has been used with fantastic results to finish wood, bamboo, concrete, stone, brick, and even metal surfaces. 
China wood oil is a favorite for finishing wood floors, cabinetry, decks, siding, furniture, guitars and other musical instruments, handmade toys, and more. 

China wood oil can be used in the following industries:
Lubricants, Paints & Coatings

China wood oil can be applied as:
Other Oleochemicals, Base Fluids

Easy-to-Follow Steps for Applying China wood oil to Your Projects

1. Clean the surface:
The proper application of China wood oil depends on you starting with a clean and prepared surface. 
Before you start, make sure there’s no grease, oil, dirt, dust, or other contaminants on the surface.

If necessary, start by sanding or stripping the surface to remove any coating or finish that’s already there. 
China wood oil can only be applied to bare surfaces or over another coat of China wood oil. 

Follow that up by cleaning the surface with trisodium phosphate. 
Sand the surface one more time with 150-grit sandpaper, and then vacuum well to remove all dust.

2. Thin the oil:
A thinner will make the China wood oil easier to apply, faster to dry, and will improve penetration. 
The only time you shouldn’t thin the oil first is if you’re applying China wood oil to weathered wood, concrete, old and unfinished wood floors, or other highly absorbent surfaces. 

To thin the oil, combine China wood oil with equal parts Citrus Solvent, mineral spirits, or Odorless Mineral Spirits before application. 
Do not use a mineral spirit or odorless mineral spirit marketed as “green”, “eco-friendly”, or similar verbiage. 

These do not mix with the China wood oil and will create adverse effects on your finish. 
You could also choose one of our pre-thinned options, Half & Half or Dark Half, to use straight out of the bottle!

3. Apply a generous first layer
You can apply the oil with a natural bristle brush, a sponge brush, or a soft and lint-free rag. 
Apply the oil liberally to the surface. 

Unlike varnish, which sits on top of the wood, the goal with China wood oil is to thoroughly saturate the wood cells. 
When you’ve applied the first coat, let the oil absorb.

4. Apply subsequent coats:
After the first coat has absorbed, apply a second coat. 
Continue this process of applying coats, waiting 40 minutes between coats if necessary, until over 80 percent of the surface stays glossy for at least 40 minutes. 

This means the wood cells have been saturated and you can move to the next step. 
Decorative items may need two to four coats, while functional surfaces that will be handled, used, or walked on will need a minimum of three to five.

5. Removing unabsorbed oil from the surface:
After you’ve applied multiple coats and the wood won’t absorb any more oil, use a clean rag to wipe the surface. 
If there are any puddles of oil on the surface, mop them up with the rags. 

This is important as you don’t want the China wood oil to start curing on the surface.
At this point, your surface is fully saturated. 

However, the pure China wood oil will settle inside the wood/material overnight on through the next day.
To get the best finish we recommend applying one or two more coats of the oil, following the instructions previously stated, after this period of waiting. 

Make sure to wipe up oil that’s on the surface that does not absorb. 
Hang oil-soaked rags separately outside to dry before disposing.

6. Let the oil cure for up to 30 days:
From here, the oil will need a week to 10 days to start curing, and 15 days to 30 days to fully cure. 
Do not put the China wood oiled object in direct sunlight for an extended period of time. 

For the first 10 days of curing, check and wipe up any China wood oil that may seep to the surface. 
During this curing time, you can walk on floors with clean shoes, but avoid placing heavy objects on the floor or walking on China wood oil with dirty shoes. (Tip: put old rags under your shoes to walk across the surface no matter what shoes you’re wearing.) 

There are no other sealers or protective products needed on top of your oil. 
China wood oil naturally seals, waterproofs, and protects your surfaces!

7. Cleaning your surfaces:
Pure China wood oil is easy to clean. 
For your floors or other wooden objects, just simply use hot water and standard dish soap. 

8. Reapply as necessary to revive and provide more protection:
Surfaces that are used often or walked on frequently may need some maintenance to revive their look and add more protection. 
To do this, simply mix 2 parts thinner to 1 part China wood oil and wipe down your surfaces. 
Allow time to dry as necessary.

China wood oil has been popular for thousands of years, thanks to the protective and waterproof finish China wood oil creates on wood and other porous surfaces. 
These days, pure China wood oil is also gaining momentum because China wood oil’s non-toxic, environmentally friendly, and food safe, meaning China wood oil’s ideal for kitchenware, butcher block, cutting boards, countertops, and even toys.

Applying China wood oil is easy and effective. 

The main tips to remember are: don’t leave excess oil on the surface during the curing phase, no sanding necessary between coats, no other sealer or topcoats needed and use 2 parts thinner to 1 part China wood oil for maintenance.

Applications of China wood oil:
The traditional technique for applying pure China wood oil is to dilute the oil 1:1 with solvent, then apply a succession of very thin films with a soft, lint-free cloth such as tee-shirt cotton. 
Diluents range from traditional spirits of turpentine to any of the new citrus-based thinners to naphtha. 

The choice of thinner should be guided by how fast the coating needs to set. 
Naphtha works well in spray-on applications in well-ventilated studios. 

Primary coats may be laid down at a 1:1 oil-to-thinner ratio, and successive layers, if not absorbed into the wood, at higher solvent to oil concentrations. 
This technique brings out the deepest color of the wood while maintaining a matte finish.

China wood oil finishes that start with polymerized oils or China wood oil preparations are best applied in the fat over lean principle: thinned pure oil is applied to deeply penetrate the surface, to fill pores. 
Straight oil is then applied moderately to adhere to the surface and provide a good base for the thick gloss layers. 

The polymerized oil is then applied thickly as a single layer, allowed to fully dry, buffed smooth with very fine sandpaper and 0000 steel wool. 
The surface is wiped clean with a moistened rag and allowed to dry. 

A final coat is applied fairly thickly (the oil will smooth itself into a glass-like coating) and allowed to dry for two to three days. 
Rags soaked with China wood oil can spontaneously combust (burst into flame).

Benefits of China wood oil:

Easy to Use:
China wood oil is a natural oil recognised by craftsmen to offer the ultimate hand-rubbed finish for all fine woods; just wipe on and allow the oil to cure at room temperature.

Permeates:
Unlike other finishes that form a film on the wood’s surface, China wood oil penetrates deep into the wood fibres, cures to a flexible non-oily solid, and becomes part of the wood China wood oilself

Protects:
Resistant to moisture, alcohol, oil, and everyday wear for lasting beauty and protection; lasts many times longer than mineral oil and wax based products.

Multi Use:
Amazing results on almost any surface that will allow the oil to penetrate - new unfinished wood, weathered wood, stripped wood, concrete floors and countertops, even brick, stone, and cast iron

Great for Food Contact Surfaces:
China wood oil is considered non-toxic when dry therefore is great for cutting boards, butcher blocks, countertops, wooden bowls, wooden utensils, and more.

Features of China wood oil:
Super easy to apply.
Keeps the wood strong from inside and prevents stains.

Suitable only for indoor use, but has water resistant properties.
Provides a warm glow type of finish, while keeping the original pores and natural beauty of the wood.
Completely non-toxic due to lack of any additives.

Composition of China wood oil:
The fatty acids in China wood oil and their concentration are listed in the table.

Fatty acid composition of China wood oil:
Alpha-eleostearic acid: 82.0%
Linoleic acid: 8.5%
Palmitic acid: 5.5%
Oleic acid: 4.0%

The primary constituent is a fatty acid with a chain of 18 linked carbon atoms or methylene units containing three conjugated double bonds. 
They are especially sensitive to autoxidation, which encourages cross linking of neighbouring chains, hence hardening of the base resin.

History of China wood oil:
The China wood oil tree originates in southern China and was cultivated there for China wood oil, but the date of cultivation remains unknown.
During the Song Dynasty, China wood oil was used for waterproofing on ships.

The word "tung" is etymologically derived from the Chinese 桐 tóng.
The earliest references for Chinese use of China wood oil is in the writings of Confucius around 500 to 400 BC.

The first tung tree seed was brought to America from Hankow, China in 1905 by a senior agricultural explorer for the U.S. Department of Agriculture. 
In 1912 the Bureau of Plant Industry issued a special bulletin that urged growers to plant tung orchards and offered a limited number of free one-year old trees. 

This was a perfect fit, because after acre upon acre of pine trees were cut for timber in the early 1900s, Gulf Coast farmers were looking for a sustainable cash crop for the vast vacant land. 
That same year, ten trees were planted at University of Florida’s Agricultural Experiment Station in Gainesville. 
By 1927, there were over 400 growers and more than 10,000 acres of China wood oil trees in Alachua County, Florida and surrounding areas alone.

In 1928, L.P. Moore, nephew of the Benjamin Moore Paints founder, built the first mechanized China wood oil compressing mill in the world, located in Gainsville, Florida. 
This began the commercial production of China wood oil in America. 

Other mills later popped up in Cairo, Georgia and Florala, Alabama. 
The U.S. was a prime location for this new industry, importing 100 million pounds of Chinese China wood oil in 1927, and 120 million pounds in 1933, with demand still exceeding supply. 
The industry expanded from Florida, Georgia and Alabama to Mississippi, Louisiana and Texas,with Mississippi becoming the largest producing state.

Just prior to the outbreak of WWII, China wood oil was declared a strategic item for defense use, so the government aided growers to help them to produce more and better trees. 
During the war, all ammunition was coated with China wood oil and products containing China wood oil painted all ships. 

Not only were government support programs available for US growers, but the government also assisted foreign plantings in South America, particularly Argentina. 
There was an embargo on Chinese China wood oil at the time, making domestic oil profitable. 
The Pan American Tung Research and Development League was formed between China wood oil producers in Amercica and Argentina to work jointly on research and development and to pool China wood oil from both countries to provide consistent supplies to U.S. consumers.

Identifiers of China wood oil:
CAS Number: 8001-20-5
ChemSpider: none
ECHA InfoCard: 100.029.338
EC Number: 232-272-3
UNII: 3C8NM3A2P0
CompTox Dashboard (EPA): DTXSID7029291

Substance: Tung Oil
CAS: 8001-20-5
EC number: 232-272-3
REACH compliant: Yes
Min. purity / concentration: 100%
Appearance: Liquid

Properties of China wood oil:
Density: 0.937 g/ml at 25°C
Refractive index (nD): 1.52 (20°C)

Specifications of China wood oil:
Specific weight at 25 °C: ca. 0.9320
Refraction index at 25 °C: 1.5165 - 1.5200
Free fatty acid [%]: max. 2.5
Iodine value [Wijs]: min. 158
Colour [Gardner]: max. 9
Moisture [%]: max. 0.2

Names of China wood oil:

IUPAC name:
tung oil

Other names:
China wood oil
lumbang oil
tung oil paraformaldehyde
tungmeal
tungoel