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CHINA WOOD OIL
CAS Number: 8001-20-5
EC Number: 232-272-3
Tung oil or China wood oil is a drying oil obtained by pressing the seed from the nut of the tung tree (Vernicia fordii).
The oil and Tung oil use are believed to have originated in ancient China and appear in the writings of Confucius from about 400 BC.
Tung oil hardens upon exposure to air (through polymerization), and the resulting coating is transparent and has a deep, almost wet look.
Tung 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 tung 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 Tung oil (also known as "boiled").
'Tung oil' is often used by paint and varnish manufacturers as a generic name for any wood-finishing product that contains the real tung oil or provides a finish that resembles the finish obtained with tung oil.
100% pure wood oil extracted by crushing from the kernel obtained from tung wood.
Natural Tung oil provides a hard, transparent and non-yellowing coating.
Tung oil can be used on outdoor wood and indoor furniture.
Suitable for all woods in contact with food when VOC-free.
Tung oil or Chinese wood oil is a drying oil obtained by pressing the seed from the nut of the tung tree (Vernicia fordii).
Tung oil hardens on exposure to air and the resulting coating is transparent and has a deep, almost wet appearance.
Tung oil is used Mostly to finish/protect the wood, after many coats even the finish may look like plastic.
Related drying oils include linseed, safflower, poppy and soybean oils.
Oil and Tung oil use are thought to have originated in ancient China and are mentioned in the writings of Confucius around 400 B.C. Crude tung oil tends to dry out to a finely wrinkled finish; In the United States this is called gas control: this property is often used to finish wrinkle by adding excess cobalt desiccant.
To stop this, oil is gastight, and most coating oils, also known as "boiled", are gastight.
The name is often used as a generic name for any wood veneer product used by paint and varnish manufacturers.
Tung oil provides a surface similar to the lacquer obtained with real tung oil and/or tung oil.
Agricultural oil is a kind of natural.
Drying oil widely used in woodworking projects.
When applied to a raw surface, the oil hardens to maintain and add shine to the wood grain pattern using a clean, lint-free cloth to oil the wood after sanding and cleaning the wood surface to clean previous surfaces.
Allow the oil to surface for an hour, then lightly sand to increase adhesion.
Wait 3-7 days to apply trace coats.
Tung oil may take several weeks to fully harden, but once Tung oil will provide a durable, long-lasting layer of protection.
Tung is the term, large, dark green, tung tree leaves are heart-shaped.
Tung oil is a fast growing, deciduous tree reaching a height of about forty feet when mature.
The lifespan of the tung tree is about thirty years.
The fruit bed begins in the third year of tree growth.
The fruit occurs in clusters of four or five nuts each.
About twenty percent oil when the nuts are dried and pressed.
An acre of Tung trees under favorable conditions will produce about two tons of nuts and eight hundred pounds (one hundred gallons) of crude Tung Oil per year.
Successful cultivation of tung trees requires precise climatic conditions.
Including the appropriate ratio of hot and cold days.
Major growing regions include China, Argentina, Paraguay and parts of Africa.
This pure tung oil contains no additives or distillation.
Tung oil provides a professional finish that penetrates deep into the wood, but leaves no deposits or a glossy finish.
The finish is water resistant and protects against degradation.
The oil is FDA-approved for food contact.
Apply to wood with a clean cloth and wait 40 - 90 minutes between coats.
Tung oil may take up to 30 days to fully cure.
Tung oil can be diluted with things like turpentine to reduce drying time.
Store the oil in an airtight container away from direct sunlight and extreme heat or cold.
Uses of Tung oil:
Tung oil is very popular today because of two properties: Tung oil is a natural or "green" product when first dried.
Second, after curing (5 to 30 days, weather/temperature related), the result is very hard and easily repairable finish.
That's why Tung oil used on boat decks and now on floors.
The oil is usually diluted with hydrocarbon.
Thinner ensures that the viscosity is very low and the oil penetrates the best grain wood.
This thinning agent evaporates within 15 to 20 minutes, resulting in a completely green residue.
As mentioned above, when applied in many thin/thin coats on wood, tung oil slowly hardens to a satin "soaked wood" appearance with a slight golden hue.
Tung oil resists liquid water better than any other pure oil and does not darken noticeably with age and is claimed to be less.
Tung oil is more gentle than linseed oil.
Most importantly, in all oil ends, tung oil is the only drying oil that will be 100% polymerized (fully hard).
Linseed oil, for example, never completely hardens.
As an eco-friendly wood finish, some products labeled as "tung oil" are actually blends containing other oils.
Tung oil may contain varnishes, solvents or chemical driers, and may even contain no tung oil.
Products labeled "Danish oil" may be tung oil or polymerized linseed oil.
Tung oil packaging will usually clearly state if Tung oil is pure tung.
Oil tung oil will significantly increase viscosity up to about 500°F (260°C) in an oxygen-free environment.
The film-forming quality of Tung oil.
Most polymerized tung oils are sold mixed with mineral spirits to make Tung oil easier.
Working with Limonene and D-limonene are less toxic alternatives to mineral spirits.
Wood finishing:
Tung oil is very popular today because of two properties: first, Tung oil is a naturally derived substance.
Second, after Tung oil cures (5 to 30 days, weather/temperature related), the result is a very hard and easily repaired finish, so Tung oil is used on boat decks and now on floors.
The oil is often diluted with hydrocarbon thinner so Tung 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, tung oil slowly cures to a matte/light satin look with slight golden tint.
Tung oil resists water better than any other pure oil finish and does not darken noticeably with age.
Tung oil is claimed to be less susceptible to mould than linseed oil.
Tung oil is considered safe to be used on sculptures made near waterways.
Heating tung oil to about 500 °F (260 °C) in an oxygen-free environment will substantially increase the viscosity and film-forming quality of Tung oil.
Most polymerized tung 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.
Tung 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.
Application of Tung oil:
The traditional technique for applying pure tung 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.
Dilutents 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.
Tung oil finishes that start with polymerized oils or tung 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 tung oil can spontaneously combust (burst into flame).
Starting with polymerized oils or tung oil preparations, this oil is best applied on the oil-free liquid principle: the refined pure oil is applied to penetrate deep into the surface to fill the pores.
Flat oil is then applied moderately to adhere to the surface.
And Tung oil provides a good base for thick glossy layers.
The polymerized oil is then applied thickly in one coat, allowed to dry completely, polished with very fine sandpaper, then 0000 steel wool.
The surface is wiped with moistened rags, then left to dry.
The finish coat is applied fairly thickly (the oil will be smooth to a glass-like coating) and allowed to dry for two to three days.
Rags soaked with tung oil can spontaneously burn (turn into flame).
Composition of Tung oil:
The fatty acids in tung oil and their concentration are listed in the table.
Fatty acid composition of tung 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 Tung oil:
The tung oil tree originates in southern China and was cultivated there for tung oil, but the date of cultivation remains unknown.
During the Song Dynasty, tung 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 tung oil is in the writings of Confucius around 500 to 400 BC.
Identifiers of Tung oil:
CAS Number: 8001-20-5
ChemSpider: none
ECHA InfoCard: 100.029.338
EC Number: 232-272-3
UNII: 3C8NM3A2P0
CompTox Dashboard (EPA): DTXSID7029291
Properties of Tung oil:
Density: 0.937 g/ml at 25°C
Refractive index (nD): 1.52 (20°C)
Hazards of Tung oil:
Flash point: >110°C
Names of Tung oil:
IUPAC name of Tung oil:
tung oil
Other names of Tung oil:
China wood oil
lumbang oil
tung oil paraformaldehyde
tungmeal
tungoel
Synonyms of Tung oil:
TUNG OIL
chinawood
CHINA WOOD OIL
TUNG OIL PARAFORMALDEHYD
TUNGMEAL
Tungoel
Einecs 232-272-3
Tung oil [oil, misc.]
TUNG OIL
chinawood
CHINA WOOD OIL
TUNG OIL PARAFORMALDEHYD
TUNGMEAL
Tungoel
Einecs 232-272-3
Tung oil
China wood oil
Tungoel
TUNGMEAL
TUNG OIL
chinawood
Tung oil substitutes
Tung oil,China wood oil
