Tung Oil is pressed from the nuts of Tung tree is known also as China wood oil and nut oil. Major producing countries are mainland China (Guizhou, Guangxi , Sichuan , Hubei, Hunan, Yunnan, Shaanxi, Jiangxi, Henan ) and South America (Argentina and Paraguay), United States and Africa . Tung tree farms in the southern U. S. and Argentina now supply tung oil, formerly available only from China. The oil is still known in some circles as "China wood oil".
Pure Tung Oil is water and alkali resistant. It resists marring, penetrates well, is elastic and unlikely to check. Tung oil builds quickly, consolidates the wood surface and builds a transparent matte finish. It should be kept in an airtight container with minimum air space. Pure Tung Oil contains no thinners or driers and has a light nutty odor.
Tung oil is composed primarily of eleostearic (elaeostearic) acid, with smaller amounts of oleic, linoleic and palmitic glycerides. Eleostearic acid is a crystalline unsaturated fatty acid that exists in 2 stereoisomeric forms: An alpha acid occurring as the glycerol ester especially in tung oil, and a beta acid obtained from the alpha acid by irradiation (9, 11, 13-octadecatrienoic acid). The chemical structure of tung oil eleostearic acid:
Tung oil is more durable than lacquer and is impervious to water stains. As mentioned before, minor scratches are easily repaired. It's readily available and an ideal finish for butch block tops in kitchens, as well as wooden salad bowls and other wooden food preparation surfaces. Furniture in areas of high use (or abuse) could also benefit from a tung oil finish.
The largest application for the oil is paint and varnish, and also wide utilized by soap, inks, electrical insulators, furniture, shipbuilding, etc. For 600 years the Chinese have treated boat timbers with tung oil.Tung oil can be applied pure (without additives) if a non-toxic finish is required. If this is not necessary, you can accelerate the drying process and greatly improve the penetration by cutting the first coat of oil with mineral spirits or turpentine by 50%. Remember, Pure Tung Oil becomes toxic with these substances mixed into it, although the finish produced is not toxic because the driers evaporate.
The number of coats of oil to be applied will be determined by the intended use of the piece. Two to four coats are enough for decorative work, paneling and molding. Surfaces that receive moderate use or handling will need about six coats. Heavily used surfaces, such as table tops, should be given ten or more coats for maximum protection, plus a light renewal coat a couple of times a year. Renewal and building coats are quickly applied with cheese cloth, a lint free cloth or old nylon stockings. This process will give you a surface that will stand up to vigorous use and spills: water will bead on the surface.
Pure Tung Oil is recommended for kitchen tables, chopping blocks and boards, and similar uses. Its non-toxic nature makes it particularly appropriate for children's toys and furniture. It gives good protection to wood paneling and molding.
Pure Tung Oil's matte finish will do nicely on certain pieces of furniture, but if a glossy finish is preferred you will need to buff and wax the finish, or use polymerized tung oil or a formulated tung oil based product.