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A bottle containing wood tar.
Pine tar oil, Wood tar oil
|Appearance||Blackish-brown viscous liquid|
|Boiling point||150 to 400 °C (302 to 752 °F; 423 to 673 K)|
|Solubility||alc, chloroform, ether, acetone, glacial acetic acid, fixed/volatile oils, solutions of caustic alkalies|
|S-phrases||(S2) S24 S28 S37 S46|
|Flash point||90 °C (194 °F; 363 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Pine tar is a sticky material produced by the high temperature carbonization of pine wood in anoxic conditions (dry distillation or destructive distillation). The wood is rapidly decomposed by applying heat and pressure in a closed container; the primary resulting products are charcoal and pine tar.
Pine tar consists primarily of aromatic hydrocarbons, tar acids and tar bases. Components of tar vary according to the pyrolytic process (e.g. method, duration, temperature) and origin of the wood (e.g. age of pine trees, type of soil and moisture conditions during tree growth). The choice of wood, design of kiln, burning and collection of the tar can vary. Only pine stumps and roots are used in the traditional production of pine tar.
Pine tar has a long history as a wood preservative, as a wood sealant for maritime use, in roofing construction and maintenance, in soaps and in the treatment of carbuncles and skin diseases, such as psoriasis, eczema, and rosacea.
History and general use
Pine tar has long been used in Scandinavian nations as a preservative for wood which may be exposed to harsh conditions, including outdoor furniture and ship decking and rigging. The high-grade pine tar used in this application is often called Stockholm Tar since, for many years, a single company held a royal monopoly on its export out of Stockholm, Sweden. It is also known as "Archangel Tar". Tar and pitch for maritime use was in such demand that it became an important export for the American colonies (later United States), such as North Carolina, which had extensive pine forests. North Carolinians later became known as "Tar Heels."
It was used as a preservative on the bottoms of wooden, Nordic style skis until modern synthetic materials replaced wood in the construction of such skis. The pine tar also helped the adhesion of waxes which aided the grip and glide of such skis.
Pine tar is widely used as a veterinary care product. It is a traditional antiseptic and hoof care product for horses and cattle. Pine tar has been used when chickens start pecking the low hen. Applying a smear of pine tar on the wound gives the attacking hens something else to do, as they are distracted by the effort of trying to get the sticky pine tar off their beaks.
Pine tar is now mainly used as a softening solvent in the rubber industry, and for construction material and special paints.
Use as a wood preservative
Pine tar can be used for preserving wooden boats (and other wood which will be exposed to the elements) by using a mixture of pine tar, gum turpentine and boiled linseed oil. First, a thin coat is applied using a mixture with greater turpentine. This allows it to permeate deeper into the oakum and fibre of the wood and lets the tar seep into any pinholes and larger gaps that might be in the planks. The tar weeps out to the exterior and indicates where the boat needs the most attention. Having the solution in place and the repairs complete, the vessel is ready for the thicker standard mix. Pine tar is also efficacious for properly saturating lead or standard oakum so that the endurance of the sealing capacity is optimal.
Such treatments, while effective, must be continually reapplied.
Use in weatherproofing rope
Traditionally, hemp and other natural fibers were the norm for rope production. Such rope would quickly rot when exposed to rain, and was typically tarred to preserve it. The tar would stain the hands of ship's crews, and British Navy seamen became known as "tars."
Use of pine tar in baseball
In baseball, pine tar is applied to the handles of baseball bats. Because of its texture, pine tar improves a batter's grip on the bat and prevents the bat from slipping out of the batter's hands during hard swings. It also helps hitters, because they do not have to grip the bat as hard and thus the hitter gets more "pop."
Rule 1.10(c) of the 2002 Official rules of Major League Baseball states that batters may apply pine tar only from the handle of the bat extending up 18 inches. The most famous example of the rule being applied is the Pine Tar Game, the July 24, 1983 game between the Kansas City Royals and New York Yankees in which George Brett hit a home run to put the Royals ahead 5–4. Yankees manager Billy Martin immediately protested that Brett's bat had more than 18 inches of pine tar. The umpires called Brett out and nullified the home run. However, league president Lee MacPhail overruled the umpires. MacPhail said that the pine tar restriction wasn't about competitive advantage, but economics. If too much pine tar was on the bat, pine tar would end up on the ball and render it unusable for play. MacPhail said that the umpires shouldn't have taken the home run off the board, but simply discarded the bat. The game was resumed from the point of the home run, and the Royals won.
Pine tar is also sometimes used by pitchers in baseball to improve grip on the ball in cold weather, although it is questionable whether it gives a pitcher any competitive advantage. However, the application of any foreign substance to a ball (except Baseball Rubbing Mud, which is applied by the umpires) is expressly prohibited by 8.02 of the Official rules of Major League Baseball. If a player is caught violating this rule, it results in an automatic ten-game suspension in the minor leagues. There is no mandatory suspension for this infraction at the major league level, although suspensions are often used to discipline offending players.
Pine tar has also been used for treating skin conditions, often as soap, though this use as a drug was banned by the FDA along with many other ingredients, due to a lack of proof of effectiveness.
Some pine tar products contain creosote, a probable carcinogen. This depends on whether they were produced in an open or closed kiln. Some soaps are accordingly advertised as "creosote-free."
It is used in veterinary medicine as an expectorant and an antiseptic in chronic skin conditions.
- Merck Index, 11th Edition, 7417. p. 1182
- "Stockholm Tar". MedicAnimal.com. Retrieved 23 Sep 2012.
- Theodore P. Kaye. "Pine Tar; History And Uses". San Francisco Maritime Park Association. Retrieved 2010-08-01.
- Hugh Chisholm (1911). "Tar". The Encyclopaedia Britannica. 26 (11 ed.). p. 414. Retrieved 2010-08-01.
- Wickstrom, Mark. "Phenols and Related Compounds". The Merck Veterinary Manual. Merck Manuals. Retrieved 16 April 2015.
- "Pineda Ejected for Pine Tar on Neck". espn.go.com. Retrieved 22 Apr 2014.
- Bonnie Aikman (1990-11-07). "Clean-Up of Ineffective Ingredients in OTC Drug Products" (Press release). Food and Drug Administration. Retrieved 2014-04-19.
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