Pine tar is a form of wood tar 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. 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. It is used in baseball to enhance the grip of a hitter's bat; it is also sometimes used by pitchers to improve their grip on the ball, in violation of the rules.
History
Nordic Iron Age Based on chemical analysis of organic residues, there are strong indications that cone-shaped pits discovered north of Uppsala, Sweden, have been used for pine tar production. Three of the pits have been radiocarbon dated. The oldest dates back to 540–380 BCE, which would make it the world's oldest known, still existing tar production facility. The other dates from 230–390 CE.
Classical antiquity In his encyclopedic work Natural History (Latin: Naturalis Historia) the Roman naturalist and author Pliny the Elder (23/24–79 CE) describes how, in Europe, tar is produced through the destructive distillation of pine wood. The wood was chopped into small pieces (billets) and heated in a furnace. The tar was used "for coating ships and for many other useful purposes."
17th century
Finland Pine tar has long been used in Nordic nations as a preservative for wood which may be exposed to harsh conditions, including outdoor furniture and ship decking and rigging. Tar demand surged in the 17th century as European nations began constructing naval and merchant fleets that required tar and pitch for ship waterproofing and caulking. In Finland, then a part of Sweden, large-scale tar production began in the early 17th century. By the late 17th century, tar was Sweden's third most valuable export commodity.
North American colonies Tar and pitch for maritime use was in such demand that it became an important export for the American colonies, which had extensive pine forests. North Carolinians became known as "Tar Heels."
18th–19th century
Sweden In present-day Sweden, large-scale tar production started around 1700. Swedish pine tar was often called "Stockholm tar" since, for many years, a single company held a royal monopoly on its export out of Stockholm, Sweden. It was also known as "Archangel Tar". Stockholm tar became synonymous with top-quality tar. Tar production peaked around the mid-1850s and gradually declined thereafter, largely due to new shipbuilding materials reducing the need for tar as a waterproofing agent, and to the decreasing use of hemp rope as sailing ships were phased out. Stockholm tar and pine tar are chemically the same and are not different substances.
Chemical composition 32 compounds have been identified in pine tar derived from Pinus nigra , accounting for 95.5% of the total composition. Their respective percentages are:
Methyl dehydroabietate: 22.44% Dehydroabietic acid: 14.59% Retene (7-isopropyl-1-methylphenanthrene): 10.08% Isopimaral: 6.18% Pimaral: 4.71% Abietic acid: 4.23% Pimaric acid: 3.59% 18-Norabieta-8,11,13-triene: 3.50% 2,3,5-Trimethylphenanthrene: 1.72% Levoglucosan: 1.44% These compounds primarily consist of resin acids and their derivatives, along with phenanthrene-based hydrocarbons. Such constituents contribute to pine tar's characteristic properties, including its antiseptic and preservative qualities.
Uses Pine tar was used as a preservative on the bottoms of traditional Nordic-style skis until modern synthetic materials replaced wood in their construction. It also helped waxes adhere, which aided such skis’ grip and glide. Pine tar is widely used as a veterinary care product, particularly as an antiseptic and hoof care treatment for horses and cattle. It also has been used when chickens start pecking the low hen. Applying a smear of pine tar on the hens' wound acts as a natural germicidal/antibacterial agent that discourages continued attacks on the affected hen due to its foreign texture. Pine tar is used as a softening solvent in the rubber industry, for treating and fabricating construction materials, and in special paints.
As a preservative and sealant in wooden boats Pine tar is combined with gum turpentine and boiled linseed oil to preserve and seal the hulls of wooden boats. First, a thin coat is applied to the hull using a mixture with a greater proportion of 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. When applied to the interior of the hull, the tar weeps out to the exterior and indicates where the boat needs the most attention. This is followed with a thicker standard mix. Such treatments, while effective, must be continually reapplied.
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."
Baseball
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