Wood preservation a long-practised method and often used in today's carpentry workshops. Technological developments mean it is also possible to spray preservative over the surface of the timber. Some of the liquid is drawn into the wood as the result of capillary action before the spray runs off or evaporates, but unless puddling occurs penetration is limited and may not be suitable for long-term weathering. By using the spray method, coal-tar creosote, oil-borne solutions and water-borne salts (to some extent) can also be applied. A thorough brush or spray treatment with coal-tar creosote can add 1 to 3 years to the lifespan
Tar Heel History of a Southern State" (3rd edition, 1973) that North Carolina led the world in production of naval stores from about 1720 to 1870. At the time, tar was created by piling up pine logs and burning them until hot oil seeped out from a spout. The vast production of tar from North Carolina led many, including Walt Whitman, to give the derisive nickname of "Tarboilers" to the residents of North Carolina. North Carolina was nicknamed the "Tar and Turpentine State" because of this industry. Somehow, these terms evolved until the nickname Tar Heel was used to refer to residents