FENCE Posts Properly Treated Have Greatly Increased Durability

Fence posts that rot quickly are a continual source of trouble and expense.  Posts that give long years of satisfactory service without renewal keep fencing costs low. Farmers who do not have a supply of durable fence-post timber on their own land may be able to purchase naturally durable wood posts or commercially creosoted posts from their local dealers. Well-creosoted posts can be relied upon for an average life of 20 to 30 years or more, and several creosoting companies are now specializing in the treatment of fence posts and their distribution through retail dealers.

If durable posts are not readily available at a reasonable cost, the farmer can use posts of nondurable species of wood and, by giving them a good preservative treatment, make them give very long and satisfactory service.

Pressure processes, such as those used by commercial creosoting companies, are most thorough and effective for applying wood preservatives but the apparatus is too expensive for farm use. A hot and cold bath open-tank process is the most thorough method of treatment that is practicable on the farm. It consists of heating the posts for one or more hours in a metal tank containing preservative (usually coal-tar creosote) at a temperature ranging from 180° to 220° F. The posts are then quickly transferred to a tank of preservative having a temperature of about 100°, and are left there for one hour or more.  Instead of a separate tank being used for the “cool" bath, the heating of the oil in the hot bath may be stopped, and the wood and preservative allowed to cool together.

Such treatments prove very effective and will give to posts of very low natural durability a life of 20 years or more. Sap pine posts, for example, which may last only 2 or 3 years untreated, can be so thoroughly creosoted by the hot and cold bath process that a life of at least 30 years may well be expected. The length of life obtained will depend upon the preservative used and the thoroughness of the treatment, deep penetration with a good preservative being necessary for the best results. Some species of wood are more resistant to treatment than others. Practically all species, however, except those of great natural durability, can be treated so effectively that the increase in durability will more.than repay the cost of treatment.

Preservative treatment is also very effective for stable floors, bridges, hog houses, and any other constructions used on the farm under conditions that favor the early decay of wood.

Applying the preservative with a brush or dipping the wood in the preservative are simpler and less expensive methods than the hot and cold bath treatment, but generally they are much less effective and not so useful. Farmers’ Bulletin No. 744-F contains detailed instructions on the preservative treatment of farm timber.