Trees on the Farm Treating Fence Posts

New Zealand Journal of Agriculture, Volume 94, Issue 3, 15 March 1957, Page 288

Trees on the Farm Treating Fence Posts

PLANTATIONS require thinning for their proper development, and there is widespread • evidence of neglect of this necessary work in the maintenance of a woodlot. The need for fencing posts, strainers, and battens is also widespread, and to assist farmers to make use .of the large quantities of potential fencing represented by material that should be thinned from plantations W. H. Jolliffe, Extension Forestry Officer, New Zealand Forest Service, here describes the simple process employed by one farmer to solve the problem.

FARMERS living handy to centres in which a commercial treatment plant is operating may prefer the easier and perhaps surer method of having their thinnings pressure treated, but for those who are more remote and to whom transport charges are a bigger burden th following description is especially directed. The process used in this case is known as “cold soaking” in creosote and success depends largely on the timber being thoroughly air dried before treatment. Preparation of Material Trees felled in thinning are crosscut into lengths and peeled as soon as possible afterward. Bark comes off more freely when the posts are freshly cut and it is also easier to peel in spring than at any other time

of the year. It is necessary to remove the inner bark as well, since it is impervious to the treating solutions. The best tool for the job is a draw knife, but a small axe is also useful and even a spade may be used when the bark is peeling easily.

After peeling, the posts are open stacked for seasoning; it is necessary that air should be free to circulate through the stack. In very dry localities the stack should be made in a shady spot, because too rapid drying results in deep cracking.

The progress of drying can be watched by regular weighing of a marked and readily ■ removable post from a central position in the stack. When this test piece ceases to lose weight from one weighing to the next it is air dry. . The owner of this plant has found that posts cut and peeled in October have been ready for treating about March, depending on the weather.

The Bath Any one of several kinds of container can be used as a bath, but the one illustrated and described here was made from five 44-gallon drums cut and welded together end to end. A drain cock was fitted to one end and metal lugs were welded to the inner sides of the lips of the open top at ' intervals • throughout its length. These lugs are to hold in place short pieces of 4in. x lin. board used to keep the posts submerged in the liquid. The whole trough is supported on hollowed blocks near one wall of a corrugated iron building. Attached to the wall above the trough is a rack to hold posts after removal from the bath. Below the rack is a sheet metal apron sloping downward to the edge of the trough

to allow any surplus liquid to drain back into the bath. The Procedure To begin treating pour the contents of, say, one 44-gallon drum of creosote into the trough and then fill this with posts. Batten down the posts by engaging the 4in. x lin. pieces under the lugs along the lips of the trough and add more creosote to cover all of the posts. Leave the posts to soak for 48 hours adding, after 24 hours, enough creosote to make up for the soakage during that period. At the end of the 48 hours lift the posts on to the draining rack and recharge the trough as before. When those on the rack have finished dripping off surplus liquid they may be removed to a stack outside; this can be done the next day when the bath is visited for topping off with creosote. The period of soaking mentioned is for air-dry posts of radiata pine sin. to 7in. in diameter. Different immersion times would be necessary for other species and other sizes. The aim is to get an absorption of slightly more than I gallon of creosote per cubic foot of wood, that is, the volume of a post 6in. x 4in. x 6ft. long. Poplar battens for instance may require only about 2 hours’ soaking. It is wise to wear rubber gloves when handling wet treated posts to guard against possible skin affections. The posts are safe to handle when dry.