Posts were separated into two groups, large and small, according to end diameter. 

 Thirty-six of the posts were classified as small and 38 were classified as large. 

 Diameters of each post were measured before and after debarking. The diameters of the 

 small posts ranged from 2.6 to 3.4 inches (6.6 to 8.6 cm) at the small end and from 

 3.1 to 4.3 inches (7.9 to 10.9 cm) at the large end. The corresponding diameters for 

 the large posts ranged from 3.9 to 5.2 inches (9.9 to 13.2 cm) and from 4.4 to 5.7 

 inches (11.2 to 14.5 cm). 



At completion of laboratory testing, the posts were taken to a commercial treating 

 plant where each post was debarked, capped, and pointed prior to treatment. At this 

 time, two large posts were discarded, leaving 36 of each size post to be treated. 

 Also, 13 air-seasoned posts from green trees were combined with the study posts for 

 control purposes. The posts were then placed upright in a series of tanks filled to a 

 depth of 30 inches (76.2 cm) with a 5 percent solution of pentachlorophenol in a light 

 crude oil. Additional preservative was added during the 6-hour treatment to maintain 

 the required depth. Three large posts, three small posts, and one control post, all 

 selected at random, were removed from the tanks at 30-minute intervals. Two control 

 posts were removed with the last group after 6 hours of steeping. The posts were then 

 returned to the laboratory for examination. 



A standard-size increment borer was used to extract a core from the approximate 

 midpoint of the treated portion of each post. This boring was reserved for chemical 

 analysis to determine the quantity of preservative absorbed. In addition, a disk was 

 cut from near the midpoint of the treated area. The average sapwood depth and the 

 average depth of penetration were determined from four measurements of each variable 

 made on each disk. A chemical-indicating solution painted on the disk surface deline- 

 ated the heartwood/sapwood boundary. 



The borings were evaluated at a commercial testing laboratory. The three borings 

 from the large or small posts treated for a specific length of time were combined for 

 analytical purposes; so 24 determinations were made of the borings from the dead tree 

 posts. The borings from the control posts, too, were combined as follows: (1) posts 

 treated 0.5, 1.0, and 1.5 hours; (2) posts treated 2.0, 2.5, and 3.0 hours; (3) posts 

 treated 3.5, 4.0, and 4.5 hours; (4) posts tre'ated 5.0 and 5.5 hours; and (5) borings 

 from the two posts treated 6.0 hours. 



Results and Discussion 



The percent moisture content and specific gravity data for the small and large 

 posts before treatment are summarized in tables 1 and 2. For the small lodgepole pine 

 posts the average moisture content of the heartwood was 15.8 percent and the range was 

 from 14.2 to 18.1 percent. The average moisture content of the sapwood was 14.6 

 percent and the range from 12.3 to 18.3 percent. The average specific gravities of 

 the heartwood and sapwood were similar 0.432 and 0.421, respectively (table 1). 

 These results indicate that the posts were sufficiently dry for preservative treatment 

 and that no decay was present. The average specific gravity for lodgepole pine is 

 0.38 (U.S. Department of Agriculture 1974). 



For the posts largest in diameter (table 2) , the average moisture content of the 

 heartwood was 23.0 percent and the range was from 18.8 to 27.5 percent. The moisture 

 content of the sapwood averaged 19.8 percent and ranged from 16.5 to 23.8 percent. 

 The average specific gravity of the heartwood was 0.430 and for the sapwood 0.419. 

 The percent moisture contents were slightly higher than those normally attained for 

 air-seasoned posts prior to treatment and were higher than the moisture contents of 

 the small posts. The specific gravity values were practically the same as those for 

 the small diameter posts. 



2 



