The commercial procedure presently used consists o£ placing the poles upright in a 

 treating tank filled to a depth of approximately 9 ft (2.7 m) with a preservative 

 solution of about 5.1 percent pentachlorophenol in a heavy oil carrier. The preserva- 

 tive solution is then heated to a minimum of 190° F (88° C) and this temperature is 

 maintained for 6 hours. At the completion of this interval, the hot solution is replac 

 with preservative solution of the same concentration, at ambient temperature. The 

 poles remain in this bath for an additional 6 hours, after which the tank is drained 

 and the poles removed. Additional preservative solution is periodically added during 

 the treatment to maintain the desired solution depth. 



After the study poles had been treated, they were returned to the storage area and 

 sampled. Sampling consisted of cutting a section, approximately 10 inches (25.4 cm) 

 from the center of the treated length. These sections, identified as to pole, were 

 used to determine the depth of sapwood, the depth of preservative penetration, and the 

 preservative retention in pounds per cubic foot. A commercial testing laboratory made 

 the post-treatment evaluations in accordance with procedures recommended by AWPA (1969) 



Results and Discussion 



The percent moisture content and specific gravity determinations are summarized in 

 table 7. These data show that the average values are fairly consistent. The overall 

 average percent moisture contents for the heartwood and sapwood were 19.5 and 20.6, 

 respectively, and the overall average specific gravity for the heartwood was 0.396 and 

 for the sapwood, 0.399. The percent moisture content indi\^idual . values ranged from 

 12.9 to 27.8 and individual specific gravity values ranged from 0.335 to 0.451. 



Table 7 . --Before treatment summary of average percent moisture content and specific 



gravity determinations made on test specimens taken from dead lodgepole pine 



poles 



Average 



Number Average , moisture content specific gravity 



Treatment schedule of poles Heartwood Softwood Heartwood Sapwood 



- - - - Percent - - - - 



6-hour hot and 12-hour 

 cold bath 



6 



17.7 - 



17.4 



0.405 



0.399 



4-hour hot and 6-hour 

 cold bath 



6 



19.3 



20.5 



.398 



.400 



2 -hour hot and 6 -hour 

 cold bath 



6 



19.4 



19.9 



.397 



.390 



9-hour cold soak 



4 



21.1 



23.9 



.400 



.414 



6-hour cold soak 



4 



18.9 



21.3 



.377 



.390 



4-hour cold soak 



4 



22.0 



22.3 



.390 



.402 



Average 





19.5 



20.6 



0.396 



0.399 



10 



