The normal procedure was followed in treating the study posts except that the 

 pressure period was reduced to 15, 30, or 45 minutes. After the pressure had been 

 applied for 15 minutes, the cylinder was drained and opened, and 11 posts, including 

 one with bark, were removed. After a second 15-minute pressure period another group 

 of 12 posts, including one with bark, were removed; and after a third 15-minute 

 pressure period, the remaining 15 posts, including three with bark, were removed. 

 Upon removal, the posts were immediately reweighed to the nearest 0.5 lb (0.23 kg) and 

 the end diameter was remeasured. 



In the laboratory, a disk was cut from the approximate center of each post, and 

 the age, sapwood depth, and preservative penetration were noted. The disks were then 

 individually placed in polyethylene bags and shipped to the preservative manufacturer 

 for chemical analysis. Increment borings, too, were taken from the post and sent for 

 analysis . 



Results and Discussion 



Percent moisture content of the specimens taken prior to treatment ranged from 

 9.1 to 24.6 percent and moisture content averaged 13.2 percent. The specific gravity 

 of the specimens ranged from 0.294 to 0.493 and averaged 0.378--about the same as the 

 published value of 0.38 (U.S. Department of Agriculture 1974). The percent moisture 

 content and specific gravity data are summarized by treatment in table 5. 



Table 5. --Before treatment summary of average percent moisture content and specific 

 gravity of test specimens taken from fenceposts cut from dead lodgepole 

 pine trees and treated with preservatives by three different pressure treating 

 schedules 



Average 



Number of Average moisture content specific gravity 



Treating schedule posts Heartwood Sapwood Heartwood Sapwood 



- - - - Percent - - - - 



30 min vacuum and 15 min 



pressure, 100 psi 



11 



. 13.3 



12.1 



0.377 



0.371 



30 min vacuum and 30 min 













pressure, 100 psi 



12 



12.3 



11.6 



.404 



.368 



30 min vacuum and 45 min 













pressure, 100 psi 



16 



14.1 



15.8 



.391 



.363 



Overall average 





13.3 



13.5 



0.391 



0.362 



Again, debarking the dead tree posts demanded special attention to prevent exces- 

 sive wood loss. Deep checks on the post surface caused the floating rosser head to 

 stop the post and gouge the surface. Also, as before, the post surface was somewhat 

 rougher than that of newly peeled green posts. A few of the study posts were of such 

 low quality and appearance that under ordinary circumstances they would have been 

 discarded. 



The ages of the posts varied from 17 to 55 years. The sapwood depth ranged from 

 0.38 inch to 2.00 inches (1.0 to 5.1 cm). Preservative penetration measurements 

 were made on the borings using Chrome Azurol S as a copper detecting reagent (AWPA 

 Method A- 3, 1969) and a mixture of 0-anisidine hydrochloride and sodium nitrate as a 

 pine heartwood indicator (AWPA M-2, 1969). The borings all showed 100 percent pene- 

 tration of the sapwood. The post- treatment data are summarized in table 6. 



7 



