The Evaluation of Wood Preservatives 



Part II 



By REGINALD H. COLLEY 



(Manuscript received September 22, 1952) 



This paper offers a review and interpretation of laboratory and field experi- 

 ments aimed at determining the necessary protective threshold quantities of 

 wood preservatives. It details the procedure followed in the soil-block tests at 

 Bell Telephone Laboratories, Incorporated. Discussion of specific criticisms 

 of the techniques involved and replies to these criticisms are included. The 

 paper also presents for the first time a correlation of the results obtained from 

 soil-block culture tests, outdoor exposure tests on stakes and on pole-diameter 

 posts as well as pole line experience. 



TABLE OF CONTENTS — Part II 



Evaluation by Treated ^ Inch Southern Pine Sapwood Stakes in Test Plots 427 



Rating the Condition of the Stakes 427 



Depreciation Curves for % Inch Stakes 431 



Estimating Threshold Retentions and Average Life 434 



Evaluation by Treated Pole-Diameter Posts in Test Plots 443 



Evaluation by Pole Test Lines and by Line Experience; Service Tests. .... 449 



Discussion 451 



Density and Growth Rate 452 



Size and Shape of the Test Blocks 452 



Toluene as a Diluent for Creosote Treating Solutions 455 



The Distribution of the Preservative in the Block 456 



Heat Sterihzation of the Treated Blocks 456 



The Weathering of Creosote and Creosoted Wood 457 



General Considerations; Creosote Fractions 458 



Creosote Losses 461 



Creosote Losses from Treated Blocks 469 



Creosote Losses from Impregnated Filter Paper 473 



An Interpretation of Creosote Losses 474 



The Gross Characteristics of the Residual Creosotes in Soil-Block Tests of 



Weathered Blocks 479 



The Evaluation of Greensalt 487 



The Evaluation of Pentachlorophenol 488 



Swedish Creosote Evaluation Tests 489 



425 



