THE PRESERVATIVE TREATMENT 



The Dipping Process consists in simply heating the 

 wood in the creosote for 15 minutes or longer. This allows 

 all checks and defects to become rilled with oil, but the pene- 

 tration and absorption of oil are slight. On account of the 

 small amount of preservative used and the large amount of 

 material that can be treated in a day, it is cheaper than open 







Courtesy of Iowa Agricultural Experiment Station. 



^ FIG. 6. CREOSOTED COTTONWOOD POSTS AFTER 9^ YEARS' 

 SERVICE. Since cotton wood is one of the woods which decays most quickly 

 when in contact with the ground, this illustration of creosoted posts which are 

 still in perfect condition after 9^2 years indicates the effectiveness and possibilities 

 of creosote treatment. It applies equally well to lumber and many other farm 

 timbers and enables both the dealer and the consumer to make use of woods 

 which are not naturally resistant to decay. Experience shows that timber which is 

 well enough treated to be sound after 10 years will last 10 or 15 years longer in 

 situations where there is no wearing away of the treated portions of wood. 



tank treatment, but it is also much less effective. It should 

 never be used except on thoroughly seasoned timber. This 



Twelve 



