TREATING POSTS 207 



Life of Fence-Posts and Shingles 



Durability of fence posts in Minnesota (Green) . 



YEARS 



Red cedar 30 



White cedar (quartered 6 in. face) 10-15 



White oak (6 in. round) 8 



Red and black oak 4 



Tamarack (red wood) 9 



Elm 6-7 



Ash, beech, maple 4 



Black walnut 7-10 



Prolonging the life of fence-posts (Willis). 



Measures for posts named in ascending order of efficiency : 

 Peeling and seasoning. 

 Charring. 

 Painting. 



At best, surface brush paintings are not very durable. Some of the 

 substances which may be applied with a brush are whitewash, petro- 

 leum-tar creosote, coal-tar creosote, and various patented products 

 of coal tar and petroleum tar. Paint and whitewash are inferior to 

 antiseptic preservatives; products of coal tar (creosote, etc.) are the 

 best. These are best applied hot, in two or more coats. A barrel (50 

 gallons) of creosote should be sufficient to paint at least 300 posts with 

 three coats for the butts and two for the tops. 



Dipping. 



One defect of brush treatment is that the preservative does not 

 enter readily the cracks and checks. This defect may be overcome 

 by dipping the posts in the preservative. Another advantage of dip- 

 ping, as compared with painting, is a saving in labor. On the other 

 hand, dipping requires a larger quantity of preservative, and, in ad- 

 dition to the amount consumed, there must be enough surplus to keep 

 the barrel or tank filled to the proper depth. This usually forbids 

 the use of any expensive preservative for dipping. Petroleum tar, 

 coal tar, and the creosotes, however, may often be advantageously 

 employed. 



Posts have been treated by dipping the butt in cement. This is 



