Wood seasoning and 

 moisture control 



Wood in nature is a material com- 

 bined with one-third to two and a half 

 times its weight of water; a freshly cut 

 log* 16 feet long and 18 inches in diam- 

 eter may have a liquid content of more 

 than 100 gallons. 



For most uses of wood it is imperative 

 that the greater part of this water be 

 removed, a requirement that gives rise 

 to the complex problems of seasoning. 

 When wood dries, it shrinks. The 

 amount of slirinkage is different in 

 different directions in the piece, and 

 the result of uncontrolled drying is more 

 or less severe damage by checking, 



splitting, and change of shape. Unsuc- 

 cessful seasoning is the cause of theJ| 

 nonuse of many wood species and tre- 

 mendous losses of material of other 

 species, and is a prolific source of difficul- 

 ties and dissatisfaction with wood in 

 service. To improve this situation 

 through adequate control of seasoning 

 operations is a major task of scientific 

 research. 



Air-drying 



Seasoning in the open air may be 

 termed the natural method of wood 



Three o£ the Laboratory's dry kilns for experimental seasoning o£ lumber. 



20 



