SAP-STAIlSr, MOLD, AND DECAY IN GREEN WOOD, 



27 



Kiln drying reduces shipping weight; makes the lumber fit for 

 almost immediate use; eliminates or reduces losses due to insects/** 

 or to checking, rotting, staining, or molding; improves the quality 

 of the lumber; reduces the amount of yard space; and saves the 

 tying up of capital and carrying costs (Tiemann, 51, p. 4, 5). 



It is possible that where several producers are located within a 

 few miles of one another, a battery of modern dry kilns, operated 

 according to the most approved methods (possibly on the community 

 plan) might solve the problem of cost of installation and operation. 



In dry kilns, stripping or cross piling the stock and providing 

 means to prevent stagnation of the confined air are absolutely neces- 

 sary if the develop- 

 ment of mold is to be 

 avoided. The water 

 spray kiln devised at 

 the Forests Products 

 Laboratory represents 

 one of the latest de- 

 velopments in the tem- 

 perature and humidity- 

 controlled type of 

 kiln.i^ 



During the first few 

 weeks of kiln drying, 

 when the humidity is 

 high and the tempera- 

 ture ranges from 80° 

 to 105° F., an abundant 

 growth of white mycelium occasionally forms between the courses 

 and interferes more or less with the circulation of the air in the kiln. 

 This is due to the presence of mold fungi, and it usually indicates 

 stagnation in the kiln (PL I, fig. 4). Steaming for one hour at a 

 temperature of 160° to 180° F. has been found effective in destroy- 

 ing or at least checking the growth of this mold (Tiemann {51). 

 p. 187). 



1^ Powder-post beetles, however, are said to cause considerable damage at times in 

 seasoned stock ; in fact, these beetles do not work in green stock. 



1" A complete description af this kiln is given iu Bulletin No. 509,. United States Depart- 

 ment of Agi'iculture (53), a copy of which may be procured from the Superintendent of 

 Documents, Government Printing Office, Washington, D. C, for 5 cents. Further infor- 

 mation concerning the design and installation of this kiln is given in Bulletin No. 894, 

 United States Department of Agriculture (50), to be procured from the same source at 

 10 cents a copy. 



Fig. 8. — Split billets loosely piled in the areaway between 

 the doors of a box car. The doorways are loosely 

 boarded up to allow for ventilation of the car and at 

 the same time prevent the stock from working out 

 while in transit. 



