


THE AIR SEASONING OF WESTERN SOFTWOOD LUMBER 33 
of drying but materially reduced degrade from stain. Seasoning of 
these woods on 8/4 crossers resulted in a depreciation of 8 per cent; 
on 6/4 crossers, in a depreciation of 13 per cent; and on 4/4 crossers, 
in a depreciation of 28 per cent. 
The 4/4 crosser commonly used in the Inland Empire is mainly 
responsible for the appreciable lag in rate of drying between the 
bottom and the top of the pile. Naturally, blue-stain depreciation of 
pine stock at the bottom is heavy. The effect of 8/4 crossers in the 
lower third of the pile was compared at several plants and was found 
to average consistently less drying time than was necessary in piles 
with 4/4 crossers throughout. The stock on the 8/4 crossers reached 
an air-dry condition on an average three and one-half weeks earlier 
than that in the lower third of the other piles. Blue-stain develop- 
ment was less than one-third of that in 4/4-crossed stock. The final 
average moisture content of the stock on the 8/4 crossers was also 
lower, and the customary lag in drying time between the top and 
bottom sections of the piles was much smaller. 
With pine, the use of two instead of one of the regular 2-inch 
crossers at evenly spaced intervals in the bottom half of the pile 
reduced the average degrade from 24.6 per cent to 12.9 per cent. 
Similar comparisons with redwood showed a reduction in degrade 
from 18 per cent to 5 per cent, and during a six-month drying period 
the stock piled with double crossers lost 28 per cent more moisture. 
Such methods are not only effective in building up the horizontal 
circulation but are easily applied in the yard. The use of two sizes 
of crossers in the individual yard is objectionable, of course, but this 
is unnecessary. ‘Two or more crossers of the customary thickness 
placed one on top of the other answer the purpose nicely. I, instead, 
4 by 6 by 12 inch blocks are placed under single crossers at inter- 
vals, this not only permits increased sidewise circulation but also 
gives entrance to the wind currents in the front and rear alleys, which 
are normally shut out by the crossers. (PI. 7, A.) 
The actual practice in the West varies greatly. In the Douglas fir 
region, where practically all stock is self-crossed for air seasoning, 
the thickness of the crosser conforms to that of the lumber being 
piled. The 4/4 crosser is the general standard in the Inland Empire, 
although some pine shop and selects, especially 5/4 and thicker stock, 
are piled on 8/4 crossers, and the practice of opening up the lower 
part of the pile with thicker crossers is increasing. In the California 
pine territory the 8/4 sticker is the standard. Strangely, in the 
redwood region, where slow drying is the big problem, the 4/4 sticker 
is commonly employed. 
In any attempt to improve seasoning conditions the question of 
crosser thickness must be analyzed carefully. It should be clearly 
recognized that positive horizontal circulation, particularly in the 
lower part of the pile is a very necessary adjunct to the natural 
downward air movement in the lumber pile. Horizontal circulation 
is imperative ii the lag in drying between the upper and lower 
halves, and hence the average drying time, is to be satisfactorily 
reduced and depreciation, chiefly from stain, is to be avoided. Varia- 
tion of the crosser thickness is the most flexible means of influencing 
horizontal circulation, 
