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THE AIR SEASONING OF WESTERN SOFTWOOD LUMBER 59 
TABLE 9.—Amount of degrade due to loose knots im 1-inch No. 1 common 

Douglas fir 
Degrade due to loose knots 
Total 
Total 
Lot No. volume degrade Proportion 
ErCen Seasoning | Machining} Total of total 
degrade 
Board feet Per cent Per cent Per cent Per cent Per cent 
Lee set 19, 733 10. 69 2.11 5. 94 8. 05 75. 30 
OAS 20° a a rene Dre ca ees US 22, 187 15. 81 3. 89 9. 47 13. 36 84. 50 
8h So ee ieee 2 16, 886 17. 06 7. 84 | 8. 34 16.18 94. 84 
eS Gly aay) a ae a 22, 795 17. 60 7. 67 9. 08 16275 95.17 
Fj ats JERS SW eemenenees A oN) 8 23, 563 8. 47 1. 58 6. 29 7. 87 92. 92 
Gi 2 > Bebe Ae ele eo puna oie 13, 200 67. 82 3. 64 | 13. 81 17. 45 25. 73 
2 | eee eg SRE ee 15, 216 39. 55 32 11. 04 11. 36 28. 72 
i eebees ere  e 8, 120 52. 37 3.00 | 24. 48 27. 48 52. 47 
po aa 10, 444 34. 37 2. 94 16. 81 19. 75 57. 46 
More serious, if indirect, seasoning losses are indicated in Figure 
10, which shows that with present practice long seasoning periods are 
required for stock piled in the period September to March. It also 
shows that during only seven months of the year may suitable mois- 
ture contents be obtained. Stock thoroughly air-dry in September 
willl pick up moisture rather rapidly until the first of the year, when 
it may contain as high as 26 per cent moisture. Existing climatic 
conditions are, of course, the primary cause of such results, but much 
can be done by way of seasoning practice to minimize these difficulties. 
RECOMMENDATIONS FOR IMPROVEMENT 
The two major air-seasoning problems of the Douglas fir region 
are the reduction of the drying period and the lowering of the final 
moisture content of stock. Prevention of checking is also of real 
importance. Suggestions for change in regional practice to meet 
these problems are as follows: 
Improved yard drainage is a rather general need. 
Rear alleys should be wider, and greater spacing should be allowed 
between the sides of the piles. 
A requirement of vital importance is that of higher foundations. 
The spacing between boards in a course should be increased, and 
gue or more chimneys should be used in piles of random-width 
stock. 
To prevent the development of season check, stock crossers should 
not be employed on select common and better Douglas fir, nor on 
No. 1 common over 8 inches in width. 
The use of the random-length type of pile should be discontinued. 
