﻿KILN DRYING HANDBOOK. 

 Table G. — Aircraft Schedule I. 



39 



Stage of drying. 



At the beginning 



After fiber saturation is passed (25 per cent) 



At 20 per cent moisture 



At 1 5 per cent moisture 



At 12 per cent moisture 



At 8 per cent moisture 



Final 



Drying condition . 



Maximum 

 dry-bulb 

 temper- 

 ature. 



120 

 125 

 128 

 138 

 142 

 145 

 145 



Minimum 



relative 



humiditv. 



Per cent. 

 80 

 70 

 60 

 44 

 38 

 33 

 33 



Wet bulb. 



F. 



113 

 114 

 112 

 112 

 112 

 110 

 110 



SPECIES FOR WHICH AIRCRAFT SCHEDULE I IS APPLICABLE. 



Ash, white, blue, and Biltmore. 

 Birch, yellow. 

 Cedar, incense. 

 Cedar, northern white. 



Cedar, western red. 

 Cedar, Port Orford. 

 Cypress, bald. 

 Pine, sugar. 



Pine, white (eastern and western). 

 Spruce, red and white. 

 Spruce, Sitka. 



Table. 7. — Aircraft Schedule II. 



Stage of drying. 



Drying conditions. 



Maximum 

 dry-bulb 

 temper- 

 ature. 



Minimum 



relative 



humiditv. 



Wet bulb. 



At the beginning 



After fiber saturation is passed (25 per cent) 



At 20 per cent moisture 



At 15 per cent moisture 



At 12 per cent moisture 



At 8 per cent moisture 



Final 



105 

 110 

 117 

 129 

 135 

 135 

 135 



Per cent. 

 85 

 73 

 62 

 46 

 42 

 40 

 40 



"F. 



100 

 101 

 103 

 106 

 109 

 107 

 107 



SPECIES FOR WHICH AIRCRAFT SCHEDULE II IS APPLICABLE. 



Cherry, black. 

 Douglas fir. 



Mahogany. 



Oak, white, and red. 



Walnut, black. 

 Maple (hard and soft). 



OAK WHEEL BLANKS. 



Several schedules hare been developed for oak artillery-wheel 

 stock — club-turned spokes and bent rims. Since oak is extremely 

 variable in its drying characteristics, extreme care must be exer- 

 cised in using these schedules. Steaming of bent rims must be 

 done with caution, since over-steaming will relieve the set caused 

 by the bending, thus allowing the stock to straighten out. Steaming 

 for from 1 to 2 hours at 160 to 180° F. may be done periodically 

 after the outer one-half inch has dried below 25 per cent. 



