50 



BULLETIN" 909, U. S. DEPARTMENT OF AGRICULTURE. 



of wood. Such highly figured pieces as burls are usually cut one- 

 thirtieth inch thick. There seems to be a tendency on the part of 

 panel makers to use thicker veneer of about one-twentieth inch. 

 Although this veneer costs more, the makers figure that it is more 

 profitable in the end; for with the thicker veneer almost no waste 

 results from the rejection of panels that have been sanded through. 

 Furthermore, the panels may be sanded more rapidly, and this is a 

 particular advantage on account of the present high cost of labor. 

 One-twentieth inch was formerly the common thickness for sliced 

 veneer, but the thickness has been reduced, as walnut has become more 

 scarce and higher in price. Sawed walnut veneer is usually one- 

 eighth or one-sixteenth inch thick. Figured stock is usually sawed 

 one-sixteenth inch thick. 



Yield by different methods. — Exact data are difficult to obtain on 

 the yield of veneer from logs of different sizes, because the different 

 processes are varied to suit each log. Moreover, there are wide dif- 

 ferences in the quality of different logs. Average yields may be 

 calculated, however, from practically clear logs, with deductions of 

 the average amount of waste in that part of the log from which, in 

 commercial practice, merchantable veneer is produced. Table 18 

 gives in terms of veneer one twenty-eighth inch thick the calculated 

 volumes to the linear foot of logs of different diameters. Table 19 

 gives the average thickness of sapwood and diameter of heartwood 

 for logs of different diameters. In the calculations of yield, a larger 

 allowance for sapwood is made than is shown in this table, for the 

 reason that the sapwood is often of irregular thickness and therefore 

 a greater waste is caused than the actual thickness of sapwood in- 

 dicates. 



Table 18. — Theoretical volumes, in terms of one twenty-eighth ineJi veneer, of 

 logs of different diameters, per linear foot of log. 



Diameter log (inches). 



Sq. ft., T V" ; 

 veneer. 



Diameter log (inches). 



Sq. ft,, T y 



veneer. 



12 



264 

 310 

 359 

 412 

 469 

 530 

 594 

 662 

 733 

 808 



22 



887 



13 



23 



969 



14 .. 



24 



1,056 



15 



25 



1,145 



16 . 



26 



1,239 



17 



27 



1,336 



18 



28 



1,437 



19... 



29 



1,541 



20 



30 



1,649 



21 











