UTILIZATION OF BLACK WALNUT. 53 



wood, is defective the yield might be made greater by cutting from 

 the sapwood side. 



In the straight-slice process the principal waste is in squaring the 

 log lengths and in the " dog board." A 20-inch log may be taken 

 to illustrate the straight-slice method. Squaring this to 14 inches 

 will remove nearly all of a 2-inch rim of " sap " and cut down to a 

 heartwood face of about 8 inches in width. If allowance is made 

 for a 10 per cent waste, as in stay-log rotary, a possible yield is given 

 of 353 square feet of veneer to the linear foot of log, after a 2-inch 

 " dog board " is deducted. As there are 16 board feet, log scale, to 

 the linear foot in a 20-inch log, each log-scale foot will yield about 

 22 square feet of veneer. The figure generally given by firms that 

 make straight-sliced veneer almost exclusively is 20 square feet to 

 the board foot, log scale. The small amount of sapwood that was 

 not removed in squaring the timber probably accounts for the differ- 

 ence in these figures. 



If it is cut in halves for slicing, the log is not squared. The sap- 

 wood is largely trimmed off, and the back, or outside, of the log is 

 trimmed down to a flat surface in order that the half log may be 

 held in the veneer slicer. As there is a little less heartwood trimmed 

 off by this method, the yield in veneer will be slightly greater. 

 Although there are two " dog boards " to a log if the half log is used, 

 each one is thinner than the " dog board " from the entire log. 



The yield to the board foot of log does not, therefore, differ greatly 

 in the three different processes — straight rotary, stay-log rotary, and 

 straight slice — the general average of 20 square feet of veneer to 

 each board foot of log applying very closely in each case. 



If dimension walnut veneer is made from small clear pieces, only 

 about 15 square feet of veneer is obtained to one board foot, log scale, 

 of the logs from which the clear pieces were cut. As a matter of fact, 

 a clear block 1 foot by 6 feet by 6 inches, containing 36 board feet, 

 which is equivalent to about 30 board feet, log scale, will yield about 

 880 square feet of veneer, or 29 square feet to each board foot, log 

 scale, in addition to a three-fourths-inch " dog board." Therefore 

 only about one board foot of the clear piece is required to produce 

 the same amount of veneer as may be obtained from 2 board feet cal- 

 culated on the basis of the entire log ; that is, only about one-half of 

 the log is used for the small clear blocks. The remainder of the log 

 not used in producing the clear pieces may be utilized for lumber and 

 dimension material. Furthermore, logs of lower grade may be used 

 than are required in making the larger-sized veneers. 



Dimension veneer, cut to the size required by factories, is often 

 obtained from veneer made by the rotary process. This plan in- 

 volves much trimming of the veneer, but it makes unnecessary the 



