September 10, 1917 



Heu-dwood Record — Veneer & Panel Section 



Natural Defects in Veneer Logs 



Reasons Why Prices of the Finished Product Cannot Be Reduced 



I ANY THINGS influence the cost of veneers other 

 than labor, equipment and overhead. One of 

 these things consists of the group of natural 

 defects in logs. They are a part of the log 

 itself and are independent of seasoning defects or dry 

 kiln troubles, or of bad manufacture. Where the log is 

 not perfect, some of the veneer will be imperfect, and 

 it must be rejected or placed in a lower grade. That 

 means expense without compensating profit and it is 

 bound to appear in the final balance sheet which shows 

 profit and loss in the operation. 



Knots constitute a common defect. Every tree has 

 them somewhere in its trunk and the veneer knife finds 

 them. They may not appear on the surface of the log, 

 and some logs are clear stuff all the way through, but 

 if the whole tree is cut in veneer, it may be accepted as 

 a certainty that the knife will find knots, and wherever 

 a bad knot is found it means a loss to the mill which is 

 cutting the stock. Sheets or parts of sheets must be de- 

 graded or else rejected altogether. It is no fault of the 

 mill. It is nobody's fault, but simply a circumstance 

 which must be taken account of. 



Sometimes a knot improves a sheet of veneer by giving 

 it figure, but that is not the usual outcome. The profit 

 is in the clear wood where knots do not occur, and when 

 a log with knots goes into a veneer mill, it may be taken 

 for granted that the product will be lowered in value 

 accordingly. This holds true whether the veneer is 

 rotary, sliced, or sawed, but since most veneer is rotary 

 cut, it follows that most damage from knots occur in 

 rotary stock. 



FIGURING THE LOSS 

 The loss on account of knots is relatively smaller in 

 low grade stock than in high, because the knots go in 

 with the clear. But in veneers intended for exacting 

 uses, a knot is a passport to the scrap pile or cull heap. 

 Where appearance is not important, a sound knot may 

 pass in veneer as in lumber, provided that uniform 

 strength is not essential. A knot hole has no strength, 

 and a bad knot is simply a disguised knot hole. 



It is fortunate that the many uses for w^hich veneer is 

 wanted lessens the loss that would result if it could be 

 used in high class work only. What is useless in one kind 

 of work may pass elsewhere, and in that way a system of 

 sorting apportions the different grades among the indus- 

 tries that can use them so that the final scrap pile may 

 not be so large. But that does not change the fact that 

 poor material means loss to the manufacturer. 



WINDSH.4KES .AND WEATHERCRACKS 



Knots are not the only defects of living trees which 



cause loss to the veneer manufacturer. Windshakes and 



frost cracks are common. These consist of cracks near 



the bases of trunks, some of the cracks being circular in 



form, others transverse. The precise origin of the two 

 kinds may not be very clearly defined, but they are sup- 

 posed to be due to the swaying of the trunk by the wind, 

 or to the splitting of the wood along weak lines by ice in 

 winter. However, the origin of the cracks is not im- 

 portant. The main thing is that such defects exist in 

 some trees and have direct bearing upon the quality of 

 the veneer and upon the price at which it must be sold. 

 To make the matter worse, the cracks are found in the 

 butt logs where the best wood ought to be found. How- 

 ever, the worst cracks lie near the heart of the tree, and 

 in rotary stock, the tree heart is Rejected because the 

 machine cannot cut down to it, but in sliced or sawed 

 veneers, the heart is worked as well as the outer portions 

 of the trunk, and every crack causes loss when the stock 

 is graded. No skill on the part of the cutter can make 

 good veneer from defective wood, and the necessary 

 loss must be taken in account in fixing prices which will 

 place the business on the proper side of the ledger. A 

 redeeming feature in working timber of that kind is that 

 bad cracks do not usually occur in the outer portions of 

 logs and therefore rotary veneer escapes in many cases. 



OTHER DEFECTS 

 Some kinds of hardwoods contain pith flecks. TTiis 



name is applied to brown spots and streaks, each quite 

 small when considered separately, but in the aggregate 

 they may lessen the value of wood by their unsightliness 

 and also because wood is weakened by them. A sheet 

 of veneer may be so weakened that it will break along 

 the brown streak. This defect is seldom very serious, 

 and sometimes it attracts little or no attention. 



The pith fleck is caused by the boring of a small beetle 

 in its larval stage. It eats passages up and down a tree 

 trunk, just under the bark, journeying to and fro, from 

 the branches to the ground, cutting a new passage at 

 each trip. TTiough the galleries thus made are no larger 

 than a darning needle, they fill with brown substance 

 and remain a blemish in the wood as long as the tree 

 lives. Year by year new layers of wood cover them, 

 and year by year new broods of beetles have fresh gal- 

 leries just beneath the bark. By that process, long con- 

 tinued, the wood of the trunk may be disfigured from the 

 heart outward. All trees are not subject to that injury. 

 Birch, particularly river birch and paper birch, suffers 

 considerably, likewise willow, cottonwood, hornbeam, 

 cherry, mountain ash, basswood and soft maple. 



WOOLLY WOOD 

 The veneer manufacturer occasionally finds a log which 

 produces what is known as "woolly wood. " The grain 

 is not smooth. Very small splinters rise on the surface 

 of the sheet and give it the appearance which is respon- 

 sible for the name w^oolly. Veneers of that sort are useless 

 for certain kinds of work. The surface cannot be polished 



