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Hardwood Record — Veneer & Panel Section 



March 25, 1917 



Warping of Veneer Work 



Some Factors That the Manufacturer Should Take Into Consideration 



E HAVE BEEN TAUGHT, in a way, that the 

 crossing and gluing together of layers of wood 

 in the form of veneer, strengthened it and pre- 

 vented the warping tendency. We find in the 

 end that usually what it does, to a great degree, is to 

 mitigate these faults and not entirely obliterate them. We 

 find more strength in built-up wood, find it much more 

 difficult to bend, to split or distort it in any manner, but 

 occasionally some warping develops, which is disappoint- 

 ing, more because of expectations of perfection than of 

 this fault being conspicuous of itself. We have complaints, 

 or rather inquiries, how to prevent this warping, from 

 both panel people and from people making veneered 

 doors, especially ^vhere they use one kind of wood for 

 one side and some other kind for the other. For ex- 

 ample, a man making doors wiih a hardwood face on 

 one side and softwood on the other, finds at times the 

 stiles ■warp after they are put up. Occasionally the same 

 difficulty develops in connection with panels made hard- 

 wood one side and softwood the other. 



This trouble from warping occasionally, when two 

 different woods are used on the faces, raises two ques- 

 tions. One is, how much will wood shrink and swell 

 after being glued up, and be induced thereby to warp? 

 The other is, do different woods swell and shrink in 

 different proportions, so that a person must be guarded 

 in using two face woods on the same work to get wood of 

 equal density? 



On the first question, that of how much veneer may 

 swell and shrink after it is dried and glued up, we find, 

 upon investigation, that it depends materially on the con- 

 dition of the wood when it is used, if wood is fresh cut 

 from the log, rushed through a drykiln, then into the 

 glue room, and made into panels, it will undoubtedly 

 do more or less swelling and shrinking, not only as a 

 result of the moisture incident to gluing but also from 

 the effects of changing conditions in the moisture of the 

 atmosphere. So long as there is a piece of wood in the 

 form of veneer or anything else, it has the same natural 

 tendencies of lumber or timber, to swell and shrink, or 

 go and come with the weather. Of course, the per- 

 ceptible results of these tendencies are very slight in the 

 thin sheets of veneer, and are also restricted by crossing 

 and gluing together. But, nevertheless, the tendencies 

 remain, and should be taken into consideration. 



Veneer, because of its lightness, should dry out much 

 sooner and easier than thicker lumber, and should sooner 

 get through the stage of repeated coming and going with 

 the weather, until it settles down to a practically per- 

 manent volume. It takes the heavier lumber about five 

 years to do this, if left standing in the air, without the 

 application of heat for artificial drying. Even with arti- 



ficial drying, while the time can be shortened, it takes 

 sometimes the second drying, after it is tempered in the 

 air, to make wood fit for cabinet work. The same logic 

 applies in a milder way to veneer, so that much of the 

 behavior of veneer depends not merely on how it has 

 been dried, but how long it has seasoned after being cut. 



Taking this question and tacking it to the other, we 

 find there is a difference in the amount of swelling and 

 shrinking between different woods, but the nearer we 

 reduce them to their permanent state of dryness the less 

 perceptible becomes this difference. If we could keep 

 a softwood veneer and a hardwood veneer both for a 

 year or two, carefully dry until they had gotten over this 

 tendency to come and go with the w^eather, they ought 

 to glue up on opposite faces of a piece of vifork without 

 causing any wrarping. Therefore, we may deduce that 

 the greener the wood or the sooner it is used after it is 

 cut, the more likely are these different shrinking pro- 

 portions to manifest themselves when two different 

 woods are used in veneer work. 



Possibly the best practical solution that can be offered 

 in connection with these problems is to carry more 

 veneer on hand, so that it may season thoroughly, and 

 depend less on getting it cut promptly to order and 

 buying it only as you need a little. There is many a 

 veneer user who, while he may not know just what he is 

 going to need next, can stock up with a variety of stock 

 close enough to his needs to work fairly well. And 

 about the best thing the average veneer user could 

 cultivate is a habit of carrying more veneer in stock in 

 advance of his needs. This stock, carefully piled under 

 shelter, where it will continue drying out, is the best 

 safeguard against lots of troubles that come in veneering. 



A. B. M. 



The claim has been made that by using oak and other fine 

 woods in the form of veneer the figure or grain shows up better 

 than when the w^ood is used in regular lumber form. This, in 

 itself, is not a fair statement. It leaves room for misunderstand- 

 ing. It is, in the first place, foolish to state that the figure w^ill 

 show up better in a thin piece of veneer than it will on an inch 

 board of the same character. But on the other hand, it is pos- 

 sible, in making a column for example, by using fine veneer, to 

 get the fine figure all the way around, while if it were made from 

 a solid piece it would show only on two sides. That is to say, you 

 don t get a better figure in veneer, but you can make a better 

 display w^ith, it. 



The best time to add new machinery and reconstruct a factory so 

 as to embody labor-saving and all the other economics, is when 

 business is dull and there is plenty of time to do the work. The 

 trouble is, we lack the inspiration at such times — which proves 

 a certain amount of shortsi(ilitedness and exjilains why most new 

 machinery is bought when trade is booming. 



