March 10, 1919 



Hardwood Record — Veneer & Panel Sect 



ion 



23 



The Uses of Birch Veneer 



The Sources of the Material and Various Uses to Which It Is Put 



ABOUT HALF A DOZEN WOODS are more im- 

 portant than birch in the veneer industry, and sev- 

 eral dozen fall below it. Its rank, therefore, is pretty 

 high among the woods on which Americans depend for 

 their veneers. Nearly twenty-five million feet of birch 

 logs are consumed annually in the manufacture of veneer, 

 and about half of the material comes from the forests 

 of Winconsin, with lesser amounts from Michigan and 

 Maine, and a dozen other states. 



Birch veneer is not all of the same kind or class. 

 Three or four species of birch are large contributors to 

 the general supply, and three or four other contribute 

 little or none. All the producers of veneer among the 

 birches belong in northern states, for birch is rather 

 scarce farther south, and what is found in the southern 

 region is not often reduced to veneer. 



Sweet birch, that tastes like wintergreen, and yellow 

 birch, furnish most of the veneer that goes into furniture, 

 interior house finish, and musical instruments, while paper 

 birch yields a pretty large quantity of certain kinds of 

 veneer. 



Little difference exists between the woods of the 

 sweet and yellow birches. Both have white sapwood 

 and red or brown heartwood, and both may have curly 

 or figured wood, but usually the wood is plain. 



It is not practicable to determine from statistics how 

 much veneer is made from each of the different birches; 

 but paper birch supplies a large share. Some of it is 

 intended for the manufacture of thin dishes and plates, 

 and some that is thicker is intended for the use of shoe 

 manufacturers. A portion of the pegs with which heavy 

 soles are fastened on are made from veneer. The shanks 

 which are employed to stiffen the shoe between the ball 

 of the foot and the heel, are cut from sheets of thick 

 veneer, which is usually paper birch. When the shoe peg 

 and the shoe shank reach their final use, they are not 

 commonly recognized as veneer, having passed that stage 

 and assumed another form. 



Birch veneer is made in many thicknesses, but most 

 of it is one-eighth of an inch or thicker. The high per- 

 centage of relatively thick stock is on account of the 

 considerable quantity used in supplying shoe factories. 



The choice wood of sweet and yellow birch, when 

 reduced to veneer, is usually cut thin. That is true in 

 particular, if it is intended for the surface of furniture, 

 musical instruments, or interior house finish, and these 

 are the situations where the best grades of veneer are 

 commonly seen. 



Nearly all birch veneer is cut by the rotary process. 

 The quantity manufactured by sawing or slicing is almost 

 negligible. Nearly twenty times as much birch is made 

 into lumber as into veneer in the United States. 



The red heartwood of sweet and yellow birch is fre- 

 quently substituted for mahogany by manufacturers of 

 furniture, finish, and musical instruments. It can be 

 stained or otherwise treated by the wood finisher until 

 it very closely resembles mahogany. However, the two 

 woods don't look much alike until they have been arti- 

 ficially finished with stains. When that is properly done, 

 the colors of the two so closely resemble that ordinarily 

 birch will pass for mahogany. It is somewhat stronger 

 than mahogany and is often substituted for that wood for 

 spindles and posts where extra strength is wanted; but 

 when these two woods are employed as surface veneer, 

 one has little advantage over the other in the matter of 

 strength. 



The red heartwood of birch is also substituted for 

 cherry with satisfactory results. It looks as much like 

 cherry as like mahogany, but it differs from both if the 

 wood is left plain. It lacks the grain of mahogany and 

 the luster of cherry; but these differences may be largely 

 overcome by the skill of the wood finisher. Birch is 

 more plentiful and less costly than either cherry or ma- 

 hogany, and that leads to its substitution for those ex- 

 pensive woods. 



However, the largest use of birch is not as a sub- 

 stitute for any other wood, but under its own name and 

 on its own account. 



Investigations Lead to New Knowledge 



The war has placed an opportunity in the hands of furniture 

 and panel manufacturers to benefit by the increased knowledge of 

 the peculiarities and characteristics of wood and glue. 



Under the stress of war and the necessity of furnishing aircraft 

 to the fighting front in large numbers and a short time, it was 

 found necessary to supplement the information available on wood 

 and glue by extensive additional research work on these two im- 

 portant construction materials. It was found in many instances 

 that factories taking government contracts for aircraft and wagon 

 work had in their desire to help, neglected to go into the situa- 

 tion thoroughly and found themselves unable to produce on 

 schedule. The rigid government inspection showed them that 

 their equipment was inadequate to meet the special demands 

 placed upon it, and their knowledge of the peculiarities of the 

 material was not sufficiently exact. 



Many varied difficulties were encountered. Vehicle manufac- 

 turers had trouble drying stock. Lumber for wagons to be used 

 in the hot, sandy sections required more thorough drying treat- 

 ment than lumber for wagons to be used in more moist districts, 

 and it was necessary to dry heavy stock quickly. Propeller manu- 

 facturers found that making propellers involved a great many more 

 variables than the mere gluing of laminations and shaping the 



block internal stresses occurred that caused warping and open 



joints in seemingly perfect blocks. Though they had been using 

 glues for many years they soon discovered that there was a wide 

 difference between high grade laminated work and the class of 

 work ordinarily accepted as commercial standard. It is not sur- 

 prising that the panel manufacturers making aircraft plywood for 



