ID 



HARDWOOD RECORD 



Seasoning of Refractory Woods. 



The proper handling and seasoning of 

 woods not readily Yielding to ordinary out- 

 r drying as usually practiced in lum- 

 ber manufacture, is a subject that is attract- 

 ing wide attention, has caused much experi- 

 mentation, and is well worth the attenti"ii 

 tv lumberman. There are large quan- 

 tities of woods, notably southern hardwoods, 

 which, from the peculiarities of their phys- 

 ics, caused by the soil and environment oi 

 growth, do not lend themselves readily to 

 open-air drying without some preparation 

 of the wood whereby the staining, warping 

 and twisting qualities may at least to soma 

 extent be elimin:i 



It is a safe assertion that not one lumber- 

 man in a thousand has ever given 

 siderable attention to the subject of tree 

 growth, tree chemistry, tree history or wood 

 ies. The average lumberman knows that 

 a tree of a specific I otanieal family and of a 

 certain size, will produce so many dollars and 

 cents when Bawed into lumber. This knowl- 

 edge satisfies the average lumberman. How- 

 ever, there are others who like to analyz. 

 ery suggestion that looks toward making bet- 

 ter lumber out of given logs and perforce ob- 

 taining higher prices for the resultant prod 

 uct. Therefore. f cer- 

 tain refractory w ts that are to be con- 

 verted into lumber and put on the market is 

 worthy the earnest consideration of ■ 

 lumber manufacturer. 



A hasty review of tree growth may 

 be of value. Certain plants are endowed with 

 iculty of secreting substances which 

 imposition for a long time and of being 

 able to fortify their tissues with it ; such 

 plants grow into trees and live for 



Other plants run th< ir brief rse of a year 



and perish as - v have gi\'ti birth to 



another gem ration. The ai i to a 



tree's growth is practically a i :a) sheath 



tapering tu a point and accommodating the 

 plant within it to it^ topmost bud, A seed- 

 ling that is tu.. years old is two yeai 

 in its inner part — its heart. The two layers 

 not merged in i ; the second is 



■ ly added. In .-. century "id tree only the 



pith and the first coat of \\ 1 bear that age. 



is only ninety-nine years "id 

 and the outermost layer but one year old. 

 We say a tree is one hundred pears old; that 

 general impression is correct but the fact is 

 not precise, as the tree as a whole is w 

 than its component parts. 



A tree, then, is a living organism whose 



coini n of various ages and dif- 



::i character. Practice rts oi 



When sawn into 

 boai ist plank will be a c 



flitch "1 bark wit! 



inner side. Tl wood 



on each edge and a strip of heart wood down 



crease in width, 

 plank, until tl 

 ill be reached. Lines will mark off cone 



from cone — annual ring from annual ring, 

 only when the section approaches the 

 horizontal that the ;.unnal rings approach 

 circular. No two planks are exactly alike in 

 every detail of figure. 



The microscope demonstrates the fait 

 no two varieties of trees have the same phys- 

 ical structure. The arrangement of fiber and 

 cells varies in each different woo. I. 8 

 trees have thin, cellular structures. Such 

 woods season readily in the open without 

 warping or twisting; an example of these is 

 the white pine. In other woods the cellular 

 structures are thick and their contents do 

 not readily escape from the cell covering. In 

 outdoor seasoning this cellular structure grad- 

 ually hardens at and t\vi>ts the fiber 

 be wood, thus producing warping. 

 it should be understood that wood, while 

 living, is a tree, but being dead it is timber. 

 A tree is composed of woody fiber and plant 

 juice or sap which is an aqueous solution of a 

 nice which serves as the food for the 



living plant. Tie- v. ly fiber is made up 



primarily of cellulose which is in part 

 changed into lignin. When the tree is sawn 

 into lumber the only valuable part of it as 

 lumber lies in the woody fiber. The sub- 

 stances contributing to the tree's growth give 

 no value to it as a lumber pn | Whei 



this i - thoroughly expellee! 



the wood fiber of the lumber it is recog- 

 nized as being dry or seasoned. The amount 

 of this material co tl'erent 



tics of wood varies materially. It is 

 I irily more abundant in hard and heavy 

 than in light and soft kinds. The 

 amount of water or sap present in wood also 

 9 with the season of the year. The per- 

 ige of water contained in different trees 

 i at a T«'ri"d of minimum amount <- 

 shown in tie- follow 



Beech L8.6 Oak 3-1. 7 



-\ le 27 " fine 



Js.T Elm -14..-I 



Blrch 30.8 Poplar 50.6 



Considering th 1 growth and 



construction, that the v ' I ■ only 



valuable port i' imber, that 



every tree contains an amount of matter 

 ii lii- "I necessity to be dispelled to make 

 the wood valuable for purposes of permanent 

 use, we must ascertain the best and most 

 economical method of dispelling these various 

 substances in order t" prepare the wood for 

 commercial use. 



Some woods are susceptible of being dried 

 in the open and with t satisfactory 



results. Various types of dry kilns season 

 other woi jfactory manner. 



But there are still "tier woods — notably the 

 gums — which are becoming a great factor in 

 lumber manufacture and which do not seem 

 to lend themsi I air drying 



or prevalent methods of kiln drying. Tho 

 in or wood fiber of these trees is very 

 much involved, 'lie- cell coverings in the 



wood arc stun g an i heavy and do not readily 

 discharge their contents, but during the con- 

 traction due to loss of moisture they inter- 

 lock with tin wood fiber and warp and twist 

 the wood. Prominent in the contents of these 

 cellular structures, making up the plant juices 

 or sap. is albumen. Many trees also contain 

 rosin, tannic acid and other properties. Trees 

 that are rid m tl>.-e substances do not diy 

 satisfactorily in the open air. The sap of 

 such woods after tin tree is felled becomes 

 sour and discolors the wood and marks the 

 first evidence .it decay unless stayed by a 

 proper treatment of the sawed lumber. 



Many woods lend themselves readily to 

 proper seasoning by modern dry kiln proc- 

 esses, ,,f which there are several on the mar- 

 ket doing excellent work. But it is rarely 

 that either red gum or tupelo gum, the latter 

 commercially known as bay poplar, has 

 been successfully seasoned by any known dry 

 kiln methods. Up to the present time the 

 most I handlers of gum woods have 



been those who 'nave subjected the wood t" 

 several bom- of teaming. One of the most 

 tors in these woods has piled 

 his gum lumb.-r on to dry kiln trucks fresh 

 from the saw, and within a wooden steam box 

 the wood t" a bath of twelve 

 hours in live steam, lie has then carefully 

 piled In- lumber in narrow piles with numer- 

 ous stickers ami a 1 eavy pitch and has given 

 it a l"ni_r p. nod of air drying. As a final 

 operation I ■ - the wood to a brief kiln 



drying. Ill this way he has accomplished a 



satisfactory result, the w 1 coming out 



straight and without warp, twist or stain. 



Both rosin and albumen as they exist in 

 sap wood- ii water — quick]] ii 



the water be h"t and slower in cold water. 

 Both, however, harden with heat, much the 

 same -lie white of an egg, which is 



Mm. ■ . It '.Mini. I seem, there- 

 r method of preparing for 

 seasoning such ods as thi 



wool.. | thi lumber fresh from the 



in hot \\ :i t . i. "i better still, to live - 

 i pressure. This latter method will in- 

 sure the breaking up and disintegration of the 



cellular structure .it the w I and "ill in 



no wi A practical demon- 



stration of tl-" fad that steam di 



jure th" fiber of h Is is that the felloes of 



wheels, wood subject t.. the hardest wear. 

 are thoroughly steamed before tiny are lit 

 This is true of other woods - very 



severe strain and wear. The only possible 

 objection that c:in be raised t" th.- steaming 

 of wood is the fact that the steam dissolves 

 the tannic acid, albumen and other coloring 

 matter contained Lb it ami tends t" obtain a 

 uniform color. I'm example, were a plank 

 of I. lack '.miIi . i led t" st. 



pressure, th" white sap 



wood would have disappeared and the plank 

 would all be brown. Therefore in ... 

 ods of high culm -t. , 



be practical as it would tied I jui 



beautiful eoloi i veining of thi wood. 



