SEASONING Of BEECH LUMUE12 AGRICULT '77 ROOM SCHOOL OF FORESTR Y

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AGRICULT '77 ROOM

SEASONING Of BEECH LUMUE12

SCHOOL OF FORESTR Y

OREGON STATE COLLEGE

.

CORVALLIS, OREGO

• -

1

ITED STATES DEPARTMENT OF AGRICULTUR E

OREST SERVIC E

OREST PRODUCTS LABORATOR Y

Madison, Wisconsi n

In Cooperation with the University of Wisconsin

• SEASONING OF BEECH LUMBER AND DIMENSION STOC K

(PROGRESS REPORT )

B y

RAYMOND C . RIETZ, Enginee r

Forest Products Laboratory, Madison, Wisconsi n

Beech is a Heavy, close textured, strong wood that ha s many general and special uses and as it does not impart taste o r odor is suitable for food containers . Its principal uses nece s sitate breaking down the logs into lumber or dimension stoc k although a considerable number of ties are produced . The seasoning of beech lumber and dimension stock without degrade is some what difficult as it shrinks greatly, surface checks and en d checks readily, and tends to warp more than most other Appalachia n hardwoods . To reduce seasoning degrade in air seasoning or kil n drying of either lumber or dimension stock, certain handling practices must be employed, cnief of wriich is the separation o f beech from the other hardwoods for seasoning . Insofar as practicable all lumber produced should be quarter-sawed . Plain-sawed lumber in narrow widths will season with less surface checkin g than lumber 8 inches or more in width .

Air Seasonin g

Lumber

If feasible beech lumber should be air seasoned in a shed ; particularly so for dimension stock . Recommendations a s to piling practice in the yard apply to the seasoning

in

sheds .

The general recommendations for the air seasoning o f hardwoods apply to the air seasoning of beech with modification s in practices

to control surface

checking . The stock shoul d always be under cover at the mill or in the yard where appreciabl e time between sawing and piling occurs . Exposure to direct sun light for even short durations of time results in surface checking . Good r seasonin practices include (1) a well-drained

surface

checking the yard probably should be located on lowe r ground not

fully

exposed

to prevailing rinds ; and (2) firm and durable pile foundations sloping 1 inch

to

the

foot

of pile length

411

81174

S and high enough to allow the air that has circulated down throug h the lumber to readily escape .

Not only is it advisable to separate the beech fro m other species for air seasoning but proper piling will be facilitated and seasoning degrade reduced if the separation is als o made with respect to thickness, grade, and length . When th e lumber is separated as to length,

piling

so as to avoid over hanging ends as shown in plate 1, A, which are liable to chec k and warp is simplified . Sometimes the separation of stock wit h re g pec to length is not feasible . Random length stock may b e

"box piled", that is, the long boards are placed in the oute r tiers and the shorter boards in tiers in between, the shorte r boards being staggered on the stickers to provide proper suppor t under each end of every board .

As a general rule lumber is piled perpendicular to th e main alley with pile spacings of various amounts depending upo n the species being dried and the general yard arrangement . The closer the piles are together the more the drying rate is slowe d

, down, which for beech is desirable as a surface checking contro l ai• "die spacing of 4 feet for beech should be a maximum with a 2-foot spacing preferred . Piles for beech lumber shoul d be fairly wide as another surface checking control measure . In the South the hardwood pile is usually 6 feet wide because of th e large number of items being cut . For beech a pile 8 or 10 fee t wide is more suitable . The pile should be pitched 1 inch to th e foot of height towards the alley . Such inclination permits th e rain to drip from the front face of the pile . Dry heartwoo d stickers of uniform thickness, 1-1/4 inch in width should be use d for piling the lumber and depending on the number necessary t o control warp in the various thicknesses as many as 9 tiers for a

16-foot pile are recommended . The stickers should be aligned so that the tiers are parallel to the front face of the pile an d they should be supported directly by a foundation beam . Special stickers, 2 inches wide for 1-inch lumber and wider for thicke r lumber, should be placed at the ends of the pile of boards . I t has been found that if these wider stickers are placed so tha t their outer edges project beyond the ends of a pile of'

'

Bdards , the drying late of the rood covered by the stickers is retarde d sufficiently to effect a material reduction in end s sh vkgiae

Tibe main air movement in a pile of seasoning lumber i s downward . ],n piling the lumber flues should be provided at leas t every 12 inches of pile width . These flues should be straigh t m}t

a

inches wide .

.fi

r L 7 ' ti ti3

1 '

f

;- -

Jti ~

11 1i

' .

-

I I •

_2_ m ' i

~ l

~ uh

~

~

I I I.~Y

le cow from alternat e and warping o f always be made o f ts . The roof should the upper laye r r, r layer, acting a s nd he

-ctic more s ards should b of air to ente-

1lnsidered suff i ade, thickness , orary shelte r the to . la e.

i v i

J. =p .5e

e • di eren t sizes and s ape : facture of fabri,

~.

Si hitate_ h th e

Woo le s

StS oSS-s ir

-,

~

4more ess co

Dimension stock may be "c with itself and having the same numb e

Crib piling permits a larger number o motored in a given space, but it is co

stir

_

T iled" o ed usi

4 of tks stock are -o tia. .

i.rld the ve•r :' -ca.l alignment of s reduce- r1Td cb.eeking

.md wa at

.Modify

the drying rate the stock can

* c ia1 stickers or it we s e

•e~r~ .b4 self a ~ Tti cicero . between : kayUss .

The placing o -

~• is,

~ . F s at t n be-

Pl tte fo-r flat stock .

a

4illus ates a piling me!+ . -

Ek* suec sive piece overla p

00 that' on .y two tL s of are xequi; red .

.gtttks, one a each 4

.

High-grade dimension stock should be seasoned in a shed such as that illustrated in plate 2, B . In localitie s where driving rains are common it is advisable to provid e louvered sides for the shed extending from 3 feet above th e ground to within 3 feet of the eaves . As with unsheltered lumber, the foundationsEhould be firm, durable, and high enough to afford ample circulation of air under the piles .

As beech end cheers readily end coating of dimensio n stock is advisable and should be applied to the green materia l as soon as possible after cutting . As a means of reducin g losses due to warp, which includes bow, crook, cup, twist, an d diamond, beech stock can be air dried as flitch or in multipl e lengths and widths . Piling practices for lumber are applicable .

The sapwood Of beech i.e

susceptible to fungous attac k and insect infestation particularly during the warm months o f the year . Blue stain fungus can be largely Controlled b y chemical treatment and correct piling practice . The powde r post beetle, which infects hickory, ash, and oak, will als o attack beech and can be killed by heat treatment . General yard and shed sanitation measures are imperative in controlling eithe r fungi or insects .

Kiln Dryin g

Lumber

Beech lumber can be satisfactorily kiln dried gree n from the saw . A successful kiln drying operation, however , demands that the kiln be under automatic temperature and relativ e humidity control and be provided with an adequate rate of circulation . If modern forced-circulation dry kilns are not availabl e the lumber should be air seasoned to a moisture content of 18 t o

20 percent . Air-dried stock at this moisture condition can b e kiln dried with considerably reduced liability of surface checking and can be successfully kiln dried in dry kilns of th e natural-circulation type . Natural circulation kilns of the progressive type, however, are not readily adapted for conditionin g treatments for the relief of casehardening .

Piling of the lumber for kiln drying whether th e lumber is green or air dried must be done with care and for f inch lumber at least 9 tiers of stickers should be used fo r

16-foot stock, The lumber should be separated as to thicknes s and piling is facilitated if separated as to length .

Most kil n installations are designed for flat piling and if forcedcirculation kilns of the cross-flow type are available, th e

0

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.

aO A

OiOltAXe d edge to edges If natural circulation dr y iIr cir j!eing used the boards must be spaced to allow for th e of air vertically in the pile . Stickers should be mad e r, stght-grained stock, entirely free from both stai n

.decay, and should be dressed to a uniform thickness . Seveneighths inch stickers are common for most classes of stock . The supports neceary for the tiers of stickers should be firm an d even, and when possible one should be directly under each tier .

Perfect alignment of stickexstabove the supports that actuall y carry the weight of lumber is e:ssentiaa,, s n .e t'4e eccentri c loading caused by poor sticker_ &li;gnmeat t+ c - IV deform th e lumber. Having in each pile boarder .of onlii_ •emt l aiw ideal condition, but where this is impossi 'r .' . t be box piled .

e dek•' oul d i

the-cking

a+s apt g to resat -

of Trite

k ber

:k

The general schechAle for kiln drying b given in table 1 . This sch..od

le ea& 1.e used for lumber is`

1i green or air-dried beech up to and ineiud :mg 6/4 inches its 4ir .

If it is necessary to kiln dry: 84 btie-th the schedule given i n table 2 should be used . In kiln drying gron lum"zr it i s essential that the kiln be controlled and schedules indicated or surface aitai l'ed t.t the dried lumber having a moisture content of l8 to 2Q pe4'cent i s not apt to surface check in subsequent Itlitt tt kiln conditions are much more seve .l., POrti mOA7 relative humidities, than those indtrcated In the. s•c~ the schedules are based on the moistur, . + li-ti,on some sort of moisture sampling syst when changes in conditions are nee% for air-dried stock indicated in the without preliminary steaming .

*kould be_~43;, c ur ess th 1

•~_

'tr6

~:~, rmine

The b4itial c5<< .dition s

,uld be tablished

"•'ITar

` r r

,

To prevent excessive warp of t load it is desirable to weight down th e road iron or any otter suitable heavy ma laced directly- l over e t i

1 abr .

lumber can be piled edge to edge . If natural circulation dr y kilns are being used the boards must be spaced to allow for th e on of air vertically in the pile . Stickers should be made

4'ear, straight-grained stock, entirely free from bo h stai n ay, and should be dressed to a uniform thickness . Seveni nch stickers are common for most classes of stock4 The necessary for the tiers of stickers should be firm an d

Mat when possible one should be directly under each tier .

L lignment of stickers above the supports that actuall y carry the weight of lumber is essential, since the eccentri c loading caused by poor sticker alignment tends to deform th e lumber. Having in each pile boards of only one length is th e ideal condition, but where this is impossible the stock shoul d

.be box piled .

The general schedule for kiln drying beech lumber i s

-given in table 1 . This schedule can be used for either green o r air-dried beech up to and including 6/4 inches in thickness .

it i necessary to kiln dry 8/4 beech the schedule given i n

J hould be used . In kiln drying green lumber it i s rift-the kiln be controlled and maintained at th e indite

-.

_ r rfa' ns e ct

~t'rianr

•.r

checking is apt to result . Aircontent of 18 to 20 percent i s

'bsequent kiln drying unless th e

4 severe, particularly as to lowe r e indicated in the schedule . As moisture condition of the lumbe r system should be used to determin e necessary . The initial condition s in the schedule should be establishe d siv warp of the top layers in the down the load with painted rail e heavy material . These weight s the tiers of stickers to preven t

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Tale 1 .

-,1 soI.Iedult

_up to 6/g. .

ii la

''ck _

Moistlae copdp-ts4i').t at which : Dry : Wet : Relative s should be

------------------------ ----- ------ -------------- -

Percent : °F .

:

°L.

Percent

45 or

1

3oP

40

30

25

26

15

10 to final

: 130

135

:

:

125

126

:

:

: 140 : 128 :

: 145 128 :

: 150 : 127 :

; 155 : 124 :

160 : 115 :

85

75

70

60

50

40

25

MoiOWNr4a4t4nt at which : Dry : Wet : Relative changes should be made :bulb : bulb : humidity

------ -

-----------------------------------

Percent : °F . : °F .

: Percent

6S-or more

40

20

15

10 to final

: 125

: 130

:

:

120 :

121 :

: 135 : 123 :

4 140 : 123 :

145 : 122 :

: 150 : 120 :

: 155 : 111 :

85

75

7 0

60

5 0

40

25

Dimension Stock s x'cula e ch tion of circu iple-length an d apilly .

1.

,- -.i-E actorp fo r eech end checks ' .- 4 es may be proly from the saw shoul essential piled in .

:-'

PLATE 1

PILING OF YARD LUMBE R

A, Poor practice . Note overhanging ends, in adequate stickering, insufficient and improper foundations, weeds, and narrow and obstructed alley all of which cause degrade, with its resulting loss .

B, Good practice with the exception of the roof . Each tier of stickers in the pil e is firmly supported by a beam, which i n turn rests solidly on three stringers .

Z M 33904 F

PLATE 2

PILING OF DIMENSION STOOK

A, Lap-piled flat dimension stock .

B, A general view of an open she d sheltering dimension stoc k during seasoning .

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