PRESERVING TIMBER.

North Otago Times, Volume C, Issue 13148, 1 September 1914, Page 3

PRESERVING TIMBER.

Si');?&#. '■;■• ■. ■'■< '■'' ■ ■>, ;:'■: ' :■?-■;' ;lea)lct;'; dealing; lyitli.tJie :|imbbr,' a/subject! higlicr qpcmeiiig; mnlef lyill 'pay; jnorp: atitoiitiOii S^^^d^fflft'Q"•of 'wood by: ; "rot:. |M^l)i|ds:bi('thbwork of living' j:°!rs^ 'temperature;'ate' I in the destructive lowly fdbcay in structural timber. Wood may, 1 be\c.pmplotely pertneated -\yith ahyor it v &y; Kbe.^ completely. ■ saturated / with :%ater,;an% '?sigh;; : Qf; (iecoinpositioii, If,; however) ■bothwater'and. air are present to a ■"sufljejfent veiteiil, tlie conditions of de-. cbmpbsitiWare, at . Uieir, .best, find ;:decay.wiir proceed more or Jess, rapidly, '; depending oriVtljie u teiTi.perature. : H;IJKOpS OP TIIEAMENT.' ~ •^;V&rface. : '.;Applications.—A ;coat, of wood assists in its preservation/:becausc it excludes moisture;' flriipb?sbrive' extent, air;'but painting, only.; be s effective if the .wood has dried before the paint .J Ois'laid:on, ; :'.Should the wood be wet to.j begm 'fmtil /or imperfectly■ • seasoned,' | pairifmg ; ''mav do more harm than good, nioistuve will be-impris-.j from escaping, and Conditions 'favourable to decay, will' be Itfierebv-'created and■ maintained; ... ; : -#esiileV'tiil paint, several: btber sub-. v stances 'to': waterproof wood, .suchjaßreoaVttar, and although the latter isVpbjectiohable from some : ppiutfl of view^kt:makes.an excellent coat,'which, 'being •rhore.oT less clastic, admits of .the cbhYraction and expansion which the wpbdOpdergoes under the influence.of dianges;! of • 'A ''coating •' tha't' ; ,c'racks.'rapidly is quite unsuitable, .because .through ' the openings' thus 'fbrmed:water and the spores of ■. fungi : entrance,- and decay is ; rapidly ■.•set : .']ap'.-v: : -: ■r: Charring.—At one time—and to some esti'nt: still—post 3 used for gates,'fences iand'sheds were charred for one oivtwo: part that would conle'immediatelv'above and below the Surface ;6f;tu'c'''.'gromid. That part of a post is the .pgiut of weakness, because : there beginij and there- it progresses wost; rapidly. The effects ■ of eliarring are ,'due. to the destruction of wood'.to the depth of half an inch pr so',\the. resins,- gums,, tannin,' etc., ;wliicji, this 'wood'.contains being driven in front of -the:heat,vuntil they saturate a layer. whiclAthen acts as. a protecting .mantle ...to the deeper wood, To "'be'effective,must proceed sb far asto'cbiipert;::a'''('onsiderable amount; pf -wood Jptd : ' .charcoal—a mere :. singeing ; or ' scorctingSif: the wood will do more harm thahV good, as it will cause ".the. wood' to crack and form- openings for the ; entrance of fungi, but williriot-have proceeded sb'far as 1o saturate a layer of .wood with. resin, etc. The destruction of the surface wood is'necessarily accompanied by a weakening of. the post; and: it is doubtful wlietheiV on the wholey the'charring of posts:is a profitable process. , •'■•:' IMPREGNATION WITH .CREOSOTE. Of the various methods that are pra'c-. tised for.increasing the durability of- ; timber,-'that-which at present- occupies the foremost place is the application of creosote. Thi.i .substance owes its efficacy to the'fact (hat it is a virulent plant poison, so that wood which contains'a considerable quantity of creosote is more- or less completely protected against the attack of> decay-in-riuciiig drgaiiisiiis such-as fuiigi. Wtfod, wheu in its natural state: holds certain substances (starch, proteins, etc.), which are the special food of fungi,, but when: these ■ are Asaturated - by creosote they '. are : mcapab'le of sustaining fungoid life.' Creosote-also acts as a -preservative to ] some; extent owing to the fact'that" it displaces': air and', water in the'tissues , af the wood, and these, as stated above, i we essential;to the' process of 'decay. I It may: be stated that many- other mb'stances besides creosote have; been rsed' as preservatives, such ''as copper sulphate, zinc -chloride, and corrosive sublimate, but.on account of.their cost,)r because, they are poisonous to anlnals, or on account of tlieir being easily ivas'hed out by rain, or because they cor- , 'ode metal;; 'they have all been supilanted more or Jess completely by creoexcept in countries where this sub--1 ita'iice much-dearer than in Britain'. .The amount of creosote or other fluid ;hatVwqod. will absorb varies greatly vith the.- species and other factors, leartwood takes up much less than sapvood, damp wood takes up. loss than Iry, pine takes Up less tliaii r ast-growny'and conifer's as : ' a rule take ip.les's tkah .broad-leaved' trees. ' The vood that is subjected more than any; ther, tq- the process of creosoting, is Jaltic :Xbllbw Deal, otherwise known as Jaltic KedWood, which is precisely; the i ame'Species as Scotch Pine, This is! he wood chiefly use for railway sleeprs aod: also used for telegraph posts, so] hat eprtno'us 'quantities 1 kye' to" be! rea'ted;aiixiUfil]y,' As a vule : the railway omp'aMes";Specify-that l each cubic foot' hall contain'one gallon .of-creosote, and; or estate/purposes this as is much as j 'since creosote now gen- j or more per gallon,' 'By.i she'absorption; of a gallon, therefore,} . be'eost'pf ihe' wood is raised by 4d or i ■lore'.per..cubic.foot;apart ; frpm con-; ■'■ iderati'6ns , ' , pf labour and j'n'tejrest' on; laiit.; 5 Certain s'oft woods, however, can ; bsorbjnpV to foiir"gallons pf greosote i er cubic foot, and many will take lip; wo. gallons. Apart from "'all question; , E- cbst7;-tJiere is little to be'gained'by j xceeding : o n e gallon, for. in the'course j f:• tinie'' : HheVc«(J'S3,' bgyou'd wh'at ; "the I lioid, will -simply flow :"'ufcinto'tlie;soil and be'lost. ' ' V' ■ plant; ■'■ ; '.', : ' ypnjmaii"es ; tates vjthp cost;bf erecting v a pressure creosoting plant iprphihitiYe; but excellent'Tes"ults ; Can ; jfOWjS|2ed-:by: ; simpler methods. : ':lfahy akp JiißJ* of, an <iroii' tank • erected ' on v -. •i.ckw'bi , jc-;Ttt ;»iin)i- B,_..iK»y..that : \the.-crop.-. ''' .; |e'can'be raised!'to Jianjytjip;lj'f)}!jng : jiipt byuneans of a Ureunderneath'-thD' ■ | ,nkl' v .lnirhersib'n• iri'-sueh'hot: creosote; : if bod.md'st of-the'benelitsrgot.frpm'two, v'tjj'ree' hours'"treafthent'in a'pressure' ;, i^hlber.TT)?e tank.'should W '.'. iainWlrmnxby:mfans pf;a:light ! roof,' ia^eeautlQ])(i';?jiit-bpHalPft'agai . e; ; :crepsote : heing -•lilghly iniiflmiiiii'blp.; '-.■; Cpld;;^Even'a'^tanlc^vliere''tlie';;Cr(ib- ; t'e'.'Cd^Ve v lieat'ed'is,'hb^ ~-,, abbraie'. at raiigemeui than is neces- .';'■■ fyspwj&fo rui: :9 v quite:small estate. , v hfWlrlong;3SSists/in driving/the ■->' e'bsft€ei?lnJp\"JJi&' ; '''w : pQd| : ;r .c01t1..! preosqtipT; tjmp ; ..> '.[ [where oiily ; a ;fe)v; ' indre(l«po;sts;.(stobs);are.-being.uieil, • wood; is'mature ' : a tank in.wliicli ?: - JWfiiNl'' eac '' I" can ' be ••- ifltsdr^WiHPfflte^^S'^bat^theiiipper "; Willi -'UMt^ateu 1 ; 1 :'■'■ uaTJjy'iiaßt'f. JpT. : many.-; yißaF's, s. i|'* ■ ■ requires' tffp.'t-' .','.; iii^fUie^osts■my, : tlie'refore,;be'Set ; ; ab"6uty one-tliifd ":': I .••'■ J. 6 ?^ l '^ )eiß g iriiinersedjiii:;the ■ ■ (i?*l r.VTT? to;treg.t'S - " rdlesj';flrid;rftiJs^tlje tank hitist 'be; ji'ro- ; • arrangement i. suffices? to' • !at: the ilo'werihalf iof; a eiicingt'ppst;; [ ••■■ "• ti' . ; ;; pT|ptiSbst:i:of■ soy : ,f betweefl^TOd^aidi,

ihersedtiiKCi^bsot^^ pii(ee(l v verll cii 1 i'y, 7anif 1 luui,; -. i'Or; al?o/admit >of • about'•'a^^iibii' ■stra'iiniigt:i)oß^s:..b i^ ji!^ii'/Wiiei)/tl^^ t rough tvt lie; Jiq ut i tl" ia! ftl i rly" tap UUy s < ab -; ■soibedj'W^ sitriiiuskbefadiieW? Tlie'pbs'tfesliould stand in the,liquid, for-■tlirieei;.or;'--"fo < iir*- : weeks,, ahd: if-'a-fresh lot; is liiaoited : without 'of!-tinic;il' : is.wiilciitfthat twb 4o /three vtliousahtlf'Cail ; L'e:; passeil 111 rbughriijja'-. year.' Four ordinaryp'ostsi; will; alisprb about' a gallon- of Creosote,' Boith|it;ithe .'ibst'pfi liiatfef lai" .f Oi 1 \ eiac'ii j is'about *bn6 : pchiiyj' aiiil •tlic-lhbbuf interest on the'cost of the' trbiigii-are prAeticnlly negligible. It is desirablq tli.it^h'c'i'frbees's'shoilld'''toe'' conducted! awayfrom• buildings,.'but a. light 'ibbf shbuld be provided'to; keepoff the.r'aini' Needie.ss tq-say, the (trier thevwooHio start witlrtiie bettor-will be'tlie'.r'e'suits, As a 40-gallon ( barrel of' creosote is rather inconvenient.to 'handle,''it is an advantage to construct a small platform atvone-.crid of '■'the; tank, oh; r to which'; •the barrels', may from: the'l Cart; v One; or; two ahfeets /of.cbfr'ugated iron; should be; placed:'in-'such 'a.posi"tiqn that when the ppMs are removed 1 from the ! tank v arid set 'up tb : drip] the creosote that runs' off shall'nbw: back into the tank.:,' : .; /... .-,'■.

."'■lt ■' is' surprising- how high- creosote Will rise in ceftaiti kmrJ3 of wood,'and it is not; unusual to see the showing on the: upper surf ace of a fivefoot post when, not more than, two feet are immersetf'in. the'■cre'osbte'.'f"-':'

•' Many miscellaneous ■'" ai'ticles ,; which come in-.cohfa'ct with'.the. soil,;such'as sheep troughs, and-poultry coops/. last much longer;];' crebso.ted, '■ : '