Western woods need special (pressure) treatment

li..lr'llru |. lltitlr '. ti.'. ,i \r,.1 ",,1 L l,. l,., .l ,Ll l1)\l\ l() lllL ,tll,Lr ktttr' Ill',llll\lll l)'r,L t,rl llt,., l,t,LIl\ lllit:l lrL tllil lll(rl\l( l l(,l)l(r\ l\ii .lll,l\ j! (Jll.llr'lrl(r l.'\ lt\i :ltr'l ,rtr'lrll\l llti ttlrtll \\ ltrlt' I t. \.ilr\\()ri\l ll tttrr:l \l)r'rle\ l\ l! illl\! l\ r',1\\ t() 1l!'11911 ,rlr'. tlrc lrtrrtltr{)r,ql q1l lrtrr,lieirllt lrll trpl's ol troorl r: ilillitLrlt. ()tlter tlrrn ntotslLllr' r'()llr'rtl lltc lttttlrttttron ol lt('rrt1* oril ,ulr j srtpworltl is l\r.rllll! llrt'rlcr'itlittg litctor lts to ll()\\ tr nrer|lrer elll lle ltcirlctl flll. \\ \lll{ltt}l(\l t)r(\\ur\

I ttcitttllen1 of r,iooll. ll('ll' it

Bcstcrtl stiut(ll)()itlt. ts atl ()periltloll tlrat corttrilts r irrirrblcs irrrtl cltallcngc; tllrt lrta).'ttot llc rccogtrizctl b!' pcoplc f'rorrt rtLl r soLl lltctrl nrarkcL irrcls. Iltstcad 0l' tlcrtlirlg rritlr ()lle l'.r.it .Ietics Frltllr (sotrthcrn ycllou ltinc-) tltal i:1'111hahll' tlte casicst t() tl'cilt. \!c\lcl tl opcfal()fs rrre ftrccd rvith sqr cl'al difl'ercnt typcs ol' wood.

'l'hc rrtost col.l.)ntott otrcs include the pincs. I)ouglas iir. ltetlt-llr. weslcrn lrrrch. rcclrvood and ce'tlltr.

'l he group cllssif recl as hctn-flr is lr.rclc ul' ,'l'sit \cpilliltc spceics: \\ cstcnr hcrllock. [)acilic silver llr. noblc flr. grarrcl fir, Calilirrnia recl flr and wlrite flr. l]aclr onc ol thcsc spccies has its o\\'11 treitting clrrtrltctcristics. and that has probablt' been thc cause of' ntanl' spiritctl discussions betu'een a irlant nrnnager and his lreating engitteer over lhc -v-cal.s, It is largely in re sponse to that prohlsnr lhat several lypcs of' wilterborne preservalives arc usecl in our weslern plants.

In the pre sstlre lrcaling ot' uotld products. it is neccssliry to lcltieve both a proper penetfation of tlte solution inttt the menrbcr as rvcll as a rclerrtion strong cn()Llgh to be

Story at a Glance

Why western woods require special treatment to meet AWPA and AWPB treating standards ., which chemicals are the most successful with western woods.

I\i lrLtlt l:trl Io ltr'.ll tlttttt \\ LlL tlrrrt|lr' litt\tl\,llt\r'\ llt,lt itlt' !Lrl! f ll\ ll, tlttl tl:r'Ll itltlLr,le ,IltTllolll,t\,ll,,,1,111 1,ll\r'llille i\ll of the rvaterborne prcservitl.ivcs nrcntioned here leave the woocj surfacc cornparatively clean, paintable. and liee f'ront clclor aller dry''ing following lreatnrenl.

I \( \) ,lllltll(rlll.rr.tl ttrlt|1'1 /llle ,tt \t lt.LLr' i 'r( u' \ ) l;1, rllllrlld CtlltliL L1\r'lt.tl!. (( ( ,\ tf,lteS ir h.c), .rrtl t lrr.nrrrlltl zittc e lrloritlc l( /( ) \\ ltrlt'rlllrrtr ot'-i'{lu lur l]lolrrrblv llrrtriiitr * itlt ( (.,\ antl its rcry lrnc pcrfinntiutco rcctlrd. lhcse ollrer prcsorvativcs ntotttioncd rllrry bc lcss wcll kuorvtr.

\( / ,\ lrlrs w'idcsltrcttd ttse irt tlrc \\ e \te rn slatos itnd providcs crccllerrt l)r'otcctiolt rrgirittsl dccal' irntl lcrrrtites. Iier,'irttse it can bc ircrrtctl nt()r'c lltr tt s()lnc rithcr Ireser'\'irllVes. 1l r'itll llrl\C ilt)ove il\ e rirg,c l)cr'rctralitlir tltrnlitics lrnd gives good rusults t() spccics tllirt rlc clil'licult l() trcat.

(l/C has proven 1o bc u goocl prcscrvative lilr use in dricr applications. llccausc it is subject to leachirrg under nct corrclitiotts, it is nttt rcconrrlende'cl lilr grouttcl contact ol in uet installations lt will Ineet \WI'A ancl ;\WPIJ stanclards lbr lbove grottncl usc.

Species coulaining large irtnounts of healt\\'ood. such as l)ouglas fir irrrcl irem-flr. lrc usuallf incised with srlall pcrlbrrrtions in orcler to forn.t l)irssagcs tirr tlte Itr:scrr irLivc lo penotrate deeper into thc rvood.

'lo rr large extent, it is bccausc of thc rl if{'ercnces of the westcrn rvoods in terms o1'their heartwoocl ancl sapriood content that several t1'pes of' chenrical formulations

Although this has been oniy a curs()ry look at waterborne tLcating in lhe wcst, I hope it has brought to !,our attentiolr solne of'tlre different species and solr"rtions that are used [rere.,\long with creating more variables to contend with, this variet-y also presents opporlunities lbr the consurner to cl.roose results irr regards to cosl, color after treatnrenl, ancl clegree of protection n ceded