RobCosmanb TECHNIQUEBOOK
A11rights resewed.No part of this book may be reproduced or transmitted in any form or by any means,electronicor mechanical,includingphotocopyng,recording,or by any rnJormahon storageand refrlevalsystem.Mthoul wntten permissionftom Rob Cosman. 02008 AvsRlcANCnarrsl,nNPunucenous Box 3260,Grand Bay,New Brunswic( Canada E5K 4V5 1-877-967-5966
rsBN978-0,9809412-0-3 Visit wr.rw.robcosman. com Photographyby Kim Hilchie Book designby JohnHoffrnann
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Hand-Cut Dovetails
TABLE OF CONTENTS 4
DEDICATION
5
PREFACE
6
SECTION1 TOOLS FOR THE TRADE
12
SECTION2 STOCK PREPARATION
15
S E C T I O N3 T H E M A R K I N G G A U G E
21
SECTION4 LAY OUT
28
SECTION5 DOVETAIL SAWING
33
SECTION6 THE FRET sAW
36
S E C T I O N7 S P L I T T I N G K N I F E L I N E S
40
S E C T I O NB C H I S E L I N G
45
SECTION9 TRANSCRIBINGTHE TAILS
50
SECTION1OSAWTNG PINS
55
S E C T I O N1 1 C H I S E L I N GT H E P I N W A S T E
51
S E C T I O N1 2 P R E - A S S E M B L YC H E C K
53
S E C T I O N1 3 A S S E M B L Y
59
SECTION14 TROUBLESHOOTING TheTailBoard ThePin Board TheJoint
Hand-Cut Dovetaih
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ROB(OSMAN3
I owe my mosthumbiegatitude to the giverof all talent.Often asI cut into wood I am humbledat thebeautythat is oursto enjoy. andlovingwife,Kimberleyhas My success in this field is largelythe resultof an encouraging andthe first to jump in andhelp.Thisbookwas alwaysbeensupportiveof my endeavors madepossibleby the manyhourssheput forth. In additionto helpingme shehasraisedand educatedour ten children.Trulya remarkablewomarywife and mother. I alsoowe a debtof gratitudeto both Kim's and my parentsthat amongmanythingstaught us the valueof hardwork. Into the livesof the fortunateentervery specialpeople.Forme this wasDr. DaleNish. Earlyrn my careerDalerecognizedmy ability and providedme with every opportunityto expandmy experienceand developmy skll. He openeddoorsthat would not talentand givingthose haveotherwisebeenopened.Dalehasspenthis careerdiscovering individualsthe opportunityto displayit to the woodworkingworld.I would alsolike to thank that I havehad the pleasureto meet,teachand the manywoodworkingstudents/friends be{riendaroundthe world.Finallymy childrerya most cherishedblessingin my life. FamilyFirst! RobCosman
4 I
] ROBIOSMAN
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Dovetails Hand-Cut
PREFACE I havebeenworkingwoodsincemy earlychildhood. On my motherssidemy grand{ather and greatgrandfather wereboth carpenters. I knew themboth andhad the opportunityto work with"Gramp".My fatherwasan industrialartsteacherfumedcarpenter sowoodworking was definitelyin my blood.Duringmy boyhoodI wasalwaysbuildingsomething,from boatsto gunhandlesandIromgo-cartsto woodenbowls.Not onlywasI fascinated with woodbut my questfor perfection nearlydrovemy fathercrazy. Duringmy earlyyearsof professional furniturebuildingI workedhardto masterthe art of dovetailing. As a studentandteachlngassistant at BYU,I usedmy access to thewoodshopto practicecuttinga row of dovetails eachmomingbeforeclass,OnceI mastered theprocess my nextquestwasspeed.I hadthe incredibleopportunityto spendsometimewith mastersLike TageFridandAlan Peters. Theirinput to my careerwasboth priceless andinspiring.It is because of thisI now feelit both an honoranda dutyto passon whatI know andhelpkeep the traditionalive.Tothis endI haveproducedthreedovetailvideos,writtenthis bookand continueto traveltheworldteachingthosewantingto learn.Sawcutto sawcutjoineryis my motto,straightfromthe sawandwithouta testfit. \A,hi1e somescom,hundredshavegoneon to do it anddo it extremely we1l. I continueto build fuiniturefor my ever-expanding familyandwith no endin sightI am thrilledat the prospect.To teachandworkwoodfor a livingis bothan honorandprMlege.
Hand-(ut Dovetails
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ROB COSMAN 5
1 TOOLS FOR THE TRADE L SECTTON I havcfonnd countrieshoi,tto hant-lcltt dovctails, of iolksin ser,eral Ater teachinghr-rtrclrecls do theiobrvellthetoolsneedto be sharpand theuseof impropeltoolsquitecommon.To fronithehandleto thatcoversevcrything properlysuitedfor the task.On a dovetailsar'r,, i,r,hat to lookfor rnrhen on to inform you ihc numberoi teeth.Thisfirstsectionis desigred brand,thebetter an-v spccific not \'\thile promoting too1s. r.naking vor-rr dovetail or choosing belon'lAs vor-r sr-Lggestcd toolsrvil1olien comewith lnostif not a1lof the character.rstics qr-ralitv yorlmavwantto fine tr.ure1,.our I haveoitendonethisandI notethose too1s, gainexperience in thetcxt. changes
in A pistolgripregisters thehandthesanrervav eachtimeit is pickedLLp. Thisallorvstheuserto dcvelopa feclforvertical a blg helprvhen sarving, sawingpins. . A thinblade(.018-.020) removeslcssrvoodai-rd is easrer to push. . Thcsetof theteeth (s1i bending ght or,rtrvarcl be of eaclitooth)shoLrld in therangeof.001kt DO\TTAILSAW .003persideto helpthe bladetrackpropcrlv (cutstraight). . Dovetailing is primarilv ripplngr,tooclvs.cross hcncethetecth cLrtting, $ppi8f shouldbefiledrip (cutl i n gf . r c rer fl , r u l lpl s l p q n d i c u. r -t n l c r r $ ho i b l ; d r ) . . PPIor points(tccth)per inchshouklbein tbe toomanv 14-16range, teeth(20+)sklvsthe lvhiletooferv sarving teeth(-12)rnakcsthe to start. san r'lifficr-rlt
DO\TTNLSAWPPI
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(OSMAN ROB
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HandtutDoveraits rl
. Barrel hme qarseq rrp
usuallyreadyto useout of thebox. . Thc vrhppl nn ' ' . ' ' - 'crrftino .-'.t]
thisgaugeis easierto sharyenthanthepin on traditionalgauges. . Themicrometer adjustmcni
el]nurq fnr rrpnr
precisesettings. . Rarrel onrropq crn hp
rolledinsteadof pushed/ pulledfor precisemarking or on difficultsurfaces -..^L DUlrr
^^ d)
^ -^--^-,, d rrdrruvv
^l^^ cu6c,
. Sawingthe buik of the wastebetureen tails
"M*iu;; .: .':::. I€r"t
^-,1 -;-^ ;- ^^-;^dl tu Pl1 tJ rJ gdJltrl
+L^u ld r l
chiseling, especially with naffowor Londonstyie tails& pins. . Frpl q:urq r:n -*"
rqp \/pn/ -'"' ''-J
finebladesthatwil1fit a naffowdovetailsawkerf. . Frpt qaurq urith ' ' ' . ' . ' 'riqid tr'* lremeq end urin o nr r I
a11ow tensionadjustments for a verytauntbladethat resistsbowingduringuse.
FRETSAW
. Toexceed the limitation of a 3" throat,theblade canbe twistedabout30 d * 'pl rm' 'p' "p*s. . 'a. t' ' ,t h - ,p' . rc'l.a. m t ) nino nnintq Thiq Lppnc lhp
frameabovethejoint on a horizontalcut.
Hand-(ut Dovetails
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ROB COSMAN
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,I
. Dividersarea more accrlrate mcthodoi tr:ansierrineciinrensious. . Six-inchdnidersarea comiortable sizcior jointlavor-rL. . Scrcith'peacljr-rstments arcbetterthanfi-iction h'pefor prc.rrenting accidental mo\renrent.
3
g
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ft ?t
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a a ? ? a a
. A gooclnrarkingkniic
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e
e P
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MARKINGKNIFE
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i:lr:
i..t'
. A six jnch sqnat-c ts larire enor-rgh to be accuratc vet small anclconrrenient to rlse.
COMBINANON SQUARE (O5MAN ROB
I
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DMDERS 1 ' 1 . . ' .1Jo-h e, ' ," t ' i , , r [ . t b lht r hold anclaccuratc to Lrse. . Tlie blaclcneedstctbc thin enoughkr passin the dorretailkerf r.ctr-igid enough to pre1,g1l1 ataatsivc flexirrerlurins nse. . If thc blacleis too sharp thc mark left in cnd erain can bc cliilicultto scc, dullingthe bladcmakes t l r , n ' . r r kr rt t l c t, t r t .rl ' . 1 > : e t to sec. . The blacleshoLLld bc rvide ct'totjshat the tip to allcnv the userto fccl jt registcr againsttlie tail.
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il
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Hand(ut Dovetails
P P P P P P P e P P e P P P P e I
Ff p
Fr Fr Fr Fr p
. Thismarkerallowsthe angledfaceandthe squareendto be marked urifh nnp cpl-tinq
. Dovetailanglesvarywith hardandsoftwood"1:7 for hardrake(8 degrees) woodand1:6rake(10 degrees) for softwood.
FT
f tr
Fo il
f
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fi
Fr Fr
A roundmalletdoesnot requiredirectionaihitting likeihe hammert1pe. Themalletshouldbe light enoughto be comfortable yet hear,yenoughto allow gravityto do most of the work.
FI
f
Ff
Fr FI il
i
t
:)i
,'"i . ":r.,
,1nEl-
il
Fo F Fr
. A steelhammerallows theuserto"feel"orread whatis happeningwith eachstrike. . ForassembLing small boxesandmostdrawer dovetails, a 12-ounce hammeris sufficient.
lrt
F p
Fo l{ Il !|
Hand-CutDovetails
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ROB COSMAN
9
-l
!:.
t
_-l
fr
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. A spatula is invaluablc for east'anclaccurate placcnrent oi e1ue. . Steclblarles arcmorc dr-nable bLrtplastic blacli.s arccasler to ctean.
f .r._t ' ' +.Ts* "
.
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CLUINGSPATT]'I-A
. Chisels nceclto bc conrtiltablekt use,lightanrl lvellbalancecl. . Thebettcrihestceland sharpcr thechisclthe lonsertheeclgcrctenturn. . Thesidcslopcon bevcl cdgedchisels nccdstcr extcndlron thechiscl backkr thetop,alloning ior clear-ance l hcncliop plnebthveentai1s.
P ? ? ? ? ? ? P
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CHISELS
G) . Uslngan insiclerabbetis an cfiectirrctvav to r-eiercncc.the tailboartlto the pln boarclu4renh-atrsfer ring d(r'ctails.Secpage18. . Thc skew,blockplancr,r'ith its fenceanclskciverlblade rurakes thc srtroothcstci-rt on crossgrair-t, . The shor-rlcler planecan alsocb tht lob though sorlctjnresncttr1-lteas cleanor as convrrtient.
P ?
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e e e e P P P
SKE\'V BLOCKPLANE www.r0br05man.(om
H a n d - (D uo t vetails
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-*J, SHOONNG BOARD
. Shooting boardsare desigredto enablethe luserto casjlvplanetlic endof a rnorkpieceat rightaneles to itstacc anci1tsedge. . ;\ goodnraterialfor shooting boarcls is I,icdir-r nr densih'fiber' board(NlDF), it is stablc, inexpci'islve andhasa longtvearing srLriacc. . Thereis no spcciflc size, ho\t'ever thisshootine boarrlis28"br,17' andis madefor bothrlghtand lefthandnsc.
. Thcbaseis 28 bv 17 bv r/r",thetopis28 bv 11 bt"/," andthefrontcleat i s1 7 b r ' 1 / i ' b v 1 , " . . Thetop'/,"piecchasa shallor,r, rabbet('/ru"bv '/r")cr-rt alongtheedgcior theplaneto ridcagainst. . Thctop,bottomandcleat afeghledanclscr-en ed togethel; it is bcstto clamptheunitilatnfiile thc glr-re sets.
ry Hand(ut Dovetails
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. Theshootine board r,r,orks bestif theienccis positioned 6-8"in fionr thecnd. . Thcicnceshouldbe a clr-u-a bleharc'hvoocl and secr-rred lvith ghreand screivs, thisoneis 10r/:" br'1 '/,' br'1'/.'. . Thcicncemustbesqr-rar-e to thcleference siclcoi theshooting board (tvhere theplancrides) andhelclback'/'"h.om touclring theplancin use
(Ost\4AN 1l ROB
SECTION2 STOCK PREPARATION
TIPS Oftenoverlooked" oneof the keysto a successful joint is to haveaccuratelymilled stock. Yourboardsshouldhavethe insidefacehandplanedflat,smoothandparal1e1 to the outside. Theedgesshouldbe planedstraighfsquareandpara1le1 to eachother.Theendwherethe joint will be cutneedsto be squareto the long edgesandthe face.Theendalsoneedsto be smoothto bettershowthe knifelayoutmarks. It is a goodideato practicewith the samewoodsyou usefor building.Themostcommon placefor dovetailsis in drawerconstructionand slncethe drawerfrontsarethickerthan the sides,throughoutthis bookyou will see13/16"stockdemonstrated for the pin board(simulating the drawerfront)and 1i2" stockdemonstrated for the tail board(simulating the drawerside). Using contrastingwoods is anotherhe1pfultip. In finishedwoodworkit is a greatwayto showoff the dovetailedcornerasthe drawergetsopened.Darkpins againstlight tailscan evenmakea so-sojoint look a lot better.\.A/hen you fust startcuttingdovetails a bit of success cango a longwayin encouraging you to persevere.
. Placeyourhandon the widestpart of the side andbe carefulnot to tip the p1ane. . Usethe longsoleof the planeto straightenthe board'sedge. . Usethe shootingboard to keepthe boardsedge and planesquareto eachother. . Do the sameto the onnocite - r r ' " _ - - ' *edoe o-'
I . Planca smallchanriertcr prerrentsplintcringof the backetlge. . Planethc chamferbv hnl, lir,' tlrp h,rrr, i rurrr: "-'''''tl
irom lireleft sicleof the lence.
'-\
PLANINGACF{AMFER
. Position thc boar-cl lvith thechamfered sidc against thelence. . Kccpingtheboardtighttcr tl.refencc,thcplanetight to therebatccl cclgeancl thc boarcliedurtop1ane, cutnntilthcchanrier" almostclisappears. . Rcpeatthesestepsrvith thetailboarcl. SHOONNCENDGRNN ,W"'
. Theinsideiaccoi thcpin andtailboarcls nrustbe plancdbciorcthcjoint is cut. . IrLanc b rcniorre themill nrarksanc'l to leavethe flat,snroothand sr.rriace finishcd.
PLANINGTHEINSIDEFACE A p l e c e o f 1 8 b r ,1 1 b ) , r / : n ' rdilrjthabottotufroltcleatat'ida'/,'topbackclcat makcsa g-eatplirningboard for wofking on short and smallprieces. H a n d ' (D u to v e t a i l s
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ROB CO5MAN 13
S E C T I O N3 T H E M A R K I N G G A U G E
TOOLTIPS . ,,
Whencuttingdovetailsthe marking gaugeis secondonly to the dovetail saw in importance. It needsto leavea clean1ine,squareto the goodsideof the scribeand angledon the waste side.Thegaugecreates partof thefinishedjoint sothebetterthe markthebetterthejoint.
of the shapeof the cutter,it pullson the gaugeasit is draggedthroughthe wood. , Because For easein making fine adjustments,somehave a one-handoperatedmicrometer. ' Theseareequippedwith two lockingscrewsthat hold the gaugefirm1yin place. Thecutterson the banel t)?e gaugesarevery easyto sharperya bit of facehoning on a fine stoneis a1lthatis needed. Alsolook for a gaugethatis well-balanced andcomfortable to use. Thesharperthe markthe betterthe chiselwiil hold in the line asyou getreadyto chop.
. Setthe markinggauge to the thicknessof the pin board.
Hand-Cut Dovetails
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ROB CO5MAN 15
. Scribethepin board thickness on all four surfaces of the tailboard It is easierto pull the gaugethanpushit.
ff# SCRTBINGTAILBOARD $*
t**;:i
. Thehvo edgesaremore easilydoneby holdingthe gaugeagainstthe endof the boardandrollingthe cuttersideto side. . Makethismarkasdeep asthe gaugewill allow
ROLLT}IEEDGE
. Setthe markinggauge about'/r"lessthanthe thickness of the tailboard.
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Hand-(ut Dovetails
. Scribejustthe hvofaces of thepin board.
SCKBEPINBOARD U
I
Thefollowingprocess will helpalignthe tailboardto the pin boardwhentranscribing thetails.
. Makethe planea rebating lnnl hrr rpmmrin o the ci,la nlafp ln pvnnqp ihp p,'lop r-*.'.".,'r""'.'.''*tr.
of theblade.
. Adjustthebladeto project irrql hprunnd fhp cdoe nf .''' '*b' ''
l-"'
"'J
""-
thetool andpara11e1 to the snlp Spt il fnr a liolrt crt
Hand-(ut Dovetails
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. Clampthe tailboard, insidefaceup andpro jectingjr-rstoff the edge of thebench.
. Adjustthe fencesothe pointof thebladeis cuitingon thescribeline.
. Balance fhetoolsoii starts,cutsandendson thesameplane.
. Theshavingneedstobe uniformin width, lengh andthickness. . A coupleof light passes areusuallybetterthan oneheavyone.
. A shoulderor rabbet planecando thejob with the aidof a fence.
. Checkyour resultswith a str"aight edgeanda backlighf it shouldbe lower andparallelto the inside faceof the tailboard. . If it is out of parallel, dependingon the condition,eitherrepair it or startwith a new tailboard.
Hand-Cut Dovetails
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ROBCOSMAN 19
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Hand-Cut Dovetails
SECTION4 LAY OUT
TOOLTIPS Thefewerstepsandtoolsln layoutthebetter.Reducethe steps- reducethe risk of errors.
Combined with a goodsteelrule,dividersarethe mostaccuratemethodfor fransferrinp dimensions. .^-^.".'''''.t]
Usea fine ballpoint pen for layout- it is easierto see,the ljnewidth doesn'tchange --l:+/^ ^l-,,^-, ^L^*l 4rru rL J drvvoyD DItdlPl
A precisejoint startswith a preciselayout.
. Secure the iailboard r*rrn. 'rti]o' .h. 'f' . i n l h c r r i q e r c o e
squareor bubble1eve1 to ensureit is plumb. . Keepthe endof the tal1boardlow in theviseto preventsawingchatter. . Seftin o thp * ' ' urnrL niono """"b
plumbhelpsdevelop the abilityto saw nprncndier rlar
Hand-(ut Dovetails
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. Thesenarrorvpin dovetails arcsimpleto l;rr nrrl hri:
"
h" " i. l- . bt "n r o h
to cutfor beginners.
LONDONDO\ETA]LS
. Markthehalfpinsby r p f p l c n c i n o n" "n- 'p- b l p o n . - f" l h p' f irrirlor rt tho e,loo nF th..
tailboard andmakinga markrviththe other. . F o r n r o q i ;- r_nf rn_l_i c- -r-t i-o n- s
'/r" will work.
. Do bothsidesar.rd sa\reth€ sclnrglu lar.,utfrreotl,ol comefsof theproject. . Usea second pairof drviders for thencxtstep. 1/2PIN LAYOUT
. Divldethedistancc betleenthc '/rpinmarks by the desirednumber of talls,leavea shallor'v nrerlz rl o.rrh irrnrlinn
Seetop of page67.
LONDONLAYOUT www.robcosman.com
Hand(ut Dovetails
. Usethedoveiailmarker to layor"rt thcjoint. . Rcfcrence both angles fromthesamemark.
DO\ETA]LMARKER
i, . Widepinsoffelmorc lvill be roomto rvorkar.rd thp qrrhic.cf .f ih{. rPct r )f " '
! 4 l '
"
thisbook. . T h l e v n r l r'r' r' i-d- c' tr- n" i' n" s l.l'r'p-
dividersettinghaskr includethcrvidthot one tailandonepin.
\\'IDEPINSAMPLE
. Balance make thc'/:pins, themr,videenoughto roqicl qnl;rinq
hrl
nnl
sowideasto be out of nronnriinn io ' ' ihe _ ' ' _ ioint T "T'- '''" l''_'-'
. '/*"is a goodsizeto start fine with thor-Lgh sor'ne tuningwillconewith prachcc. r An i r q r- r" n f h . T ' ! d l ! c ' -r J lih'h ' - n t_ h _ ' T _ _ _
mark. a shallolv . Savethisdir,idersetting for ihe othercomers. LA\{NG OUT1/2PINS Hand-fut Dovetails
!Fp{ij;:':r;:
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.lrywJ-
ROB(OSMAN 23
. Startthesecond pairof divrderson the '/: pin mark. . Wthout leavingany marksadjustthediviclers untilyoucanstepoff the desired numberof tails andlandon theopposite '/' piu.
START ON 1/2PIN
. Openthecljviders a small amountto begincxperimentingwith pin widths.
. Starton thc 1/'pin and walkacross thejoint. . Notc horvfar beyondthe '/:pin thedivider opposite leglands. Thiswili r:lti matelyreprcsent the widthof theinsidepins. . Openingthe dlviderswill increase the pin width andclosingthe dividcrs will shrinkthepin width. . Don'tpresshardcnough to leavemarksuntil the desired settingis found. STARTINC INTHE ]/2 PIN www.robcosman.com
Hand-(ut Doverails
. With the desiredstetting, LL^ l/- ^;,- ^-J )LdrL urr Lrrtr /2 PIr drru
stepacrossthejoint leavingshallowmarks a I e a c h i rr n c l i o n
Spe lnn
of page67.
DMDERLAYOUTl
. At the oppositeedge dont leavea mark h p v n n d l. h' ' 'p "'J
"-'*
Anin
li{r thp
dividerout andsiartfrom +L ILL ;r J. r / - - ; //
Plrr
. - , 1 .V^V,A^Al l , LU .A-L1\ ,
AlrU
leavinga secondmarkat eachjunction.
. T. -Jnon rrol r . - " ' . -cnmnlptinn -"r,-'-.-" J ".^ qhnrld havp vnr rr 1/,nr'n l"-'''Y' *^-l-^-l -^;-^f ^^..^l rLr4r^D drru PdlrJ ur cL]udr ^;- *^-1.^ ^^.^-+L^ l r t d r N J d L L U J J tltg P[t
board.
Hand-[ut Dovetails
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(O5MAN ROB
25
. Set e finp hallnninl non
"-'r"-"'r-" in thelhpinmarkand slidethe dovetailmarker againstit usingthedesired slope,1:7for hardwood 1:6for sofh'vood.
. Startthe penat the scribe line anddrawup. . Thispreventsaccidentally drawingbelowthe scribe line,somethingthat couldleadto sawing belowthe 1ine. . Anglethe peninto the gaugeto getan exact placement.
. Themostcriticaltailboard cutis the perpendicular acrossthe end,the Line andsawcutmustbe square.
SQUAR]NGTHE ENDMARK
Hand-(ut Dovetails
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ROBCO5MAN 27
I
SECTION5 DOVETAIL SAWING ---
TOOLTIPS Practiceso you canassembleyour ioint from the saw.Thepurposeof a dovetailsawis to cut a cleanstraightkerf that canbe giued.Intentionallyleavingmaterialto be paredlateris sawcut to saw counter-productive and non traditional,dovetailsweremeantto be assembled cut.Yoursawneedsto be up to the task,goodtoolsequalgoodwork. The peqpendicularcut on the pins is critical.Forthejoint to work the sidesof eachpin must A pistolgrip sawhandleregistersin your be straightand plumb.Thisis wheregravif canhe1p. hand the sameway eachtime you pick it up with a bit of practiceyou wili be ableto saw verticallywithout watchinga line. Rememberto alwaysplumb the work piecein the vise! Youshouldhold your dovetail saw like you would cradlea baby'shand.Holdingtoo tight is a commonenor madeby beginners.Held lightly a properlysetsawwill cut straight and leavea smoothkerf.
J J G J J J J J J J J J
a J J J
. Hold the sawwithyour indexfingerpointing down the blade. . Yourgrip shouldbe similar to the pressureusedto cradlea baby'shand. . Holding on to the sawtoo tightiy preventsit from sawingstraightand causesa raggedkerf.
28
ROB COSMAN
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Hand-CutDovetaih I
. J Jsp fho hnftnm
' f nrrrfpr **-.''
nf rrnrrr inrler . "finopr ' . { r ' ' * ' .:n,-] * thrrrrh to ninch ihp pnd
of theboardto forman anchorfor the saw. . Pinchingwith the bottom quarterkeepsthe contact pointwith the sawabove the teeth.
& FNGERPINCH TTII-,MB
. Pressthe sawlaterally againstyourfingerand thr rmh
to nrerrpnf il " T'-'.''.' ]1,^* ^l,l-r;-^ -- -.^., 1 1 v l r r ) N 1 1 L U 1 5d D ] V U
beginthe cut.
PRESSTRE LATERAL
. T lqp rrorrr anehnrirro dioiiq ""'J""."'.''."''-.t]"'D.."
to pressthe sawinto nncitinn
hacir.lo
the
lino
. Thiscutshouldbe nextto not thelinebut shor-rld removeit.
Dovetails Hand-Cut
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- t €!:;s..
29 ROBCOsMAN ?th,nCq!FEFWTrylFJ
. Startthe cut by tilting the sawforwardand taking about80%of its weight off thewood. . Continuingto presslaterallyagainstyourfingertips will increaseyour saw startingcontrofusea light touch.
. fu you cut alongthe line, focuson wherethe saw meetsthewoodand makethe necessary coreclons.
. Afterestablishing a shallowkerf pausefor a second. . \A,4ththis part of the task done,takea breath,aim the sawaiongthe angled markandheadfor the bottom. . Don't attemptmid cut conections, its betterto havethe kerf straight evenif the angleis slightlyoff.
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Hand-(ut Dovetails
. Sawrightto the scribe linel . Stopping on theline establishes yourcorners andsaves a lot of time.
STOPONTT{ESCREE
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. Sawall of thesame anglesbeforechanging yourbodypositionand 1'ourbench1amp. . Thissavestlme and you will benefitfrom therepetition.
M. REPETTTTVE CUTS
. Tosawthe othersideof the tail pull yourthumb out of I'ourline of sight andusejustyourindex fingerto anchorthe saw
Hand-(ut Dovetails
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(OsMAN ROB
. Finishthe sawcuts.
J f J
SECTION5 NOTES
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ROB COSMAN
www.r0D(0sman.c0m
Hand-CutDovetails f
SECTION6 THE FRET SAW
TOOLTIPS A goodfret sawwill havea rigid frame and a tensioningsystemthat allowsfor a very oneon the frameto takeup tauntblade.Thebettersawshavetwo tensioningmechanisms, on the endof the bladeclamp.\A4thnanowblades mostof the slackanda fineradjustment moretensionis requiredto preventseverebowingduringuse. Go slow until you get accustomedto how the saw performs.Thenanowbladedoes not providetrackinglike a dovetailsawsoyou haveto steerthe cut asweli aspushand pu1l me saw Tapingthe handlewith adhesivesport tapewill improveyour grip andmakethe saw easierto control.Thenalrower(3") th,roatsawsareeasierto balanceon a horizontalcut.
. Installthe fretbladeto cut on the pull strokeand put it undersubstantial tension. . Usea pairof pJiersor side cuttersto twist the blade at the about30degrees e]emninq nninfq
. Thiskeepsthe saws frameabovethe joint on horizontalcuts.
Hand-(ut Dovetails
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. Havingtwistedthe blade you wili needto tilt the sawsiightlybeforeyou drop it dov,nthe kerf. . Comeoffthe bottom about'Ar"beforeyou starl keepsyou a sawing.This safedistancefrom the scribeline.
. Sawascloseto the scribe asyou can.Althoughfast cuttingthis sawcanbe fficult to control,slow dov,nuntil practice enables you to saw accurately.
. Slowdownasyou the endof the approach cut to preventscaffng +L^ ^li^^^-+ rrrs 4urdlsrrr
+^il r@.
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Hand-Cut Dovetails
I
SECTION7 SPLITTING KNIFE LINES tF
a
TOOLTIPS A ballpointpen worksbestfor drawingthe tails.Howeverwith the precisework of sawing the pins to fit, a knife line is better suited.Theknifeline givesa verydefinitedividing poinf splittinga pen or pencilline canbe verysubjective. V\henyou aretransferringthe tailsto the pin board,concenhateon keeping the knife tight to the part being copied.Pushingtoo hardinto the part beingmarkedwill causethe knife to A slightlyduiledknife is easierto useand for the path of leastresistance. wanderasit searches Ieavesa wider and easierto see'\,/". When sawingagainsta knife mark on the pins,aim to take half of the knife "V" out with the saw kerf while leavingthe otherhalf of the"V"with the pin.
J J J J J J J J J
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. Think of the scribeline as a"V"shapedgroove. . Propersawingleavesone half of the'T"with the tail or pin while the otherhalJ is sawnaway.
e f e t e q -j
35
ROB COSMAN
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Hand-(utDovetails e
. Setthe iailboardleveland low in theviseto prevent sawingchatter. . Usea bubblelevelif you cant"eyeball"it.
. Useyourdigitsto anchor the sawasit startsto cut on thewastesideof the scribe. . If yourgripis sufficiently l;^Lr ^1161tLi 4)
+L^ trrC
^^,,, -+^v!DdVV J(AILJ
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cutit will slideoverto the scribedshoulder. . Thistechniquegivesthe crrlr
rn
evrat
qlrrltnq
point. reference . Thisis the reasonfor errttino dppn rmth thp
markinggauge. Seepage16.
. Splitthe scribelineby Lppnino helf fhp"V"in
thekerf. . Striveto geta perfect$ vertlcalcut. . Slowdormatthebottom to avoidscarringthe side of thetail.
HALFWAYDOW\] Hand-Cut Dovetails
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ROB COSI\4AN
37
. Sawingan angledcomer with a sawthat cutsa squarebottomleavesa bit of wasteto be removed with a chisel.
. Check)our cutsforexcess waste.Anythingabove the scribeline needsto be pared.
. If thereis materialto be removed" startwith the chiselon the marking gaugeline andundercut the surfacein the middle of theboard. . Thiq ic pnd mein cn ii
doesnot reducevaluable gluesurface. . A nanowchisela11ows greatercontrolby reducing the pressure required to cut.
. With the middleremoved you now havesmaller areasro pare. . Keepthe chiselreferenced nn fhe qlrop b**b" ""'^'-
Hand-(ut Dovetails
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S E C T I O NB C H I S E L I N G
--r ;
TOOLTIPS
I
Thechiselis probablythe simplestof commonwoodworkingtools,howeverfor it to perform it must be properly preparedand sharpened.Thebackdf the chiselmustbe madeand maintaineddeadflat.Todo thisthe sharpeningstoneshaveto be keptflat.Thismeansflattening the stonesbeforeeachuseand everyminuteor so duringheavyuse.Thecloserthe chisel " back.is to beingdeadflat the sharperyou canmakeit ani the b"etterit will perform.youcan checkflatnessby inspectingan imagereflectionon the chiselback.No distortlon- it,sflat. Distoriion- it's not flat. If thereis distortionyou needto reflattenthe chiselstartingon your coarsest stone. Yourdrisels should to be comfortableto use.Top-healychiselscanbe awkwardandtiresome sinceyou oftenhold thechiselnearthe tip to benergLudeit. Modifythemif necessary, I have cut handlesin halJto lightenthem up especia,lly on the smallersizes. Thebevel anglecan dramaticallychangea chiselsperformance.whiie 25 degrees is cornmonfor benchchiselsyou mayfind a steeperangleis neededfor mortisechise"ls (30)and a moreacuteangleoftenworksbestfor softwoods.I havea few chiselsgroundat 17degees for choppinglight woodsthat easilycrush.
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. Usea sacrificialboardto protectyourbenchtop andyourchisels. . Setthe tailboardinside faceup, startchiselingon theinsideandfinishfrom the faceside.
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40
ROB COSMAN
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Hand-Cut Dovetaik
rt j
. Positiun thc tailLroartl andchisel sovoucarl secplrlm0. . Keepthechisclplunrb or-pcrpenclcr.rlar as vouchopr.
CHISELPERPENDICULAR
ffi'r'..;:; . Chop the scribelurc kr thc midpointbetl cclr e a c ht a i l . . Note; somcnooclsnrar crushbeforcthel cr-rt. ]f so,rtr.r mav neecla narrorvchiscln,ith an aclrtecLLttlng anglc (17-18dcgces)
CHOPFL{LF\\AY
. Flipthetailboartl ovcr.and inspect thescribc hnc. . Toon'r-rch n'asteincreasts plessLLre un thcchisel bevelthr.eateniue kr push it bcronclthescribelinc.
t li ri
EXCESS \\ASTE H a n (du tD o v e t a i l s
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(O5MAN ROB
41
. If the sar'vcutwastal
M |r i# INSPECTION CORNER
.6
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Cornerslike tliis dramati ca1lv increasc thetimert takesto cuta dovctail.
INSPECTION CORNER
. \\brking frontto back, chiselto skell a narror'v cleanand critthecorncrs removethc ilebris. . Usethe straightedgeof thechiselto checkfor h,,m,rc
hah,-oon
tho trilc
be flat or the surfaccmr-Lst slightlvr-rndcrcut. 3l*,*,.,CLEANINGCORNER Hand-Cut Dor/etails
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ROB COSMAN 43
. Starton the insideface of thejoint with the tailboardsecurein thevise. . \'Viththe guidinghand anchoredagainstthe tailboard"finnly graspthe chiselcloseto the cuttingedge. . Setthe chiseledgejust insidethejoint to start the cut. . Pareto the centel,flip the boardandrepeatfiom the otherside.Easeoff asyou approach the center.
N0TE:Hffm:';:ffi:lT.i''1:ilffi ::.''*zeappLiedrorce SECTIONB NOTES
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Hand-Cut Dovetails
S E C T I O N9 T R A N S C R I B I N G T H E T A I L S
TOOLTIPS Thisis a critlcalprocess, perfectly executedtails are of no use if the transferto the pin boardis not accurate.Cuttinea shallowrabbeton the undersideendof the tailboardcan neatlyalignthefr,vo boards. Ir needsto be1/32"deep, smoothandparallel to thefaceof theiailboard. Findinga goodmarkingknifeis difficult.It needsto be thin to fit betlveenLondondovetails, flexible to bendslightlywhenpressedand wide at the tip to registeragainstthe tail.You -l .r.l d y h . lt nu m r LNas ^u "r m r r"d' v q l l rd r n6liftr "uu")
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ln crrif
Try to resistpressingthe knife hard into the end grain of the pin board.Doingsowill makethe knifedifficultto controlasit triesto followthe pathof leastreslstance. Forthis reasonit is betterdull thansharp,when dull the markis easierto seeandthe bladeeasier to steer.
. Secure the pin boardin thevise,faceout andthe top flushwith theplane.
PINBOARD INVISE Hand-Cut Dovetails
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ROB CO5MAN 45
. Pushthe planebackirom the pin boardto createa bridge.
. Usethe rabbetto register the tailboardinto poiition with thepin board.
. Pulledinto placethe hr,zo boardsarelinedup and justneedto be flushed on theedge.
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Hand-(ut Dovetails
. With drawersandboxes thereis a"bottomhousing" grooveon eachpiece thatneedsto bealigned. . Usethe dovetailmarker or anyflat surfaceto flush theedgeof eachboard.
*
I
Useyouroppositehand to preventthe tail board frommovingasyou scribe thetailsin thepln board.
. Approachthe sideof the tailwith the marking knifeat 10-20degrees andbendit to 1ayflat. . Thispressure keepsthe -k" 'n " 'i f p
tLi]ob -h t t n t h p t e i l e c i t "
lhnr tho en,.l 'iq " - .draoop,l *trtr'*
grainof thepin board. . Don'tpushdornnsohard thatit becomes difficult to keeptheknifetightto the tail.
Hand-(ut Dovetails
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{$trGF;.ffiF,
. U:e a bendrlampto checkfor strayknife marksbeforeremoving the taiiboar"d . Makeanvcorrections now andnotethemwith a markassoonasthe boardis removed.
. Bv anglingthe bench lampto shineacrossthe pin boarcfshadowswill makethe knifernarks morevisible. . liy,to avoidhighlighting wur chalkor penciJ, the baremarksarebest.
. C-hamjer theinsideedge oi eachtail. . Startthechisel'/,u,' from theend. . Forgreatercontroland safely.chokeup on the cntsel.
ROB CO5MAN
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Hand-Cut Dovetails
I
. Thechamferneedsto run dov,nthe"side"ofthe tail tn eeco eccemhkr enrj facilifetp oLrino -"--'-'..'' lr'*,''b'
CFIAMFERTT{E EDGE
. Clipthe shavings at the scribeline.
Hand-Cut Dovetails
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S E C T I O N1 OS A W I N G P I N S
TIPS Practiceso you cansawwith,confidence.Alwaysattemptto spiitthe line, don,tbe tempted to sawawayfrom the line and haveto pareto fit. Precisesawing.is a lot easierif you arerelaxed.Afterlayingout thejoint takea fewdeep breaths,look off in the distanceto giveyour eyesa quickrert Ina th.n i.sume vour work. Thereis no substitutefor good light. A werl-positioned benchlampwill go a longwayto helpingyou makeaccurate sawcuts.
. Makesurethe pin board is low in the viseand standingplumb.
. Usea dovetailmarker on its side(or a square) ln rJreur nomon,-lin'l"t
linesfromthe scribeline to theknifemarksin the endgain.
PLTIMB LINES
j| I
---{
. Minimizemistakes bv clearlymarklngthewastel
MARKINGWASTE
. Pinchwiih yourforefinger andthumbto providean rnnhor Fnr qtrrtino lhp
sawcut.
THLII4B ANDFINGER POSITION Hand-(ut Dovetails
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ROB COSMAN 5l ,.:F$i
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. Pressthe sawagainst 1,ourfingersandposition it to spiitihe line. . lhke 80%of its weight oit thewoodas1'or-r tilt the sawforwardto start thecut at the backof the pin board.
l
SAWTILTED
. Todo thisproperlythe "V"shaped knifelinehas io besplit. . Onehalfof the"V"stays with the pin whilethe otheris wastedin the sawkerf.
. Oncethekerfis estabiishedalongthetop, finishthecr,rtby salr,rng to thescribeline. . Ar optionis to establish the top kerfthenpause brieflybeforeaimingthe sal to finishthecut.
SAWTNGACROSSTHE BOARD 52
ROB COsI\,1AN
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Hand-(ut Dovetails
. Followthe lineto the bottom.
. Completethe cutby sawingto the scribeline.
. Verticalsawcutsareihe mostcritical.Practice and gravitywill makethis secondnafure.
Hand-Cut Dovetails
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. Th crr^r nn lhp onnncifp
sideof the pin your +L,.-L L^- +^ ^,,11 1..^-1. L rL U r rL U LL d J t U P U I U d L N ln oYn^co lhe lino \Tnur
the indexfingeranchors the saw.
FINGER &THUMBPOSITION FOROPPOSMSIDE *
. Usethe fretsawto cut ascloseto theline as possible.
. R i o h t s i d p n f l 'p"f t n i n' "' r"
showssomeof the"V" rpmeinino
lpft qido nf
r i-qoh__ i _n i_n_ _s h o w q t h e " V " _ r qnlit :n,l thp rioht cido nf thp rioht nin qhnurq all ljb"
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t'-h ''p " \ / " r p m : i n i n*"b'o ,',.'*,' . .Llard ' " ' - r . .ninq . " / " - ' ininino . ' . t r " ' ' . . 'qnFtpr
tailswill allowfor some cnmnrpqqinn
nf thc 6horq
. Hardpinsloininghard i:ilq rlloruq fnr . " . ' ' . rrpnr - l ' - . . ' ' littlo cnmnrpqqinn
rrnrr nood
+^ ^,-1i...+ ^-^^-.1;-^1.. LV auJuJL dllvrurrLF)ry.
(O5MAN ROB
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Hand-(ut Dovetails
S E C T I O N1 O N O T E S
S E C T I O N1 1 C H I S E L I N GT H E P I N W A S T E TOOLTIPS Thechiselwork doneon thepin boardis usuallymorediffioilt thanthat doneon the taijboard.You will find choppingend grain is easierwith a narrow chiselthanwith a wide. Thereducedeffortneededto cutwith the narrowtool meansthe userhasbettercontrol.you mayalsofind the narrowchiselcutscleanerwith lessfracturhgof thewoodascompared to thewiderchisel.In mostcasesi wouldusea 1/2"ratherthani3l4',. Effective chiselwork requiresa sharpchiselthat hasa deadflat back.Thechiselbackis the.jig.that_guides the tool.Youneedto keepthe chiselverticalasyou startto work in the scribellne-Ifyou startfiom a verticalpositionthe toolwill beginto undercutasyou nearthe centerof the board.Thisensurestherewill not be a bumpin tlie centerthat hasto be removed with anotherstep. Yorrcan.speed up the dovetailprocessby becomingmoreefficientwith eachprocedure. i'Ahen.chopping the pin waste,practiceangling the chisel to follow the side of the pin. Thiseliminatesor at leastreducesthe amountof paringto be donein the cornerpnor to assemblv
. Placethe pinboardon a sacrificial boardto protect yourbenchtop.
. Dcvclopa comiortablc nrcthodior andaccnlatc placingthecliiseledge, . It hclpsto anchorrroLupriclinghandon the nork piecebefore setting thcchiscl.
. Keepthechiselvertical rvhilechopping along thcscribc. . Practice kr reducethe numberof required malletstrikes, . Firststrrkeseatsthechisel, secondandthird tal
. Topr-s,cnt thcchiscl flomniovingpastthc scribeliner-rse a prelimi nan'chopto Lctt'tol'c excess hraste. . Lesswasteequals less later.al pressurc on thc beveloi thechiscl.
EXCESS T,VASTE www.robcosman.com
ROB iOSMAN
57
----T
. Placethe chiseltight to thesideof thepin.
. Afterseatingthe chisel with a light strikeangleit to chopdor.nn the sideof thepin.
CHISELANGLED ,
. If you canlearnto chisel alongthe sideof the pin youwill saveconsiderable timein the fina1cleanup.
,t:,;ffi, n,fl. , CLEANCORNERS www.r0DC05man.c0m
Hand-(ut Dovetails
. Secure thepin board (faceout) in the vise to freeup bothhands for paring.
. T/q eecipr
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glain with a narow chisel. It requireslesseffortto pushthru the wood and thus givesyou greater control. . Onehandpusheswhile the otheranchorsand firm1ygripsthe chisel to providecontrolling backpressure.
. Seatthe chiselhandleinto yourhandtoapplythe controlledpowerneeded fn . " r nerp * . " " . .pnd * t r . *qein ..
Hand-Cut Dovetaih
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ROBCO5MAN 59
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Hand-Cut Dovetails
S E C T I O N1 2 P R E - A S S E M B L YC H E C K
TIPS I dont dry fit my joints and I discourage my studentsfrom doingthe same.Anything learned from a dry fit canjust as easilybe discoveredduring a carefulpreassemblycheck.Dry fittingcausesa coupleof problems;it preventsyou from developingthe confidence in your layoutandexecution. Thecrutchof a dry fit lessens the needto prefectyourtechnique. The secondproblemis the risk of compressing fibersand damagngcrispedges.Thejoint wiil fit bestthe first time.
2
Be patient and take the time to make conectionsbeforeyou apply the glue.Theexcitement of seeingthejoint togetheroftengetsthe bestof us.If it isn't conectbeforeit's assembled it won't be conectafter.
'*h
Sometimesbeingtoo patientcanbe equallybad.Toomuchfettlingis oftenmoredetrimental
%' than not enough.Preciselayout is the key. Beingableto trust andwork to your markswill
."**$ensue a goodfit.
. Usea smallsquareto checkfor flat betweenthe pins,a bumpwill prevent the joint ftom seating. . ff the squarerocks,you will needto pareaway the high spot. Seepage44.
Hand-Cut Dovetails
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ROBCOSMAN 61
S E C T I O N1 3 A S S E M B L Y
T/PS I fr
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Theassembly is the final makeor breakof the dovetailjoint. once you apply the glue the processmust move forward in an orderly fashion.Thewoodwiil im.eiiatelv b.nln r., from the,glueandwhat srartsour asa rubricantw,in;";; d" # g9-r_o,r?,-ok*e sequence thoughtout and anyneededtoolscloseby.on biggerjointsit "pi"r,i.. helpsto 11,"-.th. nave an enrapanot hands. securethe pin board finnly in the vise soit doesnot moveasyou poundthejoint together. At this stageyou needeverythingto work smoothly. If,somethinggoeswrong andthejoint needsto be takenapart,insteadof beating i! use heafguo blgw dryer to softenthe glue.youmay find it easierto usetwo guns,one ro t 91 heatthe insidewhilethe otheris heatingthe outside.Yellow andwhite glueswiflsoftenat temperahreseasilyreachedwith a blow dryer
. Usea spahrlaor pallet knife to gluethe long gainsidesof the pins. . A thin evenfilm works best,don't gluethe end grain.
a
ft+
F+ ) F+ F+ F+ F+ F+
. Appl"va thin fihr on the l.r*i"l .c, , o h r i n o h n l h n i n c e r r r l tr'*'''b
tailsensures a goodioint. . If vouassemble quickly the gh,rewill lubricate thejointandhelpit go together. . Yoncanput a dabof glue on the '/rpin endgrain surfaces.
It is safest to usehand pressLlre to startthejoint.
TAILANDPINALIGNED
. Usea fullwidth-pounding blockto evenlyclosethe joint. . Poundthru the end q:in
for ihp hpqt iunqfpr
of force.
BLOCK& IIAMMER www.r00c05man.(0m
Hand-(ut Dovetails
. Kt'cptht'assembllttven br adjLrstine thelc r.oLr hit rlith lhe hanrnrr.r.
ALX4OST CLOSED
Sctfing tht nraiking g.rliger/r lt'sslhanthc tailboarrl allorvs thcjornt to scatbctbr-e theblocl< touches thcprns.Sce pauc1(r
PROLIDTNLS
. Clitck ior sqr-iar.e on the jnsitlcoi the jolnt. . Usc hand pressllfck) makr.ant crtrrt-.cli ons.
. It'sbestto re-seatthe jointaftermaking adjushrents. -t*d$g
RESE,,%ry . \Mpeoff anvcxcess gluebeforeplaningthe jointflush.
. Planetheedgesflush.
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Hand-[ut Dovetails
. If rou pressthe dividers too clecpdunngthc 1ay outtheymal'bedifficult to eliminate 1ater.
. A tighttittingshor_rlder jointshorvs well.Thisis rvorththe cxlrapracticc
I
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. Hopefullv you'recompletelrrsatisfi edrvith joint.If finished _vour not takea lookat somc repairmethods in the ll'or-rbleshooting section
I
F]NISHED
Hand-(ut Dovetails
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(O5l\IAN ROB
S E C T I O N1 3 N O T E S
Hand-Cut Dovetails
S E C T I O N14 T R O U B L E S H O O T I N G
IIPS Bepatient and checkeachstagebeforeadvancingto the next.Mostrepairs areeasierto makebeforethejoint is assembled. Remember that Jachstepbuildson th'eaccuraq,of the prwiousone. Youhaveto know when to repairand when to startover.In mostcases its bestto startover if thereis anychanceth9 will detract from the piece. Repalrs can be time consumingin lePair a three-tailcomerit couldeasilytakemoretimeto repairthanto redo. Part of being a good craftspersonis to make invisible repairs.If your repal is palnfully ' obviousit is betterto startoverthan to haveto explainor apo'logize r*u.rt
. Thisis oneof themost commonsawingenors. . Thetop of thepin is markedfromthebottom of the tail but when assembled thetop of the pin comesto restat the top of the tail. . If not sar.tm perpendicular the transferof tails to pins wiil resultin a compounded error.
Hand-Cut Dovetails
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ROBCOSMAN 69
. Tomakethisrepairyou haveto resawthe side of thetail. . Pinchtheendof the boardfirmlywith the bottomofyourfinger andihumb. . Pressthe sawlaterall,v against1'ourfingertiPs to preventthe sawfrom by the beinginfluenced errantsawkerf. . Thelateralpressure againstthe anchoring fingersis thekeyto startingthiscorrection.
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NEWKERF REPAIRMTH
71
n
?+
. On ; norm.rl sarrctttcach sideof thekerftouches thebladeandforcesit to cr-rtstraight. . In thisrepairmostof one sideof thekerf is missing, . Lateralpressure fromthe oppositefingertipsis neededto pressthesaw againstthe rightside of the kerfto guideit the entirecui. thror,rgh
. Thefinishedcut,on the lineandperpendicular across theend.
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Hand-(ut Dovetails
. If tl-rewastebctr,veen the tailshasalready been rcmovedtheprevious process will provetoo difficult. . Forthisrepairyouwill needa sharpchiscl, a blockwith a squareedge thatis at least3/.'thickand a rigd ciamp.
. Placethetailboard on a sacrificial boardon the benchwith thcrvideor f' 'l!r^r! p^ ' dr - ' Lo] n " bp ' *r- il n ] bo
f r c i n o r" rT n'
. Clamptheblockwith the squareedgeflushwith thesideof thetailnccd ine squared. . Thcclampneedsto be tiqht ' - ' _ pnnrroh ' _ ' " " - " fo _ ' rrrorrr.nf r'_ ' '
anv movement.
bCHISEL CtilDE
h*. Youwill needa sharp chiselwith a flatbackto do thisproperly. . \ M i h v o r r r 'f'i.n. oc-'.e" ,r s -k. ,- .- oT )
thechisellir:mlyagainst thebbck. . .S-l": .r-i ' t n* ,r 'r"i n bovifh
fhp
cornerof thechiselusing a sr'veeping motion. . Do thisto geta cleancut, c n i n c s" ' -l -r'.br"i' o l r f d o u r r r n r
5.-,''b
\
n c r n p r d"i"c_r' ^r' l' ^: r_ l' o " l.h- 'e_ T' T'
fibcrsmaycalrsethem b roilor tcar. . It is bestto lvorkin liom theoutsidecdgcsto
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PARE REPAJR H a n d - [0uot v e t a i l s
T _ " _ _ "
T ! 4 ' '
tromsplintering. www.robcosman.com
ROBIO5MAN 71
. Now the sideof the tail is perpendicular asshown by the penline. . Tofinish the job, trim the wasteat the base.
. Thisis not a serious problemunlessthe angle is so far off it takesaway fromthejoint. . Thisis easierto repair beforethe wasteis removed.
. Startthis repairwith the sawjust insidethe existingkerf. . Angle the sawto match the penLineanduseyour finser iinq ---'o-*r " tn hnld i+
. Wth a light touc[ saw slowlyso the teethcan cutinto the sideand establisha new kerf. . Theteetharecuttingon one sideonly andwill havea tendencyto slide towardsthe existingkerf ifyou sawtoo fastor applytoo muchpressure.
. Thewoodon theleftside nf the kerf eannni nrnrridp ""' T'"*'
asmuchsupportto the bladeastherightside because of the firstkerf. . Forthisreasonyouwill needto keeplateral n r p q q r r r p r n r i l hr r n r r r f i n o o r r'."""'.'''".-1"*'.''.tr'' i.i'nTq" : c* a ' : *i n' 's' "i ' i h p l p f t q i d p
of thesaw
KERF1/2WAY
On iho linp;nd
rprdv
to go.
. Th rpnair ihis errant qaru L e r f r u i l l r. p' 'a1r"r ,i r. p' ' 'c' h" 'a' nt rs'i,nl sr
thesizeof thepin. . I\hile it will be noticeable i_l "r'p i n i n f c a n s t i l l h p n p : l I"_"'
andtight.
Hand-(ut Dovetails 1i-GqniFry-.
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ROB COsMAN
73
I . Usethe dovetailmakerto redrawthe linesstartlng wherethelastkerfmeets the scribeline.
RE-DRAWTHELINE
. Startthissawcutasyou normallywould,useyour fingerandthumbto anchorthe saw. . It will behaveasnormal until you getnearthe bottomwherethe support on theleftsideof thekerf willdiminish.
. Slowdownandusea light touchat the bottom of the cutto preventthe sawfromfallingto the left a st h es r r p p odr ti m i n i s h e s . . Tokeepthe sawtracking useyourfingertipsto pressthebladeagainst the rightsideof thekerf.
NEARINGTHE BOTTOM (O5MAN ROB
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Hand-(ut Dovetails
l . Errenn.ithor-rtkeli sr-rppolt at the bottom of the cut voll can still finishclcan and strarsht.
\A,EDGE FALLSAWAY
. Salr,ingbelor'1,the scdbe linc lookssloppr.ancl nhile one or hvo canbe ovcrlookecl, nore than that lvi1lneeclto be repairccl or-redonc.
SAMNGBELOWTHE SCRIBE
. Thisrcpalrcanonlr,be rlonebcioretheplirs arecrit. . Setthcnrarkinggar-rge to jr-rst beloivtheilccpest l
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ll
I
t I'+ e e e e q
. A mispiaced chiselmark l" h' r t i" 'n- -l*pr 'r" n r n l q :! ! " 'q- ' tt lrb:"i' o h i
line will sholv.
}rD
\ II
v|
q
e e
CHOPPING BELOWTFIE SCREE
}'D
. T' h i s r c' rn' -r-i r c : n o " " - ' . -n- .l .r Jr h" p-
},)
donebeforethepins arecut. . Ifl'ou canaffordto lose thetailboard lengththen gaugea new scdbeline thatgoesjustbelow thevoid. . Besnreto changethe lengthof the other tailboard.
e
NEWSCR]BE LINE
. Sawingbelowthe lineis a shor:lder commonmistake. . If lpft vnr
urill ' ' ' - ' 'h:rrp ' * ' ' . . br " oan T on fhe pdop of thp inint v
"
_
"
"
!
+
'
-
'
'
,
\
-
'
_
'
!
thatis veryvisible.
Hand-(ut Dovetails
t . Setthemarkinegauee for thelolcst partof the sawcut. . \'Viththervasteaheaclv removecl thereis not muchsurface areatcr register theheaclof the gauge.
. \Alrththeheadof the gaugeheldfirmh'aeainst theendof thetailboard makesever-al iightpasses bv rollingtlrecutteracross theedge.
. I V i r h r i l h p p l h' n , ' o r r o a T-
b'"b-
be ableto finish vouma-v theshouldcr by slicingall rrnrrnd lhe p . *r|]ro' *p' :' 'r'r , l
workingtor'varr1 the mrdillc. . Theoptionis to markthc norinrolor
rrrrl rrrr,. lhn
shor-rlder r,r'rtha chisel.
SCREETHE PERIMETER wwwrobcosman.com
ROB TOSMAN 77
. \Atththe boardsecured in thevise,setthe chiselon the scribeline. . Undercutthemiddieof the shoulderleavinga qtrin nn oifhor ci,,le
. Thesenarow stripsare easyto parewith a chisel. . Becarefulto followthe outsidescribe1ine.
PARET}IE EDGES
Inspectthe pin board aftertransfering the tai1s. If severalof yourmarks aremisplaced lt maybe betterto startover. Planethe endgrainto removethe marks,scribe a new line andre-dothe tail transfer.
78
ROB COSMAN
www.rob(osman.(om
Hand-(ut Dovetails
. After transcribingthe tails and beforeyou lift the tailboard,checkwith a benchlamp for any errantknife marks. . Re-doanysuspect tails andnotetheinconect marks. . As soonasthe tailboard is removedusea pento identifythe correctmark.
. Thisrepairis easierto makebeforethepin wasteis removed. . Thepin cutshaveto be plumbfor thejoint to work. . Slopingkerfscreatea wedgeat the top or bottomof the piryone causes a gapthe other a split.
. Thisrepairusesthe sawto trim the side of thepin. . IMth sufficientlateralpressure the teeth cancuton onesidewithoutsiidingout of position. . Startthis procedurewith the bladein the enantkerfandwithyourthumbpressing tnesawteethagainst thesideofthepin. . Youwill haveto supportmostof the iaia/s weightsotheteethcanestablish a,,shelf, andnot merelyscrapethe sideof the pin. . Slowlysawthis"shelf"downthe sideof thepin until thefuli width of the bladeis cuttingwood. . At this point the sawwill startto track by itselfandyou canflnish the cut to the scribeline. Hand-Cut Dovetails
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. It\4tha plumb pin the jointwillwork.
. Thismistakeis normally fatalandthejolnt should bere-done. . If it mustbe saved,the bestwayis to sawthru the joint onceit is assembled. Seepage83. . Theextentofthe under cut will determinethe width of the sawkerf neededto maketherepair
. A sawcut on thewrong sideof the line is easier to fix afterthejoint is together.More than a few of thesewouldbe reason to startover. . Thisrepairis doneby sawingthru thejoint to estabLish an evenwidth kerf.Seepage83.
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Hand-Cut Dovetails
. Thebestwayto make thisrepairis to pare acrossthe graln.
. Paringacrossthe grainis easierif the fibersareflrst severed at thebase. . Havingbeensevered the wood fiberswlll fal1away astheyarecut makingit easierto controlthechisel.
. Usea sharpchiselthatis widerthanthe pin is ta1l. . Anchoryourforward handagainstthewood andsqueeze the chiselto providecontrollingbackpressure.
Hand-Cut Dovetalls
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ROBCOSMAN 8I
. Aq \nr
nprr lhp h:cl
nf
l' h in raise ihp chiqpl to - 'p- n r-"/ qLprlr lhp tnn '"r anrnpr -"'-'.-''
. Thiswill avoidbreaking off the cornerat the end of thecut.
. Forbettercontrolit is easierto takeseverallight -,.+- rL-^-^ l^^^--, !utJ Lttalt urtc ltcdvy.
. Worktowardthe knife markuntil the sideof the pin is straightandplumb.
ACLEANPIN
. Althoughit appearseasy to placethe chiselin the knifemarkandpare,the gralnis oftenrunningthe \,!TOng way. . Theriskis that thewood fiberswill breakand rrndormino tho nin
"''r'"
. Thisis theresultof the grainrunningagainstthe directionof the cut.
-ionx sTRFACE
. Ifthe grainis runningin therightdirectionthe cut is easyandfinishes clean.
. It is easierto repaira gap thatis uniformin width. . If thegapis narrower thanthekerfof l.our saw,simplycutthrougir theloint scribelineto scribeiine.
I
SAMNGTHROUGHTTIE GAP Hand-(ut Dovetails
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. A widergapwill needa widerkerffiom a larger saw,adjustaccordingly.
. T^ h" 'p" ' 1q *n*r 'r-e r p -e.d. bo 'c" 'n* { a
scraper doesa goodjob of deepening the corners wherethe sawcouldn' reach. . A sharpor wedgedshape couldeasilysplitthewood
. Select a pieceof wood that closelymatchesthe eroe
ln ha reneiro,l
. If you'relucly you wl1l find an off cut fromthe sameboard.
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Hand-(ut Dovetails
. Sawa filler strip,a bit thickerthan the gap. . I usemy oppositemiddle fingerto pressthe small strip againstthe bladeto supportit whilebeingcut.
. Determinethe shapeand sizeof the filler strip from the actualgap.
. Ratherthan try to drive the filler strip all the way to the bottom of the gap, I trim the insidecomer to ensurea tight fit.
Hand-Cut Dovetails
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l
. On a flat metalsurface, . ' ' ' fillpr ctrin fn " ' ' - thp rnnrrnd compress it. . Taplightlyso\.ouwon't splitthewood. . T h p m n i s h r r p i' n ' . 'l.h' p t r ' o* l' r r p will hrinq it hack in qize
''_--____andnicelrr fill thegap.
POLNDTOCOMPRESS THEFILLER
. Checkif the stripwillfit. . A littlp prfr: nnrrndinq r"''""'t)
wili makeit easierto noqiiinn ilrp fillpr ' ' - qtrin ,'' " ' - ' r in r'"^-'"-.."' L
the gap.
CHECKTF{E FII
. Orr fhin rpnrirq uzero,l nr
othercoatedpaperdoesa goodjob of spreading gluein the gap. . Workit forth andbackto getgoodcoverage.
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Hand-(ut Dovetails
. Dont pre-gluethe strip, the moisturewill cause it to swellbeforeit is in place. . Setthe fillerstripin place andtap it asnecessary
. Youcanwait for the glue to dry or trim itwhile the woodis softandpliable. . Useseveral passes with fhp enrncr nf r chem
chiselto shearoff the evnpcc
filler
ctrin
. Therepairis well camouflagedandif is hardto see thelonggrainbuttjointir thewalnut.
WTrlrTliEPL-ANE I A FEWSTROKES Hand-Cut Dovetails
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---{-i
fr
ry
ABOTITTT]EATIII]OR lor mosfof hislife. f) O0 COSV,INhasbeenwoodworking I\\Aftile earning a B.Sc.rn InduslrialTechnoJoglrfurnifure Designat BrighamYoung University, he wasDr. DaleL. Nish's teachingassistant. Robhasalsoworkedwith manyof theworld's - includingAlanPeters,SamMaloof, bestmastercraftsmen TageFrid,MonroeRobinsory andPeterKorn. Robfrequentlytravelsto demonstr"ate woodworking techniques, andhastauehthandtool skillsto hundredsof students. He has operateda customwoodshopsince1989,wherehe designsand buildsmade-to-order furniturewith an emphasis on usinghand tools.Robandhis wife Km livein New Brunswickwith their ten children.
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