281 53 5MB
English Pages 98 Year 2010
O
n a e c
Explore
r
r e s i u r c Fat Ducks
Building the Hull Concept and Hull Design - Perttu Korhonen Foils, Spars and Sail - Storer Boat Plans
2
Table of contents Licence 3 About plans 4 Views 6 Material list – metric 8 Material list –imperial 9 4mm ply layouts 10 6mm ply layouts 11 Side panel 12 Side panel framing 13 Laminate chine logs 14 Bow 15 Cabin bulkheads ply 16 Cabin bulkhead framing 17 Transom 18 Hull assembly 19 Centercase 20 Mast step 21 Mast step assembly 22 Rafter 23 Rafter and cockpit front ply assembly 24 Cockpit lockers front sides 25 Cockpit sides 26 Cockpit framing 27 Cockpit top and ceiling 28 Hatch rails 29 Hatch ( alternative 1 ) 30 Hatch ( alternative 2 ) curved top 31 Hatch assembly 32 Rudderbox and tiller 33 Finishing and Rigging 34 Double deckblock 35 Oar sockets extenders 35 Boom tent 36 Curtains 37 Trailer trolley 38 Converting millimetres to inches 39 Photos 40 --------------------------------------------------------------------------------------------------------------------LICENCE Purchasing these plans gives you license to build one complete boat. Using these plans means that you have agreed to the conditions below. The plans are and remain our property – but you have this licence to use them to build a boat for personal use. If you damage your boat, that it can´t be repaired, you can build another boat as replacement. If your friends and even strangers get excited about having a boat like yours we would really, really like it if you would direct them to download the plans for themselves for the low plan price. 3
ABOUT PLANS After I build the boat shown in photos, I received emails, if could I make plans of it. I had earlier built Michael Storer´s Oz Racer and this boat uses its spars, sails and foils. I thought, that I can´t make plans of boat, which uses parts I haven´t design. I contacted Michael and he was kind in willing me to produce plans together. Thanks to Michael, who helped me simplify boats structure and willing me play as boat designer. ( Some drawings, text and photos of this section are made by Michael Storer ) I tried to make these plans as good I can and I hope you can get some value for your money. Drawing these plans has been fun, but big project. Many beautiful sailing days was ignored. I had to buy 3d design program and maybe will ever got enough money to cover its price? My goal was not get rich with these plans. It would be fun to see people building boats and do sailing- and exploring trips around world waters. So build, sail and explore! If you have built the sprit rig version of Oz Racer, you can´t use that rig on this boat. Cabin roof is too high from mast base, but Michael´s free lug rig supplement works fine – contact him. Build and use this boat with your own risk. I have sailed it in stiff breezes and through waves affected by ships and it have survived without any damage. It is anyhow very small home build boat and could be damaged by faulty gluing or material failure. Make sure you are aware of proper and safe use of all materials – read manufacturer’s directions. Dimension shoved in plans are exact dimensions. When you proceed on building, there are going to be little difference between your boat and dimension given in plans. Always check dimensions on your boat before cutting parts too small. When stainless screws are mentioned in plans, it means that they are meant to be left on place. Countersink those screws and fill with epoxy putty. Always drill pivot holes for screws. Temporary screws are drywall or plasterboard screws and meant to be used as clamps, to reach steady pressure during gluing. To reach strong and watertight seams, glue should ooze little along entire seam length. Fill screw holes with epoxy putty. Plywood layouts are made so, that parts will be aligned correctly with grains direction. 1220mm ( 4´) should be top veneers grain direction. Information on using epoxy and saving labour read the appendices! ( in end of Ocean Explorer OzRacer sail foils spars.pdf ) Boat is meant to be sailed hatch shut and locked. If she is capsized, you should have enough time to turn the boat upright again before cabin fills with water. The design´s name is Ocean explorer, but remember, that it is very small boat and meant to be sailed in sheltered waters. It´s best suited for one person and one kid. Cockpit is small for two adults , but short trips can be made with right attitude. My longest trip with it is three days and two nights slept inside cabin. I am quite happy about the design. Start off using the boat with a great deal of care in safe waters and as you start to understand what the boat will and won’t do extend the range of what you decide to do. At all times carry safety gear including lifejackets as recommended by your local safety authorities, learn their proper use and maintain them correctly. Practice recovery from capsize at a time of light winds which will blow you towards the shore so that you will know what to do if the boat capsizes. 4
When the boat are being used by children they should be under supervision and not be allowed to move further away than you can rescue them. As they learn to rescue themselves then allow them more freedom. Ocean Explorer is inspired by Pdracers and Oz Racer, but it is not Pdracer. Name “Fat duck” cruiser means, that it should be able to carry little more gear until transom reach waterline. Some skippers may need extra pillow under aching back. ( while resting in cabin and waiting his/her turn on helm - on storming and rainy oceans… ) Pdracer ( Puddle Duck Racer ) is trademark owned by David “Shorty” Routh. Shorty’s homepage for Pdracers can be found : http://www.pdracer.com/ Oz Racer homepage is : www.pdracer.info/ Michael Storer´s homepage for boat plans and great boating information is: http://www.storerboatplans.com/ Michael Storer Boat Design Building and Repair - FAQ http://www.storerboatplans.com/Faq/faqindex.html Woodwork Forums - Michael Storer Wooden Boat Plans http://www.woodworkforums.com/f169/ Plans, hardware and great stories can be found in: http://www.duckworksbbs.com/ I have added couple very short sailing videos : http://www.youtube.com/watch?v=G0IIDQ8yC9o http://www.youtube.com/watch?v=kmP2S_eWE9w Send photos of your build and sailing adventures! [email protected] Have fun
5
6
7
Material list - metric List is made according standart lumber sizes founded where I live. Standarts can vary between countries. If lumber size shoved on list cant be found in your local store, it has to be cut from another size of lumber. PLYWOOD – READ BEFORE BUYING PLY Plywood sheets are all 8ft x 4ft (2440 x 1220mm). DO NOT USE METRIC SHEETS (2400 X 1200) We strongly recommend that the 6mm (¼”) ply is 5-ply (has 5 layers). 3 ply is unlikely to be strong enough for the bottom of the boat. Plywood ( 1220 X 2440 ) Thickness 4mm 6mm
Number Species 3 Exterior or Marine 2 Exterior or Marine
Lumber Pine can be Hoop Pine, white pine or other mostly knot free straight grained pine with good gluing properties No loose or large knots. Douglas Fir or spruce, select dry stock. Fine grain, no knots. Hemfir, Western Red Cedar, Paulownia.
Size
Part
Length
Number
Species
( 19mm lumber - could also be 18 or 20mm )
10 X 19 15 X 19
chine log laminations cockpit side stringers round hatch rails
2500 2800 1500
4 1 1
pine pine, spruce pine, spruce
15 X 28
hatch ( alt. 1 ) top mouldings rudderbox bottom stiffeners
1200 600
1 1
pine, spruce pine, spruce
15 X 45
hatch ( alt. 1 ) back frame rudderbox top stiffeners
600 600
1 1
pine, spruce pine, spruce
19 X 19
framing - bulkheads, lockers side panel shorts hatch ( alt. 1 ) rails and front moulding curved hatch ( alt. 2 ) - middle batten
3000 2000 700
5 1 1
pine, spruce pine, spruce pine, spruce
3000
5
pine, spruce
mast step back support ( sawn to 19 X 64mm ), side panels oarlocks supports, bulkheads
2000
1
pine, spruce
19 X 90
bulkheads top stringers ( curved )
2100
1
pine, spruce
28 X 28
centercase and runnerdbox spacers ( sawn to 28 X 25mm ) hatch rails blanks for bottom framing
1300 2600 2300
1 1 1
pine pine pine
28 X 45 45 X 45
curved hatch ( alt. 2 ) - frames tiller
1000 650
1 1
pine pine
Foil staves
2100
7
pine
(could be sawn from 28X45)
( one extra peace could be good idea )
19 X 45
framing for sidepanels, bulkheads, centercase cleats, mast partners and vertical hatch rails ( one extra batten could be good idea )
19 X 70
Foil lumber 25 ( sawn ) X 30+
Spar Lumber (mast, yard, boom) Douglas Fir, other pine or spruce, select dry stock. Fine grainno knots. Other pine species can be good. Need a fine grain and no significant knots. The required length can be made up by joining timber using a 6 to 1 scarf join – see spar building section for details. 62*12 38*12 38*38 42*42 38*38
mast wide staves mast narrow staves internal blocking for mast boom yard
3900 3900 1500 3400 3250
2 2 1 1 1
pine pine pine pine pine
Other materials : Glass tape 50mm wide - 10 meters ( ca. 160g/m2 ) Epoxy - ca. 8 kg + gluing powder (if coating) 3kg (if only gluing)
8
Material list – Imperial List is made according standart lumber sizes founded where I live. Standarts can vary between countries. If lumber size shoved on list cant be found in your local store, it has to be cut from another size of lumber Specially 28mm ( 1 1/8 ) lumber is not standart size in imperial standarts - my apology for that. Parts made from that size of lumber are quite short ones and could be sawn from bigger size of lumber. PLYWOOD – READ BEFORE BUYING PLY Plywood sheets are all 8ft x 4ft (2440 x 1220mm). DO NOT USE METRIC SHEETS (2400 X 1200) We strongly recommend that the 6mm (¼”) ply is 5-ply (has 5 layers). 3 ply is unlikely to be strong enough for the bottom of the boat. Plywood ( 8ft x 4ft ) Thickness 3/16” 1/4”
Number 3 2
Species Exterior or Marine Exterior or Marine
Lumber Pine can be Hoop Pine, white pine or other mostly knot free straight grained pine with good gluing properties No loose or large knots. Douglas Fir or spruce, select dry stock. Fine grain, no knots. Hemfir, Western Red Cedar, Paulownia.
Size 5/8 X 3/4
Part chine log laminations cockpit side stringers round hatch rails
Length 8 9 5
Number 4 1 1
Species pine pine, spruce pine, spruce
5/8 X 1 1/8
hatch ( alt. 1 ) top mouldings rudderbox bottom stiffeners
4 2
1 1
pine, spruce pine, spruce
5/8 X 1 3/4
hatch ( alt. 1 ) back frame rudderbox top stiffeners
2 2
1 1
pine, spruce pine, spruce
10 7 2,5
5 1 1
pine, spruce pine, spruce pine, spruce
10
5
pine, spruce
mast step back support ( sawn to 3/4 X 64mm ), side panels oarlocks supports, bulkheads
7
1
pine, spruce
bulkheads top stringers ( curved )
7
1
pine, spruce
1 1/8 X 1 1/8
centercase and runnerdbox spacers ( sawn to 1 1/8 X 1 ) hatch rails blanks for bottom framing
5 10 8
1 1 1
pine pine pine
1 1/8 X 1 3/4 1 3/4 X 1 3/4
curved hatch ( alt. 2 ) - frames tiller
4 3
1 1
pine pine
Foil staves
7
7
pine
3/4 X 3/4
framing - bulkheads, lockers side panel shorts hatch ( alt. 1 ) rails and front moulding curved hatch ( alt. 2 ) - middle batten ( one extra peace could be good idea )
3/4 X 1 3/4
framing for sidepanels, bulkheads, centercase cleats, mast partners and vertical hatch rails ( one extra peace could be good idea )
3/4 X 2 ¾
3/4 X 3 ¾
Foil lumber 1 ( sawn ) X 1 1/4+
Spar Lumber (mast, yard, boom) Douglas Fir, other pine or spruce, select dry stock. Fine grainno knots. Other pine species can be good. Need a fine grain and no significant knots. The required length can be made up by joining timber using a 6 to 1 scarf join – see spar building section for details. 2 1/2 * 1/2 1 1/2 * 1/2 1 1/2 * 1 1/2 1 5/8 * 1 5/8 1 1/2 * 1 1/2
mast wide staves mast narrow staves internal blocking for mast boom yard
13 13 5 12 12
2 2 1 1 1
pine pine pine pine pine
Other materials : Glass tape 50mm ( 2” ) wide - 32ft ( ca. 6oz approx ) Epoxy - ca. 16lb + gluing powder (if coating) 6lb (if only gluing)
9
10
" "
"
$
!
#
"
%
"#
"#
"#
"
"
"
#
!
11
12
373
130
243
305
460
915 straight
305
ply edge
515
305
305
153
110
541
1257 Cabin bulkhead position centercases front egde align on this line
( draw centercases bottom shape according side panel. Place its front edge to line 1257 from transom and top edge to gunwale - dimensions on page 20 )
Side panels
2440
130
543
305
526
100
785
745
305
nails
484
30
296
417
aw dr
e lin
305
150
(Fd2)
373
ing rd o c ac
straight line for mast step
314
d an
170
ils na o t n tte ge. a b ed sh ns u P tte ba
flexible batten
register lines
23
130
13
22 ˚
23
19
38
1136
100 19
8
2340*45*19
cabin top stringer is angled to 23 degrees
30
23 ˚
44
25
Bottom stringers can be made by laminating two 10*19 battens, ( see next page ) or by bending with heat blower gun : http://koti.kapsi.fi/hvartial/bend/bend.htm
38
8
detail view from top stringer cross section
19
19 notch
ca.326
support for oarlocks ( optional )
19
1215
70*19 ca.253
locker stringer ( optional )
651
891
255
23 19*19
45
(fd2)
Fasten framing with temporary screws.
Side panels framing
Laminate chine logs The curvature along the bottom edge of the side panel is quite extreme. The chinelog is laminated to the required curve out of two layers of timber (19 x 10mm – ¾ x 3/8”) to make up a 19 x 19mm curved chinelog.
Lay the side panel on a flat surface. Mark the curve of the bottom edge of the side panel onto the flat surface. Put brown plastic packaging tape over the tabletop or workbench which the chinelog will contact so it does not end up being glued to the surface permanently. Drive some long plasterboard screws in along the line – diagram above and left side of photo NB - A good general rule for gluing is to do a dry run to make sure that everything will hold in place with the available clamps. It is bad news to get the glue on and then find the clamping method is inadequate. Put thickened glue (about peanut butter consistency) on the wide face of two of the chine log laminations, spread and put the other two chinelog lams onto the glued surface. Use the spring clamps to clamp to the plasterboard screws (pic above). Put brown packaging tape along it to prevent the second chine log from bonding accidentally. Clamp the second chine log to the first. ALWAYS CLEAN UP EXCESS GLUE ABOUT 20 MINUTES AFTER GLUING. When glue is cured remove chine logs remove any excess glue by power sanding.
14
(Fd)
BOW 160
85
48
300
ply
540
507
507
405
side view 9 303
303
303
303
1212
22 ˚
Top stringer 615
ly edge rding p o c c a urve draw c 10 ˚
36
50
540 ply 554 10 ˚
25
Start with 19*90*670 lumber. Cut 10 degree angle to center joint and place it above stringers. Draw top curve according ply edge. Last draw smooth curve below top curve.
19
419
37 ˚
44 14
70
10 ˚
Framing 19mm 348
middle stringer 10 ˚
352
452
19
44
458
452
14 ( ply edge on another side )
70
Top edge is planed to 22 degrees. ( 9mm below top edge )
6mm ply
270 100 70
6mm ply
15
$
$
$
%
" ! #
#
! ##
$
$
$
$
&
$
" #
16
Cabin bulkhead framing 19mm wide
viewed from bow
682
90 ˚ 19 90
17
4 23 19
46
Top stringer is made from 682*90*19 lumber. Draw shape according ply edge.
45
19
22 ˚
11 ˚ 284
149
viewed from bow
265
45
11 ˚
19*19 194
164
45
149 130
19 26
90
37
45*45 support for nylon fairlead ( see page 34 )
viewed from cockpit 19
26 1212
17
(Fd)
TRANSOM
notch in top stringer
274
19
16 45 275 19
161
275
in middle
161
19
70
19
45 7 ply edge ( on another side ) 1212
side view 19 45
251 161
244 ply
45
19 ˚
7
18
!
"
" #
"
$ $
19
Centercase
(Fd2)
19
19 19
side ply 6mm 411
bow
413
412
match to bottom curve 343
45
287 28
28
centercase spacers 25mm wide
343 cleats 19*45*343
45
19*19*1212
19*19*549 19*19*549
19*19*549
Centercase should fit between bottom and cabin bulkhead. If there is too much play, adjust the height of center case. Draw line across bottom ply from marks on side panels ( 1257 from stern ). Center case front edge aligns on that line. Draw also lines to center of bottom and center of center case. Fasten centercase with screws 19*19*549 through bottom and top of cabin bulkheads stringer. ( some of screws driven through bottom could be stainless and leaved there to secure the joint if epoxy is not being used ) Clamp cabin bulkhead ply tight against centercase. Last glue bottom stringers and top back stringer (1212mm) to boat. ( I usually make rudder box in same sequence with centercase, so epoxy coating or painting could be done at the same time. )
20
(Fd)
Mast step 19*45 lumber
viewed from top
64
19
top mast partner
19
64 lower mast partner 484
484 213 149 8mm bolt 64 151
back support
22 ˚
side view 215
back view
1
viewed from side
64
2˚ 544
19
reinforced with 6mm ply 544
544
45
100
3 170 9
11
4
19
13 ˚
58
17
13 ˚ 45
45
35 37 ˚
57 82
13 ˚
27 spacer 19*45*58
21
(Fd)
Mast step assembly Fasten mast step assembly with temporary screws through bottom. Use stainless srews throught bow to all four mast partners. Reinforcement ply could be glued only with clamps.
ca.420 ca.535
28*28*535 28
21
28 19*28*1174 28 13 ˚
19
64
80 reinforcement ply 6mm
28
200
22
6mm ply to both sides
Rafter
exploded view bow
6mm ply
6mm ply
Frame - 3 lamination of 6mm ply. ( or one peace of 18mm ply ) Glue on a flat surface.
bow
frame - 3 lamination of 6mm ply 1174 294 45 152 25
124
102
98 35 9
294
536 587
6mm ply overlaps frame by 12mm and works as hatch stopper / water seal.
526
12 21
viewed from cockpit
28
6mm ply 50
23
(Fd)
Rafter and cockpit front ply assembly Rafter distance (measured from frame) to cabin bulkhead framing should be ca. 674mm. Screw stainless screws through rafter to mast step and through side panels to rafter. Screv these screws slowly, if rafter starts to split apply glue to crack and pres it together with clamp. Fasten one 19*19*674 batten between rafter and cockpit bulkhead with stainless screws.
Plane carefully mast step top edges to match shape of rafter and bow.
674
19*19*674 ca. 340
cockpit front ply viewed from bow
284
viewed from side
19 4mm ply
412
19
19
374
412
374
19*19
19
24
Cockpit locker front sides Locker ply position is front of side panels locker stringer.
19
45
(Fd2)
15 19
ply 4mm 319
19
side view
21
19 294
19 top stringer - viewed from top 259 19 7˚
259 19
stringer length 286 19
viewed from back
279
319
19
279
17 viewed from top
7˚
5
2 275
5
bottom stringer - viewed from top
19
275 19
14 ˚ 2 7˚
25
(Fd2)
Cockpit sides If possible, make cardboard template from cockpit side ply and check that it fits smoothly to your boat.
936 477
top stringer 15*19 205
252 45
ply 4mm
244 19
318
398
365
45
411 393
notches locker plys back face postioin fron stringer - both ends strait Use deck plates as locker covers. Make hole according your deck plate
Glue top stringer to sideply. Use ca.50mm piece of timber between ply and clamping support.
gluing assembly
Place clamps in middle and on both ends . Then use so many clamps you can fit to gluing assembly.
50
viewed from top clambing support lumber ca.1100 936 top stringer
exploded view top stringer 15*19
front stringer
side 4mm ply 936 top stringer
12 24 ˚ 90 ˚
15
front stringer ( under top stringer ) 19
26
Cockpit framing Place cockpit side assebly on notch of transoms top edge. Glue it to transom, locker and cockpit front plys stringer. If sipeplys bottom edge won´t take nice curved shape - fasten it with temporary battens of 45*45mm wood same way as described below. Make epoxy fillet to both sides of cockpit side ply joint with bottom ply. 265 ca.655
ca.305 230
cockpit side
160 epoxy fillet
5 ws 30 cr e 9* s 1 * s 19 les n i st a 5 th i 65 * w 9 *1 ten s 19 fa Cockpit sides position from middle line shoul be ca. 230mm ( middle of oarlock support - on sidepanel )
bottom ply
If you don´t make lockers, fasten temporary batten ( 45*45) on bottom with screws. Screw cockpit sideply to that batten to achieve nice curved shape. Apply next epoxy fillet. After epoxy has cured remove batten and fill screw holes with thickened epoxy. Or make another stringer also on sideplys bottom edge. Glue it similar as top stringer. Cut it from 19*90 lumber and pre shape its top edge to match bottom curve. Fasten it with screws through bottom. 330 115 Front windows - 4mm ( or thicker ) plexiglass It could be wise to paint interior at this stage. Paint also bows outside face around windows and fit windows by bolting them through ply. Use washers on both sides and apply clear window sealant to joint. Side windows can be installed later, by screwing them to framing.
( I used 25mm wide camping sleeping matt on bottom between stringers. )
27
Cockpit top and ceiling
529 ( grain )
Check ply dimensions on your boat. Cut parts little bigger and trim after glue has cured.
1256
689
705 grain
cut after gluing
Fasten ports side ceiling ply first. Place it little backwards on rafters middle line and use only clamps when gluing it on rafter. When clue had cured screw front ceiling to rafter slowly and carefully plywood can split easily.
705*45
Between rafters overlapping part and front ceiling ply is going to be small gap. Fill it with small batten of ply or with epoxy putty.
Draw seats according your boat. Make opening for center case only to one ply.
32
347 25
623 126
281 4
342 1257
263 reinforcement ply - check dimensions on your boat
28
3 layers of 6mm ply
Hatch rails
25
Both rails are made from same profile.
114
64
9
64 9
28
89 8
10
28
. ng m lo r gluing m 0 e 0 t f 3 a 1 ca. ngth rails final le e k Ma cut to and
16
25 19
11 41
8 19
11
174
283
top shape according top rail.
28
41
28
Rails take up position according cabin bulkhead and rafters water seal.
water drain holes on starboard rail not through to rail slot.
Clamp rails from hatch slot and drive temporary screws from inside cabin. Ports side rail could be screwed to mast partner from top. ( not through rail slot )
29
Hatch ( alternative 1 ) top mouldings
hatch back frame hatch cover 6mm ply
front moulding fasten it when hatch is on boat!!
rails 10 ˚
port side rail 16 length 700mm
viewed fron cockpit
12
19 6
24
556
27
479
starboard side rail length 700mm
10 ˚
14
479
18
12
10 ˚
16 front moulding 19*19
19
6m m
10 ˚
viewed from bow
30
b a ck
top moulding
ply
15*4 frame
5
6
520 34
18
12
10 ˚
18
ply- behind back frame
34
130
back frame 10 ˚
port side rail
starboard side rail
260 130
20 15
viewed from side top moulding 15*28
700 rail 729 ply
viewed from below 19 front moulding
15 556 ply 29
18
6mm ply
hole for lock - drill it after dry fitting hatch on boat
viewed from below hatch back frame
green = cover ply red = rails brown = back frame blue = top moulding
700 rail 729 ply
30
all parts can be fastened at this stage
Hatch alternative 2 - curved top n grai 741
559
cover 4mm ply
stop
pe
r e a le r/s
mp 6m
19*19*644
70 0m m
rail length 700mm 19
6mm
27 26
120
viewed from c o
l le
15
6mm ply
rai
6
21
21
ng th
19 15
ply 6
30
ckpit 480*28*45 front and back frames
21 14
35 19
10 ˚
120
40 35
11
14 21 240
10 ˚
rail
viewed from bow rail
29
stopper / water seal -6mm ply. 8mm above frame and rails.
8
741 side view
25 282
252
stopper
10
vertical hatch 175
700 rail
260 520
31
ly
% 1
"
"
1
! #
$
#
/
0 0
%
# & #
$
"
# '(
')*
.
,-(
('+
32
Rudderbox and tiller ( More info about rudderbox - read : Ocean Explorer OzRacer sail foils spars.pdf )
6mm ply
15*45
37 79
15*28 25
6mm ply fastened below, with stainles screws top view
25
tiller - 35mm wide
spacer 25*28*240
37
28
79
150
6˚
75
side view
9mm hole
19 635
45 85
219 ply
28 28
205
5mm (3/16") bolt with washers under
309
38
240 ply and spacer block 18
R15
15
9mm hole
33
4
!" %&
#
$
'
( ) ( !+
* ,
&
+-.
) 0
(
(% ((
1
'
/
( (
0 ( 0
3 2
)
2
0
'
&
(
( *
& (
/
2
'
0
0
(
)(
' )
0 0
0
!)
0
!
%
%
(
2 (
6
$
(
%
+
3
(
!
2 ( 2
&
2
2
6 2
2
5 ( 2 (
7$$ !
! $
2
( 5
+-1 7$$
$
2
% $
2$
$
" "89" 99 "
8$
7 $:);$:);. ( (
9
%
34
Double deckblock It´s not wise to do everythink by your self, but.. Make rollers from 12mm plastic sheet. ( nylon is too hard to be machined like this.) Cut them out with core drill bit. Lathe shape with power drill - fasten roller to power drill with threaded rod. Last drill center hole to 7,5mm dia. ( if you can't find proper plastic sheet you can always borrow your wife´s or husband´s chopping board...
6mm rope
125 30
25
9mm plywood or lamination of 4+6mm 44
( 5 0 m m wi de )
15
44
19
section view
30
12 9
7mm brass rod 15*19 lumber
Oar socket extenders Nylon oarlock fitting
Bow eye U-bolt - 25mm inner diameter. Regular U-bolt wont do the job. http://www.duckworksbbs.com/hardware/shackles/sd080285-8/index.htm adjust tightness with washers
Marine rail tube end stanchion. ( I used JUKOVA RAIL STANCHION S-25 )
616
25 mm ( outer dia ) stainless tube - 1,5mm walls
175 (7")
Fasten U - bolt to gunwale stringer. Screw rail stanchion tube fitting to oarlock stringer.
35
%$&
&' )
& %
-
5
)
,
&
)
-
& )
7
1
- %
&
& %
% $&
*
)
%
% '
&
&
6 #
5,
) ) )
" ,
!
&
!
, + %
"
%
!
)
*
%&
&
)
( "
)
!
!
"# ,
. $ . /
& ) % -
& ) ' + % ) 0 ) "
%
&
)
% ),
! +
1 &% 1
%
&
2
&
. % % && )
&
4
&
) %
1
% )
" 8 && & && 2 8 9
&+ & & )+) ) ) ) % - 5 ) )
& - 5 ) &&
+
&
)-
+
)
+
-
%&
)
5
' &0
)
+
) &
%& %
$" , )
)
)
) -
))
%
)
&
%
)
.
)
&
)-
)
+ % %
3)%
)
&
)
)
)
)
2
)
36
Tent bag - from polytarp 800 or longest saft +200mm
800
fold bag to two and make sews 275 550
ca.80
To get nice 3d shaped bottom, flatten bag so, that seam is on middle. Twist triangle to bags end and sew it - like in photo. Make similar triangle to opposite end. Turn inside out and sew ropes to neck of bag. ( rope = polytarp edge )
Curtains Oooh - Are those curtains made from Chinese silk?
1000 wire rope
450
160
fasteners 450
160
Curtains - from Chinese silk Sew hem for wire rope.
37
Trailer trolley With help of this trolley, you don't have to drive trailer lights and wheel bearings in the water. It´s very easy to use unaided and could also be used as building trolley.
Front wheels - made removable with wing nuts camping sleeping mat
4 washers between frame and wheel. Bearing made like this is very poor, but wheels have to roll only couple of meters.
All wooden parts are 32*100mm timber. 2800 1224
150 576
576 14
10
25
100 50
wheels ca. 150
1400 1464
Width according your trailer
Boat in photo is my Oz Racer. This trolley works naturally in all pdracers.
38
39
mm 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
1 inch = 25,4mm
inch 0,04 0,08 0,12 0,16 0,20 0,24 0,28 0,31 0,35 0,39 0,43 0,47 0,51 0,55 0,59 0,63 0,67 0,71 0,75 0,79 0,83 0,87 0,91 0,94 1,0 ( 0.98 )
mm 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
12" = 305mm ( 304,8 )
Converting millimetres to inches
inch 1,02 1,06 1,10 1,14 1,18 1,22 1,26 1,30 1,34 1,38 1,42 1,46 1,50 1,54 1,57 1,61 1,65 1,69 1,73 1,77 1,81 1,85 1,89 1,93 2,0
mm 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75
inch 2,01 2,05 2,09 2,13 2,17 2,20 2,24 2,28 2,32 2,36 2,40 2,44 2,48 2,52 2,56 2,60 2,64 2,68 2,72 2,76 2,80 2,83 2,87 2,91 3,0
mm 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
inch 2,99 3,03 3,07 3,11 3,15 3,19 3,23 3,27 3,31 3,35 3,39 3,43 3,46 3,50 3,54 3,58 3,62 3,66 3,70 3,74 3,78 3,82 3,86 3,90 3,9
40
Part 2 – Spars, Sail and Foils Concept and Hull Design - Perttu Korhonen Foils, Spars and Sail - Storer Boat Plans
Table of Contents Overview of spars, sails and foils........................................................................................................2 Making the Spars..................................................................................................................................3 Varnishing...........................................................................................................................................17 Centreboards and Rudders.................................................................................................................18 Rudderbox, Tiller and Tiller Extension.............................................................................................30 Making the Sail..................................................................................................................................33 General Sailmaking method..............................................................................................................37 Appendices.........................................................................................................................................47
© Michael Storer some drawings in this section by Perttu Korhonen
Page 1
Overview of spars, sails and foils These are well proven designs from the former Storer Boat Plans version of the PDRacer. It has now branched off to be the Oz Racer with a useful website at http://www.pdracer.info We spent a lot of time getting these items right and they add a huge amount of performance to the boat. I would estimate that all round performance is 20% better than less carefully made items. This makes sailing much more of a pleasure and increases the margin of safety as the boat is more likely to do what you want when you want it. There is also an important rigging page for the lug rig on my website at http://www.storerboatplans.com/GIS/GISRigging.html Please don't think for a moment that these rigging details are unimportant. Getting the details right means a great deal of extra performance as well – and it doesn't cost you anything at all. You do things if the right way and boat will sail much better. This is the right position for the lug rig sail on this boat.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 2
Making the Spars The mast is a hollow box section made from 4 timber staves 12mm (½”) thick. We tried the construction out on our two boats and we were amazed about how light the masts were and how much they would bend without showing any sign of weakness. I exaggerate . . . . . . they did show some weakness – but that’s because Biting Midge, my co-builder, didn’t use the right length of scarf joint (minimum 6:1 – pic below right) when gluing the shorter bits together to make up the staves.
Joining the timber to length If using full length pieces of timber for the masts this section can be ignored. The salvaged timber was pretty knotty old pine and we had to cut out all the knots. This is one area where good timber is worth whatever you have to pay for it – saves heaps of time to have full
lengths for the mast staves. Though if you have heaps of time and not much money – then cheaper stuff is fine too – so long as you cut out the knots and your scarfs are up to specification. (diagram right) The Biting Midge redeemed himself by working out a neat method of cutting the scarfs on his bandsaw – but the method of simply hand planing them works fine. Mark each piece with the scarf length and stack (diagram right)
© Michael Storer some drawings in this section by Perttu Korhonen
Page 3
It is important to follow the method for gluing end grain in the appendices. Make sure the timber is aligned correctly. Use fine nails to prevent the joints moving once the glue is applied. You can use plastic sheet or the brown plastic packaging tape to prevent sticking to work surfaces etc. When the glue cures the timber can have excess epoxy sanded off – now you are ready to shape the staves.
Mast Drawing
Here is the mast arawing. Some of you are about to give me a hard time for using tenths of a millimetre – but it is one of my sparmaking idiosyncrasies! Showing the tenths of a millimetre © Michael Storer some drawings in this section by Perttu Korhonen
Page 4
allows me to see the wonderful mathematics of the taper gradually increasing from a fraction of a mm to much larger differences. – it gives me a feel of just where the taper really starts and how it accelerates. Anyone offended by the idea of half millimetres – I agree – they are just not important in the scheme of things – so ignore them if you really want to.
Mark Narrow Staves Choose the best end of each stave to be the bottom end. Use the Mast Drawing above to mark the intervals along the mast. Mark one stave only with the intervals. The first interval on the standard mast is 358mm. The rest are 588mm. As the 588 measurement is inconvenient, mark it on a piece of timber, then use that to transfer the intervals onto the stave.. When completely marked just measure from the top to the bottom to make sure that there haven’t been any major errors. Being out by 10mm on the overall length is not critical. Using a square draw clear pencil lines across the width of the stave at each measurement point. Then use the interval marks on the first stave to mark the other staves – lie them side by side and mark across using the square. Much better than measuring each one individually!
Marking the final width at each Interval There are two ways you can mark the widths at each interval. Alternative 1 – If the timber is straight. Figure right. Measure in from the sides of the board If the current width of the stave is 67mm and the required width is 46. then 67-46=21. Half of 21 is 10.5 So measure in from both sides 10.5mm and put a clear mark with a sharp pencil on the interval line. Alternative 2 – If the timber is not straight. Fig right Be careful that there is enough space either side of the centreline to fit the required width. In the past where the timber I have had to use is too bent I have put it down on a wooden surface and put drywall © Michael Storer some drawings in this section by Perttu Korhonen
Page 5
screws either side of the stave to hold it more straight. Run a centreline up the stave - use a stringline (piece of string pulled tight.) between screws or nails at the top and bottom of the stave. The STRING has to be at the centre – not the SCREW or nail at the centre! Put a pencil mark on each interval line where the stringline crosses it. This becomes the centreline. Measure out from the centre half the width required. Double check each of the widths marked is correct against the drawing. The mast timber is probably the most expensive of the timber purchased, so it is worth double checking to make sure there are no errors. Mark the taper lines by clamping a stiff batten to the stave so it lines up with the marks.
Plane the edges of the narrow stave (Note – owners of routers can speed things up by using the clamped batten as a guide for cutting the taper with the router using an appropriate bit. When the first narrow stave is cut this way it can be used as a template to do the same thing for the second stave. Use plenty of clamps to prevent the batten from moving. After doing the sections between the clamps move the clamps to new locations and finish the tapering) The narrow staves have to be perfectly accurate down to the lines, When planing the narrow staves there are two things to keep track of 1/ That you don’t go past the points you are planing up to. 2/ That you are planing square to the face with the measurements on it – if not the other face will end up smaller or larger than the other. Use a square to check as you go. One trick that helps is to skew the plane so it is not pointing directly along the timber but about 10 degrees to the left or right. This allows you to feel if your left or right hand is moving up or down © Michael Storer some drawings in this section by Perttu Korhonen
Page 6
and moving the plane away from being dead flat. Use the longest plane you have. Work slowly and carefully with long comfortable sweeps of the plane carefully monitoring how close you are getting to the marks. Sight along the edge of the timber as you go. I often mark high spots by making pencil marks on the edge which I then plane off. As you get closer adjust the plane to take finer cuts.
Internal Blocking Overview. The internal blocking widths and positions are shown in the mast and boom drawing They have to fit inside the mast so they are square in cross section and the square dimension has to match the width of the narrow staves at that point.
Long Block at base The long block for the bottom end of the mast (1158mm long) need to be finished exactly 38mm square. Cut the top off at an angle as shown to eliminate the risk of the mast breaking at that height.
Shorter Blocking The top block for the mast is 50mm long and 25.6mm square. All the other shorter blocks are from scrap timber 20 to 25mm thick and cut square to the following dimensions in mm. 36, 35, 32, 29. Their sides have to be the same length as the narrow stave width for that height... Label them and their positions on a narrow stave clearly. If there are any slight size discrepancies between the blocks and the stave width the blocks can be moved along the stave slightly to match the stave width precisely.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 7
Glue Internal Blocking between the two narrow staves The next step is to make a ladder frame assembly by gluing the internal blocking between the two narrow staves. (diagram previous page) It is important to get the ladder frame assembly all in a straight line. Draw a straight line on the floor or put the brown packaging tape on one of the wide staves so that the assembly won’t glue to it at this stage and use it as a base. You can see how wobbly our setup was in the picture above – we ended up clamping it to a long piece of aluminium angle (use packaging tape to prevent accidental bonding. Check the appendices on “gluing end grain” before the blocking goes in and brush some mixed epoxy on any end grain on the blocking. If not using epoxy you will need to use clamps to get the pressure required for reliable gluing. Epoxy only require light pressure which the method below provides Work from the bottom end applying glue then clamping the long block in positions. If you don’t have many clamps then put the clamp on at one end and tighten until you get a little bit of glue oozing out the joint. Then wrap brown packaging tape tightly around the assembly close to the clamp – use a minimum of three turns of tape. Then the clamp can be removed and moved to the next section. I would expect that the long block at the base will need to be taped in three places and the other blocks will need to be taped in one. If in doubt add more tape! (Pics are of the masts for the original Mk 2 mast. The latest one has more internal blocks to make it easier to keep the mast straight) When finished just go back and check the blocking is aligned correctly with both staves. If there MAKE SURE EACH BLOCK IS IN THE RIGHT PLACE. This is a perfect use for the brown packaging tape – three times around the assembly will hold nicely – just feel through the tape that the blocks are still in alignment. When the glue has cured powersand off any excess epoxy or any areas where the blocks are projecting past the staves to get ready for the next stage.
Glue the wide staves to the Assembly It is good to have a line on the floor to make sure the assembly all stays in approximately a straight line. A small curve is OK if it is even. Put the ladder assembly edge up. Put glue on all the upper surfaces. Place the ladder frame glue side down on one of the wide staves.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 8
Check that everything looks in alignment. If the ladder frame is misbehaving turn the assembly upside down, push it into alignment and hammer a fine nail through the wide stave into the spacer block – don’t hammer the nail all the way in or it will be hard to get out later.
Put glue on all the gluing surfaces and drop the last wide stave in place. Double check that the edges of the ladder frame is aligned with the lines drawn on the wide staves. Use nails again if necessary – but leave their heads above the surface of the timber. When clamping we only used one clamp to pull the timber together intitially – just tighten until some of the glue starts oozing out the join. We aligned the bottom end and clamped. Then put three or four wraps of the brown packaging tape just next to the base of the clamp. (Pic - the two masts for our boats right) We then moved the clamp up about a foot, pushed everything into alignment and tightened the clamp. Put packaging tape around the mast as before by the base of the clamp. Move up another foot and repeat until the mast is glued up. Wait until the glue is cured (normally next day) then powersand any lumps of epoxy that are on the outside of the structure.
Tapering the Mast Base The mast base needs to be given a taper so it will fit into the mast step inside the boat. The base of the mast needs to finish up 56mm wide. Mark the width 56mm of the end of the mast (see the drawing right) on two opposite faces. © Michael Storer some drawings in this section by Perttu Korhonen
Page 9
Clamp a flexible batten along the edge of the mast with a clamp at the 500mm mark and another clamp at the 352mm point. Simply push the end of the batten in at the end until the outside face meets the pencil mark showing the final end width and draw a continuous line along the batten from the original edge of the wood at the 352mm clamp up to the pencil mark at the end. Plane two of the faces down to these lines. Repeat again for the other two faces so the base of the mast is now 56mm square.
Planing off the excess wide staves Remove the fine nails if they are still in place. The wide staves can now be planed down flush with the surfaces of the mast Run a sander over the surface to get rid of excess epoxy. Keep it flat on the surfaces.
Final Mast Finishing Round the corners to no more than a 12mm (½”) radius – a greater radius will start cutting away the width of the glue join. If planing by hand mark a line 7mm in from the edges. Then plane a flat surface along the corner as shown in the diagram below. Then plane off the corners and finish with a sander.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 10
Cut the notch for the mast step pin
Now is the time to choose which will be the back and front of the mast. There is no structural preference. The way to choose is to look at the bend in the mast. We had bend of about 20mm in our masts. It is best if there is little or no sideways bend in the mast. So the biggest bend will be fore and aft and the notch has to be oriented to make sure that happens. See the drawing below for the notch detail for the Mast Base.We drilled the 9mm hole first making sure it was very square – one of us viewed the drill angle from the side of the mast – the other viewed from the end of the mast. We then marked the sides of the slot and cut them out with a tenon or Japanese backsaw – though a jigsaw works fine if you make sure the cut is started square to the hole mark the end of the mast. There should be a little bit of clearance so the pin can slot in easily – it needs that extra bit of clearance as the mast is about to be epoxy coated and varnished which will narrow up the slot a little. Note the little bevels at the opening of the notch. Go over the mast carefully and check that it is ready to be coated – make sure all the holes from the temporary nails have been filled and all excess glue mix has been sanded off the surface. You will probably want to make the boom and do all the coating at once – so coating instructions and final glassing of the mast is after the boom fabrication section.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 11
Making the Boom
The boom is given a little taper at either end just to make it look nice and save a bit of weight. Pic below. The mast had to have an accurate taper to get the correct bending characteristics, but the boom is a lot simpler – it is not expected to bend. So use the same tapering method that was used at the bottom of the mast. Mark the width of the end of the boom (see the mast drawing above) on all the faces of both ends of the boom with a pencil. Clamp a flexible batten along the edge of the boom with a clamp at the 800mm mark and another clamp about 300mm toward the midpoint of the boom. Simply push the end of the batten in until the outside face meets the pencil mark showing the final end width and draw a continuous line along the batten from the original edge of the wood at the 800mm clamp up to the pencil mark. Repeat for all edges and both ends Plane the boom down to the lines. Radius the corners 6mm.(1/4”). Sand the surfaces to get rid of any roughness, fill any holes ready for coating
© Michael Storer some drawings in this section by Perttu Korhonen
Page 12
Cutting the yard and marking the taper
Leave the blank (piece of timber) overlength for the moment. The width of the spar is given at different heights on the drawing. Mark these heights on one face of the spar blank. (If attempting to eliminate some of the warpage put the intervals for the most tapered end of the spar toward the most warped end, strike a new centreline and measure out from that). Use the combination square to mark the intervals across the face of the blank. Use the square to transfer the interval lines onto the other three faces. Choose a face. Work along the spar measuring and marking the correct width on each interval. The object is to take an equal amount off each side - so if the blank face is 50mm wide and the required width is 46mm, then put a mark 2mm in from each side. Where fractions of a mm are given estimate the position that the mark needs to be. A sharp pencil is essential. Turn to the opposite face and mark the widths again.
Plane the taper on the first two faces Place the blank at an appropriate height for planing. The marked faces should be to the sides Clamp it down using a scrap of timber under the clamp so the timber is not crushed. Keep the clamp away from the area that you are going to be working. Work on one end of the taper at a time. Use the longest plane possible AND KEEP IT SHARP. If it gets blunt it will start to split the timber. Glue joins will blunt the plane quickly. Start planing from the areas where most wood has to be removed - plane toward the end of the © Michael Storer some drawings in this section by Perttu Korhonen
Page 13
blank to avoid lifting the grain (though this does depend on the grain direction relative to the surface being planed - if the grain starts lifting try planing in the opposite direction). Continue planing, check to make sure that you are approaching the taper marks on both sides evenly. DO NOT PLANE THEM OFF. To produce a smooth taper USE LONG STROKES OF THE PLANE. Try and remove the timber evenly - don't concentrate on one spot or you will end up with a hollow. As you get closer adjust the plane for finer and finer cuts. When the taper on that end is done do taper on other end (if any), and then turn the blank over and do the other face.
Mark the taper for the second two faces Use the square to mark the intervals on the planed faces again. Mark the taper widths on the faces that have just been planed. Follow the same procedure as before to plane the tapers. Give the edges a 10 to 12mm radius. The yard is now shaped. The holes in each end are made the same way as per the boom on the normal rig including the glass tape.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 14
Epoxying and Glassing the Spars Even if not planning to fully epoxy coat the mast and boom (yard if using the lug version) there is some fibreglassing to be done. The largest piece of fibreglass is a single layer is a piece of cloth about 100mm wide wrapped around the mast with the middle of the glass at the mast’s widest point. - it should be long enough to go around the mast twice The other ends of mast and boom are simply fibreglassed using a 50mm wide taped (see picture below) To support the spars I generally put a piece of chipboard MDF or a piece of timber around 20mm wide up on edge – maybe clamped to the workhorses or clamped to the workbench. It will need to have a top edge 500mm or longer. Put some brown packaging tape along that edge to prevent the masts and booms bonding to the MDF. If fully epoxy sealing the mast and boom you can use the “Fibreglass taping method” in the appendices to do the glassing and coating in one hit. Precut all the pieces of glass and glass tape and make sure they are big enough to do the job. The glass tapes are to prevent the mast and boom from splitting and are applied around the ends (as
shown in the pic) Both cloth and tapes need to wrap around the mast with a minimum overlap of 20mm. If doing the larger piece of glass with shorter lengths each will have to go all the way round the mast and then the next piece up the mast will have to overlap the first by at least 50mm (2”) Coat the mast (roller) including the slot in the bottom of the mast (disposable brush). The ends of the spars are all endgrain so will absorb the epoxy very readily – they will probably need a couple of extra coats along the way turn it over from the base end – put a screwdriver through the notch. Do the narrow tapes first following the method in the appendix before doing the bigger piece of glass at the base. © Michael Storer some drawings in this section by Perttu Korhonen
Page 15
With woven fibreglass cloth bought off the roll (not tape) be aware of the SELVAGE EDGE. If you look closely at any manufactured edges of the cloth you will see that there are two or three thinner threads that look quite different from the rest of the fibres. They are there to prevent the cloth from unravelling. If they are left in the cloth and they become part of your boat they are very difficult to get flat by sanding and are likely to leave a line in your paintwork. Simply find their ends and pull them gently sideways out of the edge of the cloth. The larger piece can have one edge lined up with the centreline of one of the mast staves (preferably the back or front face of the mast). Use a roller to get it wetted out on that face – add a little bit more epoxy if having problems wetting out the cloth so it goes clear.. Turn the mast over to the next face – roll the glass down. Third face. When you roll back to the original face don’t roll down the edge just yet. Have a careful look at the glassing and make sure it is sitting flat on the other three faces. Correct any bubbles etc BEFORE rolling the last bit of cloth down onto the other edge. Continue with the following coats as per the appendix (and slide the roller to keep the surface smooth after each coat) until there are three coats on the timber and the glass has received as may coats as necessary to fill 90% of the weave. Don’t forget to recoat the ends of the spars. Leave to cure. Dewax if not using Bote Cote - Sand down the edges of the cloth flush with the timber. Sand the rest of the mast and boom to a matte finish. Be careful when sanding the radiussed edges not to go through the epoxy – might be better to hand sand.
Final Details for the Spars Use a chisel or a stanley (carpet) knife to trim down the glass cloth that is covers the slot in the mast base and any glass overlap at the ends of the spars. Finish off sanding the corners slightly to get rid of any glass bumps and sharp corners. The final step is to drill some holes through the ends of the spars to allow attachment of the sails and other fittings. Use a 12mm (½”) drill bit to drill one hole through each end of the boom – the holes should be positioned in the middle of the glass taped area. Sight carefully from a number of directions to make sure the holes will be square to the centreline of the spars. To prevent splintering clamp a piece of timber to the side of the mast where the drill will exit. Sand the edges of the holes smooth. It is good if they end up with a 3 or 4mm radius where they meet the surface of the spars to prevent wear on the ropes that will eventually be tied through the holes. If there are any sections where bare wood has been exposed put a couple of coats of epoxy on them being careful not to build up much thickness (the brush should not have much epoxy in it). Gently hand sand when finished.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 16
Varnishing The spars are now finished ready for varnishing – recommend a minimum of 3 coats for epoxy
sealed masts or 6 or more for non epoxy sealed masts. The best varnish to use is a “Spar Varnish” which has lots of UV filters to protect both the timber and the epoxy. Light sand the varnish between coats.
Fitting Masts to hulls Put the pin in place in the mast step if not there already. Don’t over tighten the bolt. It should be fingertight only. Put a bit of silicone sealant (polyurethane or silicone or waterproof PVA glue on the bolt to prevent it from rattling loose. Slide the mast into place gently with the slot in the bottom rotated to match the step pin. – if it starts to resist don’t force it. Pull it out – turn it round 180 degrees and see if it goes in more easily. If it was easier the first time go back to that position. Slide it in again gently until there is some resistance. Have a close look at the mast and partner to locate the problem area. Sometimes it is possible to see the place by looking for scratches on the mast. The area of the mast partner under the deck that is rubbing on the mast should be sanded down with coarse sandpaper wrapped around a piece of timber. Remember that material can be sanded off the opposite side of the partner too. Keep going until the mast slips in without much trouble. Check the slot in the bottom of the mast is well located on the pin – look inside the front buoyancy tank. There may need to be some material removed from there as well. Put an “F” for Front on the forward face of the mast with a permanent marker just below deck level. If the boat is being epoxy sealed - seal any areas of bare timber on the mast, boom or in the partner or step area – 2 coats wet on wet with a fairly dry brush to prevent a too thick layer being applied..
© Michael Storer some drawings in this section by Perttu Korhonen
Page 17
Centreboards and Rudders Centreboard and rudder overview Once anon a time when I was starting off in racing sailboats I bought a second hand NS14 – at that time a family style boat that had lots of performance. Over the first season I did OK finishing about midway in my local fleet. I had already owned a couple of wooden boats so I was used to doing all my repairs and maintenance myself. On this NS14 the centreboard and rudder were around the normal length but the boards were a bit wide. So I decided to modify them myself. I sawed the back off both the rudder and centreboard and reshaped them in line with more modern theory – moving the point of maximum width back slightly and in the end producing a pair of really smooth shiny foils. As a result of this the boat was a little bit faster and my results improved slightly. A year later I felt that I had got the hang of the boat and was now looking to do everything possible to make it faster. A new mast, new sails the fittings reorganised so the boat would work like clockwork. It improved a bit more. Finally I decided to get rid of my homemade foils and buy the best ones available. The first time I raced the boat was a revelation. Suddenly I was in amongst the top few boats in speed. But more importantly the boat felt completely different. It would tack and gybe faultlessly coming out of the manoeuvres with heaps of speed rather than having to get the boat moving again.. When there were big waves and lots of wind it would sail smoothly – before it used to stagger and stall. When sailing in tight conditions with lots of boats around (like milling around before the start) it gave me the confidence to go in close and pick out a good spot without getting into tangles with other boats. Qualitatively and quantitatively the boat was much better – safer and more fun. The difference between my hand hewn foils and the manufactured ones is not really all that great – almost the same amount of labour – but the manufactured foils were built carefully to accurately reflect the correct airfoil (wing) section. They used templates to get that accuracy. With this knowledge I have never needed to pay someone for first class foils. About 50 dollars worth of materials and a few hours of light labour (for small boats anyhow) and I can make a set the equal of what I could buy for 600 to 800 dollars.
IMPORTANT NOTE ABOUT USING THE TEMPLATE The drawing for the foil template will not be correctly sized when you print. It will be whatever © Michael Storer some drawings in this section by Perttu Korhonen
Page 18
size your printer WANTED to print it. So it needs to be corrected. Some people have changed the scale using a photocopier, but if you measure the length of the line and email me with the length I can send you a corrected template. Simply send the measurement to me by email and ask me to send a corrected foilplot template. [email protected]
Centreboard and rudder construction comments the centreboard and rudder are the same shape and can be made in one continuous length 2100mm long (a bit over 6ft) or they can be made separately. The rudder blade and centreboard can be glued up from timber strips or layers of plywood. Both are shaped the same way – the only difference is length. The foil shape is a special section derived by Aerodynamicist Neil Pollock a few yeas ago. It is designed to increase lift over standard sections without increasing drag. It also has an advantage that the foil has a flat section on each side which provided a stable base for the foil to sit on when it is being worked on.
Comments on choice of glue for gluing the blank/s Comments on glues for gluing the strips. In the past I have always used epoxy for gluing the timber strips for the centreboard and rudder – it is the strongest and most foolproof solution and the method below is based on using epoxy. However for our OZ Mk2s we glued the timber strips for the foils together with one of the new Crosslinked PVA glues which are designed for exterior use (DON”T USE the conventional PVA glues which dissolve when they get wet.) I don’t feel that I can recommend the crosslinked PVA glues for general gluing of other structural items on the OZ Mk2s – or at least I want to have more experience with them before I do – at the moment I don’t think they are anywhere near as strong or as gap filling as the epoxy. However using the crosslinked PVA for gluing up the staves saves a lot of mess and bother and in this application the glue will be protected by the epoxy and fibreglass that sheaths the foil and carries a very large part of the structural loads anyhow. Regarding timber selection – we used the cheapest reasonably light timber we could find. In this case the staves were cut out of finger jointed softwood (Radiata pine) floorboards. We eliminated knots by simply cutting the worst ones out. Other good timbers are Western Red Cedar (thuja occidentalis) or the Kirri (Paulownia) that is starting to be exported from China and grown in some other countries (including Australia) Correct Filler powder for Epoxy Gluing the Staves Use Lightweight filler (white Q-cels) to thicken the epoxy as glue as it doesn't blunt tools as the blanks are shaped
© Michael Storer some drawings in this section by Perttu Korhonen
Page 19
Setting up the staves for gluing The Centreboard and rudder blanks can either be made up separately or made up as one long blank over 2 metres long. See below for a drawing of the finished outlines of the foils There are two main ways to set up for gluing: 1. If the staves are short and need to be joined in the body of the board use a flat surface like a table covered with a sheet of plastic. Please make sure the table IS untwisted by putting a piece of timber across the table at either end and sight along their tops. The downside of this method is it is sometimes hard to tell if the staves are sitting flat on the table surface – so care has to be taken when clamping. 2. If the staves are full length it is OK just to glue up across two sawhorses (put plastic or plastic packaging tape on them so the epoxy doesn't stick). Sight along the tops of the horses to make sure they are parallel to one another - otherwise the board will be twisted. A sheet of plastic on the floor under the trestles will catch any glue droppings later - there will be a lot of them. Lay the staves across the sawhorses, arrange them so that you will have sufficient area to cut out the shape (we made up our blank long enough for both centreboard and rudder – but it is fine to make them up separately. Using a thick pencil or chalk draw a couple of lines from one side of the laid out staves to the other. This will allow you to simply line up the lines again to reproduce the required shape. Make sure that you keep the staves in the same order.
Gluing the Staves Before mixing glue do a dry run of your clamping setup to make sure it works. Remember the hardwood trailing edge if using low density timbers like Cedar or Paulownia. Roll all the staves up on their edges. Mix epoxy and add Q-cels to make a thick paste (like peanut butter). Spread on the edges of the staves except for one at the edge. Roll the staves back down so the glued surfaces are now in contact with the adjacent stave, line up the reference lines and clamp lightly. Adjust the staves to correct the reference line and to make sure the staves are actually touching the saw horses. Tighten clamps to a firm pressure. Do not overtighten or all the epoxy will be forced out of the join (tighter if using crosslinked PVA. Leave to cure (epoxy thickened with Qcels will cure overnight in summer, in deep winter it can take a couple of days).
Thickness the blanks Both the centreboard and rudder blanks are thicknessed to 22mm The way to do this is to remove any glue lumps from the faces of the blank with a sander. Choose the best side and plane flat by hand using a long bedded plane. You can check for twist by placing a straight piece of timber (called a “winding stick) at the far end of the blank and then placing another across at the close end and sighting to see if their tops are parallel. The second stick can be moved backwards and forwards to check different areas. Planing will usually remove would remove around 1/2 to 1mm. If the blank is quite thick © Michael Storer some drawings in this section by Perttu Korhonen
Page 20
bring it down to around 24mm using the thicknesser. Always check the depth of cut with a timber offcut BEFORE putting the blank through. Set up the thicknesser using a piece of scrap timber to cut exactly 22mm. Feed the blanks through MAKING SURE THE FACE TO BE PLANED IS FACING THE RIGHT WAY. (usually upwards) This has to be right FIRST TIME.
Marking out the blank
Mark the foil outlines on one face of the blank/s. The curved part of the back edge is marked by clamping a bendy batten to the back edge with a couple of clamps – the same as the method used to taper the booms and the base of the mast (see that section in the plans). The lower of the two clamps needs to be on the 385mm position with the other one toward the top of the board. The bottom of the batten is bent forward at the base until it touches the point 66mm from the bottom corner. Jigsaw and the curve and plane to those lines. Scribe a line down the middle of the leading and trailing edges. Use a scribing gauge, Stanley knife or similar.
Making the Foil section templates The templates allow the transferring of the foil section accurately to the prepared blank. They are precisely drawn to match the final thickness of 22mm The Diagram right gives an overview of the use of the templates.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 21
The top third of the drawing right shows the structure of the foil shape (note that the three sections nose, midsection and tail are ONE piece – they are divided to show how the curve between the shapes makes its transition). The second one shows the shape of the template and how it is cut to make a leading nose template and a tail template. The final one shows how the templates are used to shape the blank. Material has to be removed from the blank until the templates sit flat on the table and the blank as shown. 1. Prepare template Ply - take a piece of ply the a little larger than the template plots. Each one must have a perfectly straight edge. Use contact cement, tape or other non water-based glue (water based glues will make the paper swell and destroy the accuracy of the printout) to glue the foil plots to one of the pieces of ply. The baseline must run along a straight edge of the timber. 2. Cut out the template, working as accurately as possible - a jigsaw clamped upside down in a vice or "workmate" seems to work well if you don't have access to a bandsaw - it works more accurately than most bandsaws (use safety glasses and keep your fingers well away from the blade). Make sure blade is set square to base. Hold ply down firmly. Work slowly and carefully running one side of the cut along the printed lines. 3. Remove bumps - use a plane or sandpaper and block.. 4. Cut template - to make two separate templates - one for the leading edge, the other for the trailing edge.
Shaping the foil section using the templates The blanks end up shaped down the leading and trailing edges with a flat area between. The bottom edge is rounded to a smooth radius.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 22
Locate the blank on a flat surface so it cannot move. I often use screws through the blank into the work surface. The templates are accurately sized to simultaneously touch down on the work surface and sit flat on the unshaped central area of the boards. I usually leave the blank screwed down while shaping, however I do make sure the screws are countersunk sufficiently to avoid the plane blades. Do the leading edge first. Start with a coarse set hand plane, moving to a finer set as you get closer. The longer the plane the better. Plane down the board parallel to its leading and trailing edges. The template allows you to continually check the amount of material being removed. It must be positioned perpendicular to the leading edge. From time to time I survey the situation by holding the template in place and marking any high spots with chalk the moving the template down the board a bit and marking the high spots there and so on – down the length of the board. As you get closer and closer the plane will have to be adjusted finer and finer, until you change over to coarse sandpaper and a long block (length of the sandpaper sheet). Hold the block so it is parallel to the edge of the foil. When very close change over to a torture board (see diagram right – the body is some 6 or 9mm ply (¼” or 3/8”)), hold the long axis of the torture board in line with the edge being worked on but the sanding action needs to be at a 45 degree angle to the edge. When the first side is satisfactory turn the foil over, screw the foil down again, proceed as before.
Final shaping The leading edge is most important as far as the performance of the foil. Check it over for any bumps, flats or hard edges and sand them into a smooth curve. Use the torture board. Keep the long axis of the timber parallel with the edge of the foil.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 23
The trailing edge is shaped by the same method as the leading edge but with the other template. Note that it finishes to a narrow flat edge DO NOT ROUND THE BACK EDGE IT IS TO BE FINISHED SQUARE - Do not round the trailing edge corners. The bottom edge of the foil can be rounded over in a smooth arc (pic above).
Explanation about Glassing and Cutting the Glass. There are two parts to the glassing. 1. The tip is glassed first and sanded 2. The body of the foil is glassed second. Cutting the glass for the body of the foil With the leading edge upwards so that the glass can be laid around the foil from the trailing edge on one side, around the leading edge to the other trailing edge in one continuous piece.. The glass is cut to drape over the leading edge (rounded edge) and cover both sides simultaneously. Cut a length of glass cloth a little larger than the area to be covered for each layer to be applied. The fibreglass for both boats will only need to be one one layer (6oz or around 200gsm) Drape the glass over the blank. Have a close look at any manufactured edges of the glass fabric. There are usually two or three fine plastic threads (selvage edge) that stop the cloth from unravelling in the manufactured edges of the cloth. Pull them sideways out of the cloth - they are very difficult to sand smooth later. Put the glass aside in a safe place where it won’t get dusty or things spilt on it. Cutting the glass for the tip The tip is glassed with a piece of double bias cloth first. Double bias might sound a bit technical, but all it means is cutting out a piece to do the tip from the glass cloth you have bought, but instead of following the edges of the cloth the rectangular piece needs to be cut out at 45 degrees to the edges.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 24
This means the threads in the piece will be at 45 degrees to the edges of the piece that you have cut out. It doesn’t need to be exactly 45 degrees if that won’t come out of the offcut from the cutting of the cloth for the body of the foils in the previous step. This is by far the BEST way to cut out glass when it will have to curve two directions at once like on the rounded tips of the foils. One of the weird things about double bias is that if you pull one end the tape gets longer – but a lot thinner – and vice versa – it is quite difficult to keep in shape so it is important to handle it carefully and cut out a piece bigger than you really need. Probably twice as wide and about 30 percent longer than you think you need.
Glassing the foils Read the appendix regarding “Wet on Wet application of Epoxy”. When happy with the shape and smoothness it is time to glass - pay particular attention when making to decision to glass that the first 30% of the leading edge should be pretty smooth. When you run your hands around the leading edge there should be no bumps or hard edges – your good work here will result in much better boat performance later. Fix up any problems using the torture board or a long block as described before. Generally I do foil glassing in two steps allowing the epoxy to cure after the first before doing the second: 1. Do the tip 2. Do the body It is possible (but slightly more risky) to do the tip first immediately followed by the body If wanting to do it in one step I predrill a hole for a long plasterboard (drywall screw in the tip of the foils before they are glassed. Then when the tip is glassed as below the screw can be put in and the foil © Michael Storer some drawings in this section by Perttu Korhonen
Page 25
suspended between two sawhorses as in the section “glassing setup for the foils” below. Glassing the tip of the foil Glassing the tip When you are epoxying you only apply resin to the areas where you want the cloth to stay – with these foils the epoxy should only go about 20mm (¾”) past the tip. Stand the foil with the tip upwards and clamp to a sawhorse or in a vice so it can’t fall over. First brush epoxy on the tip of the foil plus about 3/4” and then lay the bias tape on the surface. Use a brush with a gentle dabbing motion to apply epoxy until the glass goes clear in the defined area. Each time the resin goes tacky add another coat until the weave of the cloth is filled. Allow the epoxy to cure then using 180 sandpaper and a cork block sand the end smooth and matte ready for the flatter surfaces of the foils to be glassed. Glassing the body I usually set the foil up with the leading edge facing upward by running long drywall screws at least 25mm (1”) perpendicularly into each end of the foil. The screws need to be about 50mm (2”) behind the leading edge. The screws can then be placed between two sawhorses with the foil suspended between them. The gap between the sawhorses and foil needs to be no more than 12mm (1/2”). Place a piece of scrap timber over the heads of the screws and clamp it to the sawhorse (or screw it down with a couple of screws.
Epoxy the first layer of glass Mix epoxy and roll onto the glass. Starting from the centre of the leading edge roll the glass into even contact with the blank. Working from the middle out to either end and from the front to the back pulls the glass out and stops wrinkles from forming. The glass will go clear when the epoxy is rolled in properly. Add only enough epoxy to do this - the texture of the cloth weave should still be visible.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 26
Fill the weave Wait for the epoxy to go sticky - if more epoxy is added before the first coat has become sticky the glass will float up on top of the epoxy and the foil won’t finish smooth.. Roll a coat over the glassed surface. If the roller is held so it cannot turn and lightly pulled across the epoxy it will smooth the surface – as you do this the cloth has to be kept tensioned by working from the middle out to the ends and from the front to the back.. When it goes sticky roll on another coat, skid the roller to smooth the surface. Continue adding coats as the previous one goes tacky until the weave is filled. Runs may occur if you don't allow the previous coat to go tacky enough. With 200gsm (6oz) cloth usually there are a total of three to four coats of epoxy required to fill the weave.
Trimming the glass when the epoxy is cured When the epoxy is cured (usually overnight) the excess glass can be trimmed off. Work carefully around the foil trimming down excess to a few millimetres. The final trimming will be done with sandpaper and a cork block. Keep hands well away from glass edges. If you drag your skin along a raw glass edge it might cause a cut
Final finishing De-wax the foil if necessary. See appendix. Give a power sand with a random orbit sander to get rid of any bad lumps and bumps from glassing Use a torture board with 150 grit paper to do a rough smooth, then move to 220. Use worn out paper on the leading edge and work carefully and gently so as to not cut right through the glass to raw timber. As soon as any area loses its shine move onto the next. Use the torture board to flatten off the flat trailing (back) edge so the edges of the flat are sharp – not rounded
Final Epoxy Coat. When the foil is evenly matte (not shiny) it is ready for one very thin coat of epoxy to seal up the glass completely. When the epoxy is cured give a light sand with fine paper (300grit) to make the surface matte for Drill two 8mm holes approx 150mm apart in top of blades for rope handles.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 27
Painting/Varnishing Foils (Read Appendix on Painting/Varnishing.) Be aware that the boat’s performance will depend largely on the smoothness and fairness of the foils. It does make a huge difference. Use a two pot polyurethane for a strong speccy job, coat with epoxy hi build primer and then sand sand sand. White is preferable for heat reflection and to enable spotting of weed when sailing. Follow directions on cans Varnish is easier but will increase maintenance slightly – follow directions on can. Do three coats with a light sand between then use the method below to make surfaces really fair and smooth. Sand well between coats to remove defects – use a fine paper (280grit) on the torture board. Be VERY careful when sanding the round of the nose – use fine/worn paper with a cork block and light pressure. Apply final coat or if varnishing apply another two coats giving a light sanding between them with 280 sandpaper. Sand final coat up through the grades (you can use wet and dry paper wrapped round a cork block. 280 until it is 70 percent matte and 30 percent shiny 320 until it is 90% matte 400 grit until the shine is all gone. This is an excellent racing finish. If buffing the board (I wouldn't bother) make sure the cutting compound contains no wax or silicon as it repels water resulting in air bubbles sticking to the surface and causing extra drag.
Making the handles Cut two lengths of the 6mm rope that you are using for the mainsheet approx 350mm long. Heat seal the ends using a match and wet fingers (so the molten plastic will not stick to them). Tie a figure-of-eight knot in one end - feed the rope through one hole - take it diagonally across the top of the board, through the other hole and tie another knot. It provides a handle and acts as a stop to prevent the foil from going down too far.
Fitting the spacer to the centrecase The centrecase is larger longitudinally than the centreboard. The centreboard is about 280mm wide and the case in the same direction is 316mm. The approximate difference of 36mmis a bit large but allows errors in building to be soaked up simply. Plane down a scrap piece of timber as a spacer to fill the gap. I recommend leaving about 6mm of space behind the centreboard so it will slide up and down easily. The spacer can © Michael Storer some drawings in this section by Perttu Korhonen
Page 28
be a bit narrower than the 25mm of the case. Don't glue it in place but attach it with a single screw through the side of the case plywood just under the top stiffeners. That way, if it gets bashed up by the boat hitting something it can be replaced. We seldom see much if any damage even stopping suddenly in higher speed boats.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 29
Rudderbox, Tiller and Tiller Extension Overview I hate to be blunt but rudderboxes break if you don’t use the bolts in the drawings. The Rudderbox shown in the photos use our own homemade rudder fittings including lots of glassing to hold them on! Great if you want to save the last dollar. The info to make a similar set up on Peter's website www.pdracer.info In the building pages However, these plans will be focussing on using off-the-shelf rudder fittings – usually in stainless steel or plastic – just buy them and whack them on. As you can see from the drawings the width of some of the framing may have to be changed to match the inside width of the fittings.
Rudderbox Make up two rudderbox faces. The leading edge block has to space the ply faces apart by 25mm. Use the “One hit gluing and coating method” in the appendix to coat all the internal surfaces of the rudderbox before gluing the items together. When the glue has hardened sand any excess glue down flush with the timber. Leave the outside faces uncoated. Don’t glue on the framing yet.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 30
Plane the Rudderbox framing down to match the rudder fittings A standard stainless steel rudder gudgeon is shown at the bottom right of the drawing below. Its internal width has to match the overall width of the rudder box plus the external framework shown in the drawing above and the picture right. Note that the drawing below is from the OzRacer, but it shows the fastenings and fittings correctly – the tiller is different on the Ocean Explorer.
The 19 x 45mm stock can be planed down to match this thickness. Its width can also be reduced to save weight and bulk on the rudder.
Rudder Fittings The picture above also details the method of bolting on the rudder fittings. Note the method of bolting on the rudder fittings using one bolt through the whole rudderbox assembly and two shorter countersunk bolts fitted from the inside. The shorter bolts are simply tightened until the countersunk head is flush with the internal faces of the rudderbox. If the bolt starts to rotate a fine screwdriver head place sideways in the screw slots will stop this. Then remove the bolts and dip them in epoxy before fitting them permanently. This is a good procedure for all fastenings – it keeps the water out and increases the strength of the attachment.
Transom Gudgeons There are two types of rudder fittings for the back of the boat. © Michael Storer some drawings in this section by Perttu Korhonen
Page 31
1/ Gudgeons with holes. The matching rudder fittings are to be bolted to the transom. If using a single pin it shouldn’t be so long that it will drag in the water. If using pintles with integral pins move the top fitting down ¼” so the lower pintle engages the lower gudgeon first. It makes it LOTS easier to put the rudderbox on the back of the boat as one pintle can thread in first and then you thread the second.
Make up Tiller Extension Optional – the tiller extension allows you to sit in many different place around the boat. For best performance it is best to sit at the front of the cockpit or a little further forward providing the bow transom doesn't dig in and start slowing the boat down. The Tiller extension can be any piece of timber 780mm long with a minimum cross section of 19 x 12mm (¾ x ½”). Glue ply pad on the end.
When the glue cures round the corners and drill the 6mm (¼”) hole. Sand off the sharp edges of the hole so the rope tiller extension will not chafe. Coat with epoxy dewax if necessary and varnish.
© Michael Storer some drawings in this section by Perttu Korhonen
Page 32
Making the Sail Sail choices for the Mk2 OZ Racer? These components work perfectly on the OZ Racer. If you want to use them for a PDRacer it is your responsibility to check the rules or any rule changes to make sure they still comply. We are not responsible for ensuring that sails or other components used For your boat to be a legal puddleduck. The lug rig fits the Ocean Explorer. The sprit sail will not fit. These instruction have been adapted to match the Ocean Explorer. Our general recommendation is to make the sails to be made of polytarp. This means the sails cost about 1/12 of the cost of commercial sails.. It doesn't mean any more than a slight performance decrease compared to commercial sails as we have gone through a serious development process involving developing four masts and four different sails to work out the optimum simple design. The overarching reason is for cheapness. Materials for sails can be as little as $40 for quality polytarp plus a few hours labour. Our reason for not liking second hand sails is that it will lead to a sail “arms race”. I know I can pick up a really nice sail two or three years old for around $100 and my boat will go faster than if it had a polytarp sail. Someone else can see this and get the same type of sail but only one year old for $350. I can respond by getting a sail that has only been used in one regatta for around $500. This might be important if racing becomes regular for Oz Racers. That is getting quite close to the cost of building a whole OZ mk2! Polytarp is a great way of ensuring the sails remain cheap for everyone. The other reason is that because we have gone through a careful development process to make sure the sail works really well with the OZ racer and most manufactured sails and other rigging will not suit the boat as well. Additionally the relationship between the centre of the sail and the centreboard might be out of balance leading to a large drop in perfromance and difficult handling. When we find a better material that is also cheap and strong, available in big enough sizes to make reasonable sails with simple methods we will allow it as well
Sail Materials and Construction We still are in the early days of making these ultra cheap sails so the instructions here are for fairly conventional sailmaking methods We know they are reliable.
© Michael Storer 2006
Page 33
So far our sails have been used for about 80 hours of sailing and have been exposed to the sun for 300 hours. They still work fine though we will probably be making up new sails before the National Titles in Goolwa in March. This is probably equivalent to year of use in most racing boats and the sails are going well. The Americans have done a huge amount of practical research on sticking polytarp sails together with double sided exterior carpet tape and so on – but we just don’t know how it will hold up in Australian conditions. So we use stitching. Cheap and very reliable. More on that later.
Polytarp sizes I have drawn up our standard sail sizes to give the minimum tarp sizes for making a single sail and also for making two sails out of the same tarp. Some of the suppliers on Peter Hyndman's http://www.pdracer.info site are selling a higher quality polytarp as well as fully made up sails. Because of the simple construction and cheap fabric they are less thean half the price of regular sails. Also polysails.com can send a nice package of sailmaking materials internationally. Other configurations are possible but see the sail drawing below as one of the edges of the sail (the leach – ie back edge) needs to be in line with the long edge of the tarp. None of the existing edge reinforcements or eyelets of the original tarp can be used – none of the edges of the sail are straight. Tarps often have lots of quite heavy creases when they come out of the packaging. We pegged it out in the sun for a day and the worst of the creases disappeared.
Stitching the sail Not everyone has a sewing machine – but the sail is put together temporarily using double sided tape – so it is possible to get it all assembled than stitched afterwards.
General Comments on Lug Rigs I would like to think I am something of an expert on lug rigs ritted to small boats. I have sailed countless hours with such rigs including weekly club races against conventional boats through to classic boat regattas. My website has probably the best resource on the web (and maybe anywhere) for setting up lug rigs to sail really well – almost equal to “modern” boats. Experience sailing a OZ Mk2 with a lug rig. I did put the much larger Goat Island Skiff sail on one of the Queensland OZ Mk2s earlier this year as an attempt to take the maximum sail area record from the Americans (right). I was only game to sail in quite a light wind as the standard OZ Mk2 mast is too lightweight and flexible for such a large sail area – I was worried about breaking it. As you probably know the sail area on the OZ Mk2 is quite large as standard (82sqft) but lug rig was much larger (105sq feet).
© Michael Storer 2006
Page 34
The OZ Mk2 handled the big lug rig beautifully, sailing upwind and down sedately under control and accelerated quickly to quite high speeds in the light breeze. It tacked and gybed reliably as well. The picture on the cover of this plan supplement is of the OZ Mk2 with the Goat rig, but I have photoshopped it to give a more correct scale for this revised 90 square ft (8.3m 2) version. I don't think there is much point in going smaller as the lug rig is easy to reef to match the wind. Advantages and disadvantages. The lug rig has a number of advantages and only one disadvantage that I can think of. So let's talk about the disadvantage first. There is an extra spar to make up and I do recommend that it be made round to make best use of the flexibility to get an improved gust response for sailing in strong and fluctuating winds. It probably adds around 2 to 3 hours to the building time. The advantages are 3. The sail can be reefed easily for different wind strengths and sea conditions. I have made use of this capability by making the sail slightly larger than the original sprit rig. There is no discredit in sailing around with the sail reefed in moderate winds – particularly when you can use full sail in light winds and blow everyone away with the performance. 4. The spars are shorter allowing for easier stowage and cartopping – a maximum of 3.9m (13ft) – three feet shorter than the original rig. 5. Shorter spars reduce the timber cost and maybe reduce the weight slightly. 6. The centre of effort of the sail is a little lower allowing a larger sail to be carried. Parts and Materials for making the sail Overview – The Americans have done a huge amount of work as far as making sails with really cheap materials – like using double sided tape used to put exterior carpets down around swimming pools – some brands work well, but others don’t. These plans are being sold throughout the world and we don’t know what the quality of these different products are in different areas. So our solution is to just talk about the normal construction materials for conventional sails – reliable and reasonably cheap. If you want to experiment – feel free. The final thing is that the mast and sail of the OZ Mk2 are designed as a unit. You can’t change one without changing the other – or you can – but you will probably degrade both the performance and the ease of handling. Polytarp – we bought a polytarp to make our sails. There is nothing wrong with this approach – but companies mentioned on our website are able to supply a good quality polytarp fabric. We recommend a fabric weight of 140gsm (3oz/yd 2 ). Sailmaker’s double sided tape – this is an industrial grade double sided tape – once it sticks it doesn’t like to let go.
© Michael Storer 2006
Page 35
Eyelet kit – from a sailmaker, tarpaulin maker or camping goods shop. The best ones have little teeth punched into the washer side that grip the cloth. We were not able to find them and had no problems. Internal diameter of the eyelet should be around 12mm (1/2”). We were able to buy eyelets and the dies for around $15 as a kit. Thread – You will need a really good big spool of thread. We bought some normal size bobbins and they lasted about 5 metres. We a really big spool at a $2 shop. It needs to be polyester and get it in black or very dark blue – it resists UV light better. Also just try to break it in the shop. Masking tape – paper crepe type – 19mm (3/4”) wide String – about 6m (20ft)
Tools Sewing Machine – the sail can be fully assembled and sewn after. A good domestic machine will be fine – or take it to a tarpaulin maker/sail maker/saddler – many places that can alter clothes have industrial machines that will make quick work of the sail. A zig zag stitch is best – details in these instructions below. Scissors Ruler Tape Measure Permanent Marker – not too thick Flexible batten for marking curves – must bend smoothly around 5m (17ft). Eg Piece of aluminium section, fibreglass sail batten, piece of timber, piece of plastic electrical conduit.
© Michael Storer 2006
Page 36
General Sailmaking method The following method gives the general method of marking out the straight and curved edges of the sail and the details of adding the eyelets and hems. There are some cheats over conventional sailmaking methods, but they work quite well.
Marking out the sails
Lay the tarp out flat on a level reasonably hard surface and pull it out so it is flat. Hold it out with weights on the corners or by taping them down. © Michael Storer 2006
Page 37
Mark out the leach – (the back edge) first – it is the longest line between the corners P and C for the lug rig sail outline above – see the small inset diagram. On the drawing it is
the one marked as having to be aligned with the edge of the tarp – keep it a minimum of 50mm away from any stitching, seamed edges, hems or overlapped reinforcements on the polytarp. Next mark the “Th” (Throat) corner. This provides the baseline so you can marke the “Tk” (Tack) corner. This gives us the four corner points of the sail and the lines give us the reference points for setting up the curves of each edge.
Marking the reference points for the sail’s edge curves Mark the corners as shown with the letters H, Th, Tk, C. They have to be in the correct positon relative to the edge of the polytarp. (see next diagram) Choose one of the edges to mark from the dimensioned drawing. Use two weights (anything heavy that you can tie a string to - (housebrick, heavy tools, jug full of water) to tension a stringline that passes over the corner points of that edge. © Michael Storer 2006
Page 38
© Michael Storer 2006
Page 39
Divide the edge P to Th into four parts as shown in the detail drawing above. Their actual position is from the dimensioned sail drawing above. Mark their position with a small
cross. Mark the short lines using masking tape stuck to the sail – make sure it lines up with the cross as the base and use a square to make sure it is at 90 degrees to the stringline – be careful not to push the stringline out of position! Note carefully that some of the short reference lines go towards the outside of the triangle and others go towards the inside. Make very sure have the intervals marked on the correct sides – the side with four intervals has “H” and “T” at its ends. Next use the sail drawing measurements to mark the distances along the reference lines measured from the stringline to mark the points the curved lines must go through. Put a clear mark on each of the short reference lines.
Copy the curves from the drawing to the P – C edge and the C – Tk edge as well.
© Michael Storer 2006
Page 40
Now mark the curved edges of the sail. The curves must meet up with the corners and pass through any points on the reference lines. You can use anything that curves evenly. A wooden batten, some electrical conduit pipe etc.
That’s the outline of the sail marked out. The next part is to allow a bit more fabric so the edges can be folded over to make a hem around the sail later.
Marking the hem and corner detail The next drawing shows the detail of what has to happen. We folded a piece of paper to be the width of the hem (40mm wide) and used it to mark a dashed line 40mm outside the curved sail outline. Detail the corners as shown. Corner H is redrawn to create a width of approx19mm.
© Michael Storer 2006
Page 41
Fitting the Corner Patches Here is the drawing for the size and position of the corner patches.
The large patch at bottom right and the one along the bottom edge of the sail need to be cut from the polytarp with the long edge parallel to the edge of the polytarp. The dotted lines indicate reef points if required - the reef point eyelets at the edges of the sail need to have a total of 4 layers of sailcloth using patching like the corners of the sail.
© Michael Storer 2006
Page 42
Cut the sail outline and cut and fit the reinforcing patches The sail may be cut out – be very clear that you are cutting around the newly marked line 40mm out from the actual sail edge. Cut the corner details as in the previous diagram. The offcuts are used to cut the corner patches. The layout is shown below. The important thing is that the longest edge of each sail patch needs to be parallel to the original edge of the tarp to take advantage of the low stretch direction of the threads that make up the cloth. Lay the bottom of the sail over the scrap material to mark the long patch.
Patch measurements are shown in the drawing on the previous page. Cut them and label them with H, C or T as you go. Check the patches against the sail shape – they have to fit inside the curved outline of the sail – 40mm in from the cut edges. The biggest change is that some of their edges will need a slight curve (see diagram below). Use the sailmaker’s grade double sided adhesive tape to stick the first two patches in place as per the diagram below. Important - Keep the tape around 6mm away from the edges of the polytarp. Some tapes leave a sticky residue on the sewing machine needle which can jam the machine.
© Michael Storer 2006
Page 43
Fit the last three patches (diagram below). Also you need to make up a number of small triangular reinforcements as shown in the patch and reinforcement drawing above along
the edge between P and Th.
If you need to transport the sail to get it stitched. Now the sail is all assembled it needs to be stitched. The sailmaker’s double sided tape is strong enough to hold it together quite well for transport – if you need to take it to someone else’s house or a dressmaker or a sailmaker. If using a domestic sewing machine I would recommend that the patches are stitched first, then the hem rolled over and stitched separately. This reduces the load on the machine. I would put the double sided tape along the outside edge of the hem (the edge of the cloth) but leave the paper protection on the upper face to prevent the tape from sticking while the sail is being moved around. Then after the patches are stitched the paper protection can be removed and the hem stuck down then sewn. If using an industrial machine the hem can be rolled over now as well as it will be powerful enough to stitch through lots of layers (see the section after the following).
Stitching the sail The best stitch is a zigzag pattern that goes through the cloth 3 or 4 times per zig. Diagram right. For those who haven’t done machine stitching before you start and finish by going backwards and forwards with the machine one time for about 19mm (3/4”). The edges of all patches need to be sewn down
© Michael Storer 2006
Page 44
including the ones that run along the curved edges of the sails. Also the hidden edges of the patches need to be sewn. Next diagram.
Roll over hems, stick and sew. The hems need to be rolled over. It is important to be quite careful with this part of the work. The hems tend to crease because of the geometry of the curved edges. It is important that the creasing is minimised by folding the edges over very accurately.
Put double sided tape along the outside edge of the hem. Fold over the hem along the edge H to T first. It is easiest starting from H and work to T. Sit or kneel outside the sail and lean forward so you can keep a clear view of the curved edge of the sail – this is where the fold has to take place. Fold the hem in with hands spaced about 400mm. Try to keep a slight but even tension along the cut edge. Do T to C (start at T). Then finish with H to C – which is the most important one to get right. When the whole hem is down it can be stitched as before. Also stitch down the ends of the hems in the corners of the sail – so the whole fold is stitched down securely. © Michael Storer 2006
Page 45
Fit Eyelets The edge of the finished eyelet must finish at least 6mm (1/4”) away from the hole. This means the hole will have to be further away from the edge than 1/4”.
Eyelet kits contain a punch for making the hole – usually a tube with a sharp edge. Put a scrap wooden block under the cloth and rest the sharp edge of the hole punch on the fabric and hit the other end with a hammer – just hard enough to punch a hole.
There are usually two dies in a eyelet kit and two different parts of the eyelet itself. You assemble the whole thing from the bottom up (diagram right) then hit the top with mid strength blows from a hammer or mallet until the eyelet bottom has bent over and covered the eyelet top. Your sail is now complete.
© Michael Storer 2006
Page 46
Appendices 1. 2. 3. 4. 5. 6. 7. 8. 9.
Cordless Battery Drill with Clutch Wet on Wet Epoxy Application and dewaxing cured epoxy One hit coating and gluing Gluing and filleting using snap-lock Plastic Bags Precoating Plywood Panels before Assembly Gluing endgrain Building strong lightweight boats - a note on the use of epoxy Fibreglass taping method – coat and tape at the same time. Painting and Varnishing
Cordless Battery Drill with Clutch. A marriage made in heaven. The drill can be battery (most convenient) or mains powered. It is best if it has a variable clutch. If you have a drill without a clutch, you can often buy a new chuck with inbuilt clutch. The screws are self tapping and match a Phillip's head bit in the drill. Just hold two pieces of wood together with one hand and drive screw in with drill in other. Fast - and the screws should be removed and may be re-used. If you want to minimise the indentation where the screw head meets the ply, use a plywood pad already placed on screw. If gluing, the pad should have some plastic packaging tape wrapped around it to stop accidental bonding to the workpiece. I mass produce the pads by cutting a strip of ply (usually 6mm, 1/4" thick) about 19mm wide (3/4"), covering one side with packaging tape, then cutting it into 19mm (3/4") squares. Screws should be removed when the epoxy is hard enough – usually the following day – it should feel hard when you try to indent it with a thumbnail. If the screws ever get stuck so they can’t be undone apply some heat using a cheap electric soldering iron (right). A couple of minutes and the epoxy will soften enough for them to be unscrewed.
Wet-on-Wet Coating and Dewaxing Cured Epoxy. Great improvements have been made to Bote Cote brand epoxy in regards to this problem. It is very unlikely to occur at all. All the preparation you need for the next process is to sand the hardened epoxy surface. The wet-on-wet application method is still the best as you don't have to sand between the coats. However other brands of epoxy may suffer from wax. As epoxy cures some of the unreacted components migrate to the surface, leaving a waxy residue. This can reduce the adhesion of following coats, whether epoxy or paint and make them go "fish-eyed" (the surface finishes pitted). This is why I always use a "wet-on-wet" epoxy application method (see "epoxy coating" © Michael Storer 2006
Page 47
above). If the surface is allowed to cure it will have to be dewaxed (not Bote-Cote) and sanded (Bote Cote too). Dewaxing - When the two to three coats have cured I always de-wax the surface using a plastic domestic scourer (Scotchbrite) and water with some cloudy ammonia added. Scrub very thoroughly. You can then sand the surface to key it for further painting, epoxying or gluing.
One Hit coating and gluing An extension of wet on wet epoxying is a method for coating areas that are easy to get at now (plain plywood components) may be hard to get at a bit later when other parts are attached. A couple of examples are fitting the bottom, fitting the side decks and fitting framing to the bulkheads. For example if gluing the bottom panel in place it is easy to coat the inside of the bottom at the same time. For major gluing processes like this it is important to make sure that everything will work smoothly – do a DRY RUN without the epoxy to make sure that you have enough screws etc to hold the bottom on OK – you can use the same holes again when you are putting the bottom on permanently. This is the method (put on your disposable gloves!!!). 1/ get all the framing that the bottom will be attached to bevelled and ready to accept glue 2/ put three coats of epoxy “wet on wet” on the inside of the bottom as per the method in the appendix above. 3/ immediately put glue (epoxy plus the gluing thickening powder – make up to a peanut paste thickness) on all the framing of the hull that the inside of the bottom will be glued to – spread it out ready to take the bottom. 4/ drop the bottom on with its wet face in contact with the glue in the previous step and screw the bottom in place. 5/ clean up any excess glue that has squeezed out of the joints about 20 minutes after the assembly. If you wait till tomorrow you will be sanding forever. Use a flat piece of timber sharpened to a chisel edge on the end with a sander. The same method can be used when putting the framing on the bulkheads. Coat one side of the bulkhead immediately before gluing the framing on that side.
Filleting and Gluing using “Snap Lock” Plastic Bags Most supermarkets have varieties of “snap lock” bags. They have a seal across the opening of the bag that can be pressed together with finger pressure. They make it a lot easier to keep epoxy glue away from areas on the boat where you don't want to put it. And also areas on yourself where you don't want to put it! Make up some epoxy, thicken it to the consistency of peanut butter. Put a "snap lock" Glad plastic bag into a tin and fold the top of bag over lip of tin (like a garbage bag in a garbage bin - trashcan). Scrape epoxy into the bag.
© Michael Storer 2006
Page 48
Take bag out of tin, seal opening and cut one corner out of bag to make a hole a few mm (approx 1/4") across - size will need to vary with consistency of mix. By gently squeezing the bag a bead of epoxy will ooze out of hole in controlled way from the hole. Pipe a bead of epoxy down the angle where you want the fillet Then use a shaped piece of timber as shown right to shape the epoxy. Use a filleting stick of a radius three times the lesser ply thickness to smooth down the fillet. Practice getting it smooth and even. Remove excess from either side of fillet with a stirring stick that has been sharpened to a chisel point. It is possible to lay masking tape down either side of the join in the first place so that the excess can be removed with the tape.
Precoating Plywood Panels before Assembly. I find this the best method, where possible. It saves the effort of sanding between coats of epoxy and prevents any waxing problems between the wet-on-wet coats. Mask off all areas that you don't want coated. (Especially any areas you are going to glue to later – not strictly necessary with the Eureka.) Lay surface flat where possible. Mix resin and hardener. You don't need to add any powder when you are coating – they are only used when gluing one piece to another. Apply first coat. NOTE - If doing large areas the epoxy will go off too quickly if left in the mixing tin. You will have much more working time if you pour most of it out over the surface first and roughly spread with a squeegee, before going back with a roller to spread properly. Don’t bother to buy a commercial squeegee – just use an offcut of ply about 200 x 75+mm (8 x 3”). Make sure the working edge is straight and that you have sanded the sharpness off the edges and corners. When it is spread hold roller so it cannot rotate and pull gently along surface of epoxy. It slicks the surface smooth and pop any air bubbles. When first coat has become quite tacky, roll on second coat. Slick the surface. When second coat is tacky roll on third (if required) and slick it down. IMPORTANT - Remove masking tape when third coat is still tacky. You don't want to glue it down - forever. When epoxy is fully cured turn the panels over, sand off any drips that have come from the other side and repeat process if required. When the epoxy has cured sand the panels smooth using a random orbit sander (these © Michael Storer 2006
Page 49
tools are a very worthwhile investment but hand is fine too). 180 grit paper is about right. Sand enough to remove gloss. If you have problems getting a good finish speak to your epoxy dealer.
Building strong lightweight boats - a note on the use of epoxy Epoxy is expensive stuff, so when there is a bit left over from a process there is a temptation to use it somewhere. Don't do it! The boat has been carefully designed to be strong enough already - all you will do is add weight and ruin the boat. Where you can use it for a legitimate step, do so - but think about it first. Another time it is best to throw out epoxy is if it is starting to go off in the bag or tin. If it is starting to get too hot to comfortably hold it is going to be hard very shortly - you are unlikely to have enough time to put it into place. Furthermore, hot epoxy fillets slump badly, hot coatings wax and get fish-eye pitting, and hot glue joins end up with lumps that stop clamping. Make up a smaller mix next time and get it out on the surface earlier – straight after careful mixing in the tin or bag.
Gluing Endgrain See drawing of endgrain right.. When gluing endgrain with epoxy it is a two stage process. Mix enough resin and hardener to do the job. Stir well. Brush the mixed epoxy onto the endgrain. Wait 5 minutes - brush more epoxy on the endgrain. Now add the high strength gluing powder to the epoxy in the container and apply to gluing surfaces. And hold in place by normal method until the epoxy sets up. .
Fibreglass taping method The method for fibreglassing hull seams can use the same wet-on-wet approach as above but with a small change to integrate the application of the glass tape. It makes it a very clean and tidy process once you get the idea. Fill any screw holes, allow the epoxy to cure and sand flat. Radius the edges that the tape will be applied to. A minimum of 3mm (1/8”) is just enough to allow the glass to wrap around without lifting. A bit more is better – but don’t round the edges around the transom at the stern too much – the water wraps round the corner when sailing causing drag. Apply first coat of epoxy to hull (pic below left). Note the masking tape to prevent epoxy drips running around the corner onto the deck. The finish can be quite smooth by holding the roller so it can’t turn and lightly and slowly skid it across the surface to pop bubbles and get rid of roller marks..
© Michael Storer 2006
Page 50
Put glass tape down in wet epoxy (pic below right). I should be wearing gloves.
Detail of glass along transom.(pic below left). Use the roller or a cut down disposable brush (bristles not longer than 25mm (1”) to work epoxy into the glass tape – it goes clear when the epoxy has wetted it out correctly. An example of wetting out (pic below right) – the glass along transom is now wetted out and becomes clear. Continuing with the transom sides – here cutting tape to length.
Roller method (pic below left)
© Michael Storer 2006
Page 51
Finished taping and second coat is put on when first gets tacky (pic below right) – roll the epoxy out well so as to not add too much weight – but roll a little bit extra on the tape – too much and it will run down the side.
When epoxy goes tacky apply a third thin coat and skid the roller to give a smooth finish. If the weave pattern is still visible in the glass tape roll another coat to fill up the weave. Leave epoxy to cure. The next day – while the epoxy is still a little cheesy (if you leave it too long it will make this hard work) set a fine spokeshave fine and get rid of the edge of the glass tape. Keep the body of the spokeshave over the glass but set the blade with a tiny bit of depth on the edge side but no depth on the other. Work carefully and slowly. Then sand the glass tape using the random orbit sander and 120 grit paper. Keep the edge of the sander lined up with the edge of the glass, but keep the sander body over the tape. Angle the sander - concentrate a bit of weight on the side of the sander over the tape edge and keep the rest of the sander off the surface of the tape. Finish off by sanding the rest of the bottom to a matte finish (no gloss) but don’t go through the epoxy to the timber. Generally I brush a couple of thin coats onto any areas where I go through to the wood – allow that section to cure and give a light sand – making sure I blend the edges of the brushed area.
Painting and Varnishing Paint is more durable and will protect the epoxy and timber the best. Varnish hides a rough surface better. If you have done a rough job the timber grain will hide it. Make sure the varnish contains ultra-violet filters. My usual plan is to varnish the inside of open boats and decide to paint or varnish the outside. Generally if you can store the boat indoors when not in use there is no reason to not leave the outside clear finished. But it is going to be left outside much of the time I would consider a painted exterior including the gunwales and remember to leave the boat © Michael Storer 2006
Page 52
upside down. There are two basic types of paints and varnishes. 1.Two pot - which is very hard and durable, but can be hard to get a good finish with a brush and to touch up. You have to be careful of the fumes. No primer or undercoat is required. 2.Conventional varnishes - thin with turps, are easier to put on, but may remain soft for some time. The conventional varnishes often have a better gloss and I think they are much more pleasant to use (feel nice/smell nice). Use varnish and paints according to manufacturer's directions. A professional finish is 90 percent dependant on getting the surface smooth between each coat. My tendency for maximum durability and best appearance would be to use a two pot polyurethane for the outside, round to the underside of the gunwale, and a varnish on the interior. For rough use I would paint the whole thing. Consider masking off some of the floor areas with masking tape including nice rounded corners and using a non-skid finish. Paint and Varnish Maintenance Hose the boat out after use and mop up any water – empty the buoyancy tanks and leave the covers off. If leaving the hull outdoors for extended periods turn upside down on a couple of bricks or timber blocks to avoid contact with the ground and so that air can get under it and water can run off and put a tarp over the top to prevent UV damage. If the epoxy coating is damaged put three coats epoxy (wet on wet) on the exposed wood and touch up with varnish or paint. If varnish is continually exposed to sun it will need a light sand and two or three new coat every year (less in Northern Australia). Two pot varnish will go for a couple of years under the same conditions. Conventional paint can be given a fresh coat when it starts looking shabby (3 years?). Two pot paints should be good for 5 years or more. Keeping the boat out of the sun will reduce need for maintenance many fold.
© Michael Storer 2006
Page 53
OTHER PLANS – see www.storerboatplans.com Goat Island Skiff - Modern Performance with Classic Appearance Plans $100 15'8" x 5' x 130+lbs (hull) x 105sq ft
Eureka Canoe - Light, Pretty, Easy to build in Plywood Plans $75 15'6" x 34" x 44lbs (6mm ply) Can be built down to 34lbs
MSD Rowboat - NEW - Easily driven pulling boat for one with occasional crew. Plans $90 15'8" x 4' x 90lbs (estimate)
Handy Punt - Cartop, Stable Fishing Platform, Good Performance Plans $80 11'6" x 4'2" x 110lbs (approx) 8 or to 15hp if you want to go REALLY fast.
Quick Canoe 155 – Builds in a few hours (5.5 is common), cheap to build. Plans $30 First one took the builder 4 1/2 hours to get on the water. It has been designed to be as easy to build as possible while keeping some of the qualities of a good paddling canoe - in particular the ability to track.
© Michael Storer 2006
Page 54
How long is this distance?
To be corrected to 5 inches (126.4mm)
Baseline
Trailing edge 22mm
Do not use this template - read the instructions about the foilplot in the plans. Measure the vertical line to the left in millimetres and write down the measurement.
Baseline
Leading Edge 22mm