Priorities
for racing success
1. an enthusiastic and positive crew/helm
relationship
2. on-the-water experience
3. sail trim and boat handling
4. preparing the mast, hull, rigging and
foils
5. knowledge of rules and tactics
Preparing
the mast, hull, rigging and foils
Note: Check Class Rules for
detailed specifications and limits.
1. Hull
-
smooth with no major imperfections
-
clean fiberglass with fiberglass cleaner
-
fill imperfections with epoxy and micro-balloons
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final sanding with 600 paper
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put extra effort into the first and last three
feet of the hull
2. Rudder
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front edge must be vertical when in sailing
position
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sides of the blade to be smooth and flat
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leading edge to be rounded into a parabolic
shape
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shape leading edge to razor sharp for 1 inch
above & below water line
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trailing edge to be tapered to a “V” shape (Al’s
note: This is a good wood to make the wood core. In sanding the glass or
epoxy covering, I try to give this edge an air foil shape, too. See also
trailing edge of centreboard.)
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the back of the “V” is to be cut off flat about
1/8 inch wide
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tapering of rudder (chamfer) is not be more
than 2 inches in from the edge (max. permitted by Class Rules)
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rudder fittings must be strong and well fastened.
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through-bolt fittings wherever possible.
3. Tiller
-
must be close fit into rudder stock: no “play”
- if necessary, put tape around the wood so that it just fits.
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rudder tie-down to be heavy, double shock cord
(Al’s note: I like to use mostly 4-mil pre-stretch
rope with a 6” loop of ¼” shock cord just before the end that goes
around the hook under the tiller. I use a bowline to tie another 6” piece
of 4-mil rope onto that loop. I then use that little piece of rope to drag
the shock cord over the tiller hook. This holds the rudder down very well!)
-
need a tiller extension with good grip (tape
every 6”) – try “golfball” technology: a golf ball fastened to the
end of the tiller extension makes it easy to steer when hiked.
4. Centreboard
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sides of the blade to be smooth and flat
-
leading edge to be rounded into a parabolic
shape up to 2.5" in from the edge (max. allowed by Class Rules)
-
trailing edge to be tapered to a “V” shape up
to 2.5" in from aft edge (see also note on trailing edge or rudder)
-
the back of the "V" is to be cut off flat about
1/8 inch wide
-
when the CB is fully down, the leading edge
must be raked slightly back so as to make an angle of no more than 83º
(Class Rules)
-
when fully down, the CB must extend down from
the keel no more than 3’ 3 5/8” (Class Rules)
5. Mast & Rigging
a) spreaders
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length to be 20 inches from shroud to mast
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set angle so that distance between shrouds is
3' 2"
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angle the spreaders up slightly from mast to
shrouds, hold in place with duct tape on the shrouds (Al’s
note: the theory being that the spreader should bisect the angle made when
the spreader pushes the shrouds outboard)
-
if spreaders are adjustable, angle further forward
(restricting mast bend) for strong winds and further back (allowing more
mast bend) in light winds
b) shrouds
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Use adjustable stainless steel straps to fasten
the shrouds to the hull. These are stronger, easier to adjust and more
reliable than the bottle screws/turnbuckles.
-
Check that all pins which fasten the shrouds
and forestay to the mast and hull are well secured. Tape the curled wires
(split or circular pins) which hold
the pins in place to avoid accidental loss of a pin and resulting mast
failure
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When under sail, the rig should have approx.
330 pounds of tension in the shrouds. This is set by varying the jib halyard
tension. Since most people do not have a tension measurement device, simply
increase jib halyard tension while sailing to windward until the leeward
shroud is no longer slack. This will require a very tight jib halyard in
strong wind and relatively little tension in light air.
-
Jib halyard tension is controlled by either
a Highfield lever or a magic box. The magic box is preferred since it is
easier to adjust while sailing and has a wider control range. The magic
box is either mounted on the mast or along the side or top of the centerboard
housing. If the magic box is on the CB housing pulling back on the
halyard a block must be fixed behind the foot of the mast to prevent it
from moving back too far thus creating excessive mast bend.
(Al’s
note: There are those who find such mast bend assistance quite useful to
promote bend in light airs. Excessive bend in windier conditions can always
be prevented by chocking and spreaders angled further forward.)
c) mast rake setup
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Tighten the jib halyard to put tension on the
rig but not enough to cause mast bend.
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Fasten a tape measure to the main halyard and
hoist to the top of the mast.
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Check the distance from the top of the mast
to the bottom of the bridge created by the traveller bar over the transom
opening for the tiller. This should be 23’ 6” (+/- ½”).
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Adjust the two shroud lengths evenly until the
desired rake is set. For shrouds with the adjusting plates, each
hole change affects the measured mast rake by 2”.
(Al’s note: Shroud plates with double rows of offset holes give 1” changes
as you move diagonally up or down.)
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Check that the mast is perfectly vertical by
measuring the distance from the top of the mast to each end of the traveller.
This distance should ideally be the same to both sides.
(Al’s
note: A difference of up to ¼” is no big deal in my opinion!)
-
Place plastic tubes over the shroud adjustment
plates, or wrap with plastic sheet to protect the pins and prevent them
from coming loose or tearing sails.
d) mast bend check
-
Here, your Uncle Al
will take the liberty to replace Derwyn’s suggestion which was:
Tape cardboard to the side of the mast at the level of the spreaders.
Leave it pointing aft behind the mast with ½” graduations marked
on it for 2 inches. Check that the spreader length and angle are set correctly.
Tension the jib halyard for approx. 330 pounds tension on the shrouds.
Tighten the main halyard from the top of the mast to the gooseneck. Appropriate
mast bend results in the main halyard being out 1½” from the mast
at the cardboard marker behind the spreaders. Hence the mast has
bent forward 1½” at the spreaders due to the tension on the jib
halyard.
Uncle Al’s note: The trouble with the
above system is that it cannot take into account the additional bend caused
by mainsheet and vang tension once you’re under sail in any kind of a breeze.
My own invention is just as cheap as Derwyn’s but works under all conditions:
Using indelible black magic marker, put four “inch-marks” on the luff of
the sail at spreader height, starting at the luff rope. Fasten about 18-19’
of coloured whipping thread to/near the aft edge of the top of the mast.
Tie a 6” loop of thin shock cord to the other end. The thread should be
of such a length as to put some tension on the thread once the shock cord
is looped around the gooseneck or its wingnut. We do this so that the thread
runs down the starboard side of the mainsail. With this system, we can
adjust mast bend (spreader angle mostly) out on the water before the race(s).
We then sail close-hauled on starboard and see which inch-mark the thread
passes. In medium airs, our mainsail has its max. draft nicely at 50% aft
when we have 2-3” of mast bend. Other sails may be slightly different.
I’m not good at judging stuff like draft position and sight up the sail
using a little plastic gizmo called a Sailscope put out by North Sails
as part of their North U. Fast Course which has a grid marked on it (see
image below). (I bought a couple of these separately as spares from
the North Sails loft in Toronto in the early 90's but am not sure if they're
still available. The gentleman who designed the whole course is Dave
Dellenbaugh who now publishes the Speed
'n' Smarts newsletter!)
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Lower mast bend can be partly limited by inserting
wooden shims/chocks between the front of the mast and the slot in the foredeck.
Encourage mast bend in light air and heavy air (no shims). Discourage
lower mast bend in medium air by inserting some shims.
-
Pressure from the shims usually will damage
the front of the mast. This can be avoided by installing a protective
sleeve around the mast. The aluminum sleeve should extend from say
2 or 3 inches above the deck down to say 8 inches below the deck level.
Such a sleeve is available from Proctor Masts. It redistributes the
force over a wider area thus eliminating damage to the mast.
-
Lower mast bend can also be limited by installing
a U-shaped channel under the mast step. As the mast bends, the foot
travels aft along the channel. This travel can be limited by a bolt through
the U channel. The amount of travel to allow is controversial. Currently,
I allow a max. of about 1½” of movement at the foot of the mast.
e) forestay setup
-
The forestay primarily serves to hold up the
mast when the jib is not in use. When the jib is up and winds are
strong, the rig tension is provided mainly by the jib halyard.
-
When the wind is light, it is helpful to use
the forestay to provide rig tension. This allows the jib luff to be kept
looser thus facilitating some luff sag. Luff sag is built into each jib
and it adds to the power of the sail.
-
Forestay tension control can be provided by
shortening the forestay by about a foot. Install a small block on
the foot of the forestay. Install a block on the bow bracket.
Run a strong 4 mm pre-stretched line from the bow bracket up to the forestay
block, back down to the block on the bow bracket, then along the deck,
back to a jamb cleat near the mast. Install a short section of line from
the bow bracket up to the forestay as a safety line in case the forestay
control line breaks or comes undone.
-
Keep some tension on the forestay even under
medium and strong wind conditions so that it will be straight under all
conditions of jib halyard tension. This is very useful as a reference
for checking sag of the luff of the jib. Under most wind conditions,
target for approx. 2 to 3” of sag between the middle of the jib luff and
the forestay. This is set by adjusting the jib halyard tension.
f) miscellaneous mast issues
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Always use a mast head fly to help show the
wind direction. Tape to the top of the mast with duct tape. Extend
as far above the mast as practical for clear air.
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Install shims between the sides of the mast
and the opening through the deck as well as on the vertical supports just
below the mast pivot bolt. These shims help keep the mast from bending
sideways. Wood or plastic is fine or even use rubber from a hockey
puck.
-
Install a large ring on the front of the mast
for hooking on the spinnaker pole. It makes it much easier to connect
and disconnect.
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File fine notches in the main and jib halyard
blocks (Al’s note: ?????) and lubricate
them regularly to insure that they turn freely under the loads imposed
by the wire halyards.
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Install strips of black electrical tape where
specified by the class rules on the mast and the boom. This will show the
maximum allowable positions of the corners of the sails.
6. general boat & sail security
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Tape all pins & rings to prevent unexpected
loosening or failure. This also covers sharp ends which could rip
a spinnaker.
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Cut off the ends of any bolts or screws to just
the right length so as to prevent ripping of sails and minimize weight.
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Put on a little silicone sealer after assembly
of nuts & bolts to prevent loosening and cover any sharp ends. Especially
important if trailering for long distances. (Al’s
note: If anyone should know about this, it’s Derwyn who, at least four
times, has trailered W4615, Big Bird, 3321 km from Calgary to Toronto [and
back, of course – another 3321 km])
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When sailing, securely fasten anything of value
in the boat to minimize losses when you capsize. Some net bags and
Velcro straps are handy for this.
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Carry a small tool kit in a “floatable" container
for on-the-water repairs. (knife. duct tape, some light wire, spare
pins (and rings to hold them in place), length of light line, needle nose
pliers & adjustable wrench, pencil & sun tan lotion) Fasten
this kit to the boat.
Carry a large bailing bucket (say 20 liters)
and tie it with a long enough line to reach anywhere in the boat.
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