7.
Plastic housing
—Attach the safety wire to one eye in the hull
nut.Lead the wire in a counterclockwise direction and thread it
through one eye in the cap nut, the pull ring, the second eye in
the cap nut, and the second eye in the hull nut.Twist the wire
securely to itself.
Metal housing
—Wrap one end of the safety wire tightly around
the housing and twist it together with the long end.Lead the wire
straight up and through the eye in the cap nut.Loop the wire
through the pull ring and twist it securely to itself.
Caution
:If your sensor came with a connector, do not remove it
to ease cable routing.If the cable must be cut and spliced, use
Airmar’s splash-proof Junction Box 33-035 and follow the
instructions provided. Cutting the cable or removing the
connector, except when using Airmar’s junction box, will void
the warranty.
8.Route the cable to the instrument
being careful
not to tear the
cable jacket when passing it through the bulkhead and other
parts of the boat.To reduce electrical interference, separate the
sensor cable from other electrical wiring and the engine. Coil
any excess cable and secure it in place using zip-ties to prevent
damage.
9.Refer to the instrument owner’s manual to connect the sensor
to the instrument.
Checking for Leaks
Warning:
Never install a thru-hull sensor and leave the boat in the
water unchecked for several days.
When the boat is placed in the water,
immediately
check around
the thru-hull sensor for leaks. Note that very small leaks may not
be readily observed.
Do not
leave the boat in the water for more
than 3 hours before checking it again.If there is a small leak,
there may be considerable bilge water accumulation after 24
hours.If a leak is observed, repeat “Bedding” and “Installing” on
page 2
immediately
.
Installation in a Cored Fiberglass Hull
The core (wood or foam)
must
be cut and sealed carefully.The
core
must
be protected from water seepage and the hull
must
be
reinforced to prevent it from crushing under the hull nut allowing
the housing to become loose.
Warning
: Always wear safety goggles and a dust mask.
1.Drill a 3mm or 1/8" pilot hole from inside the hull. If there is a rib,
strut, orother hullirregularitynear theselected mounting location,
drill from the outside.(If the hole is drilled in the wrong location,
drill a second hole in a better location. Apply masking tape to the
outside of the hull over the incorrect hole and fill it with epoxy.)
2.Using the 51mm or 2" hole saw, cut the hole from outside the
hull through the
outer
skin only
(see
Figure 4).
3.From inside the hull, use the 60mm or 2-3/8" hole saw to cut
through the
inner
skin and most of the core.The core material
can be very soft. Apply only light pressure to the hole saw after
cutting through the
inner
skin to avoid accidentally cutting the
outer
skin.
4.Remove the plug of core material so the
inside
of the outer skin
and the inner core of the hull are fully exposed.Clean and sand
the inner skin, core, and the outer skin around the hole.
Caution
: Completely seal the hull to prevent water seepage
into the core.
5.If you are skilled with fiberglass, saturate a layer of fiberglass
cloth with a suitable resin and lay it inside the hole to seal and
strengthen the core.Add layers until the hole is the correct
diameter.
Alternatively, a hollow or solid cylinder of the correct diameter
can be coated with wax and taped in place.Fill the gap between
the cylinder and hull with casting epoxy.After the epoxy has set,
remove the cylinder.
6.Sand and clean the area around the hole, inside and outside, to
ensure that the sealant will adhere properly to the hull. If there
is any petroleum residue inside the hull, remove it with either
mild household detergent or a weak solvent (alcohol) before
sanding.
7.Proceed with the “Bedding” and “Installing” on page 2.
Operation, Maintenance
,
Repair, & Parts
How theValve Works
The sensor incorporates a self-closing valve which minimizes the
flow of water into the boat when the paddlewheel insert is
removed.The curved flap valve is activated by both a spring and
water pressure.Water pushes the flap valve upward to block the
opening, so there is no gush of water into the boat.
WARNING:THEVALVE IS NOT AWATERTIGHT SEAL.
Always use the paddlewheel insert or the blanking plug
secured with the safety wire for a watertight seal.
Using the Blanking Plug
To protect the paddlewheel, use the blanking plug when:
• The boat will be kept in salt water for more than a week.
• The boat will be removed from the water.
• Aquatic growth build-up on the paddlewheel is suspected due to
inaccurate readings from the instrument.
Warning:The O-rings must be intact and well lubricated to
make a watertight seal.
1.Inspect (and replace if necessary) the O-rings on the blanking
plug and lubricate them with the silicone lubricant supplied or
petroleum jelly (Vaseline
®
).
2.Remove the paddlewheel insert from the housing by removing
the safety wire and unscrewing the cap nut (see Figure 3).
3.Grasp the pull ring and remove the paddlewheel insert with a
slow pulling motion.
Note
: In the unlikely event that the paddlewheel insert cannot
be removed, see “Servicing the Valve Assembly” on page 4.
4.Slide the blanking plug into the housing with the arrow on the
top pointing forward toward the bow.Seat it into place with a
pushing twisting motion until the key fits into the notch.Screw
the cap nut in place and
hand-tighten
only.
Do not
over-tighten.
Reattach the safety wire.
Figure 4. Preparing a cored fiberglass hull
inner skin
core
outer skinsolid or hollow cylinder
pour in
casting
epoxy
9-12 mm
(3/8-1/2")
larger than the
hole through the
hull’s outer skin
hull thickness
3
