Airmar ST600 User Manual

INSTALLATION INSTRUCTIONSOWNER’S GUIDE &

Thru-Hull, Retractable with Valve

Speed & Temperature Sensor

Model ST600

Follow the precautions below for optimal product
performance and to reduce the risk of property
damage, personal injury, and/or death.

WARNING: Always wear safety goggles and a dust

mask when installing.

WARNING: The valve is not a watertight seal! Always
use the insert or blanking plug secured with the safety

17-038-01 rev. 04 04/12/11

wire for a watertight seal.

WARNING: The o-rings must be intact and well
lubricated to make a watertight seal.

WARNING: Always attach the safety wire to prevent the
insert or blanking plug from backing out in the unlikely
event that the cap nut fails or is screwed on incorrectly.

WARNING: Immediately check for leaks when the boat
is placed in the water. Do not leave the boat unchecked
for more than three hours. Even a small leak may allow
considerable water to accumulate.

CAUTION: Never use a fairing with a plastic housing;
the protruding sensor would be vulnerable to damage
from impact.

CAUTION: Never install a metal housing on a vessel
with a positive ground system.

CAUTION: Never pull, carry, or hold the sensor by its
cable; this may sever internal connections.

CAUTION: The arrow on the top of the insert must
point forward toward the bow.

CAUTION: Never use solvents. Cleaners, fuel,
sealants, paint, and other products may contain
strong solvents, such as acetone, which attack many
plastics, greatly reducing their strength.

IMPORTANT: Please read the instructions
completely before proceeding with the installation.
These instructions supersede any other instructions
in your instrument manual if they differ.

Applications

• Plastic housing recommended for fiberglass or metal hull only.

Never install a plastic housing in a wood hull since swelling of
the wood may fracture the plastic.

• Bronze housing recommended for wood or fiberglass hull only.

Never install a bronze housing in a metal hull because electrolytic
corrosion will occur.

Pretest

Connect the sensor to the instrument and spin the paddlewheel. Check for a
speed reading and the approximate air temperature (in appropriate). If there
is no reading(s) or it is inaccurate, check the connections and try again. If
there is still a problem, return the product to the place of purchase.

Record the information found on the cable tag for future reference.

Part No._________________Date___________

Tools & Materials

Safety goggles
Dust mask
Water-based anti-fouling paint (mandatory in salt water)
Electric drill with 10 mm (3/8") or larger chuck capacity
Drill bit: 3mm or 1/8"
Hole saw: 51mm or 2"
Sandpaper
Mild household detergent or weak solvent (alcohol)
File (installation in a metal hull)
Marine sealant (suitable for below waterline)
Additional washer [for aluminum hull less than 6mm (1/4") thick]
Slip-joint pliers (installing a metal housing)
Grommet(s) (some installations)
Cable ties
Installation in a cored fiberglass hull (see page 3)

Hole saw for hull interior: 60mm or 2-3/8"
Fiberglass cloth and resin
or Cylinder, wax, tape, and casting epoxy

Mounting Location

CAUTION: Do not mount the sensor near water intake or

discharge openings; behind strakes, fittings, or hull irregularities
that will disturb the flow.

CAUTION: Never mount the sensor directly ahead of a depth
transducer, since turbulence generated by the paddlewheel’s
rotation will adversely affect the depth transducer’s performance,
especially at high speeds. Mount side by side.

CAUTION: Do not mount in line with trailer rollers or bunks that
may damage the transducer’s face.

Turbulence-free water must flow under the paddlewheel at all
speeds. Choose an accessible spot inside the vessel. Allow a
minimum of 200mm (8") of headroom for the height of the
housing, tightening the nuts, and removing the insert.

• Displacement hull powerboats—Locate amidships near the
centerline.

• Planing hull powerboats—Mount well aft to ensure that it is in
contact with the water at high speeds.

• Fin keel sailboats—Mount on or near the centerline and
forward of the fin keel 300–600mm (1– 2').

• Full keel sailboats—Locate amidships and away from the keel
at the point of minimum deadrise.

paddlewheel
insert

outside wall
below
lowest o-ring

paddlewheel

paddlewheel
cavity

housing

paddlewheel

insert

pull
ring

cap
nut

Installation

Hole Drilling

Cored fiberglass hull—Follow separate instructions on page 3.

1. Drill a 3mm or 1/8" pilot hole from inside the hull. If there is a rib,
strut, or other hull irregularity near the selected mounting
location, drill from the outside.

2. Using the 51mm or 2" hole saw, cut the hole perpendicular to
the hull from outside.

3. 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.
Metal hull—Remove all burrs with a file and sandpaper.

exterior flange
of housing

bore of housing
up 30mm (1-1/4")

Figure 1. Anti-fouling paint

Copyright © 2001 Airmar Technology Corp.

Figure 2. Assembly

Copyright © 2001 Airmar Technolog y Corp.

Anti-fouling Paint

Aquatic growth can accumulate rapidly on the sensor’s surface
reducing performance within weeks. Surfaces exposed to salt
water must be coated with anti-fouling paint. Use water-based
anti-fouling paint only. Never use ketone based anti-fouling paint,
since ketones attack many plastics possibly damaging the sensor.

It is easier to apply anti-fouling paint before installation, but allow
sufficient drying time. Reapply paint every 6 months or at the
beginning of each boating season. Paint the following surfaces
(see Figure 1):

• Outside wall of paddlewheel insert below lowest o-ring

• Paddlewheel cavity

• Paddlewheel

• Bore of housing up 30mm (1-1/4")

• Exterior flange of housing

• Blanking plug below lowest o-ring including the exposed end

Assembly

Slide the cap nut along the cable until it rests on the top of the
paddlewheel insert. Attach the pull ring to the insert capturing the
cap nut (see Figure 2). Similarly attach the pull ring to the blanking
plug capturing the cap nut.

Bedding

CAUTION: Be sure the surfaces to be bedded are clean and dry.

Apply a 2mm (1/16") thick layer of marine sealant around the
flange of the housing that contacts the hull and up the sidewall of
the housing (see Figure 3). The sealant must extend 6mm (1/4")

higher than the combined thickness of the hull, washer, and hull
nut. This will ensure there is sealant in the threads to seal the hull

and to hold the hull nut securely in place.

Installing

1. From outside the hull, push the housing into the mounting hole
using a twisting motion to squeeze out excess sealant (see
Figure 3). Align the arrow on the flange of the housing to point
forward toward the bow. If the sensor is not installed on the
centerline of the boat, angle the housing slightly toward the
centerline to align it with the water flow.

2. From inside the hull, slide the washer onto the housing.
Aluminum hulls less than 6mm (1/4") thick—Use an
additional rubbery, plastic, or fiberglass washer. Never use a
wood backing block, since swelling of the wood can overstress
the plastic housing causing a fracture. Never use bronze since
electrolytic corrosion will occur.

3. Screw the hull nut in place being sure the notch on the upper rim
of the housing and the arrow on the flange are still positioned
forward toward the bow (see Figure 7).
Plastic housing—Do not clamp tightly on the wrenching flats,
causing the housing to fracture.

Plastic hull nut—Hand-tighten only. Do not over tighten.
Metal hull nut—Tighten the hull nut with slip-joint pliers.

2

paddlewheel
insert

marine

sealant

plastic housing metal housing

pull ring

safety wire

cap nut

(plastic)

hull nut

washer

hull

Figure 3. Bedding and installing

Copyright © 2001 Airmar Technology Cor p.

paddlewheel
insert

marine
sealant