Airmar S650 User Manual

INSTALLATION INSTRUCTIONSOWNER’S GUIDE &

Thru-Hull, Retractable with Valve

Speed & Temperature Sensor

Models: S650, ST650

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

17-129 rev. 08 04/12/11

use the insert or long blanking plug secured with the
retaining pin, safety rings, and safety 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: Stainless steel housing in metal hull—Be
sure the washer contacts the hull. Do not tighten the
hull nut with the washer against the isolation bushing,
as the housing will not be firmly installed. If necessary,
sand the isolation bushing until the washer rests
against the hull.

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.

WARNING: When the valve assembly is removed,
always insert the short, emergency plug with the cap
nut secured with the safety wire for a watertight seal.

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: A stainless steel housing must be isolated
from a metal hull to prevent electrolytic corrosion. Use
the isolation bushing supplied.

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

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.

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

Part No._________________Date___________

P17
Low Profile

Plastic Housing

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 fiberglass or wood hull.

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

• Stainless steel housing compatible with all hull materials.

Recommended for aluminum hulls to prevent electrolytic corrosion
provided the stainless steel housing is isolated from the metal hull.

Tools & Materials

Safety goggles
Dust mask
Water-based anti-fouling paint (mandatory in salt water)
Electric drill with 10mm (3/8") or larger chuck capacity
Drill bit: 3mm or 1/8"
Hole saw: 51mm or 2" (plastic or bronze housing)

57mm or 2-1/4" (stainless steel housing in a metal hull)

Countersink tool (installing a flush housing)
Sandpaper
Mild household detergent or weak solvent (such as 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

Pretest

Connect the sensor to the instrument and spin the paddlewheel.
Check for a speed reading (and the approximate air temperature if
applicable). If there is no reading(s) or it is inaccurate, return the
product to the place of purchase.

Mounting Location

CAUTION: Do not mount the sensor near water intake or

discharge openings; behind strakes, fittings, or hull irregularities
that will disturb the water 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
boat speeds. Choose an accessible spot inside the vessel. Allow
a minimum of 280mm (11") 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 the sensor
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– 6 00 mm (1 –2').

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

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 paint, since
ketones can attack many plastics possibly damaging the sensor.

It is easier to apply anti-fouling paint before installing the sensor,
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 the paddlewheel insert below the lower o-ring

• Paddlewheel cavity

• Paddlewheel

• Exterior flange of the housing and valve assembly

• Bore of the valve assembly up 30 mm (1-1/4")

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

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 appropriate size hole saw, cut a hole perpendicular to the
hull from outside.
Flush housing—Use a countersink tool to create a ‘seat’ in the hull.

paddlewheel

housing

insert

outside wall
below
lower o-ring

paddlewheel

paddlewheel
cavity

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

exterior flange
of housing and
valve assembly

Figure 1. Anti-fouling paint

Copyright © 1996 Airmar Technol ogy Corp.

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.

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 2). The sealant must extend 6mm (1/4")

higher than the combined thickness of the hull, washer(s), 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.

Stainless steel housing in a metal hull—To prevent electrolytic
corrosion, the stainless steel housing must be isolated from the
metal hull. Slide the isolation bushing onto the housing. Apply
additional sealant to the surfaces of the bushing that will contact
the hull, filling any cavities in and around the bushing

Installing

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.
Removing the waterproof connector or cutting the cable, except when
using a watertight junction box, will void the sensor’s warranty.

1. From outside the hull, push the housing into the mounting hole
using a twisting motion to squeeze out excess sealant (see

plastic housing

2

(P17 shown) stainless steel housing (SS557 shown)

bronze housing (B17 shown)

paddlewheel insert

retaining
pin

Figure 2. Bedding and installing (low profile housings shown)

Copyright © 1996 - 2002 Airmar Techno logy Corp.

pull ring

safety ring (2)

safety wire

cap nut (plastic)

emergency plug

hull nut

washer

hull

marine sealant
on flange and sidewall

in metal hull

isolation bushing

with marine sealant