Anti-fouling paint, Mounting location, Installation – Airmar CS4500-650—Ultrasonic Speed User Manual

Page 2: Hole drilling

metal housing

safety ring (2)

sealant on flange

ultrasonic insert

safety wire

cap nut

hull nut

washer

hull

retaining pin

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)
Grommets (some installations)
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

Anti-fouling Paint

Aquatic growth can accumulate rapidly on the ultrasonic 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 2):
• Outside wall of the ultrasonic insert below the lower o-ring
• Active face of the ultrasonic insert
• Exterior flange of the housing and valve assembly
• Bore of the valve assembly up 30mm (1-1/4")
• Blanking plug below lowest o-ring including exposed end

Mounting Location

CAUTION: Do not mount near water intake or discharge openings
or 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 housing 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 sensor.

Turbulence-free water must flow under the ultrasonic sensor at all
speeds. Choose an accessible spot with a minimum of 280mm
(11") of headroom inside the vessel to allow for the height of the
housing, tightening the nuts, and removing the insert.
• Fin keel sailboats—Mount on or near the centerline and

forward of the fin keel 150–300mm (1/2–1').

• Full keel sailboats—Locate amidships and away from the keel

at the point of minimum deadrise.

• Displacement hull powerboats—Locate amidships near the

centerline.

• Planing hull powerboat—Mount well aft to ensure the sensor

is in contact with the water at high speeds.

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 the hull.

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.

Figure 2. Anti-fouling paint

bore of

valve assembly

exterior flange of housing

and valve assembly

outside wall below

lower o-ring

ultrasonic

up 30mm (1-1/4")

housing

insert

active face

& valve

assembly

housing

Figure 3. Bedding and installing

plastic housing

Figure 4. Assembly

valve

housing

medium

cap nut

o-ring

large

o-ring

assembly

emergency plug

and side wall