Furuno NXT-600 Operator'S Manual Download Page 29

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APPENDIX 2 INSTALLATION OF TRANSDUCERS

AP-5

Checking for Leaks

When the boat is placed in the water,

immediately

check around

the transducer 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”

immediately

(see

page 3).

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 transducer to become loose.

CAUTION

: Completely seal the hull to prevent water seepage into

the core.

1. Drill a 3mm or 1/8" pilot hole perpendicular to the waterline from

inside the hull (see Figure 6). If there is a rib, strut, or other hull
irregularity near the selected 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 appropriate size drill bit, cut a hole from outside the

hull through the

outer

skin only.

Be sure to hold the drill plumb,

so the hole will be perpendicular to the water surface.

3. The optimal interior hole diameter is affected by the hull’s

thickness and deadrise angle. It must be large enough in
diameter to allow the core to be completely sealed.

Using the appropriate size drill bit for the hull interior, cut through
the

inner

skin and most of the core from inside the hull keeping

the drill perpendicular to the hull. The core material can be very
soft. Apply only light pressure to the drill bit 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 is fully exposed. Sand and clean
the inner skin, core, and the outer skin around the hole.

5. Coat a hollow or solid cylinder of the correct diameter with wax

and tape it 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 “Cutting the Standard Fairing” on page 2.

Anti-fouling Paint

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 transducer. Reapply anti-fouling paint every 6
months or at the beginning of each boating season.

Maintenance, Parts & Replacement

Cleaning

Aquatic growth can accumulate rapidly on the transducer’s
surface reducing its performance within weeks. Clean the surface
with a Scotch-Brite® scour pad and mild household detergent
taking care to avoid making scratches. If the fouling is severe,
lightly wet sand with fine grade wet/dry paper.

Replacement Transducer & Parts

The information needed to order a replacement transducer is
printed on the cable tag. Do not remove this tag. When ordering,
specify the part number, date, and frequency in kHz. For
convenient reference, record this information on the top of page 1.

Lost, broken, and worn parts should be replaced immediately.

Model

Hull Nut

Fairing Type

Fairing

B45

02-031-3

Standard

33-351-01

High-Performance

33-509-01

B258, B271W