Airmar, Installing the transducer & fairing, Sealing the cable in the stuffing tube – Airmar Stuffing Tube User Manual

Page 2: Checking for leaks, Parts

Metal hull—To isolate the stainless-steel stuffing tube from the
metal hull, slide the isolation bushing onto the stuffing tube.
Apply additional marine sealant to the surfaces of the isolation
bushing that will contact the hull, filling any cavities in and
around the bushing.

7. From outside the hull, push the stem of the stuffing tube

through the mounting hole using a twisting motion to squeeze
out excess sealant.

8. From inside the hull, slide the rubbery washer onto the stuffing

tube.
Metal hull—The rubbery washer must contact the hull. Do not
tighten the hull nut with the rubbery washer against the isolation
bushing. The stuffing tube will not be firmly installed. If
necessary, sand the isolation bushing until the rubbery washer
rests against the hull.

9. Screw the hull nut in place. Tighten it with slip-joint pliers.

Wood hull—Allow the wood to swell. After the hull has
expanded, tighten the hull nut securely.

Installing the Transducer & Fairing

Follow the instructions that came with the transducer and fairing.
After they are installed, follow the instructions below to seal the
cable inside the stuffing tube.

Sealing the Cable in the Stuffing Tube

WARNING: To form a watertight seal inside the stuffing tube,
stagger the splits in the compliant bushings.

1. The stuffing tube kit contains two sets of plastic washers. Four

are marked 8mm (0.33") diameter and four are marked 12mm
(0.47") diameter. Choose the set of plastic washers with the
smallest diameter that will fit around your cable. (Discard the
other set; it is not needed.)

2. Put two of the plastic-washer pieces around the cable and

press the halves together to form a closed ring (see Figure 2).

3. The kit also contains up to four sets of compliant bushings with

four bushings in each set. Choose the set of compliant bushings
with the smallest diameter that will fit around your cable.
(Discard the other sets; they are not needed.).

4. Place the four compliant bushings around the cable above the

plastic washer (see Figure 3). Arrange the bushings so that the
splits are staggered—not aligned. At the top of the stack, press
the second pair of plastic washers together to form a closed ring.
Be sure the plastic washers and compliant bushings are
stacked as shown in Figure 3.

5. To seal the cable inside the stuffing tube, push the plastic

washers and compliant bushings into the stuffing tube forming a
tight stack. Be sure the stack of plastic washers and compliant
bushings is seated securely inside the stuffing tube.

6. Screw the compression nut into the stuffing tube until it is snug.

Using slip-joint pliers, tighten the compression nut 2-1/2 turns.
This will compress the compliant bushings slightly to form a
watertight seal. Do not over-tighten.

Checking for Leaks

WARNING: Do not leave the boat in the water unchecked for
several days.

Figure 3. Sealing the cable in the stuffing tube

installed

exploded view

compliant

compression

plastic

nut

washer

bushings

washer

cable

Figure 2. Plastic washers

—12mm (0.47”) diameter shown

exploded view

NOTE: stagger the

splits in the

When the boat is placed in the water, immediately check around
the stuffing tube for leaks. Note that very small leaks may not be
readily observed. Do not leave the boat in the water unattended
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 around the stuffing tube, tighten the
compression nut another quarter turn and see if the leakage
stops. If the stuffing tube continues to leak, repeat the installation
and sealing procedures immediately.

Parts

Bronze Stuffing Tube

(B165)

33-511-01

Stainless-steel Stuffing Tube

(SS571)

33-541-01

Plastic Washers

20-457-01

Compliant Bushings

20-488-01

Obtain parts from your sensor manufacturer or marine dealer.
Gemeco

Tel: 803.693.0777

(USA)

Fax: 803.693.0477
email: [email protected]

Airmar EMEA

Tel: +33.(0)2.23.52.06.48

(Europe, Middle East, Africa)

Fax: +33.(0)2.23.52.06.49
email: [email protected]

AIRMAR

TECHNOLOGY CORPORATION

35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA

•

www.airmar.com

compliant bushings