Furuno GP-3700F Instruction Manual page 69

9-12 mm
(3/8-1/2") larger
than the hole
Pour in
through the hull's
casting epoxy
outer skin
Hull thickness
Solid or hollow cylinder
Figure 6. Preparing a cored fiberglass hull
Copyright © 2005 Airmar Technology Corp.
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 pages AP-5 to AP-6).
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 housing to become loose.
CAUTION: Completely seal the hull to prevent water seepage
into the core.
1. Drill a 3 mm or 1/8" pilot hole 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 outside hull hole saw, cut a hole
from outside the hull through the outer skin only (see table
on page AP-5).
3. From inside the hull, using the appropriate size hull interior
hole saw, cut through the inner skin and most of the core.
The core material can be very soft. Apply only light
pressure to the hole saw 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. If you are skilled with fiberglass, saturate a layer of
fiberglass cloth with a suitable resin and lay it inside the
hole to seal and strengthen the core. Add layers until the
hole is the correct diameter.
Alternatively, a hollow or solid cylinder of the correct
diameter can be coated with wax and taped in place. Fill
the gap between the cylinder and hull with casting epoxy.
After the epoxy has set, remove the cylinder.
APPENDIX 2 INSTALLATION FOR TRANSDUCER (THRU-HULL MOUNT)
6. Sand and clean the area around the hole, inside and
Inner skin
7. Proceed with "Bedding" on page AP-5.
Core Maintenance & Replacement
Anti-fouling Paint
Surfaces exposed to salt water must be coated with
anti-fouling paint. Use water-based anti-fouling paint only.
Outer skin
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.
Cleaning
Aquatic growth can accumulate rapidly on the
transducer's face, reducing its performance within weeks.
Clean the surface with a Scotch-Brite® scour pad and
mild household detergent, being careful to avoid making
scratches. If the fouling is severe, lightly wet sand it 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 AP-4.
Lost, broken, and worn parts should be replaced
immediately.
Obtain parts from your instrument manufacturer or
marine dealer.
35 Meadowbrook Drive, Milford, New Hampshire 03055-4613, USA
Copyright © 2005 - 2013 Airmar Technology Corporation. All rights reserved.
outside, to ensure that the marine 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.
Model Hull Nut Washer
P19 04-004 09-452
B60 02-133-01 09-813-01
B75H/M/L
02-143-01 09-1012-01
B150M 02-030 09-452
B619
SS60 02-563-01 09-813-01
02-520-02 09-452
SS150M
SS619
SS565 02-563-01 09-813-01
Gemeco
(USA)
Airmar EMEA
(Europe, Middle East, Africa)
www.airmar.com
Isolation
Spacer
Bushing
- -
- -
- -
04-646-01 -
- 04-660-01
04-646-01 04-186-1
- 04-589-01
Tel:803-693-0777
Fax:803-693-0477
email:sales@gemeco.com
Tel:+33.(0)2.23.52.06.48
Fax:+33.(0)2.23.52.06.49
email:sales@airmar-emea.com
AP-5