Garmin GPSMAP 168 Owner's Manual And Reference Manual page 109

Appendix G
Mounting the Transducer
Weight transducer
PVC Pipe
to hold it in place
or a Can
Strip Caulk
or RTV Sealer
Hull Surface
Testing the Location
Apply twisting motion
Weight transducer in place
to eliminate any
for at least 24 hours
trapped air bubbles
Installing the Transducer
98
168 Manual Part 2.indd 98
To avoid drilling a hole to mount a thru-hull transducer, a transom mount transducer may be used
with epoxy inside a boat ("shoot-thru-hull" installation). For a transducer to be mounted inside the hull
(shoot-thru, not thru-hull), the boat must be fi berglass, no core (contact your boat manufacturer if you
are unsure). Test by placing a small amount of water inside the hull, placing the transducer on top of
the water, then verifying the accuracy of the locators versus the current water depth. If they are the
same, use epoxy (non-silicone based) to affi x the transducer to the inside of the hull.
Shoot Thru-Hull Installation
The in-hull transducer is designed to be mounted inside a fi berglass hull. The standard plastic
transom mount transducer can also be mounted in this fashion using this method. If using a
temperature sensing transducer, the temperature displayed will refl ect the hull temperature.
Selecting a Location:
Fill Pipe or Can
with water or a
1. The location has to be solid fi berglass, devoid of any air bubbles, laminates, fi llers or dead air space.
light mineral oil
The location needs to be in an area of clean water at all speeds. Do not place the transducer over
any strakes or behind any obstruction on the hull that would create turbulence at speed.
)
Many modern hulls have a prelocated pocket for thru-hull transducer installation. If
you are unsure if your hull is equipped with a prelocated pocket, contact your hull
manufacturer.
Testing the Location:
1. Place the transducer in the water, pointed directly at the bottom and set unit for optimum
Slow cure
performance. Place the transducer in the test device as show on the side bar. If the sonar
2-part epoxy
performance is signifi cantly degraded, another location will need to be tested.
Installing the Transducer:
Strip Caulk 1. Lightly sand the surface of the hull and face of the transducer with 400 grit wet or dry sandpaper.
or RTV
2. Build a dam using strip caulk about 1/4" tall. Pour about 1/8" of two part, slow cure epoxy in the
Sealer Dam
dam. Place the transducer in the epoxy, turning the transducer to work out any air bubbles.
3. Weight the transducer in place and allow to cure for 24 hours.
11/18/2002, 3:38:15 PM