Eagle Group 128 Manuel D’Utilisation

14

SHOOT-THRU-HULL PREPARATION
The transducer installation inside a fiberglass hull must be in an area
that does not have air bubbles in the resin or separated fiberglass
layers. The sonar signal must pass through solid fiberglass. A
successful transducer installation can be made on hulls with flotation
materials (such as plywood, balsa wood or foam) between layers of
fiberglass if the material is removed from the chosen area.

Epoxy the transducer to a solid portion of the hull.

For example, some (but not all) manufacturers use a layer of fiberglass,
then a core of balsa wood, finishing with an outer layer of fiberglass.
Removing the inner layer of fiberglass and the balsa wood core exposes
the outer layer of fiberglass. The transducer can then be epoxied
directly to the outer layer of fiberglass. After the epoxy cures, the hull
is watertight and structurally sound. Remember, the sonar signal must
pass through solid fiberglass. Any air bubbles in the fiberglass or the
epoxy will reduce or eliminate the sonar signals.

WARNING:

Do not remove any material from your inner hull unless
you know the hull's composition. Careless grinding or
cutting on your hull can result in damage that could sink
your boat. Contact your boat dealer or manufacturer to
confirm your hull specifications.

To choose the proper location for thru-hull mounting, anchor the boat in
60 feet of water. Add a little water to the sump of the boat. Plug the
transducer into the sonar unit, turn it on, then hold the transducer over
the side of the boat. Adjust the sensitivity and range controls until a