Installation - Raytheon HSB L760 Owner's Handbook Manual

2-20

Installation

Note: To install the thru-hull transducer in a cored fiberglass hull, follow the
instructions on Installation in a Cored Fiberglass Hull on page 2-26.
Drilling Holes
WARNING:
Always wear safety goggles and a dust mask when drilling.
1. Drill a 1/8" (3 mm) pilot hole perpendicular to the water line from inside
the hull (see Figure 2-12).
If there is a rib or strut near the mounting location, drill from the outside.
If the pilot hole is drilled in the wrong location, drill a second hole in a bet-
ter location. Apply masking tape to the outside of the hull over the incorrect
hole and fill it with epoxy.
2. Cut a hole from outside the hull:
Fiberglass or wood hull – Use a 2" (51 mm) hole saw.
Aluminium or steel hull – Use a 2 1/8" (54 mm) hole saw to accommodate
the isolation sleeve used to prevent contact between the stainless steel
housing and the metal hull.
3. 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 a mild household detergent or a weak
solvent (alcohol) before sanding.
Cutting the Fairing
1. Measure the deadrise angle of the hull at the selected location using a digi-
tal level, or bubble level and protractor (see Figure 2-12).
2. Tilt the band saw table to the measured angle and secure the cutting fence
(see Figure 2-15).
HSB Series L755 and L760 Fishfinder