Garmin FishFinder 340C Owner's Manual

Also see for Fishfinder 340C: Owner's manual Quick reference Install guide Declaration of conformity Owner's manual

14 Fishfinder 340C Owner’s ManualINSTALLING THE FISHFINDER 340C > M OUNTING THE TRANSDUCERSelecting a Location for a Shoot-Thru-Hull InstallationWhen installing a transducer, the installation location must be thefollowing:• Solid fiberglass, without any air bubbles, laminates, fillers, ordead air space.• In an area of clean (non-turbulent) water at all speeds.• The location must not be over any strakes or behind anyobstruction on the hull that would create turbulence at speed.NOTE: Many modern hulls have a prelocated pocket forshoot-thru-hull transducer installation. If you are unsure if yourhull is equipped with a pre-located pocket, contact your hullmanufacturer.To test the location:1. Fabricate a test device from a section of PVC pipe or a can,as shown in the following illustration.2. Temporarily seal the test device to the hull with caulking orRTV sealer, and fill with water or light mineral oil.3. Place the transducer in the water, pointed directly atthe bottom and weight it down. Set the unit for optimumperformance. If the sonar performance is significantlydegraded, another location must be tested.Testing the LocationStrip caulkor RTV sealerHull surfacePVC pipeor a canWeight the transducer tohold it in place.Fill a pipe or can with wateror a light mineral oil.To permanently install the transducer:1. Lightly sand the surface of the hull and face of thetransducer with 400 grit wet or dry sandpaper.2. Build a dam using strip caulk about 1/4" (6 mm) tall. Pourabout 1/8" (3 mm) of two-part, slow-cure epoxy into thedam.3. Place the transducer in the epoxy, turning the transducer towork out any air bubbles.4. Weight the transducer in place, and allow it to cure for 24hours.