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Proper Fluid for a Garmin In-Hull Transducer's Base / Tank

If a Garmin or Airmar transducer is being mounted inside of a hull and sits inside a base / tank, the base / tank must be filled with propylene glycol or mineral oil to produce any sonar signal. When securing the base / tank to the hull, follow the instructions and recommendations in the transducer's installation guide.

Using any other fluids, sealant, resin, or epoxy is not recommended and could void the warranty of the transducer. Aggressive chemicals like acetone, gasoline, or mineral spirits can degrade the materials within  transducers rather quickly and should not be used.