For people who boat in freshwater, poor connections caused by corrosion in electrical connectors and light sockets is not much of a problem. However, it's a different story in saltwater boating areas where even the salt in the air can cause corrosion in electrical connectors and light bulb sockets.
If you are a saltwater boater, how many times have you activated a light on your boat and it didn’t work? Not only is this aggravating, it can be downright dangerous, as is the case with navigation lights that don’t work when you need them. This is a common problem that is easy to prevent.
Electrical System Corrosion in Saltwater Environments
Most electrical connectors and light fixtures are exposed to trace elements of salt that is always present in the air near saltwater. The salt tends to accumulate on surfaces exposed to the air. Accumulated salt absorbs moisture from the air. Since salt and salt laden moisture are excellent electrical conductors, galvanic corrosion occurs in metal connections and light bulb sockets. The corrosion continues until it interferes with the electrical connection. At that point the circuit is broken and, in the case of a light circuit, the light suddenly stops working.
Corrosion Protection for Light Bulb Sockets
Disconnect the battery or turn the main switch OFF, then remove and inspect the bulbs. Replace burned out bulbs or badly corroded bulbs and light fixtures. Clean corroded light bulbs or sockets with fine emery cloth. Coat the metal contact areas with dielectric Teflon or silicone grease. The sockets should be sprayed with an electrical and metal corrosion protector. I always use a product called Boeshield T-9® for this purpose because it leaves a waxy coating that provides long lasting protection.
Care must be taken not to get any oil or grease on the glass portion of the bulbs, as this will cause the bulb to overheat and burn out prematurely. When a bulb is replaced, always remember to protect the bulb base and socket. Make sure to put grease in the connectors and sockets for removable stern lights. Also, don’t forget cockpit and cabin lights.
Corrosion Protection for Switch and Terminal Connections
If your boat is equipped with push on or ring terminals at the switches or terminal block, remove the terminal, clean corrosion with fine emery paper if necessary, coat the terminal with dielectric grease and reconnect. If your boat has fuses, remove each fuse and coat the contacts with the dielectric grease as well. You should only have to do this once, unless a fuse, switch or terminal block needs to be replaced. Then the connectors on the new components should be protected. Finish up by spraying the electrical components behind the helm and switch panels with Boeshield T-9® corrosion inhibitor.
I know it seems like a lot of work, but it is not difficult and your efforts will save you a lot of time and frustration down the road. Remember, you only have to do it once.
Additional Good Things to Know:
- When replacing light bulbs in marine light fixtures, always use a bulb with the same rating as the original. Using a different bulb could cause the fixture to overheat and melt or short circuit.
- Always turn the battery switch OFF or disconnect the battery ground cable before working on electrical circuits.
- When replacing light fixtures, always use heat shrink butt connectors to prevent corrosion.
- Use only emery paper or fine sandpaper to clean corrosion from bulbs, sockets and connectors. Never use steel wool, or a steel wire brush. The steel fragments will cause rust spots in the gelcoat.
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