Article by Capt. Steve Katz
Corrosion Inhibitors
On a daily basis, especially this time of the season, I observe a poor or failing electrical connection of some type. Just today, while troubleshooting a radar power supply, a new glass AGC type fuse was installed into the fuse block and still the circuit did not have power. We cleaned and tightened the fuse block clips and then had some intermittent power that went out when the fuse block was wiggled.
Again, we wire brushed and cleaned the supply wiring, cleaned the load wiring and finally was able to get electricity to flow through the fuse block consistently. While the fuse block did not look too bad, in reality, it had a buildup of corrosion on the mating surfaces, limiting the ability of the electrical current to flow. The customer said, “It worked last year! What happened? The boat was on land and I did not even use it”.
Keeping electricity flowing on a boat is always a challenge for many reasons, primarily because saltwater and electricity seem to attract each other and won’t let go. In our coastal area, within miles of the ocean, salt air causes corrosion on most metal surfaces, let alone our boats electrical systems, and in this case, on the fuse block behind the helm.
How to we combat this corrosion? Spray, wrap, grease, coat and paint.
All of these may be part of a maintenance plan to combat corrosion. A walk down the dock or the isles of a marine store will allow you to see the many products targeted to help reduce corrosion, particularly electrical corrosion.
Like talking politics, discussing these products with fellow boaters may be a long and opinionated discussion. Popular products include Boeshield T-9, Corrosion Block, CorrosionX, CRC Heavy Duty Corrosion Inhibitor, CRC QD, LPS 1, CRC 6-56, CRC Premium Electronics Grease, Tef-Gel, WD-40 and many more.
While I would like to tell you the best product to use, I can’t. There is no single product that will do everything for every electrical situation. The products above all have their place. You need to determine which is best for your application. We will review the products and when to use which type of product.
If an existing electrical connection is problematic, (in this case a connection is a joint, junction, terminal, plug etc. where electricity is designed to flow or conduct through) the connection should be powered off, disconnected and cleaned. Upon examination you may even find the connection is damaged and needs to be repaired. The best way to clean oxidation, corrosion and salt is to use a brush; nylon, wire, a tooth brush or even sandpaper or steel wool may work well depending on the surface and accessibility. During this cleaning, I do not usually use any chemical spray, except an electrical cleaner, checking to be sure it is safe for the surrounding material such as rubber or plastic. A spray of electrical cleaner can help flush away and dissolve debris, grease, oil and dirt and even leftover wire brush pieces.
Now that you have a clean connection or even a new connection, how can you keep it corrosion free? That is the hard part, especially depending on the type of connector and where it is. Some of the corrosion fighting products listed above will result in a thick film and some even leave a waxy heavy coating meant to coat and seal connections and can even be used on circuit boards to help prevent corrosion. Some of the waxy products though can attract dust, dirt and debris and can drip or weep, so they might not be the best for exterior components. Some of these products leave a thin transparent film, good for circuit boards and connectors where a heavy build-up is not desired. Often the heavy sprays are hard to remove when it comes time to handle or work on the parts, so if it is something you use or touch often, a lightweight thin protection may be the best. Be sure to check the product compatibility with nearby rubber and plastic. Some products can quickly degrade these materials.
Another popular product is dielectric grease – which by definition is an insulator of electricity and also referred to as non-conductive grease. People often use this on plugs and connectors. This should not be used inside or near any switches or devices where arcing can occur (inside a battery switch, circuit breaker, relay, switch, etc.) since electrical arcing can result in the creation of silicon carbide, causing the switch to fail. A light film of dielectric grease could be used on gaskets and seals of electrical connectors, but it should be used sparingly, or not at all, on the actual mating surfaces of electrical connections, since it does not conduct electricity. If you have a bad connection, do not use dielectric grease because it could even make it worse. It will never improve a connection.
Be sure to check with the manufactures recommendations on both the corrosion prevention product and the electrical/electronic product. They often have tested these products much more extensively than we have and know what works the best.
Captain Steve Katz is the owner of Steve’s Marine Service and holds NMEA, AMEI and NMEA2000 certificates along with ABYC Master Technician certification and factory training from many manufacturers.
