I read that galvanic corrosion is due mainly of having the boat connected to shore power to keep the batteries charged. I see many boats sitting on trailers for weeks with no shore power connection. What happen to their batteries? If I use the boat on a weekly basis, can I just count on recharging the batteries by running the engines?
Galvanic corrosion
- Thread starter Arnold
- Start date
Arnold, I don't think it's a normal situation for shore power to cause galvanic corrosion. I believe you have to be putting current into the water for that to happen. Just because your shore power and boat aren't a problem you don't know what's going on with the boats docked around you. They may be the source of the stray current causing the problem. Boats stored on trailers don't need power for the refrigerator and battery charger to be sure there is battery power to run the bilge pumps.
- Joined
- Feb 3, 2006
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- 20150
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If the boat is sitting on a trailer you can remove the plug to keep bilges drained. Not an option in the water. If you have a leak develop in the water battery powered bilge pumps are the solution. But large capacity pumps consume fairly large chunks of power and could drain the bakeries a a bad time is not checked. The result could be catastrophic.
Maybe you could supplement with a shore powered bilge pump as a stopgap. If shore power ges out you're still at risk.
Best solution is frequent checks. How reliable is your dockmaster?
Maybe you could supplement with a shore powered bilge pump as a stopgap. If shore power ges out you're still at risk.
Best solution is frequent checks. How reliable is your dockmaster?
- Joined
- Sep 23, 2002
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- 10265
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- 9,958
A trailer boat is a completely different boat than a in water boat.
When you pull your boat, pull the plug.
Turn off your battery.
Store boat so any rain water runs out drain hole.
You will never have a issue and battery will charge as soon as you start!
Just remember to put the plug in before launch!
When you pull your boat, pull the plug.
Turn off your battery.
Store boat so any rain water runs out drain hole.
You will never have a issue and battery will charge as soon as you start!
Just remember to put the plug in before launch!
Galvanic and Electrolytic Corrosion are different animals. Galvanic does not have to have electric power. It just needs dissimilar metals and preferably sea water. Electrolysis is when electric current is flowing between them eating the less noble metal.
As just said above, corrosion has many many forms. Galvanic and stray are both concerns of boaters but they are generated differently.
Galvanic is when two dissimilar metals come in contact within an electrolyte. Sea water is highly conductive due to its salt content. You ward off Galvanic corrosion by placing more "active" metals within the circuit. Zinc anodes are an example, sometimes called sacrificial anodes because they seem to dissolve over time.
For example on outboard motors. The Zinc dissolves to protect the Aluminum housing and prop and the steel shafts and internal gearing.
It also could be as simple as a drop of salt water in an engine compartment bridging the gap between a bolt and its mating member. A salt water free engine is a happy engine.
Stray current is caused by current flow local sources, other boats, docks etc....
Galvanic is when two dissimilar metals come in contact within an electrolyte. Sea water is highly conductive due to its salt content. You ward off Galvanic corrosion by placing more "active" metals within the circuit. Zinc anodes are an example, sometimes called sacrificial anodes because they seem to dissolve over time.
For example on outboard motors. The Zinc dissolves to protect the Aluminum housing and prop and the steel shafts and internal gearing.
It also could be as simple as a drop of salt water in an engine compartment bridging the gap between a bolt and its mating member. A salt water free engine is a happy engine.
Stray current is caused by current flow local sources, other boats, docks etc....