Despite my best attempts to protect my bilge pump from corrosion and drying it off with alcohol after every battle, it finally succumbed to corrosion and permanently seized up. The rust is simply too thick and I cannot break it loose, no matter what I do. It's time to get a new pump. I've tried everything I can think of to protect my previous pump, from coating it with Corrosion-X to rinsing it with rubbing alcohol every time it got wet, but it wasn't enough. Then I read about how modern ships have zinc plates placed on the bottoms of their hulls to prevent the rest of the hull from corroding. Apparently the dissimilar metals in water makes only the zinc corrode. I find that idea very interesting, and I am wondering what metal would be appropriate to do the same thing for my bilge pump motor. Should I be looking for copper? zinc? gold? or something even more exotic? I am also curious if the concept can be used to protect other components, such as nuts and bolts and servo connectors.
What they are utilizing is galvanic corrosion... basically when a more anodic metal contacts a less anodic metal, the more anodic metal will corrode away before the more cathodic (less anodic) metal. http://en.wikipedia.org/wiki/Galvanic_corrosion http://corrosion-doctors.org/Definitions/galvanic-series.htm It may work, but you would need to find out exactly what part is corroding away. If it is the brushes, you would need to have a metal that is considerably more anodic than the metal of the brushes connected close to the brushes, electrically speaking. Simply putting a bit of zinc on the can will not protect the core/brushes, that are electrically isolated from the can... Look at the table and look at the potential table. Zinc is highly anodic compared to most other common metals (other than magnesium) and is used as the anode because of that...
Perhaps a brush assembly retrieved from a dead motor could be used on the end of the shaft to electrically connect the anode to the core.
Pump should be rebuildable with a new motor. All of my pumps are set up the same way. I can swap one out for another between all the ships. I can replace a large one with a small one if need be. Spring cleaning includes replacing any motors that are getting tired. Usually a pump motor will last a season and I tend to buy the cheapest I can find at $3-$4 per.
