Hi. Any reason not to put a set of shaft zincs on my 45 Cabo? I have the shaft brushes in the engine room but I'm putting new props on this winter and I don't want any potential electrolysis. Just curious if shaft zincs cause or increase cavitation burn potential. Thx
Yes, over zincing a boat is bad. It will cause corrosion also by creating more of a ground type scenario. As long as your brushes, bonding wires, and transom zinc are good, do not put shaft zincs on. Below is the best explanation of it I found online. "Over zincing, putting too much zinc, on causes the opposite problem. It will reverse the flow of current in the other direction and actually cause corrosion. Over zincing is discernible when you find your props all covered with a coarse layer of zinc oxide. It will feel like sandpaper. This condition will reduce your boat's speed significantly and increase fuel consumption. I'll bet that statement got your attention!!!" http://www.yachtsurvey.com/corrosion.htm
When in doubt, drop a volt meter over the side. Maybe a lil help here; http://www.boatzincs.com/anode_weight_calculation.html