Prop "Corrosion"?

[JimS123]

Just came back from a 7 day vacation. The boat was in the water the whole time, on floating docks with power and water. Mercury 4-stroke with a Vengeance SS prop. My zincs showed a lot of corrosion. This was the second Summer at the same location. Last year no problems.

My issue is the prop. It has a heavy coating of "something". It comes off with a lot of elbow grease and a scotchbrite with auto bumper cleaner. The prop is a high polish SS, so the change is noticable. Is there an easier way?

The hull and painted parts of the motor show no contamination.

 

[porscheguy]

Do yourself a favor and pull the prop off ASAP and add grease to splines of the prop shaft. If your zincs are showing signs of heavy corrosion, replace them now before things get really nasty.

If the dock has power and especially if other boats are docked there, then the likely culprit is stray current coming off another boat or the dock wiring. I would tell the owner of the dock about this occurrence and they may wish to check things.

 

[JimS123]

The zincs show corrosion, but they don't need replacing yet. I plan to pull the prop. Mainly looking for suggestions on how to polish it back up again.

 

[Scott Danforth]

The zincs show corrosion, but they don't need replacing yet. I plan to pull the prop. Mainly looking for suggestions on how to polish it back up again.

4-1/2" angle grinder or 6" bench grinder
buffing wheel https://www.harborfreight.com/6-in-spiral-cotton-buffing-wheel-69700.html
rouge https://www.harborfreight.com/1-4-quarter-lb-dark-grey-polish-compound-96769.html

or a big can of this