Pink prop

[MikeBz]

Our prop is looking somewhat dezincified. Does the panel think that it should be replaced?

 

[Topcat47]

Not yet, but check to make sure there's no simple cause. I cleaned my prop with Viakal once and it came up a very similar colour. Polishing it every season since has brought it back to something like it's original colour and it still drives the boat.

There doesn't seem room for a shaft anode so make sure there's an earth across the shaft coupling. I have to replace mine every year.

 

[Tranona]

Tap it with a hammer. If it rings it is OK, if it is a dull thud then it is dezincified. Also scratch the surface as that looks like just surface discolouration. As suggested make sure it is connected to an anode, probably through the gearbox casing with a bridge across the coupling if it is the flexible type.

 

[Modulation]

+1 for the hammer test. The difference between a good and a dezincified prop sound is remarkable.

 

[MikeBz]

Thanks, I'll try the hammer test. There is an anode on the prop (which had mostly gone) and another on the shaft.

 

[MikeBz]

Well it's still a ringer so that's good. Except that it's proving a right ****** to get it properly clean.

 

[longjohnsilver]

Well it's still a ringer so that's good. Except that it's proving a right ****** to get it properly clean.

Have you tried brick cleaner? And then a wire brush attachment on your drill, just make sure to wear a mask and eye protection.

 

[Topcat47]

The copper bits are softer than the brass alloy so a wire brush will make the surface more uneven. The same is broadly true of any cutting medium, from Emery cloth to Brasso. At least the Brasso would give you a smooth finish. Brick cleaner would make matters worse too. You'll need to to manage the situation. There's no guarantee that you'd polish back to good brass and if you did, the prop would probably need re-profiling. If you're that worried take it to a specialist, such as Hamble Propellors.