The importance of anodes on a propeller

[MedwaySailor]

The flexofold 2B has no anode fitting. The 3 blade does but it's a big price hike. We have only had the boat for one year but the anode on the old fixed 2 blade was badly eaten away. During the summer we are on a swinging mooring on the Medway and assume the aggressive galvanic action is due to the continual tidal race. Opinions on the importance of the anode fixed to the propeller please.

 

[vyv_cox]

The anode protects the galvanic couple(s) between the prop and shaft and any other couples, such as stainless steel pivots in a bronze body and blades. Nothing to do with flow rate.

 

[VicS]

The flexofold 2B has no anode fitting. The 3 blade does but it's a big price hike. We have only had the boat for one year but the anode on the old fixed 2 blade was badly eaten away. During the summer we are on a swinging mooring on the Medway and assume the aggressive galvanic action is due to the continual tidal race. Opinions on the importance of the anode fixed to the propeller please.

IF you are talking of props for saildrives ITYWF that it depends on the version of 2 blade Flexofold

The new "composite" Flexofold is made of materials which make it immune to galvanic corrosion
2-Blade Saildrive Composite Folding Propeller

The standard version has anodes #11 in this snip



If you are concerned about the high rate of loss of anodes, which I am sure is due to the electrochemistry resulting from small zinc anodes and the large surface area of the propeller blades immersed in salt water rather than ant effect of tidal flow, consider the new composite version.

If you are talking about shaft drive props then presumably the martials used make cathodic protection unnecessary but a shaft anode may be an option

 

[alahol2]

We've got a Flex-o-fold 2B on a shaft drive. It is only protected by the hull anode, no corrosion evident in the last several years since fitting. Portsmouth harbour so subject to tidal flow.

 

[jellidreamer]

I also am moored on the Medway and have a folding prop. I found painting the propeller blades and hub reduces the galvanic signature and i get through a season on one set of anodes. Cost wise its the same as Using Two anodes because of cost of paint i use on anti fouled prop. As they say you take your choice.

 

[RichardS]

The flexofold 2B has no anode fitting. The 3 blade does but it's a big price hike. We have only had the boat for one year but the anode on the old fixed 2 blade was badly eaten away. During the summer we are on a swinging mooring on the Medway and assume the aggressive galvanic action is due to the continual tidal race. Opinions on the importance of the anode fixed to the propeller please.

I have Flex-o-Fold 2 saildrive blades and they have half-spherical anodes bolted with a central bolt to the end of the hub. I think that earlier versions had no anode but the later ones do.

Richard