Propeller Shaft Grounding Strap

[pratkins]

I have a wooden yacht powered by a Yanmar 2QM20, a brass shaft and a bronze propeller and dynal sheathed below the waterline. Can someone tell me the reason/s I should consider fitting a Propeller Shaft Grounding Strap. I did not know about them until today.

 

[VicS]

I have a wooden yacht powered by a Yanmar 2QM20, a brass shaft and a bronze propeller and dynal sheathed below the waterline. Can someone tell me the reason/s I should consider fitting a Propeller Shaft Grounding Strap. I did not know about them until today.

As a means of earthing the stern gear to an anode ??? ,
May provide a better connection than the usual method of connecting the anode to the engine block or gearbox and bridging any flexible shaft coupling.

http://www.keoghsmarine.com.au/product_details.php?ProductID=110

An alternative is MG Duff''s "Electro Eliminator" . (qv)

If you have no corrosion of the stern gear its not necessary.

 

[vyv_cox]

As VicS says, if you don't have a problem don't do anything. Electrolytic issues on wooden boats are a very special topic that may need complex methods to solve. Leave well alone if you can.

 

[Tranona]

I have a wooden yacht powered by a Yanmar 2QM20, a brass shaft and a bronze propeller and dynal sheathed below the waterline. Can someone tell me the reason/s I should consider fitting a Propeller Shaft Grounding Strap. I did not know about them until today.

You say a brass shaft, but suspect if it is not stainless steel it is bronze and the same (or very similar) material to the propeller. Therefore no anode should be required. Presumably the boat has some age to it, so if their is no evidence of dezincification of the propeller then no need to do anything.