Flexofold composite props, blade anode erosion

[jastic]

I've fitted a pair of Flexofold composite folding props to our cat and have noticed significant blade anode erosion after just 2 weeks in the water (med). The vp drive leg anodes look fine (?) and I haven't been in a marina or hooked up to shore power. Both props are the same. Any thoughts?

 

[Tranona]

The props are isolated from the saildrive. The anode is to protect the blades as they pivot on stainless steel pins. Normally erosion is low on Flexofold - indeed my early all bronze 2 blade has no anodes at all. I would take it up with Flexofold.

Long term it is a good idea to coat the blades with Velox as not only is this an effective antifoul it will reduce significantly the area of bronze exposed to seawater. This is my prop - the hub is coated in Trilux.

 

[jastic]

The props are isolated from the saildrive. The anode is to protect the blades as they pivot on stainless steel pins. Normally erosion is low on Flexofold - indeed my early all bronze 2 blade has no anodes at all. I would take it up with Flexofold.

Long term it is a good idea to coat the blades with Velox as not only is this an effective antifoul it will reduce significantly the area of bronze exposed to seawater. This is my prop - the hub is coated in Trilux.

many thanks for the tips, I've messaged Flexofold they can't offer an explanation......

 

[Daydream believer]

The props are isolated from the saildrive.

In your picture you seem to have an ambassador rope cutter. If the drive pins locate onto the plate on the back of the prop thus byepassing the rubber bush ( assuming your prop has one) then I think that you have effectively broken the isolation between shaft & prop via the rope cutter. As I understand it the delrin bearings in the cutter do not isolate the 2 parts.
Next time you change the saildrive anode, have a look at the cutter & you will see what I mean

 

[Tranona]

No sign of a cutter in the OPs photo and given that the blades and pins run in a composite rather than bronze hub it is irrelevant anyway.

 

[Daydream believer]

No sign of a cutter in the OPs photo and given that the blades and pins run in a composite rather than bronze hub it is irrelevant anyway.

Apologies. I was mislead by the fact you posted a picture & assumed it had a bronze hub ( because you mentioned bronze) & cutter& you were suggesting it was isolated from the saildrive, which may well have been incorrect. But not so & it is me that is confused

 

[Tranona]

Yes, I have had a cutter fitted for more years than I care to remember on 2 boats with both a standard aluminium prop and for the last 10 years with the bronze Flexofold. Never any problem with galvanic action.

 

[Slowboat35]

My Featherstream (bronze hub, stainless blades) ate an entire anode in 9 months and left the blades covered in the hardest and most tenacious calcium deposits I've ever seen. Very annoying.

 

[Tranona]

Don't think the deposits are anything to do with the anode (or lack of). Suggest you coat the blades with Velox.