Does a standard 3 blade fixed prop on a volvo penta sail drive have a prop anode ?

[schrimpy]

Hi , recently bought a 2009 bavaria 50 cruiser Sailing boat with a Volvo D2-75C engine and volvo saildrive with a fixed 3 blade prop,

I found an anode on the saildrive and a mushroom anode stuck to hull.

I had a folding prop before with also a cone anode on the prop on the similar boat and engine.

Am I correct to assume fixed props dont need this cone anode on prop?

 

[VicS]

Hi , recently bought a 2009 bavaria 50 cruiser Sailing boat with a Volvo D2-75C engine and volvo saildrive with a fixed 3 blade prop,

I found an anode on the saildrive and a mushroom anode stuck to hull.

I had a folding prop before with also a cone anode on the prop on the similar boat and engine.

Am I correct to assume fixed props dont need this cone anode on prop?

The anode on the saildrive is there to protect the saildrive leg. It is vitally important that you maintain this anode , if it goes the next thing that will go is the saildrive leg.

Folding props are often/usually fitted with anodes due to the mix of metals used in their construction. A fixed bladed prop should not need an anode if it is made of a corrosion resistant alloy such as manganese bronze. Presumably no signs of dezincification but keep an eye on it

Cannot say what the hull anode is for. What is it bonded too ?

 

[nigelmercier]

Am I correct to assume fixed props dont need this cone anode on prop?

No.

 

[scottie]

No.

Yes normal saildrive cone nut is alloy

 

[Davegriff]

My 110s saildrive 2 bladed prop is alloy with a bronze (I think) hub. The hub is insulated from the the prop by rubber bushing and a nylon washer, and neither the cone or the prop has an anode; presumably because the latter is totally insulated electrically from the leg.

 

[nigelmercier]

To clarify my answer above, the OP asked:

Am I correct to assume fixed props dont need this cone anode on prop?

To which the answer is: "No", as in you are not correct that fixed propellers don't need a cone anode. Some do.

Best way to find the answer is to look up your drive here: http://www.marinepartseurope.com

 

[haydude]

No.

+1 NO

 

[Slowtack]

Mine is 3 bladevolvo folder on 120SB with a saildrive anode and also a hull teardrop type which is wired to the engine/gearbox interface. The prop has no anodes but I have seen other models which do have them.

 

[Tranona]

Mine is 3 bladevolvo folder on 120SB with a saildrive anode and also a hull teardrop type which is wired to the engine/gearbox interface. The prop has no anodes but I have seen other models which do have them.

I hope that it is to the gearbox and not the engine. The saildrive housing is protected by the ring anode and any additional anode should be connected to the gearbox housing, not the engine.

 

[scottie]

Volvo offer I size fits all alloy cone for saildrives

Other brands and configurations may differ

 

[schrimpy]

thanks for all your replies , very helpful , so I basically have the 3 fixed blade aluminum prop on the 150S VP Saildrive, which according to VP and the website posted above and a phone call to Volvo agents , the fixed blade std Alum props dont have an anode but an alloy cone that fixes with a screw through it. What confused me is that the boat when lifted had only the screw and no cone.

 

[VicS]

No idea what alloy the cone is? An aluminium alloy presumably ?

If the cone was missing then not a lot holding the prop on.

It looks as though it is insulated from the prop by a plastic washer (#5) :

 

[schrimpy]

No idea what alloy the cone is? An aluminium alloy presumably ?

If the cone was missing then not a lot holding the prop on.

It looks as though it is insulated from the prop by a plastic washer (#5) :

thanks, ordered them attached is a photo of the prop, seems previous owner loss his cone !
looked something was missing from the start

 

[nigelmercier]

It looks as though it is insulated from the prop by a plastic washer (#5) ...

I think "insulated" is a bit misleading, there will be an electrical connection via the bolt and the shaft.
[Later] As Vic points out in #15, there is a rubber bushing in the propeller which will insulate it from the shaft.

I assume the OP is aware at what looks like huge anodes on the saildrive, see picture.

And the thin gaiter between the saildrive and the hull needs replacing.

 

[VicS]

I think "insulated" is a bit misleading, there will be an electrical connection via the bolt and the shaft.

I am assuming that the prop is insulated from the shaft by an insulating rubber bushing??

The the cone is electrically connected to the shaft via the retaining bolt and the plastic washer insulates the prop from the cone.

Is that not so?

 

[Tranona]

thanks, ordered them attached is a photo of the prop, seems previous owner loss his cone !
looked something was missing from the start

Is that boat in Greece? Somebody there makes that lock nut as a replacement for the (expensive) Volvo cone. The one i had on mine also had a grubscrew in the side to lock it. The cones have a habit of coming off if the big screw in the middle is not replaced with new each time or Loctited in place.

 

[schrimpy]

Is that boat in Greece? Somebody there makes that lock tight. as a replacement for the (expensive) Volvo cone. The one i had on mine also had a grubscrew in the side to lock it. The cones have a habit of coming off if the big screw in the middle is not replaced with new each time or Loctited in place.

Boat is in Italy, bought a kit , which comes with cone ,screw,washer and locktight, original volvo for €75 , I would rather keep everything as should be for a few euros.
Thanks for all your suggestions

 

[Slowtack]

I hope that it is to the gearbox and not the engine. The saildrive housing is protected by the ring anode and any additional anode should be connected to the gearbox housing, not the engine.

Not sure what is the implication Tranona? The gearbox is bolted direct to the engine. The engine has no pencil type anode in the waterways or heat exchanger. I gather this is standard for the model. The engine and drive are both 30 years old working well.

 

[VicS]

Not sure what is the implication Tranona? The gearbox is bolted direct to the engine. The engine has no pencil type anode in the waterways or heat exchanger. I gather this is standard for the model. The engine and drive are both 30 years old working well.

You dont say what model engine you have but I Think you will find that the sail drive is insulated from the engine in the case of a D2-75 and 150S as are various other VP models

A fresh water cooled engine would not have anodes in the waterways , anymore than your car does, it should be protected by the corrosion inhibitor in the coolant.

The design and material used in the construction of VP heat exchangers are such that they do not usually require an anode.

 

[Davegriff]

I am assuming that the prop is insulated from the shaft by an insulating rubber bushing??

The the cone is electrically connected to the shaft via the retaining bolt and the plastic washer insulates the prop from the cone.

Is that not so?

That is correct. Your discription is much better than my earlier attempt at doing so.