Duoprop 290 anodes - is this insane, or what?

[skipjack27]

Am I insane (quite possibly), or do Volvo Penta make life difficult just for the hell of it (also quite possible, I suspect)?

See the picture: the prop shaft anode (upper anode) is a continuous circular structure. This means that in order to replace it (which needs to be done often in my area), both props need to be removed. It is impractical to slip the boat every time the anodes need replacing, and removing and replacing both props is anything but fun in the water. And hiring a diver is expensive.

I would dearly love someone to tell me why they can't make this anode in two halves that bolt together. That way, it would be unnecessary to remove anything in order to replace the anodes. This was the way it worked in my previous boat: two anode halves that I just swam down and bolted onto the shaft (this was a shaft drive boat).

Why can't this anode be made in two halves that bolt together? If other anodes are made like this, why not THIS anode??

Regards

Jeff

 

[Bondo]

Re: Duoprop 290 anodes - is this insane, or what?

I would dearly love someone to tell me why they can't make this anode in two halves that bolt together.

Ayuh,... They do that Because,...
It forces you to pull the props,+ Hopefully you'll be smart enough to Grease the propshaft...
You be surprised how many props are Destroyed takin' off, because the shaft Don't get Greased regularly....

 

[lmannyr]

Re: Duoprop 290 anodes - is this insane, or what?

Just curious, how often do these zincs get changed when slipped? I would think this is a every season deal. Which should then be done with everything else that should get every season, (bottom paint, alignment, oil changes, grease nipples, bellows inspection, etc...). IS the oil change in the B3 the same as A1.....

 

[RicardoMarine]

Re: Duoprop 290 anodes - is this insane, or what?

Ayuh,... They do that Because,...
It forces you to pull the props,+ Hopefully you'll be smart enough to Grease the propshaft...
You be surprised how many props are Destroyed takin' off, because the shaft Don't get Greased regularly....

Agree with Bill. I've had to cut some very nice Duo Prop propellers from shafts because of corrosion whereby the owner was no savvy to this!

These props need to be removed at least annually, if not more often, depending on river/lake water vs salt water.
While there, simply replace the ring anode and at least check the shield anode!

.

 

[lmannyr]

Re: Duoprop 290 anodes - is this insane, or what?

Ricardo.....thanks, good to know...

 

[skipjack27]

Re: Duoprop 290 anodes - is this insane, or what?

Thanks, guys: interesting comments. I'm aware of the problems props can present if not removed and greased reasonably regularly. But surely once a year is enough, even in (estuary) salt water?

These darned leg anodes appear to be lasting no longer than 3 months. So, this means that 4 times a year I have to:

1. Slip the beast just to replace anodes (sigh, sigh), or

2. Don my goggles and snorkel and try to remove props, grease shafts, replace anodes, and put props back on - in the murky and difficult conditions of a marina, and in sometimes very cold water (not to mention a bit of stray mains current - we have 240v in my country), or

3. Hiring a diver to do all that. Probably cost as much as slipping.

Not good. I particularly resent being "forced" by the anode design to decide how often I grease the prop shafts - since the frequency of anode replacement required in any given situation is utterly unrelated to desirable frequence of shaft greasing.

Jeff

 

[JustJason]

Re: Duoprop 290 anodes - is this insane, or what?

Am I insane (quite possibly), or do Volvo Penta make life difficult just for the hell of it (also quite possible, I suspect)?

Nope... it makes perfect sense if your Sweedish

But surely once a year is enough, even in (estuary) salt water?

These darned leg anodes appear to be lasting no longer than 3 months. So, this means that 4 times a year I have to:

What body of water are you floating in? Any evidence of galvanic corrosion on the drive itself?
I will agree that 4 times a year is alot.

You may have come stray current issues at your dock. You may want to hire (or have a marina if your floating there) hire an electrician/marine electrician with a reference electrode to see how much electricity in that battery of saltwater around your boat is producing.

 

[sean whiteman]

Re: Duoprop 290 anodes - is this insane, or what?

I have worked on many VP duo props in the Mediterranean as well as in Ireland and If the props are not removed and greased annually you are in for a lot of work to get them off..........Props, props shafts, saltwater = GREASE and some more GREASE.

 

[Bondo]

Re: Duoprop 290 anodes - is this insane, or what?

(not to mention a bit of stray mains current - we have 240v in my country), or

Ayuh,... So it's Volvo's fault they designed a drive that protects itself, when you're boating in battery electrolyte,..??

I'd think your complaints should be with the Marina Owner,... Not Volvo...

I'd think there's No reason that the stray current can't be contained...

 

[mariner1900]

Re: Duoprop 290 anodes - is this insane, or what?

Hi Jeff,
Do as Jason says and have the area around your boat checked with a reference cell to check for stray currents. The marina will probably deny there is any stray currents and not do anything anyway.

Since the anodes that are fitted aren't lasting you may have to fit some extras on the transom and then bond them to the drive unit to add extra protection.

As a temp measure buy a 2kg anode. Connect a heavy cable to the anode at on end and a couple of heavy clamps at the other. Lower the anode into the water and connect the clamps to the drives. This will provide some extra protection and extend the life of the existing anodes. (you must remember to remove the anode before taking off for the day)
We did the above every night when we tied the Sydney, Aust, hydrofoils up at night after the days running.