Volvo Saildrive 130S B Split Anode Replacement

[Ian_Rob]

I am just in the process of replacing the anode on my Saildrive. It's the Ambassador Stripper Version. The Saildrive surface below the anode has been previously painted so I have just sprayed it with Prop O Drev. However reading the instructions for installing the anode it says that mating surfaces should be scraped to ensure good metallic contact. Does this mean between the two halfs of the anode or between the anode and the Saildrive leg? Do I need to scrape off the paint I have just applied?

 

[VicS]

I am just in the process of replacing the anode on my Saildrive. It's the Ambassador Stripper Version. The Saildrive surface below the anode has been previously painted so I have just sprayed it with Prop O Drev. However reading the instructions for installing the anode it says that mating surfaces should be scraped to ensure good metallic contact. Does this mean between the two halfs of the anode or between the anode and the Saildrive leg? Do I need to scrape off the paint I have just applied?

The manual I believe makes it clear that the mating surface on the drive must be scraped clean. Good electrical contact between the anode sections and the drive leg is essential for the anode to be effective.

The same applies when replacing the prop anodes

 

[Ian_Rob]

That makes sense but having just removed the paint I applied the surface below is painted and must have been since new.

 

[duncan99210]

The surfaces that should be bare metal are those surrounding the mounting holes, not the entire surface of the area covered by the anode. So looking at your picture, there is little or no paint on the lugs the mounting bolts go through but there is paint on the remaining surfaces. That's how it should be. I'd just clean the surface of the lugs and the inside of the bolt holes.

 

[RichardS]

View attachment 63650That makes sense but having just removed the paint I applied the surface below is painted and must have been since new.

I'm not sure what we're looking at in the photo but my procedure is that anything which is actually in contact with zinc should be bare metal. Anything which is not actually touching zinc is better painted.

Richard

 

[pvb]

The surfaces that should be bare metal are those surrounding the mounting holes, not the entire surface of the area covered by the anode. So looking at your picture, there is little or no paint on the lugs the mounting bolts go through but there is paint on the remaining surfaces. That's how it should be. I'd just clean the surface of the lugs and the inside of the bolt holes.

That's my understanding. The two lugs through which the anode bolts pass are the electrical contact. The rest can be painted.

 

[VicS]

The surfaces that should be bare metal are those surrounding the mounting holes, not the entire surface of the area covered by the anode. So looking at your picture, there is little or no paint on the lugs the mounting bolts go through but there is paint on the remaining surfaces. That's how it should be. I'd just clean the surface of the lugs and the inside of the bolt holes.

I'm not sure what we're looking at in the photo but my procedure is that anything which is actually in contact with zinc should be bare metal. Anything which is not actually touching zinc is better painted.

Richard

That's my understanding. The two lugs through which the anode bolts pass are the electrical contact. The rest can be painted.

"Mating surfaces" is what the manual says.
Agreed the rest can, and should, be painted.

 

[Tranona]

Yes, the carrier is the contact, not the anode against the housing. Not sure there is any need to paint any of it, though. Never had a problem with fouling of the carrier.

 

[RichardS]

A rather confusing thread .... we seem to have arrived at a "dual consensus" comprised of two completely different opinions.

So, no change there then.

Richard

 

[Tranona]

A rather confusing thread .... we seem to have arrived at a "dual consensus" comprised of two completely different opinions.

So, no change there then.

Richard

What leads you to that conclusion. There is no doubt the electrical path is through the carrier so the mating faces should not be painted - all agreed? whether the rest of it needs painting is optional. Paint will have no effect on the electrical circuit, but I have never bothered because it does not seem to foul on my boat(s).

 

[RichardS]

What leads you to that conclusion. There is no doubt the electrical path is through the carrier so the mating faces should not be painted - all agreed? whether the rest of it needs painting is optional. Paint will have no effect on the electrical circuit, but I have never bothered because it does not seem to foul on my boat(s).

It sounds like I've misunderstood. I thought that when you said "the carrier is the contact, not the anode against the housing" you meant that where the anode presses against the saildrive housing is not electrical contact and therefore that area could be painted, whereas Vic and I are saying that any area where the anode touches the housing should definitely be left unpainted.

Sorry if I've misunderstood.

Richard

 

[VicS]

It sounds like I've misunderstood. I thought that when you said "the carrier is the contact, not the anode against the housing" you meant that where the anode presses against the saildrive housing is not electrical contact and therefore that area could be painted, whereas Vic and I are saying that any area where the anode touches the housing should definitely be left unpainted.

Sorry if I've misunderstood.

Richard

I dont know what this "carrier" is you and others refer to. AFAICS the anodes fit directly to the bearing housing.

With the saildrive in one hand and the anodes in the other it should be obvious what constitutes the "mating surfaces". I assume it is the area I have coloured in the diagram below.

I would paint the area behind the anode, as was apparently done originally, but not antifoul it, leaving just the mating surface unpainted.

Once fitted it would be wise to check for continuity between the anodes and the dive leg but once the leg is fully painted that may not be so easy

 

[RichardS]

I dont know what this "carrier" is you and others refer to.

I've only referred to "carrier" because I'm quoting Tranona so you need to take that up with him.

As far as I'm concerned, any part of the anode, either the zinc or this "carrier" thing, which touches the saildrive casing should be unpainted as should the casing itself at that point.

Richard

 

[Ian_Rob]

I dont know what this "carrier" is you and others refer to. AFAICS the anodes fit directly to the bearing housing.

With the saildrive in one hand and the anodes in the other it should be obvious what constitutes the "mating surfaces". I assume it is the area I have coloured in the diagram below.

I am pretty sure the green area doesn't really touch the anode. It might but it isn't a tight mating surface. I just cleaned the two lugs and the holes and the corresponding surface on the anode and assembled it using the recommended Loctite 243. Seems to me there is potential for the Loctite to act as insulator particularly between the screw and hole but hopefully there is contact.

 

[pvb]

I am pretty sure the green area doesn't really touch the anode.

I think you're right - the electrical contact is through the 2 lugs which the anode halves are bolted on to.

 

[VicS]

I am pretty sure the green area doesn't really touch the anode. It might but it isn't a tight mating surface. I just cleaned the two lugs and the holes and the corresponding surface on the anode and assembled it using the recommended Loctite 243. Seems to me there is potential for the Loctite to act as insulator particularly between the screw and hole but hopefully there is contact.

I think you're right - the electrical contact is through the 2 lugs which the anode halves are bolted on to.

Fair enough. I did wonder about that but it seems such a small contact area when potentially the anodes could clamp around the green shaded area , just as a shaft anode clamps to the shaft. As I said with the anode in one hand and the sail drive in the other it should be obvious what the mating surfaces are.

Presumably then the anodes make direct contact with the lugs rather than through the screws.

 

[Harry Brown]

The red circles indicate the area of paint that needs to be removed on the 130S.
Its not the clearest of pictures, but if you look closely at the top hole, you will see a spotface.
These areas (both sides) should be clean of paint, and is the only contact points that the split anode touches the 130S Sail Drive.