Rapid Outdrive Anode Loss

[Horigan]

I'm finding that the anodes on our Volvo 290DP drives are being consumed in about four months, while slipped in saltwater. Is typical for these drives?

The previous owner of the boat had painted hull anti-fouling paint right up to the drive transom mounts, which we stopped adding to for the past two years. We're now painting the hull one inch away from the mounts, but haven't actively removed the hull paint in that area. Could that be a contributor to the rapid anode loss?

 

[Scott06]

Do you have correct annodes for salt water and is there shore power on your boat or nearby boats. Likely some stray current in the water.

on my mercruiser i found better performance with oem merc annodes vs aftermarket. They lasted longer and i had less drive corrosion .

 

[Scott Danforth]

If you are slipped by yourself, anodes last about 6 months.

If you are slipped in a marina, 4 months may not be bad with all the stray current at marinas

 

[Horigan]

Thanks guys. I'm slipped in a marina with shore power with other boats using Volvo zincs. Thank goodness I can remove the props and access the zincs from the swim step.

 

[mike_i]

Do you know for sure that the anodes are either zinc or aluminum and all are the same?

 

[Lou C]

Go on to boatzincs.com they sell a reference electrode that you can use to determine if you have enough protection…my boat is moored in salt but no shore power and the anodes could easily last 2 seasons but I still change them each season…

 

[Horigan]

Do you know for sure that the anodes are either zinc or aluminum and all are the same?

Yes. The boat is salt water only using zincs.

@Lou C , I'll check that out. Thanks!

 

[Lou C]

They also sell a large anode that you can hang over the side that adds protection if needed.
I didn’t need to use the reference electrode because I’ve never had a problem with rapid anode deterioration but if I did that’s definitely the way to go. A little pricey but worth it…

 

[Scott Danforth]

They also sell a large anode that you can hang over the side that adds protection if needed.
I didn’t need to use the reference electrode because I’ve never had a problem with rapid anode deterioration but if I did that’s definitely the way to go. A little pricey but worth it…

Martyr makes it. 10# anode that looks like a fish

 

[Horigan]

Yeah. We have one over the side also.