Anode Question.

Alistairr

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So the boat or new boat stays in Loch Lomond, and the boat or New boat both use Bravo 3 drives.

Still a bit concerned about B3 Corrosion,
Which Anode is best???
I know i've to use Magnesium, instead of Zinc, Correct? But what about Aluminium Anodes, would they be better for our fresh water instead??

Also while the boat is tied up most of the time to the pontoon, and connected to the shore power, is it worth me hanging extra Anodes of the rear of the boat, and should i fit a secondary mercathode system? (I'm presuming the Mercruiser MPI/B3 package has one already fitted??)

Many thanks

Alistair.
http://arweb.co.uk/argallery/alistair
 

MidlandsOnSea

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I too have Bravo 3s, and the threads about the corrosion scared the hell out me. I digested the feedback on this forum and did some research elsewhere and reached the following conclusions:

1. I lifted my boat (after it had been in the water for about 4 months) to see if there was any sign of corrosion and to check the anodes. At this point, I figured I would have known if I had one of the 'problem' units which have been referred to.
2. Fortunately, all was well but the anodes had wasted quite a lot so I took advice from this forum and made sure that they were replaced with genuine Mercruiser anodes.
3. I checked the bonding system and found a loose connection, which wouldn't have helped.
4. I too have shore power all the time (which you need if the Mercathodes are not to flatten the batteries) and I had a galvanic isolator fitted.
5. I now know that the anodes should be good for at least another 4 months and I will lift her again then to check on the anodes at that time. Eventually, I reckon I will get a feel for how long the anodes last, and thereby protect the drives
6. After asking around, I decided against fitting 2nd Mercathodes, but mainly because I concluded that I don't seem to have 'problem' drives or a problem berth.

I now sleep much better at night!
 

D3B

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Ok so frighten some who really dont know.

is this a unique probelm to Bravo 3 and Mercruisers or is it likely to happen on other boats?

i will/do have shore power connected to the boat when away to keep batteries charged fully and the beer in the fridge cool.
and the white wine for SWMBO
/forums/images/graemlins/grin.gif
 

JKay

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24 Jan 2005
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Only on sealine 29's!!! /forums/images/graemlins/wink.gif



good luck with your new boat let us know when your leaving Burton and we will come and wave you off

cheers Joe
 

D3B

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Thanks Joe
Seen your details will look out for you.
She is due to leave Sealine by end of month so will be playing early next month before i move her.
Any advise on the run to Hull for me?

Doug
 

tinstaafl

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23 Jun 2004
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Leeds, UK, Earth
[ QUOTE ]
Thanks Joe
Any advise on the run to Hull for me?


[/ QUOTE ]

Well, don't drink out of that river /forums/images/graemlins/smile.gif

I'm still jealous about your boat...

tinstaafl
 

mercman

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All depends on water content.
Mercruiser make 2 types of anode

1. aluminuim alloy for salt water
2. Magnesium for fresh water

zinc anodes are non genuine anodes and WILL NOT PROTECT YOUR STERN DRIVE CORRECTLY!!

It is a good idea to hang an extra anode off of a cleat or stanchion base just remember to bond whatever you hang off to a ground i.e engine earth or battery neg.
 

mercman

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Its mainly Bravo 3`s although it can happen on any stern drive. It just so happens the Bravo 3 is a popular drive which has many issues regarding protection or rather the lack of it. This is hopefully sorted on the new drives that are just starting to hit the shores.
I was involved with the Sunseeker at Eastlands (a friend of Solitaire i do believe) here on the south coast and i have to say there was a Fairline there which was under a year old. The Volvo agent RK was adding extra anodes to the unit by drilling and tapping extra bolt holes and fixing them to transom plate and cavitation plates.
But this could be down to problems with dodgy shorepower or pontoon electrics maybe.
 

Medskipper

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I don't think cathode protection is specific to a make of boat or a make of engine/outdrive!

I have had outdrives for many years and had little or no problems. The anodes I have used have been magnesium for fresh water and zinc for salt water conditions. I have no experience of aluminium anodes and in fifteen years of boating have heard very little about them! but I bow to the experienced!

In my humble opinion, it is best to leave the vessel during the summer with no connection to the mains power. You dont need to have the battery charger on all the time any way, because unless its a computer controlled good quality charger the batteries will just get cooked and die before their time! In the winter if power is left connected, just hook up one or two more anodes and dangle them in the water close as possible to the stearn gear you wish to protect. Obviously these extra anodes must be earthed back to the engine.

Good Luck

Barry
 

BrendanS

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Mercruiser outdrives are now shipped with aluminium anodes as standard after a series of problems with Zinc anodes
 

mercman

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Merc drives are now shipped with aluminium anodes as standard.

they have been since 1995 its old news.

As for magnesium anodes Alistair any Mercruiser dealer will have them. I only carry a set for each drive only because im in a salt water area and rarely have a boat used in fresh. At this point in time i have none in stock and am awaitng an order to come in. Your best bet is Windermere Aquatic
1. because they are a merc dealer.
2. coz they nearer to you .
3. because they in fresh water area more likely to loads in stock.

As for the post on here before mine scrolling through this guys stock if he can get merc anodes they are gonna be mgduff. Because hes a dealer for them. This whole thread is a carry on from a thread a while ago and we are back to square one.

Im going to sit these discussions out
1 coz its doing my head in trying to advise
2 coz im going to let you lot fit incorrect parts and await you on my doorstep with rotten drives, transom plates and rams crying you eyes out coz im going to have to quote you lots of money to repair the bloody thing. Where if any of you had listened in the first place.......ah never mind

good luck!
 

BrendanS

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It might be old use to you, but it's obviously not old new to everyone, so why have a go at me?

PS my 99 alpha drive came with zinc fitted, not aluminium
 

duncan

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I think it's the BIII reference that has got lost in the later posts Brendan.
Equally I believe that 'zincs' have become a generic (like Hoover) for anodes and that also confuses people.
At least more people are having the need to check/replace anodes on BIII drives mid season highlighted - I still believe that it is that single issue that has been responsible for the majority of drive galvanic corrosion issues (although mine was the fitting of pattern parts by a well meaning mechanic). My logic here is that if the anodes are required to work hard because of the area and conditions then the faster they go the faster/harder the drive will suffer too.
I was never advised that they might need replacing in 4 months when I got the boat and even now there is a reticence to highlight this as it can involve significant additional costs in a boating season.
 

BrendanS

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Yes, but I wasn't commenting on B3's. "All MerCruiser sterndrives come standard with aluminum sacrificial anodes & 3-year warranty against certain types of corrosion" - straight from their website (as you can see from the fact that americans can't spell aluminium! <g>)
 

Alistairr

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Mercman, I am really sorry you feel like that.

As you are a Merc Dealer i felt you were the perfect person to answer my questions, And so far you have been more than helpful and given me the true answer to my questions.
Your answer to my points on this thread and the 'Volvo v Mercruiser' thread have been very detailed and of great interest to me and i'm sure to plenty other people.

My question regarding Anodes was a query to the uses of Aluminium anodes, that said, i now know that they are for Salt water use, and of no use to me. I will stick to the Magnesium type as they are best for me.

I always use where possible genuine Parts, and will continue to do so, What i've learnt from this post is cheaper other makes are not a good idea.

I see you said you are out of stock at the moment,awaiting some coming in, If its ok with you, i'd like to place an Order for a full set of Magnesium for the B3.
If you wish we can discuss this via Pm, or give me your no. and i shall phone you.

Mant thanks

Alistair.
 
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