2005 Bravo3 corrosion issue needs addressing.

[Beerlust]

2005 300 sundancer

Bought this boat a few months ago. The out drives are showing mild corrosion.

Fresh water boat had original zinc anodes, now replaced with magnesium.

Also, gen intake not bonded, now bonded

I fixed what the marine surveyor found otherwise i would have no idea. Any ideas how to slow the corrosion feel free to post your opinions here.

 

[yako]

Do you have any photos. May be easier to give thouhts.

 

[Lazy Daze]

2005 300 sundancer

Bought this boat a few months ago. The out drives are showing mild corrosion.

Fresh water boat had original zinc anodes, now replaced with magnesium.

Also, gen intake not bonded, now bonded

I fixed what the marine surveyor found otherwise i would have no idea. Any ideas how to slow the corrosion feel free to post your opinions here.

Are they NOW showing corrosion, or were they when you bought it? It's not clear from what you wrote. It might be that Al will be a better choice. Best way is to check with experienced locals (at least a few years in your area) with similar drives.

Did you have the Mercathode system checked?

And, don't be afraid to search - there is SO MUCH information on this forum that we're not going to be saying anything new to you that hasn't already been said dozens of times.

I plugged in "bravo corrosion" and got this:

http://clubsearay.com/search.php?searchid=3144630

 

[Beerlust]

Yako. Having trouble loading pictures, i will work on this.

Daze, i will research the sources your recommended. I bought this boat end of year and actually did walk around other boat with bravo3 in the yard, wasn't able to see a trend. Speaking with other boaters in the area would have been smart. However, my marina has informed me the outdrives could/might fail in ten years if unchecked. Basically the mercruiser stickers are beginning to fall off. Also, i am vague because i am not sure what is important. Thanks for your patience.

 

[Beerlust]

A1 is an option but i will get them redone and check grounding , ect for now. The boat has the original zinc anodes, now replaced all with mag.

Also, the surveyor found the gen intake not bonded. Could this increase Galvanic corrosion? The intake is now bonded properly.

 

[Beerlust]

Thanks i will try

 

[Mark I]

There are three things you must do with B3s.

You must have working mercathodes. Make sure they are wired direct and are not off when the battery switches are off.

You must use OEM zincs. Use cheap crap from China and you will pay the price.

You must keep tabs on the zinc erosion. Inspect often.

Take care of them and they will be fine. I slip my boat in salt water from April to November. I do a mid season haul with every boat I have owned. This year I did not change a zinc on the haul out.

 

[Beerlust]

Good info.

I am in fresh water and my marine recommended and installed magnesium. I think it was magnesium? Otherwise the zincs were original and deteriorated for a 2005 in fresh water.

 

[src]

Good info.

I am in fresh water and my marine recommended and installed magnesium. I think it was magnesium? Otherwise the zincs were original and deteriorated for a 2005 in fresh water.

From what I understand, it really depends on the quality of the water you boat in. If your water has higher mineral content or otherwise has something that increases conductivity, magnesium can be a bad option. But if it is what is recommended by the other locals who boat where you do, it is probably a reasonable choice.

 

[Stray Cat]

I am in fresh water and my marine recommended and installed magnesium. I think it was magnesium? Otherwise the zincs were original and deteriorated for a 2005 in fresh water.

Magnesium is the prefered annode for the waters you currently are in. Unfortuanately the zinc offered little if any protection since the boat was new. As mentioned, make certain your Mercathode is working before spring launch. Inspect the reference electrode on both your drives before launch to make certain it doesn't have any breaks in the electrode. If there is a lot of crud build up on the electrode look for a break where the electrode makes connection to the housing.

I fight the corrosion with new annodes each season. I sand off any lose paint or corrosion as best I can and dust it with a coat of SEM self etching primer (black) The Merc paint alone will not hold up on its own.

 

[AFD]

I have some very minor corrosion on my alpha one's. again very minor and when i put the new pumps in this month i plan on sanding down the chipping paint and slightly pitted aluminum and spraying http://www.foreandaftmarine.com/94-Y5499A.JPG

my question is, does anybody have a wiring diagram of the proper mercathode setup? my boat has engines it did not come standard with and i'm not sure if the mercathode system was set up properly. if someone could post the diagram it might help future searches with this thread. I wasn't trying to steal the thread.

 

[src]

my question is, does anybody have a wiring diagram of the proper mercathode setup? my boat has engines it did not come standard with and i'm not sure if the mercathode system was set up properly. if someone could post the diagram it might help future searches with this thread. I wasn't trying to steal the thread.

Here's a diagram I found. It shows the wiring with the additional pucks, but subtract those and and it should be good. http://clubsearay.com/showthread.php/64061-Outdrive-Corrosion?p=729505#post729505

 

[Beerlust]

I know my manual has all wiring diagrams for my boat. Have you checked your manual or requesting it from the maker.