Corrosion on stern drive?

[valkyr]

I've got some kind of corrosion going on with my stern drive. Its a Bravo I and it looks powdery like the batteries get around the posts. The corrosion is the silver deterioration shown in the pictures.

What do I need to do to 'nip this in the bud' ?

Pics attached...

 

[Wotknot]

Re: Corrosion on stern drive?

.......a possiblity

The Quicksilver MerCathode System has a 20 amp in-line fuse in the wire which connects to positive (+)
terminal on controller. If fuse is blown, system will not operate and a loss of corrosion protection will result.​

 

[valkyr]

Re: Corrosion on stern drive?

.......a possiblity

The Quicksilver MerCathode System has a 20 amp in-line fuse in the wire which connects to positive (+)
terminal on controller. If fuse is blown, system will not operate and a loss of corrosion protection will result.​

What else wouldn't operate? Everything electronic seems to work fine....

 

[Ryan00TJ]

Re: Corrosion on stern drive?

Are your anodes in good shape? They should be replaced yearly depending on use? I agree about the Mercathode maybe not working. I assume the boat sits in the water thru summer?

Notice the corrosion taking place around areas of stainless. When two dissimilar metals are close that's where the corrosion normally starts.

 

[valkyr]

Re: Corrosion on stern drive?

Ok, I've been reading up on the mercathode protection system.

The boat only sits in the water when I'm using it as I trailer it back and forth to the lake. I bought the boat a few weeks ago and not sure if the corrosion was there. Not sure how quickly this type of corrosion can occur?

Next question, where are the anodes? Having a hard time finding a pic of the location of these babies. I realize I should have magnesium anodes for freshwater use. One picture I looked at looked like one guy had one at the end of his prop?

Any pics of drive with the anodes pointed out? (Assuming the anodes are part of the drive, or do they mount on the boat?)

Thanks!!

 

[valkyr]

Re: Corrosion on stern drive?

Ok, I've read through the corrosion section of manual 11 and have a better idea of the different anodes. I have no idea when they were last replaced.

I know the trim tab anode looks to be in good shape. I'll check the rest this evening.

How fast can this corrosion take place if I only have the boat in the water for a few hours at a time? Any ideas?

 

[bruceb58]

Re: Corrosion on stern drive?

Since your boat is a trailered boat and is in the water for short times, you don't really need to worry about Mercathode or anode replacement.

Looks like you have a few places that the paint peeled off and they can be touched up with some primer and paint.

 

[valkyr]

Re: Corrosion on stern drive?

Bruce are you sure about that? Because those areas are powdery...Like the way battery acid does around the metal posts? (I don't doubt you, but want to make sure I protect my drive

Thanks!

 

[stevieray]

Re: Corrosion on stern drive?

Not much corrosion takes place in a few hours. Make sure you sand down & touch up the bad spots with paint or they will continue to corrode. You probably won't see much wear on your new anodes.

 

[valkyr]

Re: Corrosion on stern drive?

I don't have new anodes "yet". I'm not sure if the anodes have ever been replaced as I have only owned the boat for a few weeks.

Thanks

 

[stevieray]

Re: Corrosion on stern drive?

If the existing ones are older, they may be zinc. If zinc ones sit out in the air, they get a coating on them that renders them useless. I'd replace with new aluminum or magnesium ones for the peace of mind.