ADVICE - super bad corosion on gimble
 

I had 2 brand new gimbles put on my Sea Ray a little over a year ago. The paint has just disentigrated, and it is corroded into the gimble ring etc. Annodes are still in tact.

Could it be a paint problem from Merc?? Shouldn't these things be able to stay in the water all the time without this problem??

Ideas???

Sounds like a grounding issue. You should have a little cable that goes from the gimbal ring to the housing if my memory serves me correctly. Maybe when the ring was replaced it wasn't reinstalled?

Could be several things. Lack of bonding on the drive assembly, stray electricity in the water from your boat, neighbors boat, docks, or even bare wires hanging in your bilge if there is water in there.

Does the corrosion appear more around SS components, gearlube fill/vent plugs, prop hubs or SS studs?

+1 a lot of people overlook all the little things in the Mercathode system that are required to make it work. All those connections and ground straps are pretty important and easily overlooked, without them the anodes cant do their sacrificial job.

Guys that put these things in checked yesterday and said that all of the straps are installed properly.

I am just gonna have to check myself and blast them down and put some kind of anti fouling paint on them.

Funny how the old ones didn't corrode, and none of the other boats at the marina have this problem either??????????????

Sounds like there is one common element........You!:evilb:

You know what's funny is that I havn't turned a wrench on that boat, so it couldn't be me.......

LMAO :lolhit:

Gotta use antifouling w/o copper, otherwise they will corrode while you watch. The reason you see a 1" unpainted strip around the transom assemblies, no aluminum contact with anti fouling paint. Interlux makes a paint just for outdrives in a spray can.
But not sure if antifouling paint is going to help with corrosion problems. There are 2 types of corrosion issues, dissimilar metals (alum, SS) and stray electricity.
Are your Mercathodes working.. fuses good? They should be wired directly to battery, or the non switching side of the battery switch so they can not be shut off. Same as bilge pumps.
Galv. isolator good?

Anti-fouling paint is great for barnicles but won't do a thing for corrosion. The fact that your old rings didn't have a problem and that the anodes are not showing an issue still tells me you have a grounding problem. Get out an ohm meter and make sure you have continuity between the ring and other components of the drive. There are a dozen things that can cause corrosion problems, but yours seem to be isolated to the rings.

It's got to be in the way they were installed, boat will be out of the water for quite a while, so I can check and se what is not right and causing this problem. I may even pul them back off so that I can sandblast and re paint and check everything from scratch.

The big indicator is that this boat didn't have a problem for 15 years until the new ones were installed, so I need to work backwards from now till then and I will figure it out.

THanks for the help. These are basically the same answers that my own research has revealed all ready. :coolcowboy:

Did you check that the ground wire inside the bilge was reinstalled, the one that screws to the steering lever and to the inner transom plate?

It doesn't really matter how it happened. It will get fixed. I appreciate all the input so I know where to start looking. :coolcowboy:

Is it possible that a bad battery bank (meaning dead) would cause the mercathodes to not function properly? This could be the problem.

About 3 months before I took it out of the water, my genset and battery bank for the starboard engine went dead and I could never get them to charge back up. The corrosion does not look like it has been there for a year. It looks like it had only been there for a few months.

Am I thinking along the right path here?

If all the batteries would have stayed HOT? Would I have not had the problem.

Not sure that there is anything wrong with the instalation. Still checking, but I think that issue has been put to bed all ready.

Figure it out eventually. Weather is getting warm here so I need to get her back in the water one way or the other.

Possibly. Mercathodes require 12v to operate. Usually a fuse at the controller. Can see if there is voltage there and not blown. Normally these are wired for full time 12V, just like a bilge pump, so their operation can not be defeated by turning off the battery switch. So may depend on which battery bank they are powered from.

B3's need all the protection they can get. Assuming this is what you have on the Sea Ray