Adding additional Mercathode pucks?

[SeaNile31]

My boat, 2004 Rinker 312 with Bravo 3 drives, does have corrosion on the drives and I want to do my best to preserve these drives because replacements are very expensive as we all know. So I have confirmed both drives have the Mercathode puck under the drive. Whether it's working or not I do not know at this point (boat is on land and shrink wrapped). I looked all around the marina today at other boats that also have the B3 drives, almost every boat had an additional Mercathode puck, some had two additional. The boats with twins had 4 pucks, two for each drive. Also spoke to a local mechanic at the marina and he also recommended adding the 4 pucks to my boat. Called Mercruiser and they recommended the additional puck per engine and said adding 4 total pucks would be a good idea.

So before go and have these additional pucks added, and I am leaning towards getting 4 pucks and replacing the existing Mercathodes and getting the red hi voltage controller....am I doing the right thing? I'll be changing all the zincs, Al, with the prop nut, sanding and painting the drives, etc.

Thanks for the help.

John

 

[Don S]

Re: Adding additional Mercathode pucks?

You need to do some measurements before you go blindly adding "pucks", or you could go the wrong way and cause even more corrosion.
Download this service bulletin, it explains how to test.

http://www.4shared.com/office/ViLRp-nH/02-06_Corrosion_Prevention_and.html?

 

[LilRedNeckGirl]

Re: Adding additional Mercathode pucks?

You say " DRIVES", Plural.
There is something ive wondered about, but have never seen addressed. Food for thought if you will.
@ I also run twins, 3.0 mercruisers. Does the fact that your dealing with two seperate electricial systems factor in at all, especialy in brine, when talking about and dealing with galvonic action/corrosian?
I stay in fresh water mainly, and home port is all fresh water, so even a run to the brine line gets washed out before i park the boat. My corrosian issues are non existant. Nothing ever seems to corrode, so im guessng my rig is set up right, @ 1985 Wellcraft 248 sportsman, but for those with issues or brine use, how do twins factor in?

 

[Don S]

Re: Adding additional Mercathode pucks?

If a boat is wired correctly, it shouldn't be a problem. That's why you need to do the tests outlined in the service bulletin I posted earlier.
His problem may be due to boats parked next to him, or the docks shore power. But you can go to far with the protection, in which case the outdrives tend to turn into anodes to protect the Mercathodes.

 

[Bondo]

Re: Adding additional Mercathode pucks?

Does the fact that your dealing with two seperate electricial systems factor in at all,

Ayuh,.... Even though you've got 2 alternators, 'n several batteries,...

You've still only got 1 electrical system....

They're all tied together through the Grounds/ Bonding of the hull...

 

[Thalasso]

Re: Adding additional Mercathode pucks?

My boat, 2004 Rinker 312 with Bravo 3 drives, does have corrosion on the drives and I want to do my best to preserve these drives because replacements are very expensive as we all know. So I have confirmed both drives have the Mercathode puck under the drive. Whether it's working or not I do not know at this point (boat is on land and shrink wrapped). I looked all around the marina today at other boats that also have the B3 drives, almost every boat had an additional Mercathode puck, some had two additional. The boats with twins had 4 pucks, two for each drive. Also spoke to a local mechanic at the marina and he also recommended adding the 4 pucks to my boat. Called Mercruiser and they recommended the additional puck per engine and said adding 4 total pucks would be a good idea.

So before go and have these additional pucks added, and I am leaning towards getting 4 pucks and replacing the existing Mercathodes and getting the red hi voltage controller....am I doing the right thing? I'll be changing all the zincs, Al, with the prop nut, sanding and painting the drives, etc.

Thanks for the help.

John

tester.

Was browsing through old post and saw this. I hope it isn't to late but this is how i handeled the same problem with Bravo III's.
You need to get a silver chloride tester and digital multi tester. See what your reading are after a day or two of the boat setting. The reading should be in the neighborhood of 900-1000 on the digital multi tester. Somewhere on your engine should be a blue mercathode controller with 4 or 5 wires out the back. Get another controller of the same color ( they come in blue and red ) and wire it terminal 1 to terminal 1 and so forth until all wires are hooked up to the origanal controler. What this does is increases the protective field around the outdrives. In fresh water that has a current it tends to break down the field around the drives. As Don said, you can over protect your drives.That will make the paint peel off your drives. If your in freshwater you need Magneisum anodes. I don't know what your referring to when you mention puck , but if you have the Mercathode it will be mounted on the transom. It will resemble a heat sink. It will be retangular in shape and about 2x3