Zinc Activity

Discussion in 'General Discussion' started by hd2002hd, Mar 2, 2012.

  1. hd2002hd

    hd2002hd Member

    388
    Jul 20, 2010
    St. Louis
    1996-Sea Ray 215 Express Cruiser/1996-Sea Ray 330 Sundancer/1998-Sea Ray 400 Sundancer/1996-Sea Rayd
    5.7 Mercruiser/454's/454's w/V drive/120HP
    Just returned from the marina. They were pulling the boat out to repair the swim platform. I noticed the starboard zincs on the outdrives looked new. However, the port side had a little corrosion building up. Not bad but very noticeable. All zincs were changed a month or so ago. I went to the shop manager and had him take a look. The ground wire seemed to be intact. What issues could be causing this?
     
  2. Bucit

    Bucit New Member

    Mar 12, 2010
    St. Petersburg Florida
    2005 280 Sundancer
    2004 SPD-104 Achilles w/ 8hp Yamaha
    Twin 4.3 MPI's with Alpha drives.
    Maybe electrolysis in the water that is close to the starboard side and that zinc is taking the brunt of it?
     
  3. Great lakes pirate

    Great lakes pirate Member

    486
    Jan 5, 2010
    Lake St. Clair
    2000 35 Tiara Open
    Cummins 370
    I assume you are on a fresh water lake. What type of anode did you use? You should be using Magnesium or Aluminum. Make sure that zinc anodes were not used.
     
  4. chandalen

    chandalen New Member

    367
    Aug 7, 2011
    Alexandra Bay,NY
    '83 Sundancer 270, Humminbird 593c
    Twin merc 305, with new SEI 106 drives
    My magnesium anodes on my starb. engine showed more wear than the port. My only conclusion is that the side closer to the dock (starb) had a bit more electrical activity than the port.

    I did notice, upon changing the anodes, that the prior owner at some point, painted over the transom mounted anodes. So.. lot of good they were doing.
     
  5. electricaldoctor

    electricaldoctor Active Member TECHNICAL Contributor PLATINUM Sponsor

    May 14, 2008
    Thousand Islands, Rockport, Ontario.
    1988 390 EC
    454 Mercruiser Gassers
    I take all of mine off every Spring and grind all of the crud off of them and they are good for another season.
     
  6. hd2002hd

    hd2002hd Member

    388
    Jul 20, 2010
    St. Louis
    1996-Sea Ray 215 Express Cruiser/1996-Sea Ray 330 Sundancer/1998-Sea Ray 400 Sundancer/1996-Sea Rayd
    5.7 Mercruiser/454's/454's w/V drive/120HP
    Yes, it is on a fresh water lake and always has been. Not sure of the alloy but certain it is correct for water. It just seemed odd one side was visibly different after only a out a month. One side was not any closer to the slip than the other. Even the shop manager thought it was unusual. GE said they would look into it. I was just looking for some input from this board. Lots of great knowledge here
     
  7. chandalen

    chandalen New Member

    367
    Aug 7, 2011
    Alexandra Bay,NY
    '83 Sundancer 270, Humminbird 593c
    Twin merc 305, with new SEI 106 drives
    I read that grounding issues could cause this, esp. if your attached to shore power. Also, is the surface the anodes attach to clean on the anode and the boat parts?
     
  8. hd2002hd

    hd2002hd Member

    388
    Jul 20, 2010
    St. Louis
    1996-Sea Ray 215 Express Cruiser/1996-Sea Ray 330 Sundancer/1998-Sea Ray 400 Sundancer/1996-Sea Rayd
    5.7 Mercruiser/454's/454's w/V drive/120HP
    I wondered if it had to do with shore power but was confused since it was only the port engine. Good question on the surfaces. I would think the Marinemax mechanics made sure everything had good contact.
     
  9. njmello

    njmello New Member

    90
    Jul 1, 2007
    Hemet, CA
    1978 21' Cuddy
    Mercruiser 260 A-1 O/D
    The whole electrolysis issue in a marina can get absolutely goofy at times.

    Knew of a similar circumstance (One side eroding almost entirely and the other side not) - was eventually determined to be a boat in the next slip (on the eroded side) had a shore power grounding issue that 'leaked' electricity that 'found' it's way back to the shore power circuits through my friend's shore power hook up. Crazy!
     
  10. Uplate

    Uplate New Member

    977
    Oct 13, 2008
    Nashville, TN. Percy Priest Lake
    1998 Sea Ray Sundancer 310
    Westebeke 4KW Generator
    Twin 5.7 Mercruiser Carbuerated.
    Alpha 1 Drives
    What sort of metering or other process is used to determine where the leaking voltage is coming from?
    i may have a suspect houseboat next to me that is causing problems.
     
  11. Pack66Dad

    Pack66Dad New Member SILVER Sponsor

    Aug 26, 2010
    Browns Point, Washington
    1997 41 Convertible
    Caterpillar 3126 Diesels
    good god!

    You fresh water guys have the life!

    I have a diver go down every 3 months and usually change zincs twice a year..... :smt089
     
  12. njmello

    njmello New Member

    90
    Jul 1, 2007
    Hemet, CA
    1978 21' Cuddy
    Mercruiser 260 A-1 O/D
    I don't know how a marine electrical technician can find out where the problem is - I'm sure they have instruments to do it.

    I suggest replacing the bad zinc and if you can, disconnect the boat from shore power and leave the boat in the slip - that will take your boat out of the shore electrical circuits - if there is no noticable corrosion after a month - the problem is not your boat, but originates somewhere else, making it a marina problem. Normally, if the ground fault is on YOUR boat, the corrosion would be equal on ALL of the zincs.
     

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