How to diagnose cause of going through anodes too quickly? - SailNet Community

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Electrical Systems
 Not a Member? 
  #1  
Old 06-13-2011
josrulz's Avatar
Unpaid Intern
 
Join Date: Oct 2006
Location: Maryland
Posts: 989
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 8
josrulz is on a distinguished road
How to diagnose cause of going through anodes too quickly?

Hi all,
OK, so obviously I'm no electrical guru. Please hang with me while I learn this one. As is obvious from the title of the thread, we're going through anodes (zinc) somewhat quickly. We put 2 zinc on the shaft in spring, and they need to be replaced in less than 2 months. This has been consistent over the last couple of years since we bought the boat. The good news is, the zincs do their job.

A bit about the boat: No battery charger, so we're never hooked up to shore power. I mean never. Like 3 days in 2009 was it. Our electrical system is simple: 2 batteries, one in each "bank", no refrigeration or AC, just lights, stereo, VHF, GPS, and radar. Metal hardware is bonded (was done by Sabre factory)

So while I realize going through zincs in a couple months isn't an emergency, I'd like to know why, in case there's something I can do about it.

Any suggestions on how to diagnose? Specific items I should check? Is it possible this is because of a neighbor, or is that out of the question because we're not connected via shore power?
Thanks,
J
__________________
1984 Sabre 34 Mk I
Reply With Quote Share with Facebook
  #2  
Old 06-13-2011
SlowButSteady's Avatar
Senior Slacker
 
Join Date: Feb 2010
Location: SoCal
Posts: 4,223
Thanks: 0
Thanked 17 Times in 15 Posts
Rep Power: 5
SlowButSteady is on a distinguished road
Your boat could be acting as a "bridge" between two other boats, or between a "hot" boat and some other ground. This can be a problem if your underwater fittings are all bonded together; the electrical path through you boat's bonding system will have less resistance than the surrounding seawater.

You might be able to detect a bit of voltage by using a multimeter and some long probe wires. Put one wire in the water at the bow of the boat, and one in the water at the stern and connected the multimeter between them (using its most sensitive setting). Check for both AC and DC voltage. Try the same thing with the wires on either side of the boat. Alternatively, you can find a convenient place in the bonding system to insert the multimeter and look for voltage that way (but you may just get a reading from the galvanic potential between dissimilar metals in the circuit).
__________________
Never forget them. Do something to prevent it from happening again.
Charlotte Bacon, Daniel Barden, Rachel Davino, Olivia Josephine Gay, Ana M. Marquez-Greene, Dylan Hockley, Dawn Hochsprung, Madeleine F. Hsu, Catherine V. Hubbard, Chase Kowalski, Jesse Lewis, James Mattioli , Grace McDonnell, Anne Marie Murphy, Emilie Parker, Jack Pinto, Noah Pozner, Caroline Previdi, Jessica Rekos, Avielle Richman, Lauren Rousseau, Mary Sherlach, Victoria Soto, Benjamin Wheeler, Allison N. Wyatt

Last edited by SlowButSteady; 06-13-2011 at 04:43 PM.
Reply With Quote Share with Facebook
  #3  
Old 06-13-2011
AdamLein's Avatar
Senior Member
 
Join Date: Nov 2007
Location: Coquitlam, BC
Posts: 1,866
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 7
AdamLein will become famous soon enough
I think that for galvanic corrosion to occur you need three things:

1) dissimilar metals
2) immersed in an electrolyte
3) electrically connected

If you have no shore power connection, then the only things that your zincs can be electrically connected to are other parts of your boat.
__________________
s/v Essorant
1972 Catalina 27
Reply With Quote Share with Facebook
  #4  
Old 06-13-2011
Senior Member
 
Join Date: Feb 2007
Location: New Jersey
Posts: 1,908
Thanks: 4
Thanked 31 Times in 31 Posts
Rep Power: 8
Tempest is on a distinguished road
Sabres seem to be notorious for eating zincs. I've had the same problem with mine. Last year I put 2 on the shaft and one on the max prop.

Made it through the season with about 1/2 one left on the shaft..but I got in the water late in the season.
__________________
Tempest
Sabre 34
Morgan, NJ
Reply With Quote Share with Facebook
  #5  
Old 06-13-2011
josrulz's Avatar
Unpaid Intern
 
Join Date: Oct 2006
Location: Maryland
Posts: 989
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 8
josrulz is on a distinguished road
So maybe there's not much I can do about it, if other S34s have similar problems. I don't mind changing the zincs, really, but as we start to add to the electrical system, I'd like what's there to be healthy.

When we add a battery charger, we'll include a decent galvanic isolator along with it, so hopefully, hooking up to shore power won't accelerate the eating of zincs.

We'll see.

Thanks for all the responses, folks.
-J
__________________
1984 Sabre 34 Mk I
Reply With Quote Share with Facebook
  #6  
Old 06-14-2011
tdw's Avatar
tdw tdw is offline
Super Fuzzy Moderator
 
Join Date: Oct 2006
Location: Sydney Australia
Posts: 14,356
Thanks: 5
Thanked 67 Times in 62 Posts
Rep Power: 10
tdw is a jewel in the rough tdw is a jewel in the rough tdw is a jewel in the rough
Quote:
Originally Posted by josrulz View Post
So maybe there's not much I can do about it, if other S34s have similar problems. I don't mind changing the zincs, really, but as we start to add to the electrical system, I'd like what's there to be healthy.

When we add a battery charger, we'll include a decent galvanic isolator along with it, so hopefully, hooking up to shore power won't accelerate the eating of zincs.

We'll see.

Thanks for all the responses, folks.
-J
Come on now. Going through anodes in two months ? I don't care how hard on anodes Sabres are supposed to be, it is not healthy to be going through them in only a couple of months.
__________________
Andrew B

"Do you think God gets stoned? I think so... Look at the platypus." Robin Williams.
Reply With Quote Share with Facebook
  #7  
Old 06-14-2011
TropicCat's Avatar
Senior Pirate
 
Join Date: Oct 2008
Location: Cape Canaveral, FL
Posts: 2,296
Thanks: 2
Thanked 12 Times in 12 Posts
Rep Power: 6
TropicCat is on a distinguished road
This is a mystery. Zincs are purposely placed within a circuit to erode before anything important does. The current in this circuit is the catalyst for the erosion. From what the OP posted, he doesn't have a circuit. A conundrum for sure.

The OP didn't mention if he was in salt water. What if the marina has defective wiring and salt water is conducting the current to his boat? I'd say .. change slips and see what effect this has on the problem.

Just an idea...
__________________
Tropic Cat

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Share with Facebook
  #8  
Old 06-14-2011
josrulz's Avatar
Unpaid Intern
 
Join Date: Oct 2006
Location: Maryland
Posts: 989
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 8
josrulz is on a distinguished road
We're in brackish water, more or less. On the South River, just south of the Severn River and Annapolis.

Yes, it could be something about the marina or another boar. So that's why I'm asking how I could diagnose what the problem actually is, especially since I'm not connected to shore power. If it's something about our boat, I'd like to fix it. If it's someone else, then it would at least be good to know.
__________________
1984 Sabre 34 Mk I
Reply With Quote Share with Facebook
  #9  
Old 06-14-2011
tdw's Avatar
tdw tdw is offline
Super Fuzzy Moderator
 
Join Date: Oct 2006
Location: Sydney Australia
Posts: 14,356
Thanks: 5
Thanked 67 Times in 62 Posts
Rep Power: 10
tdw is a jewel in the rough tdw is a jewel in the rough tdw is a jewel in the rough
hmm.. finding the cause is the hard part unless it is an obvious wiring fault in the boat itself. I'm guessing a neighbouring boat or two but thats only a guess.

On Raven we had our forward hull anode (she's steel) start to erode at double time. I never did track down whether it was another boat (there was a bit of a steel clunker nearby) or a piece of stray wiring from the anchor windlass I was rebuilding at the time. When we lifted her again the anode had gone back to normal erosion.

You could of course hang an anode or two over the side when you are berthed. This could/should help preserve your fitted.
__________________
Andrew B

"Do you think God gets stoned? I think so... Look at the platypus." Robin Williams.
Reply With Quote Share with Facebook
  #10  
Old 06-15-2011
SlowButSteady's Avatar
Senior Slacker
 
Join Date: Feb 2010
Location: SoCal
Posts: 4,223
Thanks: 0
Thanked 17 Times in 15 Posts
Rep Power: 5
SlowButSteady is on a distinguished road
Quote:
Originally Posted by josrulz View Post
We're in brackish water, more or less. On the South River, just south of the Severn River and Annapolis.

Yes, it could be something about the marina or another boar. So that's why I'm asking how I could diagnose what the problem actually is, especially since I'm not connected to shore power. If it's something about our boat, I'd like to fix it. If it's someone else, then it would at least be good to know.
Try the multimeter trick I posted above. It may, or may not, work (you may need a pretty sensitive meter to get a reading). But, a positive result will at least give you an idea as to the cause. Alternatively, you could ask the marina for a different slip (if one is available). If moving the boat slows the zinc wasting, it's a good bet that you've been the victim of stray current from other boats; if it stays the same, there may well be some problem with dissimilar metals on your boat.
__________________
Never forget them. Do something to prevent it from happening again.
Charlotte Bacon, Daniel Barden, Rachel Davino, Olivia Josephine Gay, Ana M. Marquez-Greene, Dylan Hockley, Dawn Hochsprung, Madeleine F. Hsu, Catherine V. Hubbard, Chase Kowalski, Jesse Lewis, James Mattioli , Grace McDonnell, Anne Marie Murphy, Emilie Parker, Jack Pinto, Noah Pozner, Caroline Previdi, Jessica Rekos, Avielle Richman, Lauren Rousseau, Mary Sherlach, Victoria Soto, Benjamin Wheeler, Allison N. Wyatt
Reply With Quote Share with Facebook
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Anodes disappearing quickly steveg353 Gear & Maintenance 32 10-18-2010 06:12 PM
Diagnose my engine's smoke (video attached) FishFinder Diesel 25 10-11-2010 03:46 PM
Diagnose your diesel engine RickQuann Gear & Maintenance 2 07-18-2008 06:58 PM
Diagnose my diesel. jr438234606 Gear & Maintenance 37 09-13-2007 08:39 AM


All times are GMT -4. The time now is 01:05 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.