Electrolysis???

DaisyF32 · Post by **DaisyF32** » Tue Apr 28, 2009 3:37 pm

I am a new (1 year) owner of a 1972 Trojan F-32. I am a first time boat owner and unfortunately have no clue...I hear all of you moaning right now.

I am the third owner and pretty much bought Island Daze on a whim, I saw her and just had to have her. Last year she ran great I had no problems. She has 2 Crusader Engines that were put in in 1988 (I am assuming that is old) but I don't push her. She takes me out I anchor and she brings me in.

I kept her in the water all year round. 2 weeks ago I took her out for the first cruise of the season just to get her cob webs out. When...all of a sudden my starboard pull was gone and I make a big J in the middle of the river. I initially thought it was my tranny. When I put the engine in gear there was no pull and there was an odd noise. I was able to limp back in to the slip, and took her to the boat yard just this week.

When Daisy was pulled from the water the mechanic was able to pretty much diagnose the problem immediately. My starboard prop and part of its shaft are completely missing. The culprit was Eletrolysis...I spoke with the mechanic yesterday and what he said made me very nervous, so I have been researching the topic. The only thing I seem to find; is that electricity not grounded correctly can eat way at different metals on the boat. It can come from inside my boat or the dock. Zincs and or a Galvanic Isolator can help.

I am nervous because the mechanic said on a scale of 1 to 5, I am at about a 10. I see definitely see the damage to the props and shafts, and understand there could be issues with my through hulls.

So in all I am thinking of replacing my props, shafts, and through hulls, as well as have the mechanic check my wiring an make sure the eletrolysis is not coming from inside my boat.

Are there other things that I could be or should be doing? Are there other things that could be deteriorating that I am not thinking about? Can someone give me a straight up answer on how bad this it? I do some times worry the mechanic sees me as a target because I am obviously in the dark on boat care.

Sorry for the long post...Thanks for any help you guys can provide.

I have pics if that helps just don't know how to post them.

Cheers,

randyp · Post by **randyp** » Tue Apr 28, 2009 4:07 pm

Electrolysis is a continual problem with salt-water boats. That being said the fact that it ate away your starboard shaft (assume the prop was not eaten away, but dropped off with the end of the shaft), obviously is NOT a good thing and the first thing you need to do is have the marina take a look at all exposed metal parts below the hull. Stray current from just about any electrical component needs to be corrected, but you're looking at some crazy replacement dollars if the electrolysis have taken as big a toll as I think.

Sacrificial zincs are added to the props and other under-hull metal parts to get eaten away so that this problem of yours does not occur.

There are a lot of folks on this forum who can give you very good advice, but most of the repairs needed will most likely be best done in the hands of a pro.

My 2 cents

Stripermann2 · Post by **Stripermann2** » Tue Apr 28, 2009 4:14 pm

Are you in a marina along with other boats? The power pedistals, other boat's bonding systems could be affecting your condition as well.

I seem to eat zincs every season although at an acceptable level, for me. And all grounds and bonding plates okay.

Check to be sure all grounds are clean and tight, check for stray current from power cords or pedistals and keep the zincs up.

ready123 · Post by **ready123** » Tue Apr 28, 2009 4:18 pm

Before you do anything to your boat have an electrician check the water in the marina. Your situation sounds so severe that either you have a bad grounding problem or the marina is the cause. What about nearby boats have you spoken to them? Have you seen any other electrical problems in your boat? blinking lights, batteries discharging quickly, breakers/fuses tripping?
How is the other shaft? Is it furthest from the dock?
Have the thru hulls been checked visually? I would expect them to be fine as they should be electrically isolated from anything in your boat and so not conduct the current to/from the water.
Your props and shafts are in contact with the engine which has electrical conduction capability hence really the only spot you will have problems.

I would get a marine 'electrician' to inspect your boat for current leakage, he can check the marina/water too. I'm sure there is someone in the area that is a specialist, the marina would have to be really large to support one internally fulltime. He can do the checks very quickly... the expense will be in his time to fix the cause.

Zincs on your props/rudder/trim tabs really only protect against galvanic currents of the dissimilar metals (SS shaft, bronze prop etc) and do little against the larger DC leakage that seems to be your problem here. I would put them now.
You leave it in all winter does this mean that bubblers are used in the water? They can cause problems... Can't tell where you are, maybe you should add location to your profile.
If you are worried about the mechanic why not get two people to look at your boat to check the grounding and give you a detailed quote for work needed. That will give you a read on if he/they are being fair.

Look back in the posts to see guides on how to post picture... you need to have them on the web and you could put links in your message and we can go there to see them.

DaisyF32 · Post by **DaisyF32** » Tue Apr 28, 2009 5:17 pm

First off Thanks for getting back to me, your responses were great.

I do have a couple more questions to show my ignorance off even more.

Other than metal that is in below the water line: props, prop shafts, through hulls, etc. what other issues could I face? Am I understanding correctly that this electrolysis, could be like a boat cancer moving from the prop shaft to my tranny and potentially my engines?

Am I incorrect that electricity comes from my batteries on board and shore power? Will it come from any where else (other than boats next to me at the marina)? When I purchased the boat it came with a Letra San waste treatment system which I have never seemed to get to work, and was afraid to take it out. However there are 4 batteries on my boat that are there just to run this thing. Could these additional batteries be part of the problem, if they are not grounded properly? Other than these 4 batteries I have another 2 one as a starter and one as a backup.

Any thoughts?

ready123 · Post by **ready123** » Tue Apr 28, 2009 5:54 pm

DaisyF32 wrote:Other than metal that is in below the water line: props, prop shafts, through hulls, etc. what other issues could I face?

Through hulls may not be a concern in your fibreglass boat if they have no path for the current... if they are not in contact with other metal that can route this current to the grounding system... i.e. if the through hull meets a non metal hose and has no electrical bond (wire) it will be OK.

DaisyF32 wrote: Am I understanding correctly that this electrolysis, could be like a boat cancer moving from the prop shaft to my tranny and potentially my engines?

Unlikely to be major as it will likely go from the shaft to the tranny casing and then the ground wire to engine/battery. Also the main action is where it is entering from the water if it is marina generated.... what your's may be from your description. Pictures may help.

Am I incorrect that electricity comes from my batteries on board and shore power? Will it come from any where else (other than boats next to me at the marina)? When I purchased the boat it came with a Letra San waste treatment system which I have never seemed to get to work, and was afraid to take it out. However there are 4 batteries on my boat that are there just to run this thing. Could these additional batteries be part of the problem, if they are not grounded properly? Other than these 4 batteries I have another 2 one as a starter and one as a backup.
Any thoughts?

No other areas other than galvanic action of two different metals touching each other which is much lower action.... zincs on your prop shafts deals with that.
Those other batteries could be a source of the DC power but the problem is caused elsewhere poor grounding, poor wiring causing leakage.
Do you use water bubblers?
I suggest you get an Electrician to look at your boat... we are all commenting from in the dark here really as we have not seen your boat or marina.
Put your hand in the water at the marina and hold onto something grounded does it tingle/tickle???

DaisyF32 · Post by **DaisyF32** » Wed Apr 29, 2009 12:25 pm

Michael - thanks for the input...I can't feel the left side of my body now...

For now I will replace my props, prop shafts and all my zincs!!! I will also do a check for leaks with the electrician.

Thanks for all your input!

kevin babineau · Post by **kevin babineau** » Wed Apr 29, 2009 12:28 pm

if u notice there r green wires running around to everything metal make sure those r connected and to have actual shafts gone is like u said on a scale 1 to 5 thats a 10 so really check into everything never said if ur had run a de-icer

moondance · Post by **moondance** » Wed Apr 29, 2009 4:55 pm

Unfortunately, you can only ruleout your part of the problem. Disconnect sure power if you're not there and keep up with your zincs. Make sure you don't have anything crosswired onboard.
However...after you've done all this, you can't controll the idiot three boats down. Ya see, he's improperly wired up every piece of home electronics to include the 1.21 jigawatt bose system and he's frying everyones zincs like sugar cubes to a hot cup of starbucks.
We just dealt with this at my dock. In total, the Meathead caused about $10g's worth of damage to other peoples boats.