electrolsis problem

Hi all, I am have a big problem. I will try and make this short. I just bought a 16 ft aluminum runabout with a 80 Mariner outboard. The problem was NOT here when I bought it, I have created it by adding some stuff and changing the wiring. I am looking for the most probably cause of ELECTRLOISIS.

Last week I discovered severe electrolisis issues with the outboard. Reverse pin had been completely been eaten away. My enitre outdrive (part in water) was covered in white, hard, power-type stuff. I thought it was creatures making a home but mech. says its "electrolsis". Parts on on order, thats not the problem.

I have to discover what I did wrong when I was upgrading her this winter in garage.

From all I have read online there may be some leaking electricity some where. I have a dead battery also when I come back to boat after a few days while she is at dock. There is no power at dock so this is not an issue. So somewhere, there is leaking juice. I just can figure where. I only added to existing circutry. Added straight lines of wire for radio and fishfinder directly to battery.



I added a small radio with CD player--with two speakers. I grounded the radio to the aluminum boat is this a problem?

I also added a new bilge pump and installed a three way switch (on-auto-off)with breaker on the switch panel. I attached the bildge pump to the alumimun fin in bottom of boat with a TIN piece. Wired it onto the exact wires that where there for the old one. works fine but has this tin caused a major electrolisis thing???

There are two farm lights used for docking that are grounded to the boat too... could this be a problem? Only thing is these where there before.... I did not change wire set up only put new lights on. The guy did not have the problem before me.

I also put new steel bolts in the transum supports as they where missing a few.

I also added a fish finder with an external transducer holder made of alumumiun on the outside of the transum. Could this cause issues?


I am going to have to rip out all I did and put it back the way it was prior to buying. The guy never had this issue. What do you think is the most probably cause of my electrolsis issue??

I am not sure if my boat has anodes....the point is however that the guy before me never had issues.

Thanks a million guys!!!!

Joel toronto Canada

 

first NEVER ground anything to the boat......
try to keep like metals but the tin plate is not your big problem, in water stainless hardware is 10 times better than steel
don't go yanking all your hard work out just fix it you have just made a small mistake and working for an alumuniun boat builder this is done very often so don't take it hard just learn
what i have to ask is what is killing your battery when your not using the boat this is going to be your biggest clue to your electrosis. this can be done just be putting a test light between your neg battery terminal and the ground wires
good luck and drink heavily after you fix it not before

 

As a long time builder of alloy yachts I can tell you that we always ground the battery!! Hamilton jet will not warranty their product unless the battery is grounded Your battery is grounded through the hull anyway, by way of the outboard motor, but making a proper ground is best .in saying this,. it is best to try keep your wiring a two wire system back to your board, your neg buzz bar should be isolated Some stuff is one wire and hard to isolate
Electrolysis is most often caused by the action of metals that are apart on the galvanic scale, google up, galvanic scale, people tend to confuse the issue, and mix it up with how the boat is wired
Try to isolate metals, like with nylon sleeves and gaskets, use a compound called lanacoat on threads Put an isolating switch on the positive wire from the battery, if you have a multimetre(walmart 10 dollars,) measure the voltage from batt pos to earth hull, that way you will find leaks, then disconnect various stuff til the leak has gone
hope this helps you)

 

electoloysis

Thanks Redtech, I agree with you the leaking battery is definiatly part of problem. The guy at radio shop told me they were having problems with there radios leaking even in off position, They told me to install a switch to power wire and kill it that way and not just on/off. I did this and it seemed to work great, but I wonder if the radio is still leaking? The parking lights were there before. The fish finder goes straight to battery, + and neg. The radio is the only thing I ground to the frame. Do you think this could be it? A little old radio with a kill switch installed? ahhh I am starting to drink heavlity now, before I even get out there!!!

Joel

 

maybe this is the problem

Ok just thought of something. On my bildge pump switch, I have on/off/auto....I assumed that "auto" was to be put on you when your away from boat (for a few days) so the pump works. Is this right? When I click "auto" a small green light comes on and stays on. Is this my power drain? Should I turn off the pump when away and shes at the dock? If this is an issue how do it affect the sudden onset of electrolysis?

Just a thought

 

it will not affect, but yes if your battery is nine plate, or 11 plate, it may well run it down, fisrt take your batt to a shop and have a quick drain test put across it, will be free
Well turn off pump is your choice you SHOULD have two batts, one for crank one for house, separated by a blocking diode(80 bucks),

 

lazeyjack is right about disimilar metals and has also given another method of finding draws on the battery so try his or mine they both work great.
the green light on the autobilge pump should be on only when the pump is running so check your wiring there that to can kill the battery and your radio gay is right about the switch both memory and power should be switched this to draws off the battery
have a little work to do so have a drink now cheers

 

ok guys your input great appreciated. but if you had to guess what causing the electolysis problem? Radio grounded to boat.......external aluminum transducer holder fish finder straight to batt (-+)....bilge pump screwed to boat chasis with tin L bracket....docking lights grounded to boat......one interesting point of info was when I was hooking up everything, I had Fish finder, bow and stern lights, docking farmers headlights, motor starting, hooked to one battt..... when I hooked the radio up this system also, the Farmer headlights came on!!!! Right out the blue. Even with switch off, they came on and stayed on.... So..... I hooked up the radio to seperate battery (trolling) with the trolling batt...) Does this make any differnce?/ Very appreciateded of the info guys

Joel

 

first what everyone is calling electrolysis is really called galvanic corrosion. Galvanic corrosion simply put is the plating off of one metal on to another metal. This is exactly what happens in your battery. Zinc is plated off onto lead plates to create a current, which is a very useful thing because then you can use this to power stuff on your boat. However, if you deliberately (or accidentally) impose a current between two dissimilar metals on your boat then one part (your outboard) begins to disappear. By connecting the ground to the hull you have done just this. You have allowed current to be imposed on the hull and in the water. ELectric current always tries to find a path back to ground, so now if you have a positive fault somewhere that puts current on some part of the boat as well you have current flowing through a continuous circuit. That is why you battery is dead!

What you need to do is this. The ground on almost all outboard boats is the engine block of the outboard. There is probably a wire that runs from the outboard to the negative terminal on the battery and another wire from the negative terminal to a electrical strip of connectors. This wire should be black. The positive wire should be red.

This strip is where your ground wires should go. Under your console may be two strips of connectors. One is positive the other is negative. On boats dc negative wires are all supposed to be black. You can pretty much assume that any wire that is not black is positive. Find the strip where the wires are black. One wire on this connection board should go back to the negative terminal on the battery, or to the strip near the battery that is connected to ground.

It will probably be easier to connect your grounds to the ground strip under the console.

Then go through all your positive connections and make sure everything is properly hooked up and there are no inadvertant shorts to metal parts of the boat.

Anyway, after you get the wiring straightened out your galvanic corrosion problem should go away and your battery should stop draining itself.

Then go get new anodes for your sterndrive, clean it up and install them.

Meanwhile read this on basic DC wiring.
http://newboatbuilders.com/pages/electricity1.html

 

wel IF you had read my post you would have seen , first thing I said, galvanic series)

 

sorry. Yes you did say galvanic scale.