bertram31.com

Need a little direction,after I hauled noticed no zincs on the port shaft all the others in place.Last season had most of the zincs gone and I repaired rear bilge wires which were hanging in bilge water.Checked boat to my port his zincs were all good,not sure where or what to look for?Thanks again to all for any help and Happy Thanksgiving.
Bill G.

Was there a boat docked on your port side? Was that boat plugged in to shore power all season?

That happened to me once. I assumed I didn't install it well enough and it worked its way loose.

Mike,.............there was someone to port and plugged in and I did look at his boat when hauled and his zincs were all good?.I use 2 zincs each shaft so I don't think both would fall off.

Your neighbor boat could very well be the source of a stray current that eats only your zincs. A simple thing such as a bad galvanic isolator on his boat could cause it. There is only one way to be sure what is happening: testing.

To check out your boat and it's zincs, you will need a Silver/Silver-Chloride Reference Rlectrode and a good quality digital multimeter. You dangle the electrode over the side and read DC voltages.



When conducting this test, a vessel’s bonding system should have with a DC voltage between -900 mV and -1100 mV (relative to a silver/silver-chloride electrode) to properly protect underwater metals from galvanic corrosion. Readings less than -900 mV indicate the cathodic protection system (zincs) is weak and/or failing. Readings higher than -1150 mV indicate overprotection (over-zinked), a situation that could damage underwater steel, aluminum alloys and and wooden thru-hull backer plates.

Start taking readings with nothing connected to the boat (no shore power) and everything OFF. Voltage readings changing dramatically as you turn electrical circuits on or off indicate a problem with that particular circuit leaking out current into the water. You shold check each AC and DC circuit and appliance, one at a time.

Don't forget to check with your engines running too. An alternator that does not have an independent ground wire back to the battery can throw big stray currents.

If your boat comes out clean, then you either have bonding system troubles, or there are stray currents from a source other than your boat. Both are easy to test for.

The most common stray current path is from your shore power ground. Test your galvanic isolator to see if it is doing it's job. There will probably be a small voltage (less than 1.0 V) across it's terminals, this is normal. Take a curent reading however, and any current at all running through it means it's not working. If a stray current's voltage exceeds 1.5 volts then your galvanic isolator will be overpowered anyway - that is all it can stop.

I would also take a reading with everything as is, then disconnect the neighbor's shore power (with his permission of course) and take another. If the readings are different... bingo

Testing your bonding system has been documented in detail by Capt. Pat in the hints section.

Did you beat them with a hammer when installing to get them tight?

Andre ,not to hijack this post but my kid was asking about you yesterday,he was out fishing for two days in a tournament and asked how is that guy with the kool curly mustach from LA doing .WE hope you can make the next rendevous in the northeast the franzoni family

Ha , Neil. Tell him hello for me. I'm sure he's alot bigger now! And still a pistol.
Yes, I still have my mustache (just shaved my Gustav beard).
I really enjoyed reading all about it this year and sorry I had to miss it and seeing all of you. I know it was a great time.
I look forward to a future rendevous.
The Family of Bertram31.com.

Bill

Two years ago I had a new slip neighbor. When I pulled my boat my zincs were still there but seriously eaten at and my bottom paint actually looked burnt. Normally my zincs show signs of deteriation but never like that.

I assume it was a leak from his boat and that the copper in the bottom paint was also reacting to his leak.

Andre..........did the hammer thing on both shafts,Tony good hear from you hope all is well. Thanks-Bill

One other possibility......

Did you happen to have two good quality zincs on one shaft, and two poorer quality zincs on the other?

Mike, I replaced all last spring all the same.I was kinda thinking that I may have a ground issue on that motor?

Check the ground on your 110 line. Walter

One more question.......

Do you have those rubber or plastic shaft savers installed between the shaft and transmisson?

Bill

All is well still working on the repower. Should be finished this winter. I really need to catch up with Frank F. Have not talked with him for a while.

Anyway, another way to find the leak on your boat is to disconnect your batteries and hook an Ohm meter up to the disconnected batter cables. Turn off every electric circuit you have. Make sure all the electronics and other electric appliances are turned off. Turn them on one by one and don't forget the bilge pumps. If the Ohm meter stays at 0 all is well. If you turn on a circuit or electronics and it gives you a reading, then that is the leak. Found a bad bilge pump that way a number of years ago. We were going through zincs every 3 weeks until we figured out how to find it.

How do you turn on anything if your batteries are disconncted? Russ