A Zinc on my keel is completely detroyed in a month. There is no ground or electric connection. How do I find this problem. Thanks for your suggestions
O'Day 35 Electrolysis
- Thread starter Jehu Dodge
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Humm, I don't have a zinc on my keel. How are your other zincs doing? Is you keel bare metal? I've enclosed mine by heavily coating in in epoxy and several coats of bottom paint which seems to be holding up well. Admittedly, a cast iron keel is a pain to maintain.
The Karma's keel is bonded to the other significant metal for the purposes of lightning protection. As 34's and 35 are basically the same design, I'd expect that yours is as well.
When you say there is no ground or electrical connection, are you saying that you don't keep shore power on the her when docked or the boat is moored?
The Karma's keel is bonded to the other significant metal for the purposes of lightning protection. As 34's and 35 are basically the same design, I'd expect that yours is as well.
When you say there is no ground or electrical connection, are you saying that you don't keep shore power on the her when docked or the boat is moored?
Where is the zinc on your keel? I don't have one on my 35. Also for lightning protection I think it makes sense to have the mast grounded to the keel by a wire from the mast or mast step plate to one of the keel bolts. Should be a large diameter wire for the current and voltages in a lightning strike. That huge hunk of lead in the water is a nice conductor to run a lightning strike into the water. My 35 has all through hulls, and mast bonded with solid copper wire and connected to the engine ground and through there to the shaft. So the shaft zinc is basically protecting the whole deal. Others have suggested not to bond the through hulls so I am not sure which is better, but for 27 years they have been bonded and are still intact. I go through a couple shaft zincs per year. I always unplug my shore power cord unless I am on the boat. This decouples your boat from the grounding system in the marina AC but I can't say whether it is an issue in your case, only that it makes sense to me. I'll let others chime in that are electrical experts.
I have a lead keel and boat is connected to the AC power all the time to protect the power drain by the fridge. I have had this problen for some time now in that each summer the 2 Zincs on the shaft is completely destroyed & my keel is pitted with the antifouling paint corroded hard in that u have to use a grinder to remove it. This spring I removed the bonding from the engine ground from the keel ( I kept the mast Lightening #6 wire connected to the Keel) I also removed the ground wire (green) from the ground bust. I also, added a tear drop zinc to the rear bottom end of the keel. Result.. same as last year, maybe a bit worst. The wiring in my boat is in excelant condition and all test have been negative. It appears that I have alot off stray currents. Where do I go from hear?? By the way, I understand electrical issues, but this one got me baffled. My boat is a 1986 O'Day in excellant condition. Any advice would be appreciated. Thank you. (boat in the water from late may untill early Oct.)
you might want to try installing a galvanic isolater. It connects to the ground wire of your AC circuit. Try shutting off the fridge and unplugging the shore power cord for three months or so and see what happens. Since you are leaving this AC circuit on all the time my guess is that is a big part of the problem. Using a meter see if you have any current in the AC ground wire. Your not looking for much in terms of voltage.
Regarding pitting of the lead, it will also pit due to oxidation, I had trouble keeping bottom paint on mine since paint doesn't stick too good to lead oxide. I ground it down to bare lead and coated with epoxy, two coats, then two coats of barrier coat to give it a good base for paint adhesion, then the paint. Has held up very well ever since, around ten years or so.
Regarding pitting of the lead, it will also pit due to oxidation, I had trouble keeping bottom paint on mine since paint doesn't stick too good to lead oxide. I ground it down to bare lead and coated with epoxy, two coats, then two coats of barrier coat to give it a good base for paint adhesion, then the paint. Has held up very well ever since, around ten years or so.
Yes, zinc issues can be vexing and a bit scary. I've attached a document that was forwarded to me concerning testing between shore power and boat ground. It seems to take a pragmatic approach to resolving at least that issue.
Like Jibes I don't leave Karma connected to shore power unless I'm on board. I've installed a 50W solar panel it insure that the batteries are fresh. If your fridge is DC powered you may consider going solar to keep the chill on and disconnecting from the grid whilst away. Panels have gotten cheaper so that may be an appropriate solution.
I'm by no means an expert however there are two processes at work here; one is galvanic and the other is electrolysis. Both should be studied as possible issues.
Like Jibes I don't leave Karma connected to shore power unless I'm on board. I've installed a 50W solar panel it insure that the batteries are fresh. If your fridge is DC powered you may consider going solar to keep the chill on and disconnecting from the grid whilst away. Panels have gotten cheaper so that may be an appropriate solution.
I'm by no means an expert however there are two processes at work here; one is galvanic and the other is electrolysis. Both should be studied as possible issues.
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