I have a 1992 H28. At the end of last season when I hauled my boat (see picture), I noticed that both the oblong zincs I had put on at the beginning of the season were completely gone (no trace other than the marks on the prop shaft). I keep my boat on a mooring on a back river in Maine (not may boats around and no marinas). Does anyone want to hazard a guess as to where they went? Could the bolts have loosened up and they simply fell off or is it more likely they corroded? Thanks.
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Of course they fell off
as oppposed to being stolen
, but probably the result of corrosion. I get six months out of mine in salt water marina and I can see the shaft from the dock. The zincs get small then they get gone.
as oppposed to being stolen
, but probably the result of corrosion. I get six months out of mine in salt water marina and I can see the shaft from the dock. The zincs get small then they get gone.Need a tie breaker
I appreciate your inputs. I now have one for "fell off" and one for "corroded off." Anyone want to weigh in with a tie breaker? I am trying to remember how I put them on. As I recall, I had to use an allen wrench and I tightend them until the wrench started to bend. Should I have used a pair of pliers on the allen wrench (close to the fastener) and tried to get another turn out of it?
I appreciate your inputs. I now have one for "fell off" and one for "corroded off." Anyone want to weigh in with a tie breaker? I am trying to remember how I put them on. As I recall, I had to use an allen wrench and I tightend them until the wrench started to bend. Should I have used a pair of pliers on the allen wrench (close to the fastener) and tried to get another turn out of it?
fell off
hello, my boat is on a mooring in Mt. Sinai harbor, a small harbor in the long island sound. My zinc is 1.5 years old and is still in fine shape. If your boat is on a mooring and you turn off the power when you leave, I doubt it dissolved.
hello, my boat is on a mooring in Mt. Sinai harbor, a small harbor in the long island sound. My zinc is 1.5 years old and is still in fine shape. If your boat is on a mooring and you turn off the power when you leave, I doubt it dissolved.
I tend to agree with Barry
Although my boat is in salt water (Sheepscot River), it is hard for me to believe that two new zincs were completely corroded away. I do turn off all power and there are no sources of electric current in the area (unless there is an underwater power cable that is bad - which I doubt). I have two new zincs that I will put on this year. I will use a thread lock and tighten them to the point I think they might break. We'll see what's left at the end of this season!
Although my boat is in salt water (Sheepscot River), it is hard for me to believe that two new zincs were completely corroded away. I do turn off all power and there are no sources of electric current in the area (unless there is an underwater power cable that is bad - which I doubt). I have two new zincs that I will put on this year. I will use a thread lock and tighten them to the point I think they might break. We'll see what's left at the end of this season!
Zincs
At haulout this year I put Removeable Loctite on the screws that hold on my zincs. I also now dangle a grounded wire with a zinc on the end over the stern when I am not using the boat. There is a ton of electricity discharge hanging around our marina. Only once have I motored off without hauling it in. After six months it is showing some corrosion that could have damaged my boat. Well worth the effort. Peter
At haulout this year I put Removeable Loctite on the screws that hold on my zincs. I also now dangle a grounded wire with a zinc on the end over the stern when I am not using the boat. There is a ton of electricity discharge hanging around our marina. Only once have I motored off without hauling it in. After six months it is showing some corrosion that could have damaged my boat. Well worth the effort. Peter
Not Installed Properly?
Steve, are the zincs installed properly? If the zinc has a copper BB in the middle of the slot, then it should be made to keep contact. Use two hammers. One should be placed on the back side of the "other" side as a "backer". Rap the front side with a hammer to squeeze them together. Rotate the shaft and do the same to the other side. Then tighten up the allen screws each time. Do this serveral times. This will "seat" the zinc and allow you to tighten up the slack. This should be done to all zincs, BB or not. Zincs should be changed annually not matter what condition they are in. See my related link under the Member's Only section.
Steve, are the zincs installed properly? If the zinc has a copper BB in the middle of the slot, then it should be made to keep contact. Use two hammers. One should be placed on the back side of the "other" side as a "backer". Rap the front side with a hammer to squeeze them together. Rotate the shaft and do the same to the other side. Then tighten up the allen screws each time. Do this serveral times. This will "seat" the zinc and allow you to tighten up the slack. This should be done to all zincs, BB or not. Zincs should be changed annually not matter what condition they are in. See my related link under the Member's Only section.
Zincs
Are there to corrode. IF they corrode quickly, then you need to find out why. If your on a mooring that has your boat away from other boats, then I would say it's obvious that you have electrolysis occurring on your boat. To know for sure if they are corroding quickly, make dives down to check on them during the season (like every two weeks) because what happens is when they corrode to a point and then fall off. On the other hand you don't want to be tearing your boat apart looking for an electrical problem when the problem is that you just aren't putting them on correctly (right size, evenly, tight). I lost two zincs in 6 months last year but I put them on underwater while holding my breath so I'm not so sure I put them on correctly (visiability here isn't good under water).
Are there to corrode. IF they corrode quickly, then you need to find out why. If your on a mooring that has your boat away from other boats, then I would say it's obvious that you have electrolysis occurring on your boat. To know for sure if they are corroding quickly, make dives down to check on them during the season (like every two weeks) because what happens is when they corrode to a point and then fall off. On the other hand you don't want to be tearing your boat apart looking for an electrical problem when the problem is that you just aren't putting them on correctly (right size, evenly, tight). I lost two zincs in 6 months last year but I put them on underwater while holding my breath so I'm not so sure I put them on correctly (visiability here isn't good under water).
50 degrees in August!
Good thing I got a full wetsuit for Chirstmas! If I do dive under the boat, it will be an experience I won't soon forget. The water here is really cold all year long. I think I'll do a good job attaching two new zincs (before my launch 8 May) and then do ONE dive in August to see what's going on. I usually get hauled in October. Can I get a damaging electrical current generated from my own boat? I leave the master switch and all the breakers in the OFF position when I leave the boat. Could something be happening when I turn the DC on or wehn I run the engine?
Good thing I got a full wetsuit for Chirstmas! If I do dive under the boat, it will be an experience I won't soon forget. The water here is really cold all year long. I think I'll do a good job attaching two new zincs (before my launch 8 May) and then do ONE dive in August to see what's going on. I usually get hauled in October. Can I get a damaging electrical current generated from my own boat? I leave the master switch and all the breakers in the OFF position when I leave the boat. Could something be happening when I turn the DC on or wehn I run the engine?
Hey BC Peter
Can you give me the blow by blow on your hanging zinc, wire spec and connections and where grounded?
Can you give me the blow by blow on your hanging zinc, wire spec and connections and where grounded?
Could do hanging zinc
Now that I think about it, I could hand a zinc (like BC Peter) and check it each time I go to the boat. If it isn't getting corroded, I should be able to assume that the zincs on the prop shaft are OK also -- does everyone agree? It's definately better than diving under the boat in Maine waters!
Now that I think about it, I could hand a zinc (like BC Peter) and check it each time I go to the boat. If it isn't getting corroded, I should be able to assume that the zincs on the prop shaft are OK also -- does everyone agree? It's definately better than diving under the boat in Maine waters!
An accurate voltmeter
can be used with one lead in the salt water and one lead connected to a common ground on your sailboat. If you detect any potential difference, then you can suspect that your exposed metal surfaces are now acting like a battery.
can be used with one lead in the salt water and one lead connected to a common ground on your sailboat. If you detect any potential difference, then you can suspect that your exposed metal surfaces are now acting like a battery.
Hanging Ground
Scott in Seattle, It is quarter-inch plastic-covered copper wire. Grounded/earthed to the boat's ground plane. ie. chain-plates, thru-hulls, engine block etc has a small electrical ring-type connector on the end to which a zinc is screwed. Toss it overboard off the stern when in the marina or moored. Put retrieval/deployment on your mental checklist before dropping the gear shift into reverse or just after you have opened your first beer having survived yet another great voyage. Peter
Scott in Seattle, It is quarter-inch plastic-covered copper wire. Grounded/earthed to the boat's ground plane. ie. chain-plates, thru-hulls, engine block etc has a small electrical ring-type connector on the end to which a zinc is screwed. Toss it overboard off the stern when in the marina or moored. Put retrieval/deployment on your mental checklist before dropping the gear shift into reverse or just after you have opened your first beer having survived yet another great voyage. Peter
Hey, Crimson Star
Can you (or anybody else for that matter) explain how in simpler terms how to use a voltmeter or some other device to check for stray current. My prop just cracked in two along the shaft and the zinc was gone even though it was two weeks old. There's got to be some current around there. How do I check to find out where it is? Is there a way I can find out from whose boat it's coming from? I'm at a dock with many other boats docked around me.
Can you (or anybody else for that matter) explain how in simpler terms how to use a voltmeter or some other device to check for stray current. My prop just cracked in two along the shaft and the zinc was gone even though it was two weeks old. There's got to be some current around there. How do I check to find out where it is? Is there a way I can find out from whose boat it's coming from? I'm at a dock with many other boats docked around me.
measuring stray current
This isn't as simple as using a digital voltmeter which is WAY too insensistive. As an example, it's probable that stray current corrosion is in the range of 0.1 to 10 milliamps; no common digital voltmeter/ammeter can measure that low. In this example, this current well below the sensitivity of the voltmeter can equate to 200+ amp hours per week; more than enough to eat zincs and props and you'll never see it on a common voltmeter. Without going through the analytical stuff, that current can eat pounds of zinc/year. To do it precisely, you'd need a silver chloride cell and a millivolt meter. Don
This isn't as simple as using a digital voltmeter which is WAY too insensistive. As an example, it's probable that stray current corrosion is in the range of 0.1 to 10 milliamps; no common digital voltmeter/ammeter can measure that low. In this example, this current well below the sensitivity of the voltmeter can equate to 200+ amp hours per week; more than enough to eat zincs and props and you'll never see it on a common voltmeter. Without going through the analytical stuff, that current can eat pounds of zinc/year. To do it precisely, you'd need a silver chloride cell and a millivolt meter. Don
freshwater?
How big an issue is electrolysis in a freshwater lake? I am tied up at a marina with a bunch of boats that I'm sure are throwing stray current. But how much do I need to worry in freshwater? I put a zinc on last July - haven't looked at it since. Plan to as soon as water warms up.
How big an issue is electrolysis in a freshwater lake? I am tied up at a marina with a bunch of boats that I'm sure are throwing stray current. But how much do I need to worry in freshwater? I put a zinc on last July - haven't looked at it since. Plan to as soon as water warms up.
microamps
Ross Are you sure you really mean microamps? Your voltmeter has 5 significant digits in the readout???
Ross Are you sure you really mean microamps? Your voltmeter has 5 significant digits in the readout???
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