The boatyard pulled Delta Dawn yesterday and called me to come and look at her with them. To my suprise and horror the 5 Thru Hulls and the grounding plate were no longer there. The new prop was covered with a white brown residue. My first thought was they had already taken the through hulls out. The yard owner assured me that was not the case and he was just as suprised when he pulled her to see they were gone. The thru hulls where there on December 18th when the boat was put back into the water after instaling a new engine at another boat yard. However the 12 volt did not work properly. The new yard found that the 12 volt ground wire was not connected to the engine. It would appear that electrolysis devourered the thru hulls in 3 months. The yard thinks the 110 volt may be the cause and plans to check that for me, but I wonder if it was the 12 volt with the charger. Any thoughts?
Secound question is the yard is recomending replacing the seacocks with thru hulls and ball valves. I know this system is used on other boats and is much less expensive, especially if new seacocks are needed also. The seacocks are to be looked at when disassembled. Any Comments?
I never dreamed when I bought Delta Dawn in November I would have all these expenses. A novice horror story. PS I still wouldn't trade her for any other boat, the few times I have sailed her she has been great.
Otter777@aol.com
CD 30 Seacock Leak -Thru Hulls are gone!!
Moderator: Jim Walsh
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john doyle
Re: CD 30 Seacock Leak -Thru Hulls are gone!!
All this & she didn't sink? Obviously there was 110 AC current which ate away the bronze. Through hulls are cheap compared to having a boat salvaged off the bottom & also sounds like the yard who installed the new engine had a wiring problem.Jim wrote: The boatyard pulled Delta Dawn yesterday and called me to come and look at her with them. To my suprise and horror the 5 Thru Hulls and the grounding plate were no longer there. The new prop was covered with a white brown residue. My first thought was they had already taken the through hulls out. The yard owner assured me that was not the case and he was just as suprised when he pulled her to see they were gone. The thru hulls where there on December 18th when the boat was put back into the water after instaling a new engine at another boat yard. However the 12 volt did not work properly. The new yard found that the 12 volt ground wire was not connected to the engine. It would appear that electrolysis devourered the thru hulls in 3 months. The yard thinks the 110 volt may be the cause and plans to check that for me, but I wonder if it was the 12 volt with the charger. Any thoughts?
Secound question is the yard is recomending replacing the seacocks with thru hulls and ball valves. I know this system is used on other boats and is much less expensive, especially if new seacocks are needed also. The seacocks are to be looked at when disassembled. Any Comments?
I never dreamed when I bought Delta Dawn in November I would have all these expenses. A novice horror story. PS I still wouldn't trade her for any other boat, the few times I have sailed her she has been great.
redzeplin@yahoo.com
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Olli Wendelin
Re: CD 30 Seacock Leak -Thru Hulls are gone!!
Jim,
I expect the electrolysis was due to improper wiring of your electrical system, the dock's electrical system, or that of a nearby boat. Either 110 or 12 volts could have caused it.
I would recommend you have a marine electrician check your system due to the severity of the problem. You could also check out the "Boatowner's Mechanical and Electrical Manual" by Nigel Calder, which goes into detail on the grounding of boats and electrolysis. It sounds like you leave your shore power cable hooked up all the time. This should not be necessary, and will further complicate the problem.
My vote is for traditional tapered plug seacocks.
Olli Wendelin
BLUE MOON
Charleston, SC
wendelin@spawar.navy.mil
I expect the electrolysis was due to improper wiring of your electrical system, the dock's electrical system, or that of a nearby boat. Either 110 or 12 volts could have caused it.
I would recommend you have a marine electrician check your system due to the severity of the problem. You could also check out the "Boatowner's Mechanical and Electrical Manual" by Nigel Calder, which goes into detail on the grounding of boats and electrolysis. It sounds like you leave your shore power cable hooked up all the time. This should not be necessary, and will further complicate the problem.
My vote is for traditional tapered plug seacocks.
Olli Wendelin
BLUE MOON
Charleston, SC
wendelin@spawar.navy.mil
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Matt
Re: CD 30 Seacock Leak -Thru Hulls are gone!!
Jim,
Sorry to hear about the problems. If I had a choice I'd probably go with spartan seacocks. They are original equipment and when you go to sell the boat some day ball valves may raise some eyebrows. Ball valves work well for other boats and are lower maintenance. I wonder if they would be as safe if you had another dissolving incident.
This sort of problem got lots of press on the west coast several years ago when some boats sank due to the same problem. I read somewhere that some marinas do not allow boats to stay plugged in for this reason. Pull your prop shaft and inspect it carefully. It could be trashed as well. You can tell if it is the marina by checking the voltage between the green ground wire in the marina and the water. With all of the other boats plugged in the voltage should be roughly the same as with zinc. If it is more noble than bronze, you know the problem. Attach a seacock handle to a digital multimeter probe and drop it in the water. Do the same with a piece of zinc on the other probe. Note the voltage difference (DC). Now compare the green ground wire to the zinc. If the difference is greater than the difference between the zinc and the bronze there is a problem with the ground. If the marina knows about this the problem may be fixed already.
You will want to buy a galvanic isolator so this does not happen again.
If it is a marina wiring problem someones insurance may handle the cost.
Let us know what you find.
Matt
mcawthor@bellatlantic.net
Sorry to hear about the problems. If I had a choice I'd probably go with spartan seacocks. They are original equipment and when you go to sell the boat some day ball valves may raise some eyebrows. Ball valves work well for other boats and are lower maintenance. I wonder if they would be as safe if you had another dissolving incident.
This sort of problem got lots of press on the west coast several years ago when some boats sank due to the same problem. I read somewhere that some marinas do not allow boats to stay plugged in for this reason. Pull your prop shaft and inspect it carefully. It could be trashed as well. You can tell if it is the marina by checking the voltage between the green ground wire in the marina and the water. With all of the other boats plugged in the voltage should be roughly the same as with zinc. If it is more noble than bronze, you know the problem. Attach a seacock handle to a digital multimeter probe and drop it in the water. Do the same with a piece of zinc on the other probe. Note the voltage difference (DC). Now compare the green ground wire to the zinc. If the difference is greater than the difference between the zinc and the bronze there is a problem with the ground. If the marina knows about this the problem may be fixed already.
You will want to buy a galvanic isolator so this does not happen again.
If it is a marina wiring problem someones insurance may handle the cost.
Let us know what you find.
Matt
mcawthor@bellatlantic.net
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Bill
Re: CD 30 Seacock Leak -Thru Hulls are gone!!
When I put shore power on Rhapsody last year (1999) I talked with a WM "<B><U>advisor</B></U>" who informed me that his marina would not allow the AC curcuit grounded to the engine at all for this very reason!!!Matt wrote: This sort of problem got lots of press on the west coast several years ago when some boats sank due to the same problem. I read somewhere that some marinas do not allow boats to stay plugged in for this reason.
FWIW
Bill
cd25d@rhapsodysails.com
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Larry DeMers
Re: CD 30 Seacock Leak -Thru Hulls are gone!!
Holy smokes! That is the worst case of electrolysis I have ever heard of! Wow..well, without looking the wiring over, I would not be able to tell you if the problem was with the 120vac or 12vdc system wiring, but there is certainly a problem in one or both areas.
Regarding using a Ball valve:
I would not allow a ball valve on my boat. They tend to build up corrosion and scale on the ball, which impedes it's rotation. Over time, that means that the range of motion for that ball will be continually reduced as you fight the scale that blocks the ball from moving, losing a little rotation each year, unitl it is stuck. Now surely there are exceptions to this happening, but the rap against these valves has always been that they do indeed foul out eventually.
Incidently, there is really no provision for lubrication on the ball itself. Use a good Spartan bronze seacock, and it will outlast you more than probably.
Sorry for your misfortune. There are ways to check on the amount of electrolysis using a voltmeter set to a millivolt scale. It's actual use will depend entirely on how your system is wired. If possible, try to make a schematic of the wiring -from 120vac at the service entrance, to the breaker panel, and all grounds and where they are grounded. You may also have some things to talk about with the people that worked on the boat, once a cause has been identified.
Another poster mentioned (correctly) that this could even be a problem with your neighbors boat, so be careful, as more than probably there is a hot 120vac line causing the problem. That spells trouble. DO NOT touch any other boat while touching yours. DO NOT go swimming near your boat at the dock. At least, not unitl the problem has been identified and repaired. Email me offline if I can be of further help diagnosing this problem.
Best of Luck..please let us know how it is going and what you find out.
Cheers~!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Snowed in on Lake Superior~~~
demers@sgi.com
Regarding using a Ball valve:
I would not allow a ball valve on my boat. They tend to build up corrosion and scale on the ball, which impedes it's rotation. Over time, that means that the range of motion for that ball will be continually reduced as you fight the scale that blocks the ball from moving, losing a little rotation each year, unitl it is stuck. Now surely there are exceptions to this happening, but the rap against these valves has always been that they do indeed foul out eventually.
Incidently, there is really no provision for lubrication on the ball itself. Use a good Spartan bronze seacock, and it will outlast you more than probably.
Sorry for your misfortune. There are ways to check on the amount of electrolysis using a voltmeter set to a millivolt scale. It's actual use will depend entirely on how your system is wired. If possible, try to make a schematic of the wiring -from 120vac at the service entrance, to the breaker panel, and all grounds and where they are grounded. You may also have some things to talk about with the people that worked on the boat, once a cause has been identified.
Another poster mentioned (correctly) that this could even be a problem with your neighbors boat, so be careful, as more than probably there is a hot 120vac line causing the problem. That spells trouble. DO NOT touch any other boat while touching yours. DO NOT go swimming near your boat at the dock. At least, not unitl the problem has been identified and repaired. Email me offline if I can be of further help diagnosing this problem.
Best of Luck..please let us know how it is going and what you find out.
Cheers~!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Snowed in on Lake Superior~~~
Jim wrote: The boatyard pulled Delta Dawn yesterday and called me to come and look at her with them. To my suprise and horror the 5 Thru Hulls and the grounding plate were no longer there. The new prop was covered with a white brown residue. My first thought was they had already taken the through hulls out. The yard owner assured me that was not the case and he was just as suprised when he pulled her to see they were gone. The thru hulls where there on December 18th when the boat was put back into the water after instaling a new engine at another boat yard. However the 12 volt did not work properly. The new yard found that the 12 volt ground wire was not connected to the engine. It would appear that electrolysis devourered the thru hulls in 3 months. The yard thinks the 110 volt may be the cause and plans to check that for me, but I wonder if it was the 12 volt with the charger. Any thoughts?
Secound question is the yard is recomending replacing the seacocks with thru hulls and ball valves. I know this system is used on other boats and is much less expensive, especially if new seacocks are needed also. The seacocks are to be looked at when disassembled. Any Comments?
I never dreamed when I bought Delta Dawn in November I would have all these expenses. A novice horror story. PS I still wouldn't trade her for any other boat, the few times I have sailed her she has been great.
demers@sgi.com