leaving a boat in the water
04-01-2012, 09:58 PM
#21
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Location: burlington, iowa
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i would only apply paint to cover exposed metal. look at other boats were you keep yours, look at drives especially for erosion. if 110 volt is not properly wired, this will show up in accelerated erosion. if there is problem might look into some kind of lift or airbags.
04-01-2012, 10:19 PM
#22
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Location: Grosse Pointe Farms, MI
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Mine is in fresh water from May to Sept every year. Magnesium anodes all the way. Zinc anodes will do NOTHING in freshwater. Aluminum anodes are OK but Mag does a far better job.
Zinc = Saltwater
Alum= Salt or Fresh
Mag= Fresh Only
I run my Mercathode and new Mag anodes every year. Virtually no corrosion to the drive with this setup. I touch up the drive every year with Merc phantom black enamel paint. Jump in and wash the drive, sides and what I can reach of the bottom every weekend.
Zinc = Saltwater
Alum= Salt or Fresh
Mag= Fresh Only
I run my Mercathode and new Mag anodes every year. Virtually no corrosion to the drive with this setup. I touch up the drive every year with Merc phantom black enamel paint. Jump in and wash the drive, sides and what I can reach of the bottom every weekend.
I was going to post about the Mercathode system. Does it help?
04-02-2012, 08:31 AM
#23
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If your plugged into shore power make sure your connected to at least 1 8' ground rod close to the shore power source. Ground potential differences can cause electrolysis.
04-23-2012, 11:24 AM
#27
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Usually the Mercathode system is used in conjunction with your zincs. I say "usually" but really mean "always".
If you leave your boat in the water with shore-power applied to charge your batteries, you would be an absolute fool to not have a galvanic isolator in line with your power cord. Stray DC current can be present on the ground line of your shore cable and this can cause very real damage in a short amount if time. This changes the voltage level of your boats grounding system and really amplifies the properties of dissimilar metals (this is when the Mercathode is fighting AGAINST from happening). The ideal amount of voltage between the boats ground and the anodes is appx -1.1 volt. Yes, minus 1.1 volts. Anywhere btween -0.9 and .1.15 is good for having alumnum outdrives. These numbers fluctuate a bit in brackish and fresh water thought.
Most marinas have a small amount of "leakage" like this. A friend of mine had a 30-ft Trojan at a neighboring marina. It took less then 1 month for both struts and rudders to almost entirely disintegrate. He had a part of one rudder left the size of your hand and both shafts were swinging free after they left the boat via the stuffing boxes. Said he had a little vibration until he pulled it. Lol! This was due to an extreme case of galvanic action.
My steel-hulled Chrish Craft Roamer would literally blister the paint off the hull because my active corrsoion control system was out of whack. To MUCH protection is also very bad. Maybe even worse in some cases.
If you leave your boat in the water with shore-power applied to charge your batteries, you would be an absolute fool to not have a galvanic isolator in line with your power cord. Stray DC current can be present on the ground line of your shore cable and this can cause very real damage in a short amount if time. This changes the voltage level of your boats grounding system and really amplifies the properties of dissimilar metals (this is when the Mercathode is fighting AGAINST from happening). The ideal amount of voltage between the boats ground and the anodes is appx -1.1 volt. Yes, minus 1.1 volts. Anywhere btween -0.9 and .1.15 is good for having alumnum outdrives. These numbers fluctuate a bit in brackish and fresh water thought.
Most marinas have a small amount of "leakage" like this. A friend of mine had a 30-ft Trojan at a neighboring marina. It took less then 1 month for both struts and rudders to almost entirely disintegrate. He had a part of one rudder left the size of your hand and both shafts were swinging free after they left the boat via the stuffing boxes. Said he had a little vibration until he pulled it. Lol! This was due to an extreme case of galvanic action.
My steel-hulled Chrish Craft Roamer would literally blister the paint off the hull because my active corrsoion control system was out of whack. To MUCH protection is also very bad. Maybe even worse in some cases.
