Electrolysis

[Celestialsailor]

This is my second week with this vessel. The prior owner was in poor health for some time and passed away. The boat sat at a dock for a few years with zero maintenance. There is evidence of flooding to just below the floorboards as the waterline stain shows it squatted at some point recently. There was no corrosion on the engine pan but the sump is large and deep and could easily hold 2000 lbs of water. The attached pictures show where the leak occurred. It was a miracle that the boat did not sink.
You will see the green stud. It was bronze that went through the hull for the rectangular zinc plate. Both were rotted off flush with the outside hull and the only thing holding the studs in the hole was the fuzzy oxidization.
The other two pictures were way scarier. It was the galley sink thru-hull under the waterline. It also had a green stain indicating a leak and someone in their infinite wisdom used underwater epoxy on it. When I grabbed the valve in my hand, it snapped off. I could not of used a pound of force.

[Target9000]

Stuff like this scares the hell out of me.

[minaret]

How did this pass survey, if you've only had her for a few weeks? Just curious...

[Celestialsailor]

A survey was done last year. This was obviously going on for much longer than that. I bought the vessel for a fraction of what these boats sell for, so my concern is not so high. When ever I purchase a boat, I go through everything such as thru-hulls, valves, hoses, electrical and so on. As long as the hull is sound, built at a good manufacturer, it's a go for me.
My friend and myself were joking about it. We figured the surveyor was probably a really large guy that couldn't get in tight places and wore really thick glasses.
I'll add that when the zinc attachment failed, there was even electrolysis on the bottom paint!

[barnakiel]

Yep. A boat sitting at the dock for ages is a ticking bomb. Touch nothing, lift, dry, replace anything that CAN break. Start with the seacocks ...

b.

[zeehag]

oxidation is different than electrolysis. green is oxidation. looks like the problem has been of many years duration-- not has been repaired, in someones mind once anyway already.
people forget that survey is for bank loans and insurance of boat comprehensive insurance. it isnt for all that is wrong with boat. many things will not be "found" on survey.
first thing always to do to and with a boat is inspect the THRU HULL FITTINGS -- seacocks are not as important. the thru hull fittings will sink yer boat NOW the seacocks MIGHT sink your boat soon.
this could have been found by prospective owner prior to purchase with a digital camera taking pix of where the eye cannot see.

[Celestialsailor]

Originally Posted by zeehag

oxidation is different than electrolysis. green is oxidation. looks like the problem has been of many years duration-- not has been repaired, in someones mind once anyway already.
people forget that survey is for bank loans and insurance of boat comprehensive insurance. it isnt for all that is wrong with boat. many things will not be "found" on survey.
first thing always to do to and with a boat is inspect the THRU HULL FITTINGS -- seacocks are not as important. the thru hull fittings will sink yer boat NOW the seacocks MIGHT sink your boat soon.
this could have been found by prospective owner prior to purchase with a digital camera taking pix of where the eye cannot see.

I don't believe I stated the green (cupric oxide) was electolysis. In fact, I called it fuzzy oxidization Just stating that the green stain indicated water entering the boat.

[zeehag]

thye fact of their being green doesnt mean water was here--- bronze oxidizes in moist air-- you will find your thru hulls take on patina at about 2-3 yrs of age. the patina means nothing. the thick oxidation and loss of metal does mean a lot. means the fitting should have been addressed about 5+ yrs ago. the goop at the base of the fitting is sign of water intrusion -- and an attempt, poor one, to repair that. that looks like an original thru hull, no matter the age of boat. looks like my 1979 fitting did in 2004. salt water intrusion on bronze doesnt look green. i know--i have that in my formosa.
and you DID title the thread/post as electrolysis.......

[Celestialsailor]

Well Zee...I guess ya had to of been there. It was meant to be an informative post. You want to critique the stains...go ahead.

[zeehag]

i HAVE had exactly that looking thru hull--- have you????
mine came from an allegedly well kept snot club boat, an ericson 35--and i replaced it within the first 2 weeks of ownership in the water by competent divers.
showed me exactly how well maintained snot club boats are kept.