My 2005 Hunter 33 has seacock fittings with the inside wall of the thru-hull section reduced to the extent that the thread cuts are exposed right through with clear daylight showing over most the length from outside of hull to locking nut . I will replace all 5 with a better quality fittings. Anyone else experienced this? - what age boats should this level of failure be expected?.
Thru hull fittings
- Thread starter James Eastwood
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Attached photo shows treaded hull fitting that snapped off inside the hull with the elbow (to take the seacock) still mounted on the top - note daylight through the threads.
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Looks to me like there may have been an electrolysis situation deteriorating the metal. Look at all your underwater bronze including the prop and shaft. If the metal has a discolored pink quality, is pitted and weakened, the boat has experienced some stray electrical currents resulting in electrolysis in the underwater exposed metals.
Oh boy, you have electrolysis acting on your boat. Or a very bad batch of fittings. One of my funniest boat stories is when I was down inside the lazarette repairing something and I brushed lightly against the head thru-hull. It broke off - and like the little Dutch Boy I put my finger in the hole to stop the water flow. I was alone and had to find something to plug it. Used some rope line as I recall 
Yes, you are doing the right thing inspecting and replacing all of your thru-hulls. I would also look at other fittings on the boat as they may be in the same condition. All of the bronze fitting need to be bonded (grounded). I don't think age has too much to do with it if you have excessive electric current going through the boat it doesn't take long to destroy metal fittings.
Yes, you are doing the right thing inspecting and replacing all of your thru-hulls. I would also look at other fittings on the boat as they may be in the same condition. All of the bronze fitting need to be bonded (grounded). I don't think age has too much to do with it if you have excessive electric current going through the boat it doesn't take long to destroy metal fittings.
Are you the original owner?? Did someone add that nipple?? Is that a nipple screwed into an ell or is it a male threaded ell?? Something about that fitting looks wonky.. Looks like someone re-threaded too deeply.. The size (flanks) of the threads themselves looks too big.. Might be just electrolysis, but it just doesn't look right to me.. Maybe Mainesail can get an explanation on that one??
Appears to be SEVERE electrolysis to me. In what condition are your zincs?
Check for incorrect AC (or even DC) grounding through the hull (ground plates). Does your 115VAC ground to the hull/keel/engine block at all? --it shouldn't unless you have a generator with a 3-pole ship/shore switch. If it does, the problem could be coming from something in your boat, or your neighbor's, or the marina itself. ANY stray current in the water is bad for everyone.
You should investigate the electrolysis issue and then replace the seacocks with Forespar Marelon which will not entertain this (nor many other issues) in future. On Diana I have exactly two pieces of metal underwater-- the keel and the rudder stock. Everything else is avoided with Marelon of just by having it.
Check for incorrect AC (or even DC) grounding through the hull (ground plates). Does your 115VAC ground to the hull/keel/engine block at all? --it shouldn't unless you have a generator with a 3-pole ship/shore switch. If it does, the problem could be coming from something in your boat, or your neighbor's, or the marina itself. ANY stray current in the water is bad for everyone.
You should investigate the electrolysis issue and then replace the seacocks with Forespar Marelon which will not entertain this (nor many other issues) in future. On Diana I have exactly two pieces of metal underwater-- the keel and the rudder stock. Everything else is avoided with Marelon of just by having it.
thanks for the input and suggestions. the picture is the remains of the thru hull fitting as it snapped off at the hull - the section through the hull was so depleated that I just shoved it down through the hull and didn't retrieve it as I had dried out on the "grid" alongside a marina wharf to carry-out replacement. Tomorrow I will replace all 4 remaining fittings. The anode on the prop shaft was about 50% eroded (and now replaced).
Is it advisable to wire all thru hull fittings and keel bolts etc together? - heard this idea recently...
Is it advisable to wire all thru hull fittings and keel bolts etc together? - heard this idea recently...
Thru hull fitting
I have the same boat like yours, but mine is 2008 model. My fitting leaks when there are few months old, they sent me new replacement plus raw water and engine pick filters. I think they over tighten it and stretch the tread. The workmanship are of very poor quality. For the last 1 1/2 year I have been rectifying and modifying what is need to be done to have a better boat. If you do need further help please free to write to me.
Hi James,
I have the same boat like yours, but mine is 2008 model. My fitting leaks when there are few months old, they sent me new replacement plus raw water and engine pick filters. I think they over tighten it and stretch the tread. The workmanship are of very poor quality. For the last 1 1/2 year I have been rectifying and modifying what is need to be done to have a better boat. If you do need further help please free to write to me.
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