Frozen thru hull fitting

[boatpoker]

Originally Posted by MicHughV

Interestingly, all the bronze thru' hulls were bonded together by a heavy bonding wire that led to bronze grounding plate under the hull.
I can only surmise that some kind of electrolysis was at play here, the source of which I never discovered.
!

Sintered bronze ground plates are what are used for SSB/HAM ground planes and on occasion as lightning grounds altho' that is somewhat controvertial as they tend to explode when hit by lightning . Sounds like someone didn't know what they were doing.

"electrolysis" cannot occur on a boat. You are either dealing with stray current or galvanic corrosion in both of which the anode is negative and cathode is positive. Electrolysis is the exact opposite with negative cathode and positive anode and is an induced process in industry and labs ... it is a cool sounding word tho'

[Montanan]

Meme:

[MicHughV]

That theory has been posited before, in that the pitting in my thru' hulls was caused by the dock electric system where I was at, which was in deplorable condition.
The docks were wood, with the power cables slung underneath. At low tide, everything was in the mud, some docks even canted to one side. I have no doubt that the electrical power cables came under considerable strain and likely exposed wiring or connectors, especially so, where two dock segments were connected and at the ramp location.

If it were just one thru' hull, the source would have been easier to identify, but it was all of them.

Yes, the boat was equipped with SSB/Ham and had two of those sintered bronze grounding plates.

I bought the boat used with all that equipment already on it.

[Americanrancher]

Mark, Beneteau uses dangerously inferior thru hulls and sea cocks. Without question you must haul the boat and replace EVERYTHING below the waterline. I mean all thru hulls and all seacocks! Google these terms so you can see what they are. If you are interested there a numerous YT videos of Beneteau owners with broken off thru hulls and frozen sea cocks being replaced. I wouldn't sail the boat without doing that, however it's probably not the reason you bought the boat anyway. Ben S/V DAWN

[W5PAD]

I have a 2005 Beneteau. Circa 2018 I had one original sea cock that didn't fully close, so when I was hauled out I planned on changing it. While trying to unscrew it from the thru hull, my wrench slipped and bumped the one next to it. This one sheared off completely. Good thing I was hauled out when a small bump on this thru hull could have flooded the boat.
To save cost, Beneteau uses brass instead of bronze. I highly recommend you haul out, replace ALL original sea cocks and thru hulls, and any that are not bronze. I replaced all mine with TruDesign.

[Americanrancher]

Originally Posted by W5PAD

I have a 2005 Beneteau. Circa 2018 I had one original sea cock that didn't fully close, so when I was hauled out I planned on changing it. While trying to unscrew it from the thru hull, my wrench slipped and bumped the one next to it. This one sheared off completely. Good thing I was hauled out when a small bump on this thru hull could have flooded the boat.
To save cost, Beneteau uses brass instead of bronze. I highly recommend you haul out, replace ALL original sea cocks and thru hulls, and any that are not bronze. I replaced all mine with TruDesign.

This such a common problem with Beneteau's it is scary!
Another odd thing is that the boats have dozens of thru hulls. Beneteau must have figured out that it was cheaper to have more holes in the boat than combine them? Bottom line take all of their junk out!

[boatpoker]

Originally Posted by Americanrancher

This such a common problem with Beneteau's it is scary!
Another odd thing is that the boats have dozens of thru hulls. Beneteau must have figured out that it was cheaper to have more holes in the boat than combine them? Bottom line take all of their junk out!

I like to identify as to purpose/condition and test all seacocks in a survey.
Here is a page from the survey report of a Beneteau 50 which is very sadly ... typical. I have others with more than 20.

[sfbaysailor]

I’ve have a few frozen “nuts and bolts” kind of stuff over my 75+ years as a mechanic and a boat owner. I would suggest that you apply libel amounts of something along the lines of BP B’laster or WD 40 to the the valve stem and, if possible, remove the hose and apply to the ball itself. Do this for several days and then carefully use a good heat gun or a propane torch to attempt to free the valve.
An old injun trick….if the valve is stuck closed try to close it just a bit more or viseversa. Sometimes this is just enough to set it free.