Frozen thru hull fitting

[mark lennoc]

I have a Beneteau 2005 with a frozen thru hull fitting. The fitting appears to be bronze and it is a gate valve set up which looks to be in decent condition. I really don’t want to haul the boat to change it especially if there’s an easier fix. I’m pretty certain this isn’t the first time someone has posted this type of issue but darned if I can find out much on the site.
Thanks in advance for any suggestions.

[Dockhead]

A gate valve?! Are you sure? There is no place for gate valves on a boat. Surely what you have is a BALL valve, no?


Beneteaus of that era often had inferior brass underwater fittings, and if that's what you have, you need to change them all.


If you'll photograph and post the markings on the fitting, we can help you identify it.


You can change an underwater fitting without hauling out, but it's a pretty dicey operation. You can plug it from below with a wooden cone, then screw off the ball valve and replace it. But if you twist the through-hull in the hull, you're in a world of hurt. Better to haul out and do them all.

[Smokeys Kitchen]

Agree with Dockhead on the gate valve/ball valve issue.

For the couple that have stuck on us, we use CRC break free over a few days to two weeks along with heat. Spraying the CRC, light taps with a mallet, then a hot hair dryer. Repeat until it comes free. You could possible use a small torch if you are careful, but I have not.

[deblen]

Some seacock info :
https://marinehowto.com/
http://coxeng.co.uk/
https://www.cruisersforum.com/forums...er-211436.html
Google SEABUNG
Cheers/Len

http://www.pcmarinesurveys.com/Paul%...20Seacocks.pdf

[MicHughV]

oh lordy lordy....don't mess with that thing until you haul out. I've seen this kind of thing before, while it may be bronze it is still susceptible to pitting, etc.
Trying to force it would be tempting fate.

[boatpoker]

Originally Posted by mark lennoc

I have a Beneteau 2005 with a frozen thru hull fitting. The fitting appears to be bronze and it is a gate valve set up which looks to be in decent condition. I really don’t want to haul the boat to change it especially if there’s an easier fix. I’m pretty certain this isn’t the first time someone has posted this type of issue but darned if I can find out much on the site.
Thanks in advance for any suggestions.

I've surveyed quite a few Beneteaus of that vintage and never seen a gate valve on a Beneteau throughull. Their stock valves are cheap domestic plated brass ball valves that should never have been fitted on a boat.

If it is a gate valve it was probably added by know nothing owner. I'd be concerned about what else he did.

[HopCar]

Actually gate valves were once pretty common on thru-hulls. The problem was that most of them available in the market had brass stems that would eventually break. The body of the valve might be bronze but the stem was the problem.

Replace the gate valve asap preferably with a real seacock or at least a marine quality ball valve.I like Groco products.

[boatpoker]

Originally Posted by HopCar

Actually gate valves were once pretty common on thru-hulls.

Gate valves had pretty much disappeared by the early 80's. Of the 168 Beneteaus I have surveyed (earliest being 1984 models). None of them had gate valves.

[MicHughV]

it's clear that you don't want mess with it until the boat is out of the water...

[Shrew]

If this is a threaded ball valve, I would not attempt to remove it in the water. I'm sure there are plenty of folks who will say "I've done it". My only concern is what happens something unexpected occurs.

What happens if the threaded stem snaps off during removal?

[mark lennoc]

Hey Guys. Thanks a bunch for all the help. I will try to confirm the type of thru hull on my boat first. It appears I could have messed up on that front. I could try to post a photo but unsure how to do that.

[mark lennoc]

Okay, I have confirmed that the 2005 Beneteau 373 has ball valves, not gate valves like I had said.
It sounds like I could try a few simple, stress free tactics but avoid the use of the sledgehammer until safely ashore.
Given it’s a ball valve that’s frozen should I try anything not already suggested?
Thanks all.

[Enfant Du Vent]

Ahoy Mark:


Once you've resolved the issue I recommend the following:
Once a month close and then reopen all through hull valves,
AND check the sacrificial zinc anode on the engine!


(I still remember the shocked look on the face of the other crew member of a Hinckley I crewed on all one winter in the Caribbean. When I asked him in he'd bought any spare anodes he said, "Yes, why?" I held up the one I'd taken from the engine.....and it was a less than 1/4 inch nub! He knew all things technical, but nothing about sailboats in a salt water environment....and they were about to leave Panama for the South Pacific.)

[MicHughV]

Here's a story. My previous boat, the Landfall, had all all bronze thru-hulls.
I found that one thru' hull (in the forward head) didn't want to close properly for some reason, even with the lever down, indicating closed, it leaked, ie, water from outside the boat was entering the hose.
Eventually I hauled the boat, and I removed the tapered plug of that particular thru' hull for a closer look. Much to my surprise, both it and the housing were severely pitted. This prompted me to check all the other thru' hulls, all bronze, only to find much the same thing. I tried lapping the plug with lapping compound, but the pits were too deep and too many and lapping proved to be fruitless.
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.
It ended up being a very expensive haulout.

Nonetheless, my advice here remains the same. Trying to exert any pressure on a stuck ball valve could lead to problems that will compound beyond your ability to fix or address.
Have the boat hauled first !!

[Bowdrie]

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.

The metals that we commonly call "bronze" span quite a distance on the galvanic scale.
Undoubtedly the "bronze" ground plate had a higher nobility, the wires connecting the seacocks to the ground plate completed the circuit.
Now you had electron flow from the battery that was created.