Through hull appears to be leaking

[felizcortez]

I have a through hull for the galley sink that appears to be leaking at the threads a bit. see attached pic.

Do I just close the through hull put a pipe wrench on it separate the pipes and clean them, put new pipe dope on it then reassemble? Is pipe dope the right stuff to use?

[Pete7]

In theory yes, but that assumes the yellow handle closes the valve. The last one I took out nearly closed the valve but not quite. Thankfully it was the sink which drains above the water line so no drama.

However, you have something else going on there, looks like a 1.5" hose has a reducer to fit a smaller seacock and a link fitting. Not a great idea. Also the hose tail the hose connects to looks grey, please tell me that isn't galv pipe.

When are you lifting out next, because that might be the time to rip it all out and start again with the right sized seacock to match the pipe.

Pete

[sailormed]

I think the grey pipe is standard PVC plumbers pipe. Do NOT overtighten this!

[Cheechako]

I dont see any wetness. Often some condensation forms. The green is not uncommon.
A couple things:
-The grey barb fitting should be handled with care while in the water. They can drip if not tightened well though.
-That appears to be a small thru hull fitting with a lot of length and weight above it. Not a great situation. If it were me I would wait until you haul out and replace the fitting with a proper size to fit that hose, rather than adapt with all that weight leveraging the thru hull fitting. The thickness of the bronze thru hull fitting at the thread root may be less than 1/16" thick and is already a stress riser.
-What type of white hose is that? If that is poly like from the hardware store (or marine store) I have a caution: Often that hose is so tight to get on grey pvc fittings that it splits! I re did head hoses with that once because I heard it doesn't get smelly so bad. I had to put the end in hot water to get it on. It wasn't boiling water. A month later I discovered a spray coming out of the hose! It has split from stress right at the end of the barb fitting.

[tkeithlu]

Are you sure that the seacock and from there to the water is OK, and all the leak is above the ball valve? Can you close the seacock gently without stressing that steel connector and stop the leak? If so, rebuild right now attending to the concerns of Pete7. If not, then

You're floating? This through hull is below the waterline? It's leaking? How long will it take you to very carefully get your boat into a sling? If this sucker does what it is suggesting it is about to do, it's lift out now, or be there with a soft wood cone and a mallet until you lift out.

Seriously, I don't think I would approach this without pulling the boat and inspecting all the bronze on all your seacocks. If someone put iron plumbing in with bronze, and resized a seacock, what else have they done? Residential brass? Seacocks are dangerous. Pop one where you can't reach it very quickly and you will fill the boat to the depth of the ambient water. Manufacturers put them wherever they need water in or out in order to avoid hose runs. You may have lots, and in very difficult places.

[sailorboy1]

I don’t see leakage in the photo and personally I would LEAVE IT ALONE

You start trying to “fix it be trying to tighten etc. and then you are going to have a real leak when i5 goes bad

[tkeithlu]

OK, it's PVC, not iron. So, I'm being a little bit, but not a big bit, alarmist. At least inspect them all now, and close the ones you don't need at dock or when off the boat, and make a list of ones to rebuild. Approach all underwater openings with the thought that even a small leak in one that is under the waterline will sink your boat in a few hours. You'll come back to the boat and use the mast as a depth gauge. The inside of a seacock IS YOUR HULL, and your hull in this case is an easily split piece of residential PVC. That's your hull when this seacock is open.

[felizcortez]

It appears to be leaking a bit from the PVC connection. I can see it dropped down from there.

What do you mean resized the seacock? Are you talking about closer to the water line of from the valve or on the other side after the valve.

[felizcortez]

And the white is sanitation hose like for a head. It says Sealand brand on it.

[deblen]

Some good advice at this link. / Cheers/Len


https://marinehowto.com/category/plumbing/

[mvweebles]

Originally Posted by deblen

Some good advice at this link. / Cheers/Len[emoji2]


https://marinehowto.com/category/plumbing/

Great link on installing a seacock backing plate. As an aside, suggest considering seacock vs straight mushroom fitting with inline valve certainly for below waterline. Much stronger and more compact. Unfortunately, more expensive.

Example.

https://www.go2marine.com/Groco-Bron...BoCeuoQAvD_BwE

[Cheechako]

Another good link regarding through hulls... https://marinehowto.com/seacock-thru-hull-primer/

[stormalong]

Originally Posted by felizcortez

It appears to be leaking a bit from the PVC connection. I can see it dropped down from there.

What do you mean resized the seacock? Are you talking about closer to the water line of from the valve or on the other side after the valve.

He means replace it all with the proper size fittings. Through hull, flanged seacock and tailpiece. Your installation does not meet current ABYC recommendations. With that type of installation I question if that is a proper seacock or a brass ball valve. Current recommendation deal with mechanical stress on the fittings. If the fitting were to be stepped on would it break off? Granted, where it is located being stepped on is highly unlikely but a long series of fittings means a lot of leverage. Stress at the top has mechanical advantage. That coupled with unknown materials could be a time bomb. Brass does not age well in salt water.

I have a similar situation on my boat although not as severe. Half of my seacocks are not flanged but they are Marelon and so are the through hulls so no corrosion. Those are the originals, I have replaced half of them with flanged Marelon seacocks. I prefer Marelon because there is no chance of galvanic corrosion with plastic and no question about the quality the metal alloy.

[Pete7]

Originally Posted by felizcortez

What do you mean resized the seacock? Are you talking about closer to the water line of from the valve or on the other side after the valve.

Impossible to tell the hose sizes from the photo but it looks like 1" hose going into a 3/4" seacock. So first off, if it's the galley sink, what size hose is joined to the sink outlet? The inside diameter of the hose is the important bit.

Next does the seacock have any markings on it which could relate to its size?

Pete

[Lepke]

If you can't see a leak, my money is on condensation settling on the bronze fittings over time.

Unless you're having flow problems, the reducer isn't a problem. If it's not broke, don't fix it.