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Rusty seacock

4K views 11 replies 9 participants last post by  camaraderie 
#1 ·
I just bought a 36' sailboat that I am using as a liveaboard.

I just discovered a seacock that I was unaware of. It is rusty, loose, and leaking a very small amount of water from the threads between the hull fitting and shutoff valve.

I am fairly new to boats but assume that this is a critical problem. What can I do short of a haul out to temporarily stabilize this problem? I simply don't have the cash for a haul out right now. I am afraid that at any moment the entire seacock will break loose and sink the boat.

Thanks.
 
#2 ·
As you indicate, a rusty, loose, & leaking seacock assembly represents a critical problem; which could jeopardize your entire investment.
As a (very) TEMPORARY measure, you could try encasing the problematic parts of the assembly with a polyurethane structural adhesive/sealant, such as 3M #5200 (or #4100).
Others may counsel against 5200/4100, due to it's EXTREMELY tenacious adhesion (you'll have difficulty getting it off).
Whatever you dam it up with, do NOT use a silicone sealant.
FWIW,
Gord www.CruisersForum.com
 
#4 ·
Rather than encasing it in adhesive sealant, I would try using silicone self-fusing tape to seal the leak. Rescue Tape or Rubbaweld are brand names for this tape. It will be easier to clean up.

I also agree you should have a tapered wooden plug, but it should be softwood, like pine, and you need to keep it in a plastic bag, so it stays dry until you need it. That way, when you pound it into the hole, it will absorb water and swell up, essentially holding itself in place...which is why you need to keep it dry.
 
#5 ·
I’m going to disagree with the experts. Rust is never a good sign and with the seacock already leaking I would guess you have major structure problems with it. I would recommend being ready for it to break but I would not seal it with anything or mess with it at all. I’m not sure if you are in a cold environment but I’m thinking that if you are then the seacock might have frozen and the reason for the leak is a crack. Any movement could cause it to fall apart turning a small problem into a major issue. Get some good plugs as everyone has suggested and have an extra pump on hand in the event that she lets loose.

Stat saving money and as soon as possible get the boat on a lift and fix the problem. This is not the kind of thing you want to leave the marina with.
 
#7 ·
Since the original poster is reporting a "rusty" condition with his through-hull fittings, why is it that no one has yet questioned the use of ferric metals on a boat's hull?

I was not even aware that iron through-hull valves were used below the waterline by boat builders during the last century.
 
#8 ·
What is the sea cock for?? Engine cooling (supply/discharge)? Sea water for the sink? For Wash down water? Sewage overboard? Or Toilet flushing system?
Now can you live with out it? Need It?

Can you plug it from the outside and try to see if you can repair it by removing the old valve, chase the threads and put on a new valve?
Do you have to replace the entire through hull fitting?

But what you have described is a boat sinker if left unattended. It must be taken care of, immediately. In the mean time have a couple of plugs ready for usage.

Check all of your other through hull fittings also. To see if there are others that may need to be replace.

It could be a one or two day haul out if below the water line. Or see if a list on the boat will bring it clear of the water and repair it from a punt. But a haul out would be the best way to do it.

Oh!! Make sure your pumps can keep up with that size hole if the valve breaks off. And have an alarm system on you pumps so you know when they start up.
 
#9 ·
patrick when you say rusty are you referring to green corrosion or actual red rust? as to the water weeping/running around the threads around the nut, is there a wood pad/glassed over under the nut. can you move the nut by hand at all? if you can try gently turning the nut down onto the pad while holding the thru-hull from turning. you don't say where you are, but if you are where the tide drop is great enough can you careen the boat against a sea wall or posts to hold her up right wait for the tide to recede and then fix the thru-hull properly
 
#10 ·
TB-

Some ball valves are made of stainless steel, as is the case in the "Marelon" ones made by ForeSpar. The bodies of the seacock are fiberglass-reinforced nylon, but the ball itself is stainless steel. You could get rust from stainless steel.

I would definitely want to schedule a haul out to replace said throughhull and seacock as soon as feasible.
 
#11 ·
Update...

Okay, this morning I went and bought a 1 1/4 inch cap for the thru-hull. Being new to boats I had assumed that the water pressure created by an open pipe to the sea would be extreme. Well, apparently it isn't and I was able to screw the sea cock off and place the cap with less than a gallon of water entering the boat. Most of the corrosion was on the sea cock although there is definitely some corrosion on the thru-hull, a combination of green and red. It doesn't seem severe, though. I am hoping that I will be able to hold off on replacing the thru-hull until I paint in a couple of months. Now that the corroded areas of the pipe are completely dry will the corrosion stop, or will it continue? Is there anything I can do to the thru-hull to slow down or stop the corrosion? Thanks.
 
#12 ·
Patrick...glad it worked out easily for you. Corrosion on a bronze through hull is likely galvanic caused by stay currents either from your boat or others in your marina. Do you have a zinc on your prop shaft in good condition? Are there hull zincs that need replacement? If you think you need zinc protection the easiest way till haulout will be to hang a zinc fish over the side. You can get them relatively cheaply in most chandleries.
P.S. ...the fact that you were able to remove the sea cock without the through hull crumbling means it probably isn't in too bad a shape!!
 
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