Hi all
Went to do a little preventative maintenance on the weekend - changing hose attached to seacocks. In doing so, discovered that the seacock connected to the galley sink and fridge drain, although the lever turns nicely, is in fact stuck open internally. That freaked me out somewhat as I don't know how long it has been like this. I close all cocks each time I leave, however the only thing stopping this particular one from flooding the boat is the length of hose attached to it!...and now I can't sleep at all.
I'm going to stick with Bronze, but is there any difference in brands/suppliers of bronze skin fittings and cocks? I'd like to get the best I can and get another 10 years or more out of them.
Appreciate any feedback
Gos
not trying yo take over the post , just adding to it ...... no answers here . just more questions ....... so about 7 years ago i changed most sea cocks over from gate valves to ball valves . But i,m starting to think gate valves may have been a better option . what does the crew think ?
My friends that live on a catamran they built replaced all there sea cocks 8 years ago with plastic ones, they still look new and require very little maintance.
not trying yo take over the post , just adding to it ...... no answers here . just more questions ....... so about 7 years ago i changed most sea cocks over from gate valves to ball valves . But i,m starting to think gate valves may have been a better option . what does the crew think ?
Hi Gos,
Have a look at this article mate, I found it really interesting.
trip.ayy.fi/wordpress/wp-content/uploads/2014/08/Seacocks.pdf
I have all plastic ones now, they've been surprisingly low maintenance, and much cheaper and lighter to carry spares!
G'day SandS,
I'm no guru , but ball valves for me. Gate valves can leak if they get buildup or foreign objects in/on the sealing surface, a ball valve has a much more positive seal due to the ball design, ie: when it's closed its closed.
I installed some seacocks from Bias Boating on Trek. Two years (or less) later the levers had corroded off and disappeared. Rubbish seacocks. We have to operate them with a shifter now. If you buy Bias Boating seacocks ask what the warranty is. I would never buy theirs again.
There are seacocks [tapered valve], gate valves and ball valves. Do you have a real sea cock or a gate valve. Gate valves are probably the most common in older boats. Seacocks are usually found on quality yachts.
Sounds suspiciously like you have a cheap gate valve. Quality gate valves are all bronze. The cheaper ones often have brass pins and gates that disappear leaving the boats security down to the valve body as you have found. Good gate valves are expensive. One inch ones used to be about $80. Years ago when I had my fishing vessel out of the water for the annual survey I had to have all the valves pulled apart on display for the surveyor to check. There had been a run of crappy valves sold by ship chandlers at the time.
Seacocks have to be serviced and greased. The taper can be reground if needed. I have two frozen at the moment the result of poor maintenance!
Valves should always have rubber tails and two clips on any under water installation for security.
There are seacocks [tapered valve], gate valves and ball valves. Do you have a real sea cock or a gate valve. Gate valves are probably the most common in older boats. Seacocks are usually found on quality yachts.
Sounds suspiciously like you have a cheap gate valve. Quality gate valves are all bronze. The cheaper ones often have brass pins and gates that disappear leaving the boats security down to the valve body as you have found. Good gate valves are expensive. One inch ones used to be about $80. Years ago when I had my fishing vessel out of the water for the annual survey I had to have all the valves pulled apart on display for the surveyor to check. There had been a run of crappy valves sold by ship chandlers at the time.
Seacocks have to be serviced and greased. The taper can be reground if needed. I have two frozen at the moment the result of poor maintenance!
Valves should always have rubber tails and two clips on any under water installation for security.
Hi Ramona
What I have ( I believe) is bronze through-hulls with bronze ball valves attached. The one in the picture is the one that has failed and surprisingly is in the best (looking) condition of them all. The lever works well and feels good but is no longer turning the ball valve inside...bit worried about all the others now.

ShaggyBaxter - Great article thanks.
I have looked into the idea of plastic/nylon from TruDesign in NZ, but have read a few disturbing comments about them too. Not trying to start the Bronze v plastic argument here.
Any thoughts on Stainless steel thru hulls and ball valves in stead of Bronze?
Love the wisdom here
That's a ball valve in the picture. Bronze body and usually a SS ball. Not much can go wrong with them except the shaft corroding away. If you have bronze through hulls then stick with bronze gate valves or ball valves. If you decide to go with nylon then use nylon through hulls as well. I can't see the point of using SS at all. I have one nylon valve and the rest are bronze seacocks. The seacocks are in a combination with the through hull so they are much more compact. The downside is they need to be maintained, greased and the taper reground occasionally. They are more expensive as well. The lack of maintenance on my part will probably mean I shall have to replace them eventually. I will most likely go with the nylon filled ones. Marelon or the NZ ones, they both get good reviews. My engine cooling intake valve is not in the engine compartment so there is no reason to stick with bronze.
I have looked into the idea of plastic/nylon from TruDesign in NZ, but have read a few disturbing comments about them too. Not trying to start the Bronze v plastic argument here.
Hi Gos, I have one of the Trudesign plastic ones in my hull, plus some bronze ones. I tend to feel the most likely point of failure for the plastic throughulls would be the shaft breaking as you twist it when it's stuck.
Seeing you mention above "disturbing comments" about the plastics makes me naturally curious - without debating the merits, any chance you could point us to where we can read a bit more about the drawbacks/experiences of the plastics?
Hi all
Went to do a little preventative maintenance on the weekend - changing hose attached to seacocks. In doing so, discovered that the seacock connected to the galley sink and fridge drain, although the lever turns nicely, is in fact stuck open internally. That freaked me out somewhat as I don't know how long it has been like this. I close all cocks each time I leave, however the only thing stopping this particular one from flooding the boat is the length of hose attached to it!...and now I can't sleep at all.
I'm going to stick with Bronze, but is there any difference in brands/suppliers of bronze skin fittings and cocks? I'd like to get the best I can and get another 10 years or more out of them.
Appreciate any feedback
Gos
Snap! Discovered the same thing with my head sink seaock on the weekend, so I'll be hauling out to replace it. I'm considering the Trudesign composite ones. Interested in hearing what the best type of grease is for ball valve style seacocks generally?
There are seacocks [tapered valve], gate valves and ball valves. Do you have a real sea cock or a gate valve. Gate valves are probably the most common in older boats. Seacocks are usually found on quality yachts.
Sounds suspiciously like you have a cheap gate valve. Quality gate valves are all bronze. The cheaper ones often have brass pins and gates that disappear leaving the boats security down to the valve body as you have found. Good gate valves are expensive. One inch ones used to be about $80. Years ago when I had my fishing vessel out of the water for the annual survey I had to have all the valves pulled apart on display for the surveyor to check. There had been a run of crappy valves sold by ship chandlers at the time.
Seacocks have to be serviced and greased. The taper can be reground if needed. I have two frozen at the moment the result of poor maintenance!
Valves should always have rubber tails and two clips on any under water installation for security.
What is a rubber tail Ramona?