I all - On my '78 Catalina 30 I discovered an ever so-small salt-water mystery leak on the port side of my engine (we are talking a few ounces at best). The bilge is pretty much dry and I can't trace any leakage coming in from the aft-sections (i.e. rudder-post, engine shaft, cockpit drain thru-hulls). I have a PSS dripless on the engine shaft. I do have a sea-cock tucked away on the port-side for my sink drain (I need to get in there and fully inspect it but its hard to do without first removing the entire galley vanity). I usually keep it closed while not on the boat - that would be the only port-side entry for sea-water that I could not fully examine. I put a flashlight on it last weekend and noticed the brass was greenish but I could not tell if it was leaking. The PO replaced all the seacocks with brass ball valves some years ago but I am not sure when (my guess about 15 years). The valve opens and closes but does have a slight resistance compared to the other ball valves I have on the boat. I replaced the hoses and clamps coming off the valve about 4 years ago so I doubt they are leaking….besides, even if they were the valve usually stays closed. The engine raw-water thru-hull is dry and in good shape. I noticed this prior to running the engine this year. I wet store my boat up here in NY so before I started the engine up just this past weekend (after I realized this leak) – there was anti-freeze in the raw-water cooled block so there are no leaks from the coolant system to blame on this. This weekend I plan to pull the sink-vanity assembly so I could get a better look at the situation….just thought I would post and see if anyone here had any pre-advice on thru-hulls and sea-cock inspections. I am hoping there is not a crack or something wrong with the valve. The amount of water is not even enough to make it all the way down into the bilge prior to evaporating….just puddles and blotches. Such a mystery… Thanks - Rob
Mystery Leak: Do Thru-Hull Sea-Cocks Leak?
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Think Rain..
...have you thought that it could be CONDENSATION collecting on the interior of the boat?..or maybe RAIN WATER that came thru some small leak somewhere?? If all else checks out those would be my next sources to look at. Good Luck >>> David
...have you thought that it could be CONDENSATION collecting on the interior of the boat?..or maybe RAIN WATER that came thru some small leak somewhere?? If all else checks out those would be my next sources to look at. Good Luck >>> David
Yes, they can
Everything and anything can leak on a boat, seacocks included. It might not be the unit itself, but the seal between the unit and hull. Is the outlet submerged when the boat is heeled? Could be a suspect. After owning a boat for several years, I have become convinced that the easiest way to solve the world's water supply shortage is to buy boats for all. It doesn't matter where you put them; close them up at night, and in the morning, regardless of the weather or temperature, there will be water in the bilge. Guaranteed.
Everything and anything can leak on a boat, seacocks included. It might not be the unit itself, but the seal between the unit and hull. Is the outlet submerged when the boat is heeled? Could be a suspect. After owning a boat for several years, I have become convinced that the easiest way to solve the world's water supply shortage is to buy boats for all. It doesn't matter where you put them; close them up at night, and in the morning, regardless of the weather or temperature, there will be water in the bilge. Guaranteed.
Check your anti siphon valve
on your engine raw water intake. I have found water in the engine pan that was overflow from the anti siphon valve. As for checking small leaks at hard to get at through hulls, sprinkle talcum powder around the through hull. You'll be able to see if it's leaking.
on your engine raw water intake. I have found water in the engine pan that was overflow from the anti siphon valve. As for checking small leaks at hard to get at through hulls, sprinkle talcum powder around the through hull. You'll be able to see if it's leaking.
Mystery Leak
I replaced the "volcanoes" on my 1983 Catalina 30TR. If you haven't done so you should replace them as they were a poor design. Could this be your problem?
I replaced the "volcanoes" on my 1983 Catalina 30TR. If you haven't done so you should replace them as they were a poor design. Could this be your problem?
Follow-up
Thanks all. I am not sure what the Volcanos are - are you referring to the original design thru-hulls Catalina used? I think mine were replaced as I have all brass ball valves now. It is definitely not engine or exhaust related as I noticed this prior to running the motor for the season.....prior to that I had anti-freeze throughout the system. The water is seawater because I tasted it - salty. Rob
Thanks all. I am not sure what the Volcanos are - are you referring to the original design thru-hulls Catalina used? I think mine were replaced as I have all brass ball valves now. It is definitely not engine or exhaust related as I noticed this prior to running the motor for the season.....prior to that I had anti-freeze throughout the system. The water is seawater because I tasted it - salty. Rob
Leak and brass through hulls
Since you said it was salt water I assume it is unlikely that it is condensation or some of the other sources mentioned (although if its in a place that once had salt water in it, condensate or other fresh water could take on a salty taste). You mention that the sea cocks are brass. My understanding is that some sea cocks are in fact made of brass, but this is a pretty vulnerable material for the salt water environment. Bronze or other materials are much more durable. So if the sea cock is sticking, I would do some research into whether the sea cock is the culprit. There was a detailed thread about this some time ago on another email list, and the attached article goes into detail on why brass is just the wrong material for through hulls and sea cocks. Surprisingly, though, if you do a web search there are numerous brass through hulls sold without regard to saltwater use. Its much less of a problem in fresh water because of less risk of galvanic corrosion.
Since you said it was salt water I assume it is unlikely that it is condensation or some of the other sources mentioned (although if its in a place that once had salt water in it, condensate or other fresh water could take on a salty taste). You mention that the sea cocks are brass. My understanding is that some sea cocks are in fact made of brass, but this is a pretty vulnerable material for the salt water environment. Bronze or other materials are much more durable. So if the sea cock is sticking, I would do some research into whether the sea cock is the culprit. There was a detailed thread about this some time ago on another email list, and the attached article goes into detail on why brass is just the wrong material for through hulls and sea cocks. Surprisingly, though, if you do a web search there are numerous brass through hulls sold without regard to saltwater use. Its much less of a problem in fresh water because of less risk of galvanic corrosion.
Mystery Leak
The volcanos were what Catalina did for thru hulls. It was just a piece of brass pipe that was glassed in with a valve attached. I would suggest even if this is not your mystery leak to change over asap. I did it myself. If you are handy and like grinding and drilling through fiberglass in tight quarters you might consider doing it yourself.
The volcanos were what Catalina did for thru hulls. It was just a piece of brass pipe that was glassed in with a valve attached. I would suggest even if this is not your mystery leak to change over asap. I did it myself. If you are handy and like grinding and drilling through fiberglass in tight quarters you might consider doing it yourself.
Ball valves and through hulls...
Are not the proper or safe way to make a sea cock. It's rather simple. A through hull is a straight thread and designed to screw into a flanged sea cock which also has straight threads. Flanged sea cocks are through bolted to the hull and then the through hull is threaded into it. Using a ball valve with NPS threads or tapered threads with a straight thread through hulls is NOT a safe practice...
Are not the proper or safe way to make a sea cock. It's rather simple. A through hull is a straight thread and designed to screw into a flanged sea cock which also has straight threads. Flanged sea cocks are through bolted to the hull and then the through hull is threaded into it. Using a ball valve with NPS threads or tapered threads with a straight thread through hulls is NOT a safe practice...
Follow-Up on Leak
I would like to give a huge "THANK YOU" to the board here. Turns out my sink drain - thru-hull was in extremely bad shape when I checked it out closer based off the advice from the board. I just thought that because thru-hulls were brass or bronze they would last 100 years. I was very wrong and suggest everyone read this thread. The leak could have easily been mistaken for condensation - especially if I had not upgraded to a PSS dripless stuffing box. My bilge has always been dry and free of any salt-seawater especially after the installation of the dripless. I wet-store my Catalina 30 in salt water. Maybe an ounce or two of seawater was found making its way under my engine and to the bilge...really not enough to set off any alarms. After reading about the dangers of electrolysis with brass on thru-hulls and seacocks...I took the situation more seriously. This weekend I pulled out my galley for a better inspection on the sink drain seacock and thru hull. The thru-hull was not original to the 29 year old boat - a yard installed it maybe 10-15 years ago (under the PO). I think they used a brass seacock as I noticed the metal turning pink. Along the nut that butts up against the hull in absence of a backing-plate was damp with seawater and cover with green mush. Having not posted and read about thru-hulls prior to my inspection - I would have probably just put a pipe-wrench on the nut and...snap away! I am not sure how much is left on the metal threads...I will find out soon enough. The boat is being hauled out tomorrow and the yard is installing a new bronze thru-hull and seacock. All Bronze. I have 4 other thru-hulls and seacocks on the boat. They all except for one were installed with backing plates and seem to be OK - dry, no corrosion or pinking of the metal. Next time I haul for a bottom paint I will fill in one thru-hull in the aft quarter that is not being used (and does not have a backing plate) and replace all other seacock valves with either plastic or bronze just to play it safe (although they look alright). Thanks again all - Rob
I would like to give a huge "THANK YOU" to the board here. Turns out my sink drain - thru-hull was in extremely bad shape when I checked it out closer based off the advice from the board. I just thought that because thru-hulls were brass or bronze they would last 100 years. I was very wrong and suggest everyone read this thread. The leak could have easily been mistaken for condensation - especially if I had not upgraded to a PSS dripless stuffing box. My bilge has always been dry and free of any salt-seawater especially after the installation of the dripless. I wet-store my Catalina 30 in salt water. Maybe an ounce or two of seawater was found making its way under my engine and to the bilge...really not enough to set off any alarms. After reading about the dangers of electrolysis with brass on thru-hulls and seacocks...I took the situation more seriously. This weekend I pulled out my galley for a better inspection on the sink drain seacock and thru hull. The thru-hull was not original to the 29 year old boat - a yard installed it maybe 10-15 years ago (under the PO). I think they used a brass seacock as I noticed the metal turning pink. Along the nut that butts up against the hull in absence of a backing-plate was damp with seawater and cover with green mush. Having not posted and read about thru-hulls prior to my inspection - I would have probably just put a pipe-wrench on the nut and...snap away! I am not sure how much is left on the metal threads...I will find out soon enough. The boat is being hauled out tomorrow and the yard is installing a new bronze thru-hull and seacock. All Bronze. I have 4 other thru-hulls and seacocks on the boat. They all except for one were installed with backing plates and seem to be OK - dry, no corrosion or pinking of the metal. Next time I haul for a bottom paint I will fill in one thru-hull in the aft quarter that is not being used (and does not have a backing plate) and replace all other seacock valves with either plastic or bronze just to play it safe (although they look alright). Thanks again all - Rob
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