I'd like to replace the frozen, original equipment ball valves for the cockpit cuppers with seacocks. If I'm lucky enough to be able to unscrew them from the thru-hulls, do I need to replace the thru-hulls as well? Or can I screw new seacocks onto the existing thru-hulls?
Thanks,
Joel Bondy
s/y Pokey II
'73 Ty #549
Bayside, NY
bondy_joelNOSPAM@hotmail.com
Replacing Ball Valves
Moderator: Jim Walsh
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D. Stump, Hanalei
Re: Thru hulls......
Captain Bondy,
Actually Sir, the ball valves ARE seacocks. A seacock is any valve that keeps out the sea. I think you mean you want to replace the ball valves with bronze tappered plug valves. Not a bad idea considering what Roger W.(Bristol Bronze) has said about the material the balls are made of.
But, to answer your question, if you are lucky, and use the proper tools, you may be able to simply unscrew the ball valves and screw on the new tapered plug valves. But, and here is the thing, you MUST hold the thru hull from moving at all while you unscrew the valve. If it moves, it will probably leak in the future because you have broken the bedding. What to do? ? ? Make a wrench to hold the thru hull from outside, a piece of mild steel, about 6 inches long that will fit into the thru hull from outside and make up against the tabs on the inside of the thru hull. Have a helper, hold this piece of flat stockin place in the thru hull in the jaws of an adjustable wrench(a big one!). You go inside, and with a pipe wrench try and unscrew the ball valve. If you are lucky, it will work and the thru hull will not be disturbed. If it doesn't work, you will probably have to cut off the valve and replace the thru hull,,but,,,that,,,is another story.
FWIW.......
D. Stump
Hanalei
Actually Sir, the ball valves ARE seacocks. A seacock is any valve that keeps out the sea. I think you mean you want to replace the ball valves with bronze tappered plug valves. Not a bad idea considering what Roger W.(Bristol Bronze) has said about the material the balls are made of.
But, to answer your question, if you are lucky, and use the proper tools, you may be able to simply unscrew the ball valves and screw on the new tapered plug valves. But, and here is the thing, you MUST hold the thru hull from moving at all while you unscrew the valve. If it moves, it will probably leak in the future because you have broken the bedding. What to do? ? ? Make a wrench to hold the thru hull from outside, a piece of mild steel, about 6 inches long that will fit into the thru hull from outside and make up against the tabs on the inside of the thru hull. Have a helper, hold this piece of flat stockin place in the thru hull in the jaws of an adjustable wrench(a big one!). You go inside, and with a pipe wrench try and unscrew the ball valve. If you are lucky, it will work and the thru hull will not be disturbed. If it doesn't work, you will probably have to cut off the valve and replace the thru hull,,but,,,that,,,is another story.
FWIW.......
D. Stump
Hanalei
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John R.
Re: Thru hulls......
Not wanting to disagree with our esteemed Nautical Traditions Officer I respectfully want to point out that I believe you will find that a true seacock is not just "any valve" that keeps out the sea.D. Stump, Hanalei wrote: Captain Bondy,
Actually Sir, the ball valves ARE seacocks. A seacock is any valve that keeps out the sea. I think you mean you want to replace the ball valves with bronze tappered plug valves. Not a bad idea considering what Roger W.(Bristol Bronze) has said about the material the balls are made of.
But, to answer your question, if you are lucky, and use the proper tools, you may be able to simply unscrew the ball valves and screw on the new tapered plug valves. But, and here is the thing, you MUST hold the thru hull from moving at all while you unscrew the valve. If it moves, it will probably leak in the future because you have broken the bedding. What to do? ? ? Make a wrench to hold the thru hull from outside, a piece of mild steel, about 6 inches long that will fit into the thru hull from outside and make up against the tabs on the inside of the thru hull. Have a helper, hold this piece of flat stockin place in the thru hull in the jaws of an adjustable wrench(a big one!). You go inside, and with a pipe wrench try and unscrew the ball valve. If you are lucky, it will work and the thru hull will not be disturbed. If it doesn't work, you will probably have to cut off the valve and replace the thru hull,,but,,,that,,,is another story.
FWIW.......
D. Stump
Hanalei
It normally is a through bolted or otherwise affixed (welded or fiberglassed) valve assembly. It is not a basic valve simply screwed onto the stem of a thru hull, such as is the case with some ball valves, not all. If you look at a typical "UL listed" seacock you will note that it always (from my observations) has a flanged body where it can be securely fastened to the hull in one manner or another. Obviously the thru hull screws into the body of the valve once the seacock (valve) has been properly secured to the hull.
In essence, the practice of simply screwing a valve body onto a thru hull stem is not a seacock installation. It is what it is, simply a valve screwed onto a thru hull and nothing more. It does not have the strength of a true seacock installation.
Worse case scenario......If the thru hull were to fall victim to galvanic corrosion and/or break apart then the result would be that you are then left with nothing more than a hose connected to a valve that is connected to nothing and water is pouring into the boat with no way to close it off other than driving a plug into the hole.
A through bolted seacock prevents this horrible possibility from occuring. Even if something happens to the through hull you still have the valve securly attached to the hull with the important benefit of being able to stop any water flow.
Be prudent....use securely mounted seacocks!
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Jim Stull
Re: Thru hulls......
Hi John
VERY good explanation. We just spent 4 hours today removing the big plug valve that provides the possibility of flushing the head overboard on a CD27. It was a miserable job trying to get the valve out. Just as you say, the valve was only held to the hull by the thru hull, which was frozen into the valve body! I could put a pipe on the wrench which fit into the thru hull but had no good way to hold the valve! I had not thought this thru until I read your write up,and planned to rebuild the valve. It now goes into the scrap bin. This appeared to be a factory Spartan valve. Fortunately the others were all bolted to the hull. (I had expected this one to be a pain and saved it for last.)
Thanks
Jim
jtstull@earthlink.net
VERY good explanation. We just spent 4 hours today removing the big plug valve that provides the possibility of flushing the head overboard on a CD27. It was a miserable job trying to get the valve out. Just as you say, the valve was only held to the hull by the thru hull, which was frozen into the valve body! I could put a pipe on the wrench which fit into the thru hull but had no good way to hold the valve! I had not thought this thru until I read your write up,and planned to rebuild the valve. It now goes into the scrap bin. This appeared to be a factory Spartan valve. Fortunately the others were all bolted to the hull. (I had expected this one to be a pain and saved it for last.)
Thanks
Jim
jtstull@earthlink.net