We are new owners of a 1980 30' Hunter and have had an exciting summer of sailing after certification. Will be hauling out for a bottom job and would like to replace our three thru hulls that have sea cocks. Any advice on the best methods and products. Thanks
Best new thru hulls and sea cocks?
- Thread starter Ternang
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Maine Sail maintains this great site that has all the info on thru hulls you'll ever want : http://www.pbase.com/mainecruising/boat_projects
Does your H30 already have seacocks? Or are you looking at valves on the original 1/2" thru-hulls? In order to add seacocks to a Cherubini that is original you need to replace the thru-hulls with 3/4".
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It looks as though they are gate valves. Two are smaller(head intake and engine intake) and one is larger for the galley sink. Also have a large one blocked off near the holding bladder. Is it possible to remove this or best to just replace it?
My boat also has the holding tank overboard thru-hull capped off. I have no plans after twelve years to do anything but leave it alone. And my galley sink also has the large gate valve. Being in fresh water for most of its life the valve is like new. A seacock that size would be expensive. Not sure of the size but a 2" seacock is about $200. and a 2.5" over $300. So the gate valve remains for now.
The pictured seacock and thru-hull will go in this winter to replace the head intake. Years ago I replaced the 1/2" engine thru-hull with 3/4" and added a seacock.
Use a 1/2" hole saw and drill through a piece of 3/4" plywood. Use the plug to glass into your fiberglass hole after removing the thru-hull. Make sure it is square. After it sets you already have a pilot hole for your 3/4" hole saw. Follow Maine Sail's instructions for a good seacock installation.
The pictured seacock and thru-hull will go in this winter to replace the head intake. Years ago I replaced the 1/2" engine thru-hull with 3/4" and added a seacock.
Use a 1/2" hole saw and drill through a piece of 3/4" plywood. Use the plug to glass into your fiberglass hole after removing the thru-hull. Make sure it is square. After it sets you already have a pilot hole for your 3/4" hole saw. Follow Maine Sail's instructions for a good seacock installation.
Rick, because there are no bronze seacocks smaller than 3/4". When I bought the boat I immediately installed bronze elbows on the 1/2" thru-hulls for the head and for the engine. That allowed me to replace the gate valves with good bronze ball-valves. Later I installed the 3/4" thru-hull and seacock for the engine cooling. This winter I will finally do the head intake.
The problem with the 1/2" solution is that thru-hulls have straight cut threads(NPS). But elbows and ball-valves have NPT or tapered threads. The result is that you cannot get enough threads turned down onto the thru-hull. I found that I could get more threads with an elbow than with putting the ball-valve directly onto the thru-hull. The ball-valve to elbow is tapered to tapered so that is a good fit.
Here's a picture of a ball-valve directly onto a 1/2" thru-hull compared to a 3/4" thru-hull and seacock. The seacock with its straight threads screws down tightly against your backing plate making for a very secure and safe "hole in the boat".
The second picture is my boat. I have a 3-way ball-valve on top of my engine seacock. One way is engine cooling and the other is for water to the air-conditioner.
The problem with the 1/2" solution is that thru-hulls have straight cut threads(NPS). But elbows and ball-valves have NPT or tapered threads. The result is that you cannot get enough threads turned down onto the thru-hull. I found that I could get more threads with an elbow than with putting the ball-valve directly onto the thru-hull. The ball-valve to elbow is tapered to tapered so that is a good fit.
Here's a picture of a ball-valve directly onto a 1/2" thru-hull compared to a 3/4" thru-hull and seacock. The seacock with its straight threads screws down tightly against your backing plate making for a very secure and safe "hole in the boat".
The second picture is my boat. I have a 3-way ball-valve on top of my engine seacock. One way is engine cooling and the other is for water to the air-conditioner.
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