Hi everyone I,am new to this forum. I,ve owned a 1981 Irwin 37 center cockpit ketch for 15 yrs. and my family (3Kids and friends) haved enjoyed her very much. I have been having an ongoing problem with the forward water tank either leaking or venting water under the cushions in the forward cabin. I know there is a vent for the center tank inside the steering pedestal but I don't know if there is another vent for the front tank. After 15 yrs. ownership I should know but I don't because I temporarly bypassed the front tank a few years back and never tried to locate a front vent. So, my question is: does anyone know if there is a front water tank vent and if so where ON THE TANK does it exit as this may be the source of the leak and save me a lot of work. TOM
Water tank Vents
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Unless the tank is a bladder, it has to be vented
All tanks--water, fuel and waste have to be ventedWithout a vent, it couldn't be filled...because the air in the tank displaced by incoming water wouldn't have anywhere to go...nor could the water pump pull more than little water out of it 'cuz there also has to be source of incoming air to replace water being drawn out. Without a vent, the pump would pull a vacuum instead. There is an exception: bladder tanks. Because bladders can expand and contract, they don't need vents. The easiest way to find the vent for your front tank is to find the vent thru-hull first. It'll be small fitting (5/8"), most likely right at the toe rail, that looks like your fuel tank vent fitting. The vent line will be connected to the tank on the top or on a vertical surface at the top. However, if you haven't used the tank--iow, there's no water in it--that can't be the source of your water leak. Most likely a connection in your by-pass plumbing has failed...if you haven't inspected it since you installed it 15 years ago, I'd bet on it. You did say it was temporary though...so if you're using the tank, and if the tank is aluminum, it's prob'ly time to replace it...it's already exceeded the average 20 yr lifespan of an aluminum water tank.
All tanks--water, fuel and waste have to be ventedWithout a vent, it couldn't be filled...because the air in the tank displaced by incoming water wouldn't have anywhere to go...nor could the water pump pull more than little water out of it 'cuz there also has to be source of incoming air to replace water being drawn out. Without a vent, the pump would pull a vacuum instead. There is an exception: bladder tanks. Because bladders can expand and contract, they don't need vents. The easiest way to find the vent for your front tank is to find the vent thru-hull first. It'll be small fitting (5/8"), most likely right at the toe rail, that looks like your fuel tank vent fitting. The vent line will be connected to the tank on the top or on a vertical surface at the top. However, if you haven't used the tank--iow, there's no water in it--that can't be the source of your water leak. Most likely a connection in your by-pass plumbing has failed...if you haven't inspected it since you installed it 15 years ago, I'd bet on it. You did say it was temporary though...so if you're using the tank, and if the tank is aluminum, it's prob'ly time to replace it...it's already exceeded the average 20 yr lifespan of an aluminum water tank.
Thanks.Probably have to do it the hard way.
Thanks for the reply.I think the front tank is aluminum but no matter what I,ll probably have to cut the tank out and replace it. I was hoping that the tank had its own vent and this was the source of the leak,exiting where I could find it easy but I can,t find one. The way these boats were built It could have only one vent for both the higher front tank and the lower center tank which were initially connected giving 187 gallons.
Thanks for the reply.I think the front tank is aluminum but no matter what I,ll probably have to cut the tank out and replace it. I was hoping that the tank had its own vent and this was the source of the leak,exiting where I could find it easy but I can,t find one. The way these boats were built It could have only one vent for both the higher front tank and the lower center tank which were initially connected giving 187 gallons.
Front Tank Vent
The front tank on our 76 37 CC is built in to the V berth and is vented at the front bow side near the top. The vent is a short piece of hose leading to the top of the anchor locker It is not vented to the outside of the boat. I had a leak in the V as you describe. Covered the anchor winch and chain hole and the leak went away. The anchor locker was draining along the front and down to the V berth area.
The front tank on our 76 37 CC is built in to the V berth and is vented at the front bow side near the top. The vent is a short piece of hose leading to the top of the anchor locker It is not vented to the outside of the boat. I had a leak in the V as you describe. Covered the anchor winch and chain hole and the leak went away. The anchor locker was draining along the front and down to the V berth area.
Never looked in that area
Thats interesting Tim as I have never thought about looking in that area before for a vent. The boat is on the hard in the severen river area now so I,ll start looking for the leak again. I'am having two more layers of cloth put on the bottom and the boat is inside with the rig down and as soon as the bottom is finished I,ll finish some projects I began a while ago.(including the leak). The boat is going through a total refit after hurricane Isabel took out part of the rub rail and cap rail. Thanks:TOM
Thats interesting Tim as I have never thought about looking in that area before for a vent. The boat is on the hard in the severen river area now so I,ll start looking for the leak again. I'am having two more layers of cloth put on the bottom and the boat is inside with the rig down and as soon as the bottom is finished I,ll finish some projects I began a while ago.(including the leak). The boat is going through a total refit after hurricane Isabel took out part of the rub rail and cap rail. Thanks:TOM
I added a vent
Hey Tom, When I fixed my forward water tank (we've talked about in your refit posting), I found that that water vent was just a piece of poly tube that ran to the bilge (and rotted the forward stateroom paneling. We added an external vent fitting inside the chain locker. Also, if your in that area, check the line connecting the forward water tank with the main tank. It was leaking too. I had to lift the deck in the main salon to gain access.
Hey Tom, When I fixed my forward water tank (we've talked about in your refit posting), I found that that water vent was just a piece of poly tube that ran to the bilge (and rotted the forward stateroom paneling. We added an external vent fitting inside the chain locker. Also, if your in that area, check the line connecting the forward water tank with the main tank. It was leaking too. I had to lift the deck in the main salon to gain access.
Forward water tank vent
Thanks David: I,ll Check Both connections. They are Painting the topsides with awlgrip this week. I,am also changing the color of the hull above the rub rail so there is a lot of taping having to be done to take care of overspray. I,ll be glad when I can get to the boat to start replacing the diesel tank and countertops. I think I am going to let the marina take care of painting the spars. And in the fall I,am going to ask for an estimate for awlgripping the decks and cabintop.But If they want to do the work during the summer(and the price is right) I think I,ll let them do it. TOM from VA.
Thanks David: I,ll Check Both connections. They are Painting the topsides with awlgrip this week. I,am also changing the color of the hull above the rub rail so there is a lot of taping having to be done to take care of overspray. I,ll be glad when I can get to the boat to start replacing the diesel tank and countertops. I think I am going to let the marina take care of painting the spars. And in the fall I,am going to ask for an estimate for awlgripping the decks and cabintop.But If they want to do the work during the summer(and the price is right) I think I,ll let them do it. TOM from VA.
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