F 28 -Water tanks draining into bilge

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Joined: Wed Nov 23, 2016 10:18 am

F 28 -Water tanks draining into bilge

Post by vtbambrick »

Picked up the sloop this summer.
Recently out with friend who noticed cabin sole awash with floorboard afloat.
New electric bilge pump couldn't keep up but it with manual pump emptied out bilge.
Thru hulls all fine and determined port water tank drained (while heeled over on port tack).
Next day while heeled over on starboard tack checked bilge and noticed a trickle of water coming from a black hose which emptied into the bilge.
Shortly thereafter, trickle became a flood.
Same deal, the water was from the starboard water tank.
The port tank was in use the first incident and the starboard tank the second.
The black hose entered bilge from forward area, seemed to run thru area below sink in head and then aft ...

On closer examination, the black hose had imprints from a hose clamp on its end.
I put a tapered wood dowel in the hose end and clamped it tight with a hose clamp.

Q1: Is the no check valve in the water tank line ?
Q2: What purpose does that black hose serve ?
Q3: Any idea what was clamped in the end of the hose ? a valve ? a plug?

Any thoughts as to cause of tanks emptying, curing problem etc. appreciated.


Tim Bambrick
Inner harbor

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Joined: Wed Dec 10, 2008 6:59 pm
Location: Freedom 33 Boston, MA USA

Re: F 28 -Water tanks draining into bilge

Post by AlanK »

Sounds like you may be talking about the vent lines. These are supposed to loop high up and then come down to the bilge. If you overfill the tanks water will run out otherwise even on a heel they shouldn't if looped high up at deck or cabin top level in a closet. If you seal the vent lines it will prevent or slow down water coming from the tanks or with a strong enough pump cause the tank it self to bend inward.

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Location: San Mateo, CA

Re: F 28 -Water tanks draining into bilge

Post by BillSmith »

Our F35-Pedrick sloop is similar as described in AlanK's post. Didn't know until we overfilled the tanks one day, the vent/overflow hose drains into bilge. Not sure if it has a high loop. We have two tanks, one under port settee and one under V-berth. Unsure if a post-production install. I will be filling both for Labor Day weekend. Imagine the port tank could drain water into bilge when heeled. Something to check those three days.

Agree with AlanK. that you cannot seal these hoses if they are in fact a vent line.


Our hoses are the clear potable water type hoses, even for this runoff/vent line. Black makes me wonder. Easy enough to tell. Overfill the tanks.
Bill & Carole Smith
Freedom 35 Pedrick
Coyote Point
San Mateo, CA

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Re: F 28 -Water tanks draining into bilge

Post by vtbambrick »

Not coincidentally, I had overfilled both tanks.
I suspect that created a siphoning effect which led to the port tank draining when on port tack and the starboard tank when on the starboard tack.

Remove the plug from the vent line and don't overfill the tanks.

Thanks for info.

Tim Bambrick

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