Removing Water From Fuel Tank

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
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Removing Water From Fuel Tank

Postby dariomez » Mon Jan 29, 2024 5:06 am

I purchased a 1978 REVENGE 19 with number 0001352. I often find water in the [fuel] tank. The previous owner replaced the [fuel] tank.

Q1: how can the problem of water in the fuel tank be solved?

In Italy

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Re: Removing Water From Fuel Tank

Postby jimh » Mon Jan 29, 2024 3:10 pm

Q1: Are you asking about the fuel tank itself?

Most water that appears in a fuel tank came into the tank with the gasoline that was purchased.

If a leak in the tank is suspected, you must locate the position of the leak.

Usually if a gasoline fuel tank has a leak you can detect it by the odor of gasoline.

Q2: Are you asking about the cavity molded into the hull where the fuel tank is installed below the level of the cockpit deck?

Water that collects in the fuel tank cavity is water that drained into the cavity from the deck. To prevent this restore the caulking at the deck sections that cover the fuel tank, and do not allow rain water to accumulate on the deck.

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Re: Removing Water From Fuel Tank

Postby ALAN G » Tue Jan 30, 2024 7:59 pm

Dario, I have owned a 1975 Revenge since it was new and I am sure we can help you with your tank....whatever the concern is. But some more info would help a lot.

Q3: How much water are you discovering and how often, and where are you finding it? Fot example, are you finding it in the bottom of a glass sediment bowl on a filter?

Q4: Does the water appear after rain?

Q6: Does it appear after running in certain sea conditions? (ie spray)

As Jim advises, water laden gasoline is a likely source. Check your gasoline before and while pumping by taking samples in a clear jug or container. Let sit and see if water settles out.

If you know the tank is full of clean, waterless fuel, and some time later you observe water in the tank, you can start looking for the external sources of a leak. The fuel fill is mounted on an angle on the aft thwart in the Revenge 19 original configuration, and has an O-ring seal around the screw in cap/cover. Rain or spray can find it's way in there if the fitting leaks or the O-ring is missing. If someone replaced the tank, and did not put the vent hose on correctly (or worse, did not renew an old hose) your water source could be rain or spray again. Note, this vent hose must have a vertical loop in it to prevent water from the entering the external portside bow mounted vent fitting and running back to the tank. The loop should be located under the deck near to the hull mounted vent fitting and is easily visible looking under the deck along the gunwale inside the boat. Trace the vent line to find it. If water is getting under the deck cover where the fuel level sender is mounted, the level sensor/gauge and its gasket should be checked for potential leakage. If water is leaking in here, it is likely that fuel is also leaking out.

As Jim advises, a gasoline leak is easy to detect by your nose. But you have only mentioned water in the fuel. You have not mentioned if there is any odor of fuel leaking out of the tank.

If the external fuel tank checks don't indicate the leak, you can pull the tank cover portion of the deck. That is not hard, but should not be the first reaction until you have systematically checked all the external potential leak sources. And don't jump to the conclusion the tank has to be air tested or even replaced until it is the last resort.


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Re: Removing Water From Fuel Tank

Postby dariomez » Tue Feb 06, 2024 5:13 am

Hi, thanks everyone. I will shortly provide you with the more detailed information you asked for. I am the intermediary between you and my father who is taking care of the boat, he is not very familiar with computers and English.