Water in Fuel took us down - Fuel Polishers

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

kurt.reynolds

Senior Member
Joined
Apr 20, 2013
Messages
134
Location
USA
Vessel Name
Grace
Vessel Make
1982 Grand Banks Motoryacht
We have a 1982 Grand Banks with two 300 gallon fuel tanks. Today we shifted from Port to Stbd tank before leaving the dock. Ran for about an hour at the dock then got underway. Shortly after (about a mile out) both generator and Main engine shutdown. Investigation revealed water in all filters.

The Stbd tank had been basically empty for about 5 months (The boat is new to us, so that is from Previous Owner).

We filled both tanks two days ago. We pumped 18 gallons of water out of the stbd tank today.

My question is about Polishing systems. We have a very simple fuel system with a Racor filter and two filters on the Lehman itself.

What options do I have to avoid this issue in the future?

Keep the tanks full is one i can think of. But if water is leaking in, that will not solve it.

Fuel polishers that keeps the tanks polished, but I know nothing about these or cost. I do have a single engine, so plenty of room for polisher in the ER.

Looking for some solution so I can use my boat and not worry about water in my fuel.

Anyone know what the pickup arrangement is in the tank? Floating?

Regards,
Kurt
 
Last edited:
Sounds like you need to change the o-rings in both your fillers.

Then pay a company to remove, install clean outs, polish and replace your fuel.
 
"We pumped 18 gallons of water out of the stbd tank today."

There are two typical methods to get that much water in a fuel tank....
- "O" rings on fuel fill caps like Xsbank points out
- Hose fill connections to fill fittings and fuel tanks


When fuel fill hose clamps loose tightness and/or fail water can run straight down inside the fill lines as well.
 
Wow I would not imagine that 18 gal of water could have made their way in the tank just because of a leaking o-ring, it looks a huge amount of water
Are you sure one day you did not mix water tank and fuel tank when filling water???

L.
 
"Wow I would not imagine that 18 gal of water could have made their way in the tank just because of a leaking o-ring, it looks a huge amount of water"


FWIW - I pumped and decanted 12 gallons of water out of one tank after a boat spent a winter on the hard with a failed "O" ring fill.
Perhaps another argument for shrink wrap but that would have only solved the symptom at the time.
 
I took about 4 gallons from a broken fuel cap over the span of a day or two.

I second the advice to hire a pro to install inspection plates, scrub the tanks and polish the fuel. I did this and never regretted it.
 
Install T fittings on the outlet of both tanks with appropriate valves to direct flow either to existing lines to engine or to new line to a new Racor 500. Install a holly red elec fuel pump after the racor. Install appropriate T's and valves so you direct flow from Racor back to either tank.

The T's and valves should allow you to polish either tank separately or to transfer from one tank to another.

Google "marine diesel fuel polishing systems with dual tanks" and click on images. There are many diagrams that should make things clear.

Interesting takeoff of a Nordhaven design can be found at
http://www.sv-jedi.org/sv_jedi/2006/11/a_new_fuel_syst.html
 
Last edited:
My vote is for bad o-rings or leaks around the fills. If the stbd tank has not been used for 5 months (easily longer since you got that info from the PO) that is plenty of time for that much water to get in over the course of a wet winter.
 
I agree. I has to be filler cap o-rings, filler tube clamps, or water from the supplier.

Removing it may not be a big deal depending on your fuel tank design. If you have a valve at the low point, and your tank is relatively clean (other than the water) you can simply drain it off after it sits for a day or two. Diesel and water tend separate very easily if left undisturbed.

If you don't have a valve at the low point, and there is sediment in the bottom of your tank it may be worth getting a contractor to polish it for you.
 
Also check the tops of your tanks for possible rust through.
A couple of months ago I took off one of the old O'rings and brought it to NAPA
a couple of dollars later I was replacing them on both fills.
Good luck
 
This vessel is new to you and for the first time you added fuel to the starboard tank - is this correct? If so maybe the PO knew of an issue and intentionally did not use that tank. If my supposition is half a$$ed correct, check the tank top for rust (holed allowing for drips to get into tank) and per chance water leaking onto it from a leaking window or teak deck.

Yes it could be the deck fill leaking, but 18 gallons is pretty spectacular for a failing O ring.
 
If I had water in fuel tanks just after filling I`d suspect the fuel supplier, but if this is a starboard tank issue only and you filled both, not likely. Did you check the port tank for water?
Sunchaser and others are right on it, but here`s a couple of thoughts. Are your decks sound? Are there signs of water penetration? Is the deck fill tube attached to the tank? Was the boat enthusiastically washed or hosed down recently?
The fuel pick up is normally low down and fixed in the tank.
Do you have drain cocks at the bottom of the tanks? Easier than pumping it out.
 
If I had water in fuel tanks just after filling I`d suspect the fuel supplier, but if this is a starboard tank issue only and you filled both, not likely. Did you check the port tank for water?
Sunchaser and others are right on it, but here`s a couple of thoughts. Are your decks sound? Are there signs of water penetration? Is the deck fill tube attached to the tank? Was the boat enthusiastically washed or hosed down recently?
The fuel pick up is normally low down and fixed in the tank.
Do you have drain cocks at the bottom of the tanks? Easier than pumping it out.

- Both tanks were filled at the same time.
- Port tank has no water in it, stbd had 18 gallons of "old" rusty, dirty water.
- Decks are questionable and I haven't checked the fills yet, not so easy on a GB42. Also, the full fills on our motoryacht are under a deck step, so not completely exposed to the weather.

I think we are going to have the tanks polished soonest. Currently running on Port Tank. I only burn 2gph, so I can run for a couple of weeks on port tank.

thanks
 
Last edited:
Sounds like you need to change the o-rings in both your fillers.

Then pay a company to remove, install clean outs, polish and replace your fuel.

Thanks Xsbank, I have found a company along the way that says he can do all you talk about, I think it is a good choice.
 
k next item on my list: check the o-rings! I would never have thought this amount of water could leak in the tank! I learn everyday!

L.
 
There is no way you got 18 gallons of water in the tank from condensation.

I agree about the filler cap O rings BUT they are not the only way water can enter the tank although the filler in this case was at fault partly. Keep them lightly greased not only to help the O rings but to prevent the threads seizing and they can.

Dockmate was going nuts with water in his tank. Would pump it out and it would refill after the next rainstorm. We have lots of those. He gave away a lot of watered fuel.

His problem turned out to be the deck plate was not sealed to the deck AND the filler hose was not tight to the deckplate hose nipple. The water was running into the boat between the deck and the deckplate. Then underneath and inside the boat the water was running down the nipple into the filler hose and then into the tank.

Change the O rings but also ensure that the hose is tight to the nipple AND the deckplate is sealed to the deck.
 
As to your question about how to stop this from happening again, if you are referring to water in your tanks, you need to figure out the source, and it can't be condensation. If you are referring to the shut down, you may want to install water sensors in your racors.
 
A bit of a drift but... Anyone find it odd that a surveyor wouldn't make note that the stbd tank was not in use?
 
If you add an electric pump to circulate fuel thru the Racor, you have a basic fuel polisher. The Racor should remove the water. Adding a good fuel conditioner will help the diesel expel the water. I hold 2000 gallons and haven't had a cup full of water since 2011 when I bought my current boat. I add conditioner every fueling. Initially you need to add 3x the normal dose.
I use Archoil 6200 that I originally bought for my diesel pu. It made a major difference in my injector operation and gave me better fuel economy. Now I use it in the boat and get 10% or more better fuel economy. The truck routinely gets 25mpg.
 
There is no way you got 18 gallons of water in the tank from condensation.

I agree about the filler cap O rings BUT they are not the only way water can enter the tank although the filler in this case was at fault partly. Keep them lightly greased not only to help the O rings but to prevent the threads seizing and they can.

Dockmate was going nuts with water in his tank. Would pump it out and it would refill after the next rainstorm. We have lots of those. He gave away a lot of watered fuel.

His problem turned out to be the deck plate was not sealed to the deck AND the filler hose was not tight to the deckplate hose nipple. The water was running into the boat between the deck and the deckplate. Then underneath and inside the boat the water was running down the nipple into the filler hose and then into the tank.

Change the O rings but also ensure that the hose is tight to the nipple AND the deckplate is sealed to the deck.
Are you describing me? [emoji12] That's exactly what happened to my boat.
 
First thing to do is figure out how the water got in. You have no idea over what time it entered, so it could be 18 gallons over 3 years. Now, it did not come from the tank being empty. It flowed in somehow. Figure that out and fix.

Then get a one time fuel polishing. It's worth it if only for confidence.

As to adding a fuel polisher, if you're just cruising coastal domestic, then it likely isn't necessary or worth it. Perhaps beef up your filters, but a true polishing system is expensive and complex, an Alfa Laval or equivalant. This shouldn't be an ongoing problem, another reason to solve it completely now. Then go about happy boating.
 
Hello,

I had same issue two years ago with dirty diesel sold by an unfair broker in a Dutch marina.

Now, I have new injectors!!!
My system aboard :
- GFC gulf coast filter as fuel polishing system ( F1)
- GFC gulf coast pre filter X 2 ( by pass filters before JD filters)
- Racor bypass prefilters X 2 ( by pass before Norther Light generator)
- last addition: a centrifugal separator ( a small model built in France by France Hélice, it polishes more or less 60 to 95 L per an hour , the machine is running 230 V, no filters or replacment part.
Two other brands (centrifugal separator) : Alfa Laval or westfalia, but they are quite big and heavy for my 57' trawler.
You can have a look on youtube, google "france helice centrifugeuse".
I expect to have more security with these two systems, considering I am sailing offshore in Atlantic...
I should have a day tank, a solution mostly used by fishermen. I have at the moment 3 tanks , one starboard 1800 Liters, on portside 1800L and the main supply centre tank: 4500 L
So run the small centrifuge separator will take time, but there is not other choice for me, I do not want to fit another "day" tank.
The water coming out from the centrifugal separator is coming first in the small tank on the centrifuge and further directed to the bilge engine room.
 
Personally I won't waste my money on a so called fuel polisher.

After you correct to source of the water leak I'd install dual Racor 900 filters with water alarms installed.

That way you could switch over to a clean filter on the fly if the first filter gets dirty or starts to collects water in it's bowl.
 
Whether or not it was a deck plate cap oring or not, change them all every year. I have 7 between water and fuel. <$5 total for piece of mind. Also have next year's 7 orings as spares on the boat.

Ted
 
" last addition: a centrifugal separator ( a small model built in France by France "Hélice, it polishes more or less 60 to 95 L per an hour , the machine is running 230 V, no filters or replacement part.""

This could be a great problem solver for folks here.

Any link or other info?
 
Steve D'Antonio wrote a very good article for Passagemaker on Centrifugal Separators, which are the true fuel polishing systems. They work great, but two negatives. They're expensive and they require being maintained like anything else. They're overkill for 99.9% of boaters and I say that although we do have them, but only on a boat we travel to many countries on and cross large stretches of ocean.

Here's the link to his article.

The Spin On Centrifugal Separation - PassageMaker

We have Alfa Laval. Here's a link to Dolphin Centrifuge where they discuss different models.

https://www.dolphincentrifuge.com/applications/diesel-centrifuge/

An interesting link to Heinkel, a manufacturer of Centrifuges. It shows some of the other applications and industries. I'm not familiar with Helice, but suspect they may also serve many applications. Heinkel sells four brands of centrifuges.

Centrifuges | HEINKEL Drying & Separation Group |

Centrifuges are interesting and work very well. Just not needed by the OP or most here.
 
Another possible source for that quantity of water is someone putting water in the wrong tank.

But I would follow other's advice and replace all filler o-rings - it's cheap and easy - then carefully monitor for further water accumulation. The amount you accumulated is too much to be from condensation, so must be getting in somehow. If it continues to accumulate, you will need to step-wise work through the possible entry points. Many good possibilities have been suggested.
 
Sorry for the possible hijacking here - is there a standard size (and a source) for the deck fitting orings?
 
Back
Top Bottom