Water in the Fuel Tank

[sms18]

I have Morgan 41.while fuel polishing there was 8 gallons of water in fuel tank. Any thoughts where water came into fuel tank?

[Nicholson58]

Originally Posted by sms18

I have Morgan 41.while fuel polishing there was 8 gallons of water in fuel tank. Any thoughts where water came into fuel tank?

condensation in the vent lines AND failed O-ring at the deck fill ports. Our marina gives out free new O-rings at the gas dock. Their observation was that most ports had leaking seals.

[Adventurebound]

Some suppliers give it you as a bonus with your pumped fuel.

[delmarrey]

Ditto what Nicholson58 said.
That's a lot of water for a 41' boat. Don't how long it's been since the last cleaning but I'd be pulling an inspection cover to see if sludge has built up. If you're in a cold climate it'd be best to keep your tank full during the cold season.

The object is to keep the inside of the tank slightly warmer then the out side and keep air circulating within the boat.

And the vent line, it's good to make a loop higher then the vent hole exit to keep any rain from back flowing into the line. And don't spray the vent exit with a wash down hose.

[sms18]

thank you so much

[belizesailor]

With that much water should check for corrossion in tank too. What material is the tank?

Also, lubricate deck plate o-rings often. I usually apply a little diesel to mine, and the deck plate threads (they can corrode and sieze), each time I take on fuel.

[model 10]

Originally Posted by belizesailor

Also, lubricate deck plate o-rings often. I usually apply a little diesel to mine, and the deck plate threads (they can corrode and sieze), each time I take on fuel.

You mean you don't blow fuel all over the deck and maybe yourself when you re-fuel?

[donradcliffe]

If my fuel polisher told me he found 8 gallons of water in my tank, I'd be a little suspicious of the polisher--unless I had a 100,000 ton freighter. I once had 40 gallons of water in my fuel tank, but that was due to the admiral using the wrong deck fill...

[gts1544]

Gentleman; I am a retired professional pilot, who also flew my own light aircraft. It is gospel that you always drain your fuel tanks (through quick drains at the low points) before every flight. It was not uncommon to drain an ounce or two of water out of your fuel system when doing this. We were told that this was due to "condensation", but I was always skeptical of this as aviation fuel tanks are kept full to avoid that problem. What I did find, in most cases, was bad seals at the filler caps on top of the wings. I would suspect that, despite the infrequent draining's of marine fuel tanks, that most of the water found in diesel tanks is introduced by other means and that is where I would concentrate my efforts. George

[sms18]

thank you so much. Will check O ring today and will see what happen...

[sms18]

By the way, water tank in my Morgan 41 is alluminum

[belizesailor]

Originally Posted by Guy

You mean you don't blow fuel all over the deck and maybe yourself when you re-fuel?

Not my preferred method, but it's effective. Had the spout pop loose on a jerry jug recently. I was not happy, but EVERYTHING got well lubed!

[a64pilot]

IF you had eight gallons of water in your tank, you either have a huge tank, or your dip tube is way too short as you have a lot of un-useable fuel.
Two theories on dip tubes, one is to keep it short and out of the water and trash, the other is to put it right at the bottom of the tank and suck out the water and trash as it appears. I'm in the have it right on the bottom of the tank and don't let the water and trash accumulate to begin with.

[sms18]

Originally Posted by donradcliffe

If my fuel polisher told me he found 8 gallons of water in my tank, I'd be a little suspicious of the polisher--unless I had a 100,000 ton freighter. I once had 40 gallons of water in my fuel tank, but that was due to the admiral using the wrong deck fill...

Have another question, I found non-significant water (fresh) in the area of under mast step, just replaced on my Morgan 41. Leak from water tanks, (alluminum) is ruled out. The level of water is constant, and come out again after heavy rain. Any thoughts? please

[a64pilot]

Originally Posted by sms18

Have another question, I found non-significant water (fresh) in the area of under mast step, just replaced on my Morgan 41. Leak from water tanks, (alluminum) is ruled out. The level of water is constant, and come out again after heavy rain. Any thoughts? please

Comes down the mast, this is normal isn't it? Or if not, I have the same problem