Filling fuel tank - when is it full....

[John_F]

OK, really dumb question.

I don't trust my fuel gauge so I keep track of my fuel usage.

When I fill the diesel tank, it foams up so to prevent the foam from spilling all over the deck, into the marina, etc., I stop filling as soon as I see foam. It foams no matter how slowly I try to fill it.

However, how do know that I've filled the tank to max for the season? I do add treatment to it at the end of the season.

Should I assume the tank is full as soon as the foam gets close to the fill port?

Thanks.

 

[Scott T-Bird]

I don't think that you should fill the tank to the deck fill because then you could be filling the vent. I did that once, and when fuel spurted out the vent, which is just below the level of the deck fill, I realized the mistake. I always make sure that I don't top off the tank above the tank level by monitoring the fuel gauge. Why not just replace your gauge if it doesn't work well? It's a relatively cheap fix.

 

[Stu Jackson]

It's usually not the gauge that's faulty, but the sender. Scott's right, though, if you see or hear the foam, your tank is full, just not the hoses that go UP from the top of it --- think about it...

I've been doing this for 16 years, not an issue. Fuel gauges are highly overrated.

 

[Ross]

I always filled from a jerry can with a small hose run from the vent on the jerry can down inside the filling port. The fuel runs freely until the level reaches the vent hose. I installed a gauge and sender but the best it
could do is tell me if I had fuel or not but never how much.

 

[Stu Jackson]

Or get a Super Siphon - Google it.

 

[Johnb]

You will need divine intervention to help you if you spill at a fuel dock in San Francisco bay, including burping any out of the overflow. The vendor is required by law to call the coast guard who will call out a clean up contractor and $5,000 to $10,000 could change hands form 1 cup of diesel.

The best is to do what Ross says, very carefully, and attach something to recover spilled fuel on the vent.

 

[Ross]

When I rebuilt my Islander I lead the vent tube up inside a station tube so that it is about a foot above the fill port.

 

[Les]

I've used a fuel whistle on my last three boats. Works all the time--nothing to break. You can hear about it here:

https://www.youtube.com/watch?v=AFf8vTkski0

I had the other item but the whistle eliminates the need for it.

 

[alexco38]

I've used a fuel whistle on my last three boats. Works all the time--nothing to break. You can hear about it here:

https://www.youtube.com/watch?v=AFf8vTkski0

I had the other item but the whistle eliminates the need for it.

why filled to the top, isn't 80% good enough? you need some room for heeling.

if the gauge is not working, replace it. don't cost $5000 either.

 

[Don S/V ILLusion]

why filled to the top, isn't 80% good enough? you need some room for heeling.

if the gauge is not working, replace it. don't cost $5000 either.

Some folks believe it somehow prevents large quantity of water due to condensation. I think they made a 'die hard' movie about it.

 

[Stu Jackson]

http://www.pbase.com/mainecruising/fuel_tankt_condensation

 

[seadaddler]

Vent

May try blowing out the vent hose to help maybe.
Nick

 

[BrassRat]

I installed a Attwood Fuel Vent Line Surge Protector in the vent line to mitigate the risk of overflow through the vent.

 

[Morgan donor]

John, I've taken my tank down to half full on the gauge. Added fuel in 5 gallon increments and used a marker on the gauge to record same. I stop when it reads full. Therefore no overfilling or spillage. You burn what? A 1/2 gal per hour max? Plenty of run time even if you're not quite full.

Fall lay up, I fill to at least 3/4 full, with a biocide and Standyne fuel conditioner dose. I have inline Racor 500's with water drains. I do not find any water when I drain a sample. Nor do I have to replace the 10 & 2 mic filters in them. Works for me at least. I'm up on Lk. Ontario so same winter weather conditions as you.
Dave

 

[zeehag]

try filling your tank S L O W E R ... no foam that way.. isnt spozed to foam, is spozed to fill. slow n steady . aint like a car.
and remember--the first guage to fail is fuel. mine never worked and never will work.

 

[drdanj]

Don't trust the Previous Owner: Hoses were wrong

Having never messed with fuel lines before, I made a mistake -- I assumed previous owners knew more than I did. They knew even less. Every time I tried to add fuel, no matter how carefully, I would get fuel out the aft vent. I finally opened up the settee and spent an hour staring at the tank. Finally, that eureka moment. The current tank was a replacement, about ten years old (my boat's a 1983). Whoever replaced it put the overflow line directly into the fill line. The overflow connection was not used. So, a hundred bucks and two hours later, I had rerouted the the overflow line to the proper connector (which is a port opening right at the top of the tank, and isolated the filler line to the port that has a filler tube going toward the bottom of the tank.

Replaced to sensor, rewired and replace the gauge. Still can't get the gauge to work right.

 

[ITMaster]

RE: Fuel Filling

When I fill, I install a fuel vent collector over the vent. When the tank is full and the overflow spills out the vent, it dribbles into the collector and contains the fuel and lets me know that it is time to stop filling. Then I uninstall the collector and properly handle the fuel in the collector. When fueling this way, there is no spill on the water

 

[dstrippe]

Tank filling

We've got a plastic tank that is reasonably easy to view so I have my first mate observing the level and relaying up top. This allows us to appropriately top it off but not spill over quite reliably.

 

[2taylorscotts]

1. Diesel fuel ALWAYS foams, so the only true option is patience and a funnel with a long spout and a vent.
2. That being said, each vessel needs it's own method.
3. My 272 has no gauge, but the fuel fill tube is short and not too serpentine. I use a length of 1/4" dowel rod that is marked at the top of the tank depth, at 1/2 and what I know to be 5 gal from full. All my marks were made starting with an empty tank after pumping out the sludge.
4. Assuming the fill tube is not really long or serpentine, try a length of light vinyl clear tubing (1/4"-3/8"). Weight the end by inserting a short piece of heavy metal that will not get loose, but carry the tube to the bottom. Cut a small notch in the tube above the weight to allow fuel to fill the tube as it's lowered. Mark the tube at the measured depth of the tank and whatever other marks suit your needs. Lower the tube until it bottoms, put your finger on the end to seal it, pull it up and you will have the exact fuel level. Release it to drain the tube and wipe it as you pull it out. If this sounds primitive that's because it works. This is an approved method for measuring water depths in drinking water wells.
5. When filling I use an absorbent pad, available in most auto parts stores, with a hole punched in the center for the funnel.
6. These are the same methods I use for my old diesel truck, tractors and boat. The KISS standard. I HATE spilled diesel fuel. Good Luck.

 

[flasailor]

The fuel tank on my boat is fiberglass and the level is easily readable by placing a flashlight behind the tank when filling.