Over filling gas tanks

L

Larry Patrick

New member
Dave Deem has a good system for filling both tanks on boat I purchased. You here a whistling noise when whistle stops you stop fueling. One tank is harder to hear. Anyway after day I picked it up and filled tanks. I had some gas dribbling down side of boat on hot day. This was okay since it was in driveway,but now that its in a slip I cant have this happen. Guess after filling up will try and burn a gallon from each tank. Dave said he had a pump you could use by removing fuel line,but I lost that post. Is this common to have gas weeping? Where would be good and easy to disconnect fuel line and what pump can you use if you find this leakage at slip. Will be needing to fill up again soon thanks.
 
I put small stripes of black tape on each of the tanks as 5-gallon markers. So I can easily see how much gas I have remaining in each tank, but also judge--quite accurately--how much gas to put into each tank.
 
Larry,
Good luck seeing thru the aluminum tanks. I would try to use the Garmin's fuel use page. That way you can be sort of figure out how much to add once you figure out how accurate the Garmin might be. Wait to fill the boat till you are going to use it. It has been my experience that fueling and keeping the boat in the water I never saw the issue with the gas expanding to the point of over flow as much as I did on the hard. You need to get a Mr. Gasket electric #12 S fuel pump if you want to be a gas jockey. I mounted mine to a piece of plywood and connected it at the fuel filters exit for the engine. That way you use the valve to switch to the other tank if need be. Hook up the 12 vdc positive first then the negative sparks and gasoline vapors have predictable results. You da bomb. Not good.
D.D.
 
Larry, the biggest problem I have found is heat expansion on a hot day. I top up my tank in the fall and it is fine all winter. The first hot day in the spring gas starts to seep out the fill. Now I don't top them up so much, or I lower the trailer tongue in the spring.

Another problem I have with my particular boat - when on the trailer the tank will take 35 gallons. When in the water it will only take about 30 gallons. I usually launch and go but suppose if I was to fill on the trailer, launch and put in a slip on a hot day I would probably have the same problem(gas seeping into the water).

Based on this experience I would not fill my tank to leave in a marina. I would top up just before putting out on a cruise. As suggested - with dual tanks it would be a good idea to burn a few gallons off the first tank then switch to the second(also helps to balance the boat).

Regards, Rob
 
Lucky we can see the level in 22's. Even though we don't get really hot, expansion can be an issue if you stuff the tanks full
I find leaving an inch or so below full stops any spill, if you're right full and start out, the boat lifts forward some and fuel wants to be level so will go up vent and fill hoses, perhaps spilling out the vent
Give it some space in the tank and you'll be ok
George
 
Thanks Dave and others for replys,good to hear its not as likely to happen on the water. Dave thanks for the extras you just sent me Flag and cutting board ect. I will stick with trying to use fuel monitors and like the idea of filling then taking it out and burning some out of each tank. When it was in my driveway it seeped for 3 days ,I stuffed paper towels in there and lowered the tounge. That was being careful and trying to stop fueling without overfilling. Definitly don't want to ever spark any fumes. Last season we were gassing up my old boat,busy marina ,big boats waiting. I took gas cap off stepped up on dock handed pump to my nephew got startron out just caught him putting a little gas in rod holder next to gas fill. I heard of this happening ,but now realize how it could happen,I will be only one to fill tank from now on.
 
Gas expansion is going to happpen....remember that gas boils at 100 degrees F. ..... fuel in a underground tank is going to be plenty cool...

I used a Magic Marker to mark the sides of my plastic tanks...every 5 gallons, plus I like to burn off both tanks just to trim out the boat... With the plastic tanks it is easy to see when the tank is full... just don't fill the filler neck.... on the tug, I have aluminum fuel tanks and I installed a simple non electric fuel gauge...it's easy to see and being my two tanks are connected together I only need one fuel gauge. (I burn a quart an hour so I am pretty safe)....
 
SEA3PO":c1tjdafb said:
Gas expansion is going to happpen....remember that gas boils at 100 degrees F. ..... fuel in a underground tank is going to be plenty cool...

I used a Magic Marker to mark the sides of my plastic tanks...every 5 gallons, plus I like to burn off both tanks just to trim out the boat... With the plastic tanks it is easy to see when the tank is full... just don't fill the filler neck.... on the tug, I have aluminum fuel tanks and I installed a simple non electric fuel gauge...it's easy to see and being my two tanks are connected together I only need one fuel gauge. (I burn a quart an hour so I am pretty safe)....
Click to expand...

I think the boiling point of gasoline is a bit higher than that in practice - more like 140-160F
 
My vents have been moved to my splashwell. When I'm concerned I put the plug in the splashwell drain and stick an absorbant pad in the splashwell. That keeps the sheen off the water!
 
Larry,
We used to use the port side tank more if you were near a water source. You can add water to the WATER TANK to help balance the boat if the port side becomes light because of gas usage. You should fill the tanks sometime and go out cruising as you normally would. Keep track of your time running the boat so you can sort of get an idea of hourly fuel burn. Then you have a second way to estimate your fuel usage. Just a thought.
D.D.
 
I purchased additional vent hose, and using a "T", I connected both the tank vents together. I routed the line to a single vent placed as high as possible inside the splash well, and secured such that fuel within either vent line drained down into one tank or the other. When I fuel, I put the nozzle as far as possible into the filler neck and slowly fill until the fuel level shuts off the fuel automatically. I have never seen more than a few drops spill from the vent, which would now go into the splash well, not overboard.
 
Also be very careful if you are putting your boat into a closed (warm) workshop for any repair work as it can result in gas on the floor and fumes in an environment where people may be using power tools (sparks).

M
 
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