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Gasoline Vapor from Fuel Tank

Posted: Sun May 09, 2021 8:30 am
by Salt_life01
I am restoring a 1984 NEWPORT 17 and adding a center console and new fuel tank. The console is shown in Figure 1.

console.jpg
Fig. 1. An aftermarket console to be installed.
console.jpg (11.71 KiB) Viewed 2849 times


A 36-gallon fuel tank will be built by Atlantic Coastal Welding. The tank will be installed under the console and will have a fuel fill with an angled fuel cap and neck on the side and a vent fitting on the side or top of the console.

Q1: what can be said about the hazard of gasoline vapor from the tank?

Q2: if the fuel system is completely enclosed am I safe?

Re: Gasoline Vapor from Fuel Tank

Posted: Sun May 09, 2021 9:14 am
by jimh
I doubt that you can get authoritative answers to your questions from random replies on a forum.

I recommend you check with the American Boat and Yacht Council (ABYC) for recommended practices on fuel tank venting for above deck gasoline fuel tanks in a semi-enclosed space.

Also, check with the Environmental Protection Agency (EPA) for current regulations regarding venting gasoline fuel tanks to the atmosphere on boats. They have regulations affecting boat fuel tanks and vapor emission.

Also, the fuel tank fabricator may have useful knowledge he can share with you.

If you have concerns about the safety of the new fuel tank being fabricated, ask the vendor to give you a manufacturer's statement of compliance with regulations regarding safety precautions associated with gasoline fuel tanks.

As a self-installer of a fuel tank, compliance with regulations regarding gasoline fuel tank installation on boats will be up to you.

Re: Gasoline Vapor from Fuel Tank

Posted: Sun May 09, 2021 11:25 am
by Phil T
I would install the fill using a recessed pocket from SSI and a proper metal fill on one side and install the vent on the opposite side with a loop in the vent line. I would not install the vent on a flat surface as it will allow water into the tank.


With a fuel tank in a confined space, there will be some smell of fuel but with respect to vapors, they would only be present due to a loose fitting or spill on filling the tank.

Safe is a relative term. If the tank is properly installed, grounded and separate from any electrical current, any risk is similar to any other above/below fuel tank equipped boat.

Re: Gasoline Vapor from Fuel Tank

Posted: Wed May 12, 2021 10:42 am
by jimh
Any metal parts of a fuel system that are interconnected by rubber hose should be bonded together electrically with a 10-AWG conductor with green insulation. The conductor should then attach to an overboard anode that will be in contact with seawater.