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New Gas Tank...Rust?
Posted: Mon Oct 14, 2019 3:57 pm
by Bill Everett
Soon we will begin the task of lifting the body off the frame and putting the new round gas tank in place.
I'm wide open to suggestions to prevent rust forming in this new tank...
Does non-ethanol gas pose a smaller chance of rust forming, or is it and ethanol gas equal in that regard?
Re: New Gas Tank...Rust?
Posted: Mon Oct 14, 2019 6:41 pm
by Allan
Bill, just steer clear of ethanol and you should be right. Ethanol absorbs water and water is needed to propagate rust.
Allan from down under.
Re: New Gas Tank...Rust?
Posted: Mon Oct 14, 2019 6:48 pm
by Scott_Conger
And store your car with a FULL tank of ethanol-free fuel to ward off condensation
Not a problem where I live now, but was a significant deal when I was in FL. I suspect you're not a whole lot drier than FL, I am guessing.
Re: New Gas Tank...Rust?
Posted: Tue Oct 15, 2019 12:36 am
by JohnM
Has anyone tried using 2 cycle chainsaw oil? You could mix it half the rate or less. If it protects the cylinder of a chainsaw, would it not coat the inside of the tank?
Re: New Gas Tank...Rust?
Posted: Wed Oct 16, 2019 5:37 pm
by Oldav8tor
Why don't you preemptively treat the inside of your tank with a sloshing sealer such as PQR15? After cleaning my original tank I treated it and it has worked well. No exposed metal means no rust

Re: New Gas Tank...Rust?
Posted: Wed Oct 16, 2019 7:00 pm
by TRDxB2
There have been many threads about tank rust attributed to ethanol gas and other factors. "When exposed to air, ethanol will pull moisture out of that air and into whatever fuel it's blended with. If the ethanol fuel pulls too much water out of the air, phase separation occurs - the ethanol comes out of solution with the gasoline. Essentially, the mixture breaks apart. When this happens, it destroys the quality of that gasoline and strips away a good amount of the octane rating of that fuel. You end up with poor quality gasoline and a layer of water and gasoline in the bottom of your fuel tank that can damage your engine if it’s sucked up into the combustion chamber by your fuel line." SO it is only a problem when too much moisture is pulled out of the air. So where does the moisture come from - your vented gas cap - which must be vented. Any moisture in your tank will condense on the inside walls where there is no gasoline. You probably see condensation right at home every day. If you wear glasses and go from a cold, air-conditioned room to outside on a humid day, the lenses fog up as small water droplets coat the surface via condensation. People buy coasters to keep condensed water from dripping off their chilled drink glass onto their coffee tables. Condensation is responsible for the water covering the inside of a window on a cold day (unless you are lucky enough to have double-paned windows that keep the inside pane relatively warm) and for the moisture on the inside of car windows, especially after people have been exhaling moist air. All of these are examples of water leaving the vapor state in the warm air and condensing into liquid as it is cools. So the inside of your tank is no exception. So its best to keep a full tank of gas, any type, because when here is no air there is no moisture. AND if you recall the sediment bulb is design to allow for the crud (water included) on the bottom of the tank to be exorcised via the petcock on the bottom of the potato.
