Gas tank for the winter

FordTudor1931

FordTudor1931

Member
In Michigan it is getting close to the point when your Model A is put away for the winter. This of course starts the question about the gas tank. Empty? Full? Additives? Ethanol free gas? Try to figure it out if you can!
Here are some thoughts that may or may not make sense, but this is trying for a logical approach.


Gasoline and water don’t mix. Gas is lighter and stays on top, meaning that any water in the tank will stay on the bottom of the tank. Water and metal means rust. Even small amounts of moisture would start the rusting process.



Now, if you have gasoline with ten percent ethanol you already have some water in the tank. Ethanol is 96 percent pure i.e. four percent is water. To get to 100% ethanol is a complicated process with benzene and a second distillation. This is not done in commercial applications. However the water in the ethanol will not start a rusting process since it is tightly bound to the ethanol.


Here is the second part to the thinking. Ethanol is hygroscopic (attracting water). If there is moisture in the tank, the ethanol would attract that moisture and make it unavailable for the any rusting process. In other words: Using gasoline with ethanol would reduce/remove the moisture in the gas tank and allow the small amounts of water to burn in the engine together with the gas /ethanol.
Granted, my knowledge base is pharmaceutical chemistry and somebody with petroleum chemistry knowledge could very well have a completely different idea.


Thoughts?
 
FordTudor1931 said:
Here is the second part to the thinking. Ethanol is hygroscopic (attracting water). If there is moisture in the tank, the ethanol would attract that moisture and make it unavailable for the any rusting process. In other words: Using gasoline with ethanol would reduce/remove the moisture in the gas tank and allow the small amounts of water to burn in the engine together with the gas /ethanol.
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Agree. E10 is probably actually better than straight gas to prevent rusted out tank bottoms.

With straight gas, any water that gets in the tank (condensation or otherwise) goes straight to the bottom and starts working on the metal.

With E10, water that gets in the tank combines with the ethanol and remains in suspension....to a point. When the ethanol is saturated with water, any remaining will go to the bottom of the tank.

When we have known water in a fuel tank, we add a product like Heet...

cc-10427f6d7658_1.dbcc84ad9776dc8c63b6a8a5fb888af2.jpg


Heet is methanol. It combines with the water, puts it in suspension so it will burn, in the same way that ethanol does.

I believe it is best to keep the fuel tank as full as possible when the car is in storage. Less moisture laden air in the tank this way...less chance of condensation.
 
My opinion is the best thing for a sitting gas tank is to be drained. Drain the carb as well. my tank is silver inside and before I got it had the tank valve stuck open and a leaky carb so it would self drain. Empty tank and a clean carb after 30 years of sitting.
 
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+1 for tank full.

ATF will mix with both water and gasoline. I add 8 ozs of ATF to a full tank.

Have successfully stored E10 & ATF for over a year with ZERO problems.
 
Regular ethanol gas: fill to the top and add Stabil.
Non alcohol gas: fill to the top and add Stabil as moisture will get in due to some condensation over the winter due to big temp changes.
Works for me in Maine.
 
I have read that ethanol is corrosive to tern plate. The inside of a model A is tern plate. Do some research because I could have stumbled on FAKE NEWS.
 
J Franklin said:
I have read that ethanol is corrosive to tern plate. The inside of a model A is tern plate. Do some research because I could have stumbled on FAKE NEWS.
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Here's another thread here on the Barn that basically says E10 does not erode terne plate.
https://www.fordbarn.com/forum/showthread.php?p=795280

Also click on the link in that thread about the guy that ran E85 in his T with no problems.

However, with posts pro and con on most forums (including this one) they are generally "anecdotal information". Rarely is there data from a valid, unbiased source.

This is the only non anecdotal article I could find and it is not specific about terne plate...

http://www.glaciallakesenergy.com/events/MN_E20_testing.pdf

"In addition to road tests, researchers conducted laboratory tests to evaluate the effect of 20 percent blends on materials commonly found in conventional vehicle fuel systems. These included components made of various metals, rubber and plastics. Test results indicated E20 was compatible with the vehicle fuel systems."

Bottom line...if you feel E10 rots your fuel tank, makes your car run badly, etc. don't use it. Life is too short :)
 
Been reading the comments and some say the tank should be as full as possible and some say empty. What about all those gas tanks removed from vehicles that are empty and stored in a garages, sheds and barns?

It appears these gas tanks don't corrode on the inside as long as the gas cap is removed with the end result being condensation will not occur any more than it would on the outside of the tank. Does that mean all those gas tanks installed in cars are far less likely to corrode as long as the fuel is drained and the gas cap is removed with maybe chicken wire placed on the tank opening to keep anything from falling inside?
 
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J Franklin said:
For those that care.

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.923.1077&rep=rep1&type=pdf
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A lot to wade through there, but it looks like E30, E85 and E100 were tested with stainless steel, 2 forms of aluminum anodizing and cast iron. No testing with E10 or terne plate (which is a tin/lead coating). Interesting reading, but I'm not sure it applies to us.

In any case the conclusion seems to be...

"The results showed that, the 304 stainless steel, Al6061 and the coating materials are compatible with the alternative fuels. The oxide coatings on both Al alloys provided effective corrosion protection in the alternative fuel environments."

Grey iron actually has greater corrosion resistance with the increase in level of ethanol in the fuel.

"The corrosion resistance of grey iron is always lower than for the Al6061 and
Al319 alloys, but increases from 10.7×103 Ω/cm2 in the E30 medium to 56.93×103 Ω/cm2 in the E100 medium."

My guess is that there is not much (if any) terne plate used in fuel systems these days and that testing like was done in this study would probably not exist.
 
Unless it's a trailer queen, drive it in the snow once or twice a month. You could also wait for clear road days. People would get a kick out of seeing it driven on Christmas.
 
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