Hi all, should I drain tank or fill it with fuel to avoid rust? Thanks

 

There are coatings you can get that would be far cheaper than filling it with gas. Search “fuel tank sealer” on Amazon for several options (some will come with pre-treatment).

Other options are to use fogging and/or penetrating oil.

Either way, make sure the inside of the tank is as rust-free as possible before applying anything.

Mild tapping with a mallet will shake free any loose rust and a car wash will help clean the rest. Set a fan up to blow air through the fuel pump opening and rotate it 2-3 times over a 24 hour period to ensure the tank walls are dry.

If it’s heavier rust accumulation, Evapo-Rust is a good product for cleaning it and can be used multiple times.

After sealing/treating it, place a bar of soap or air freshener inside the tank (anything that “smells clean” to repel rodents and bugs - or mothballs, if that’s your thing). Then cap off any smaller holes and duct tape a layer of 2-4 paper towels over the fuel pump opening (the paper towels will help regulate moisture levels).

Finally, wrap it in a plastic sheet and secure with bungee cords or rope. Do not completely seal the plastic as condensation could form inside the plastic and have no way of escaping.

Check on tank condition once a year and change paper towels and scent repellent if needed. Otherwise the tank should stay in good condition for years.

 

How long are you storing the vehicle? @Gumby22 has some great advice, but if you plan on driving it periodically, or at least cranking it, I've stored vehicles for a year without driving, using stabilizer in the fuel tank to keep the gas from breaking down. I would charge the battery before cranking it up if you let it sit that long, or crank every couple of months.

My elderly neighbor stored a 2008 Denali, virtually undriven, in his garage for over a decade, but he would crank it about once a month and let it run a few minutes. Not sure if he used stabilizer, but betting he did - he was an old gear-head. He's now passed away, and my son in law has that vehicle, with only 14,000 miles on it.

 

Hahaha - for some reason it never occurred to me that the tank was remaining attached to the vehicle.

I just took it as the tank was being stored separately. #sometimesmybrainrunsaway

In that case, I’d recommend finding a fuel stabilizer that lasts for the length of time you intend to store it - if it’s less than a year, Sta-bil should work fine.

Add the amount recommended by the label and fill the tank with non-ethanol blend fuel (if available).

 

Haha yeah I was wondering why you thought he had JUST a fuel tank to store...

On the subject of draining stuff for storage.... my elderly neighbor who got dementia and then passed away last year was a gear head, and had quite the vehicle collection, including a 1936 Chevrolet sedan, 1972 C35 dually crew cab, 1960-something Triumph, 1967 Ford Mustang, 2017 GMC Acadia, 2008 GMC Denali, and a 1982 Buick Roadmaster station wagon.

One of his sons was going to take the Mustang, which had not been cranked since an engine rebuild 8-10 years earlier. He put a new battery in it, got gas, worked and finally got it running. For 2-3 minutes. Then the engine seized up! Apparently it had been put into storage under a cover in the garage with the engine oil drained out of it, along with the gas tank emptied. Or else the engine oil all leaked out onto the garage floor over those 8-10 years... we never figured out, and no one to ask. He got the thing restored, but had to spend more than expected to replace the engine... I was so sad for him as I was working on my pickup across the street when that happened to him, and we had been borrowing tools from each other all that day.

Lesson learned for me was to check the oil in any vehicle that hasn't been cranked in a long time!