Got a tank that had eight year old gas in it. Smelled bad, looked bad. I drained the tank but it will probably be at least a year before I really work on cleaning it out. Thinking about what to fill it with in the meantime. Mineral spirits was my first thought, maybe it would dissolve some of the varnish without hurting anything while it's sitting. Any other ideas?
If you have to leave fuel in it I would use VP or Sunoco race fuel or Aviation fuel. They have a 2 year or better shelf life in the can and last in the tank as well. Not for the race part , just for the life span.
I cleaned my tank before storing it. After it was clean I put some MMO in it, rolled it around to coat the inside, sealed it up and put it away. Was just fine when I went to use it about five years later.
Take it to a radiator shop and heave them hot vat it, they can check for leaks while they are at it. Then you can seal it up and keep it in a dry place while waiting to use it. HRP
If there isn't a radiator shop close by you can get rid of any sludge using lacquer thinner then take it to the car wash to blast out all the crud with hot soapy water, once the tank is dry I'd coat the inside with some sort of oil to keep it from rusting.
Tank is still in the vehicle, car is in storage, hasn't run for at least eight years. I won't be working on this for at least a year. Once I start working on it I'll remove the tank and clean it but that's not an option right now. Just looking for ideas for what to fill it with in the meantime.
If you aren't trying to dissolve whatever is in there and just want it to be alright when you get back to it (assuming the tank and fuel system are still good), LL100 (AvGas) lasts years...and it smells delicious when you get around to firing the car up.
Sitting empty isn't going to take the smell out of it. I've got a rank smelling tank that I have had for about 5 years that was dry when I got it and still smells. I've kept it around more for mockup purposes than figuring out how to clean it and use it but might toss 5 bucks worth of vinegar at it. +
Put your used engine oil in it. I've usually got around 5 gallons of it sitting around before I make a run to the auto parts store that collects it. If you were close by I'd give you every bit of it that I have.
Mineral spirits (aka kerosene), diesel fuel / heating oil (same thing), and old motor oil will all help protect the metal, but won't dissolve varnish and the like left behind by the rancid gasoline. Gasoline is a pretty good solvent, so anything that came out of solution in it isn't likely to be dissolved by lesser solvents. Vinegar and similar aqueous solutions are sure to damage the tank if left in for a year.
Slosh some used motor oil around in it and call it good. When you do want to deal with the rust you can easily wash the oil out with gasoline beforehand.
The Jalopy Journal
