Cleaning old fuel containers?

[Troubleshooter]

Two part question here, about cleaning the "crud' out of fuel containers.



Part 1: Had two pristine fuel cans which I left with an old friend while on a yearlong overseas jaunt with Uncle Sam. Got them back and tossed them in the shed, where they sat until I needed them earlier today. Long story short, one is still as-new and the other one is full of gasoline crud and rust. Guess my "friend" must have used it and left enough in there to turn into varnish.



Part 2: Acquired a large, stand-mounted tank with several inches of bad fuel in the bottom. Again, probably gasoline turned to varnish. I would like to clean it out and use it for diesel fuel storage. Size is roughly 3' x 1-1/2' (oval shape) x 4' long. It's not marked, but I'm guessing 150 gallons or so.



So what's the best way to clean these out and get them ready for use? Obviously the 5-gallon gas can will be easier to manipulate than the large tank.



Appreciate any ideas.

 

[Superglide]

For the fuel can, clean with acetone then soap and water. Rinse well and let dry (obviously). I've been told it works quite well. I would suspect using acetone in the large tank would work as well.

 

[rscurtis]

Good suggestion. I've saved a number of gummed up carburetors with acetone.

 

[Troubleshooter]

Thanks for the ideas. I'm out of town for another week but will give a try with the acetone / soap & water when I get back. The big tank may be harder to shake and slosh that stuff around though!