Removing rust from gas tank

[heehaw]

check your local radiator shops, i had a 20 gal tractor tank done for @ $50-60...they cleaned it, soldered the holes, and coated the inside with an epoxy type stuff, cheaper than i could have bought the kits.
heehaw

 

[rollyman123]

The best way to remove rust from a gas tank is by using a product called Evapo-Rust. Evapo-Rust is safe and easy to use. I have had great success with it. Here are the steps that I follow when using it.

1. Clean out all of the gas residue using a mild detergent and water from the gas tank.
2. Fill the tank with Evapo-Rust and let set for about 12 hours. Sometimes it takes longer depending on how thick the rust is. You will notice that the Evapo-Rust turns black when it starts to work.
3. Dump out the Evapo-Rust and rinse the tank with alcohol. Make sure to save the Evapo-Rust because it is re-usable.
You may have to do this process more than once in order to remove all the rust.

The best places that I have found to buy the product are:
Rust Remover | Evapo-Rust | Concentrate Non Toxic Non Corrosive Rust Removal (This site has allot of information on how to use the product!)
Nebraskan Hotrod (This is where I normally buy it! The price is cheap and the customer service is real good!)

 

[wjoerob]

How would you change this process to remove rust from a BIG tank (300 gal. or so)? Or is there some better way? I bought a tank with a stand a year or so ago, thinking I'd combat the skyrocketing prices. Found it has some rust in it. It does have a paper filter attachment. No obvious holes. Will this Evapo-Rust work on it?