All the products that we see for rust removal on the market that say it is environmentally friendly, biodegradable and wont hurt your paint, have two things in common. One being water, two being Oxalic acid. Oxalic acid is found naturally in a lot of foods. It can be purchased on the Internet cheep. I used 1 to 1.5 tablespoons per gallon of water. Let it sit for 24 hours or more pending on the amount of rust. I submerged the tank completely. Took care of the rust on the outside as well. When your done it can be used again or dump it. Oxalic acid only works on the oxidation, not the clean steel. What original paint was left was unharmed.
