I will explain what I did but I put a link and video below that probably explains it better.
I plugged the bottom of my fuel tank and propped it up so that the filler cap was at the highest point.
I mixed about a cup of Arm and hammer washing soda with about a gallon of water and put it in my tank.
Then I filled the tank the rest of the way with water.
I inserted a steel rod into the tank and positioned it in the tank so that it did not touch the tank.
I bent the rod so that every part of the inside of the tank is within line of sight of the rod. Supposedly this process only works line of sight, If I only put a straight rod into my tank some of the shadowed areas would not be de-rusted.
I connected the tank to the negative lead of a battery charger, and connected the metal rod to the positive lead of a battery charger.
Then I set the battery charger to 12V, 2AMP, manual mode.
I let it run and checked and cleaned the metal rod every 12 hours or so.
Supposedly the process will stop when all of the rust is gone.(I’m not there yet so we will see what happens)
Warning! The process puts off hydrogen and oxygen bubbles, so make sure the area is well ventilated. I popped a coupe of the hydrogen bubbles with a match. Sounds like a firecracker going off.
Chris
Here is a link to a better explanation.
http://www3.telus.net/public/aschoep...lyticrust.html
Here is a youtube video