Folks I used a combination of vinegar and rust converter and it worked perfectly.
Not at the same time I might add.
1. Traditional vinegar method.
2. Flush and neutralize
3. I always get flash rust or other small patches so:
4. Add gallon of rust converter.
5. Fill tank with warm water.
6. Leave 24-48hr above 70°C
7. Rinse, flush with diesel, empty, fill with gas.
Diluting the rust converter slows the process but it doesn’t stop it, as long as you keep it warm. And slowing the process down with a weaker solution seems to clear the rust without taking too much good metal with it. I know it’s not supposed to do that, but it has with other projects in my experience.
Now, having evaluated the interior of the tank with a flexible camera, my tank is 100% rust free. No more fuel starvation on reserve, no blowing iron oxide dust into the cylinders.
