Cleaning rust from inside of tank...chemists step inside;)

[47Merc]

I'm no chemist but I know at full strength it makes a great soldering flux on copper and stainless steel. I would have thought you wouldn't want to dilute it too much to dissolve rust.

Why dont you mix a few small amounts at different ratios and try it on some rusty scrap metal and see what the results are before you put it in the tank.