Rusty Fuel Tank

I just picked up two GT380's. One is a 1974 and kicks over while the other is a 1972 and is frozen. Both have a fuel tanks that are quite rusted inside.

What chemical do you use to do an initial cleaning?

From what I understand you let this acid sit inside the tank for a couple days or however long is needed. Pour it out, then get a paint-like substance and shake that around inside the tank to coat all the surfaces?

Explore,
In my experience, starting with the mildest and easiest form of corrosion treatment first always works the best. Plain old soapy water and a bunch of BBs inside the tank and start a shakin'! (put some music on if you'd prefer... lol) Your local sporting goods store sells a big carton of them for the BB guns and they're pretty cheap. That usually gets it surprisingly clean. If it's just some surface rust inside the tank and the BBs clean it well, you may not even need to seal the tank. (wouldn't hurt though) Kreem is a good product and pretty easy to use.
Good luck and keep us up to date,
Tim

Right now I still have to call my city and see what to do with the bad gasoline that is currently in the tank.

What have you guys done with this is mess?

I think you can take it to your local dump and they'll charge you a little (like $5 USD). to dispose of it. Just like you dispose of paint.

I don't know about your area, but most auto shops I've worked in will let you dump a couple of gallons of old fuel in their waste oil/ recycling tank at no charge. Can't hurt to ask.

I just saw on a BMW video that most marinas have a disposal place for boats to change their oil. no charge there either.