They also make a product for lining gas tanks to prevent them from rusting out. It is used in motorcycle production quite a bit. If you had a way to get inside the tank and coat it, it would eliminate several issues. When doing bike tanks, you just dump it in and shake it around to coat it, then dump out the remaining product. Once it has cured, you're good to go.
As said before, I'm sure your supplier has a list of regulations as long as your arm for what type of container he can fill. Ask him.
As said before, I'm sure your supplier has a list of regulations as long as your arm for what type of container he can fill. Ask him.