There are few gas tanks that can't be cleaned. Many jobbers sell kits that include a cleaner (phosphoric acid), neutralizer (ketone) and a coating. I did mine using muratic acid (the same stuff used in swimming pools), baking soda water to neutralize the acid and Redkote sealer. There have been some extensive threads about this very subject. I'd advise using the search function above. Welcome to the bolt.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.