This is what I used. It did a very good job cleaning and sealing my tank. Good luck!
http://www.kbs-coatings.com/Tank-Sealers_c_7-1-0.html_________________
David G. in Los Angeles
1976 BMW 2002 "Diana" Oh Crap. I gotta smog her this year!! Damn you Arnold!!
1998 Nissan 200SX "Sayuki" Can't argue with 35 MPG!!
1987 Nissan 300ZX My Dad's old Z will soon be mine!!