Krylon and Rustoleum clear cote is not fuel proof. I have no idea what fuel proof clear cote would be compatable with Krylon, however I would think a water soluble polyurethane such as Nelson's would do the job. A mineral spirit based poly such as used for wood varnish may also work. I would stay away from anything that smells of toulene or acetone. Be sure to test a small unseen area first.