gas tank repair

When you paint the tank, ensure that you seal the tank with epoxy barrier coat--available at any marine paint source, ie, E&B, Westmarine, etc. Polyester resin is porous whereas epoxy isn't. Trying to prevent the bubbles under the paint with tank sealer on the inside is risky business because you would have to ensure that the whole inside is coated--a difficult task, whereas ensuring that the outside is covered with barrier coat is much easier. If you have any repairs to make to the tank, be sure to use epoxy resin, not polyester. Epoxy costs about twice to three times as much, but it is impervious to gasoline, and other motorcycle juices. Barrier coat is designed to prevent osmosis of water into the fiberglass laminate, but it works very well to keep gasoline from causing the paint to lift from the inside. Good luck--it's best to put gas in the tank for a month or two before you put a fancy paint job on, particularly if you're unfamiliar with barrier coat application. Incidentally, barrier coat applies just like a primer, which it is, after a fashion.

The color used to match the tank color is:
  Lacquer-
                Dupont Lucite Acrylic Lacquer
                Code 75-Red
                 1978

  Enamel-
                PPG Delstar Acrylic enamel
                Dar 72155SC
                Fleet bright red

Most people shoot the lacquer, color sand, and overcoat with enamel clear.