Hi Jim... man your in for a bit of research and input from this forum. The secret to painting the plastics is to use a good undercoat/primer that is meant for plastics and is compatible with your paint. As for your tank, just be aware that if not done properly, any fuel that goes near it will tear it apart, even a small splash or drip. I have had success with a VHT clear coat that is high temp and fuel resistant made for engines. Just cure it properly. That should go over the colour you paint your tank. Otherwise, i believe its two pack etc for the hardness and fuel resistance.
Good luck,
