Here is a picture of the gas tank. The next step after you sand the primer is applying sealer. Sealer has a few functions, it acts as a bond coat between primers and base coats, prevents topcoats from soaking into the primer and reducing gloss, and in this case will make the tank and fenders the right color for faster coverage of topcoats. I then clear coated it. This will seal the white down so when I lay out the flames there won't be any tape tracking. I also like to do this when there is going to be some airbrushing so if there is a problem I can easily fix it with out having to re-base it.