Topped my tank off a couple of weeks ago. right wing right rear excess cover has some staining along front edge. No drip marks on hangar floor or run marks to fuselage aircraft was topped off when cold and now has warmed up this week in the midwest. Probably will have to reseal excess cover, according to the maintenance manual the tank is not vented.I assumed there would be enough room in tank for expansion because of the dihedral in the wing, I assumed wrong. My AA1B is vented and I never worry about filling it up. lesson well learned with new airplane and new quirks. Next question what type of sealer is approved to be used on our Grumman”s to seal excess covers on wing tank.