[Keith True]

That tank is never going to get clean while still in the car.Clean enough to use,yes.Clean enough for sealer? No way.I always found the worst of the rust is on the underside of the top.I use the finger screen in the tank,you take the gas valve out and just press it in the opening.Nothing but the screen protrudes into the tank,so you can run it until it is bone dry.That keeps the chunks and flakes out of the valve,that is what scores them.Keep the flushing up,at some point what is loose will come out and what is tight will stay and won't hurt anything.This is a very common thing with A's.Putting the cart before the horse and painting the car before the tank is properly dealt with.