I have got the roof almost ready to paint but have a quick question on spraying. In the morning I am going to give it one more wipe down of phosphoric acid and water to neutralize but the instant it dries it turns a blueish amber color. I believe the amber to be light flash rust. If I give it another pass with a DA and 120 will I be ready? Or should I wait another 24 hours to make sure there is no moisture from the wash off? But if I wait another 24 hours I will have more flash rust.... Confused