I waited the 48 hours as indicated by the instructions on the paint can. Almost as soon as I put one thin layer of clear, it went gray!!! I dont what caused this, I cleaned and prepped the surface per the instructions. Since that time, I have been busy trying to remove/strip the paint from the cowl vent area. Right now I am waiting for the paint/clear to dry then I will sand it all down and start over. The paint/clear supposed to dry in 48 hours.