I am in the process of removing layer upon layer of old dried paint from my windows(exterior). I have been using a Black & Decker hot air paint remover. If you use a somewhat dull putty knife, damage is minimal.It is time consuming, though. Also, be sure to wear hand protection because the paint gets very hot when melted and will stick to your fingers. If someone else has a better method(besides chemical strippers), I would certainly love to hear it.