I have a steel or aluminum garage door that is about 3 years old. The
paint on it is beginning to dust off. That is, if you run your fingers
over it, you get a layer of dust on your fingers. And the color of the
paint looks faded and uneven. But the paint is not flaking off or
anything like that.
I like to repaint the door. If I use TSP and wash it with water and
then dry it off, do I need to apply primer?
Should I use semi-gloss paint? Any specific paint type to use? The
garage door is in very good shape.