Painting a vinyl door requires adhesion. After proper surface preparation, products like Emulsa Bond is an additive, or a special primer by X.I.M., will guarantee a good job.
We have been changing the color of vinyl siding, plastic radar domes on boats, and other hard to adhere to surfaces for years now. There are several techniques to achieve this goal. From additives to a quality latex paint that improve adhesion, to specialized primers that bond to the vinyl and then can be coated with a quality latex paint. Now neither of these systems is as strong as enameled metal, however they are more durable than ever before.
One of the additives for latex paint is E.B., Emulsa Bond, by The Flood Company. There is a house on my street that was a light almond color two years ago. Back then it was painted a dark country blue color with the Emulsa Bond additive. Today it still looks great, no pealing, no chips, however the side of a house doesn’t get the abuse a door may receive.
The other system of using a specialized primer first, them painting with quality latex enamel would be my first choice. One of the best primers for unusually tough surfaces to adhere to is X.I.M. 400 Primer-Bonder, by the X.I.M. Company.
Preparation for either of these alternatives is simply cleaning the door thoroughly, then lightly sanding with a scotch pad. (Plastic steel wool) Application of both the primer and the paint should be thin, even coats of product. The primer coat may show a few signs of the black color shadowing through, just a few won’t be a problem. But if there are any bare spots, or many thin areas, use two coats of the primer first. Remember not too thick of coats of product, more is not better. You need this paint job to be as flexible as the vinyl you are painting.
Either of these prime and paint systems will work great for the frame of a screen insert. Only if the screen cloth is in need of repairing, remove the cloth first and then paint the frame. It can be very difficult to paint to the edge of a screen mesh. When painted and dry then get it rescreened. One of the services we are proud of is our quality screen repair.