Laminate has a slick and glossy finish, which makes paint adhesion unlikely. However, you'll find a few methods to paint laminate. A simple process of sanding and specialised paint will allow you to paint a laminate door so the paint sticks.
Sand the entire surface of the laminate door to ensure the removal of the glossy surface. This will ensure maximum paint adhesion. Always sand in a well-ventilated area.
Wash the sanded surface thoroughly with the TSP detergent using a sponge. Wear gloves and eye protection when handling TSP detergents.
Rinse the sponge well, then use it to clean the TSP detergent from the laminate surface with clean water. Allow the door to dry completely.
Pour a small amount of paint into the roller pan or paint pan. An amount approximately as wide and round as a baseball should be enough to start.
Gently roll the foam roller into the paint. Do this two or three times to coat the roller.
Roll the foam roller onto the laminate door in a uniform, one-directional manner, lengthwise in a straight line.
Continue rolling paint onto the door until it is completely and evenly coated with a thin layer of the melamine paint. Depending on the equipment and space you have available, only paint one side of the door at a time.
Allow the paint to dry for about 24 hours, then coat with another layer of the melamine paint.
Paint three layers on each side of the door, allowing each layer to dry for about 24 hours except the final coat. Allow the final coat to dry according to the manufacturer's specifications. Most melamine paints have a curing time of about six days, though the manufacturer may indicate it is acceptable to mount doors prior to the curing process completing.
TSP detergents are solvents so handle them accordingly. TSP is an eye and skin irritant, so always wear personal safety equipment.