Thermofoil is a surface finish used by several manufacturers to coat medium-density fiberboard (MDF) products. Thermofoil is a plastic material that covers rigid MDF surfaces to give them a smoother appearance and more durable exterior. If your cabinets are wrapped in Thermofoil, they will last much longer than raw MDF cabinets ever could. Thermofoil, however, doesn't take new paint easily. The slick plastic exterior doesn't give paint much to cling to, so you need to use the right primer before you can paint a Thermofoil-wrapped cabinet.
Clean the cabinets with water, dish detergent and a sponge. Dirty surfaces don't accept primer and paint easily.
Remove the cabinetry hardware using a screwdriver. If the cabinet hardware is glued on or embedded into the MDF, cover the hardware with painter's tape.
Apply painter's tape to adjacent wall surfaces and cover the floor with plastic sheeting.
Prime the Thermofoil-wrapped cabinetry using a bonding primer, a synthetic-bristle paintbrush and a medium-nap paint roller. Bonding primers are sold at many hardware stores, and they provide high-adhesion coverage on slick and glossy surfaces. Without bonding primer, the paint will peel several weeks later. Wait for the primer to dry. Consult the primer's container for the most accurate drying estimates.
Paint the Thermofoil cabinets with oil-base paint. Use a natural-bristle brush for edges and a medium-nap roller for larger cabinetry surfaces.
Apply a second coat if necessary after the first coat dries.
Remove the painter's tape and plastic sheeting after 24 hours.
Reattach the hardware.