Prepping laminate surfaces before painting them is of the utmost importance to insure that your paint adheres. If you’re painting a laminate piece of furniture, you may need to disassemble it to paint it properly. Remove any hardware and take off any doors or other removable parts using a screwdriver or another applicable tool. Clean the surface with mild detergent, water and a sponge. Let it dry thoroughly. Remember to also make any repairs now if necessary.
If painting a countertop, remove all items from it and clean the whole surface using water, mild detergent and a sponge or cloth. Remove all dirt, grease, dust and debris. Get into every nook and cranny, including around appliances. Be sure that all grease is removed because it will affect how paint adheres to the countertop. Allow the surface to dry completely. After it has dried, go over the surface with a tack cloth or slightly damp cloth to remove dust and lint.
If your countertops have any damage, you can simply fill in holes and cracks with wood filler and then sand the filler down after it dries.
Use a fine-grit sandpaper to lightly roughen surfaces so that your primer and paint will adhere effectively to the laminate. Wipe away all dust from sanding with a damp cloth. Countertops may require additional sanding to remove any glossy polycoat on the surface to which paint would struggle to adhere. Poor paint adhesion would lead to undesirable results, especially on a countertop. You can also use a paint prep product like Savogran Pre-paint Deglosser. It will dull the finish and can be painted within a few minutes. Test in an inconspicuous area first and make sure you have good ventilation.
If painting laminate countertops or cabinets, keep in mind that your use of the room will be limited for at least a couple of days until the work is finished.
Place drop cloths on the floor where you’re working, and secure them with painter’s tape so that they won't shift around. Cover anything that cannot be removed from the countertop with plastic sheeting and painter's tape. Also apply painter’s tape where a countertop meets walls or other surfaces to keep unwanted paint off of them.
Be sure there’s adequate ventilation in the room where you will be painting. Open windows and use a fan to push out paint fumes and bring in fresh air.