No, it is not recommended to apply paint directly onto varnish without proper preparation. Varnish is a clear protective coating that creates a smooth, glossy finish on wood surfaces. When painting over varnish, it's important to follow a few steps to ensure proper adhesion and a long-lasting finish:
Surface preparation: Start by cleaning the varnished surface thoroughly to remove any dirt, grease, or contaminants. You can use a mild detergent and water solution or a recommended wood cleaner. Rinse the surface with clean water and allow it to dry completely.
Sanding: Lightly sand the varnished surface with fine-grit sandpaper (such as 120-150 grit) to create a rougher texture and promote paint adhesion. Sanding also helps to smooth out any imperfections on the surface. After sanding, remove any sanding dust with a tack cloth or a damp cloth.
Primer: Apply a suitable primer to the varnished surface. The primer helps create a bond between the varnish and the paint, ensuring better adhesion. Choose a primer specifically designed for use on varnished surfaces and follow the manufacturer's instructions for application.
Paint: Once the primer is dry, you can apply the paint. Use a high-quality paint suitable for the type of surface you are painting. Apply the paint evenly with a brush, roller, or sprayer, following the manufacturer's instructions regarding the number of coats and drying times. Allow each coat to dry completely before applying the next.
By following these steps, you can improve the chances of the paint adhering properly to the varnished surface and achieving a smooth, durable finish.