The most efficient way of painting on top of surfaces that have already been painted will depend on the current condition of the surface, type of paint used previously, and the desired finish. Here are some general guidelines:

 

Surface Preparation: Before painting, it's important to clean and prepare the surface. Remove any dirt, dust, or grime with soap and water. For surfaces that are greasy or oily, use a degreaser. If there are any cracks, holes or imperfections in the surface, fill them with wood filler, and sand it down to a smooth finish.

 

Sanding: If the surface is in good condition, you may not need to sand it down. However, if the previous paint is flaking or peeling, you will need to sand it down to create a smooth surface. Use a fine-grit sandpaper to create a key for the new paint to adhere to.

 

Undercoating and Primer Coats: If you are painting on bare wood or a surface that has not been painted before, it's important to use an undercoat or primer coat to help the paint adhere properly. For areas that have been sanded down, it's recommended to use a primer to create a uniform surface for painting. For areas that have been previously painted, you can skip the undercoat and go straight to the topcoat.

 

Topcoat: Once the surface is properly prepared and primed, you can apply the topcoat. Use a good quality paint and apply it evenly with a brush or roller. Depending on the desired finish, you may need to apply multiple coats.

 

Overall, the key to efficient painting is proper surface preparation. Take the time to clean and prepare the surface, use the appropriate primer or undercoat, and apply the topcoat evenly. With the right tools and techniques, you can achieve a professional-looking finish on any surface