Painting over finished wood without sanding is possible, but it's not typically recommended, as it can lead to issues with adhesion and the overall quality of the paint job. While completely sanding off the existing finish isn't necessary (phew!), lightly sanding the finished wood to "etch" the surface before priming and painting is usually the best practice. This helps to ensure there is proper adhesion. Let's get a bit more into the details!
(Design and photo credit: Rachael Somerville)
Here's Why It's A Good Idea To Sand
The single most important part of any painted surface is proper adhesion. Making sure that the first coat sticks properly to the material, and every subsequent coat sticks to the previous coat, prevents and chips or peeling that may occur years later.
Adhesion: Sanding the surface roughens it and creates a slightly textured surface that allows the paint and/or primer to adhere better. Without this, the paint may not bond properly to the smooth, sealed surface, leading to peeling or flaking down the road.
Smooth Finish: Sanding helps to smooth out imperfections in the wood's surface, such as rough spots, bumps, or old paint drips. It ensures a smoother and more professional-looking finish.
Even Color: Sanding can help remove any variances in the existing finish, ensuring a more even and consistent color when you apply the new paint. Having good, consistent adhesion helps with consistent and rich color, as well.
(Photo credit: This Old House)
When Is It Okay To Not Sand?
If you choose to paint over finished cabinets without sanding, it is essential to use a proper primer with excellent adhesion. These are specifically formulated to work with smoother, finished surfaces, and are compatible with whatever paint or topcoat you choose. We're big fans of keeping all finishes within the same "system" or manufacturer, so taking a trip to your local Sherwin Williams, Benjamin Moore, or local paint supplier would be a good idea. Bring a piece to sample along with you (a cabinet door or leave of a table) so they'll be able to test proper adhesion.
Here is the process for painting without sanding:
Clean the Surface: Thoroughly clean the wood surface to remove any dust, dirt, or contaminants. Use a gentle detergent and water solution, and rinse well.
TSP: Consider using a trisodium phosphate (TSP) cleaner to remove any grease, oil, or wax residues on the surface.
Deglosser: Apply a deglosser or liquid sandpaper according to the manufacturer's instructions to help create a surface that's more receptive to paint.
Primer: Apply a high-quality bonding primer designed for use on glossy or sealed surfaces. Let it dry completely before proceeding to the next step.
Paint: Apply your desired paint over the primed surface, following the manufacturer's recommendations for drying times and coats. Lightly sanding with a sanding sponge helps to ensure a very smooth surface.
To sum up, while it is possible to paint over finished wood without sanding, it's generally recommended to take the extra time to sand the surface for the best results, especially if you want a long-lasting and professional finish. Sanding ensures better adhesion and a smoother, more even finish for your paint job.
(Photo credit: Diane Liang)
Do-It-Yourself, Not By Yourself
We know just how intimidating it can be embarking on a finishing project and running into roadblocks. That, in fact, should be expected! Rather than searching YouTube for hours to get un-stuck, get an immediate answer and support throughout your entire project with our DIY Coaching. We've got several options available for projects big and small, our Experts with decades of experience are ready to help with whatever you're wanting to create!
No matter your project, we'll help you find your way home.