Drywall Mudding Over Paint in 7 Steps

If you have uneven walls, often due to over-scraping to remove old paint, you might be wondering if you can use drywall mud right over the paint to smooth it out. The answer? Yes — as long as you follow the proper steps. Get started with the guide below.

Step 1 - Wash the Walls

First, wash the walls with trisodium phosphate, or TSP, to remove any dirt, grease, or other debris. Cleaning the walls with a strong product such as TSP also etches the wall’s surface to improve mud adhesion.

Warning: Trisodium phosphate is dangerous if not handled correctly. Use caution with TSP and follow all safety instructions as provided on the product. This may include wearing gloves, safety goggles, a face mask, and long sleeves to protect your skin.

Step 2 - Scrape Off Any Loose Drywall

Before continuing, gently scrape off any loose drywall with a paint scraper. With a clean, dry rag or paintbrush, dust off any remaining loose pieces from the wall.

Step 3 - Apply Drywall Primer

Brush or roll on drywall primer to the wall thoroughly. Then, let it dry.

Step 4 - Use Drywall Mud

Use the drywall mud and a drywall blade to fill in any of the “low” areas or divots that were damaged previously, like by earlier paint removal. Smooth the mud and let dry completely.

Step 5 - Sand and Dust Wall

Now, sand the drywall flush to the wall. Then, wash and wipe the walls down again to remove any dust that’s collected.

Step 6 - Apply Final Mud Coat

While you can achieve a smooth look with some patience, it can be difficult to do. To bypass any imperfections, it’s better to rent a spackling-compound gun and shoot the walls with an orange-peel pattern. This pattern will apply small bumps all over the wall, and it will hide any abnormalities.

After you’ve using the spackling-compound gun, let the mud dry and then go over it lightly with a trowel to remove any sharp points. Then, let the mud dry the rest of the way.

Step 7 - Paint Wall

Now, you’re ready to paint your wall any color you’d like.