Use a sanding sponge with 100-grit sandpaper. Or, to speed up the work, use a pole sander. Wipe down the walls with a damp cloth when you're done and allow to dry before proceeding with your next step.
To ensure the best possible finish, it's vital that you sand your walls before any painting project. This is an important step regardless of how you have previously treated your walls.
After removing imperfections and filling in holes, the painter will sand all the walls to help achieve an even, smooth look. Depending on the condition of the walls, your painter might clean them after doing all of this.
Smoothing walls before painting is necessary for surfaces previously painted with a gloss or high-gloss paint. For previously painted water-based paint, sand with a fine-grit sandpaper. For oil-based paint, a medium-grit sandpaper (100- to 150-grit) should be used.
Which Sander is Best for Walls? Disc sanders are a good choice for walls as they rotate at a high speed, providing powerful smoothing over large areas. It is advisable to start with a coarser sanding pad to tackle rougher spots before switching to a finer grit for a smooth finish.
How much should you sand before painting? You don't need to sand too hard, just enough to scuff up the surface so the paint will adhere better. If you're sanding by hand, it shouldn't take more than probably 15 minutes to lightly scuff sand a large dresser. If you're using an electric sander, it'll go faster.
You will only need to give the wall a light sanding, typically by hand with a fine grit sandpaper. Once you have sanded the wall, make sure you brush it down with a soft hand brush and then wipe over it with a damp cloth and leave the wall to dry. Vacuum up any dust you can see.
For a lump-free finish, sand your drywalls before you roll on paint. Sanding gets rid of bumps, roller lint and other crud left from previous paint jobs. It's best to use a drywall sanding pole and 80- or 100-grit drywall sanding paper.
Use fine grit sandpaper, between 150 and 180 grit, to achieve the desired results. Some drywall sanders include a vacuum attachment to collect excess dust and debris.
Stick with Warm Water or Mild Soap
Glossy paint: All-purpose cleaner or dish soap and water. White paint: Baking soda and water. Latex paint: Dish soap and water, or vegetable oil-based cleaner. Oil-based paint: White vinegar, or dish soap and water.
Clean walls after sanding
If you've just sanded your wall, perhaps after applying a dollop of filler to a crack, then you'll need to clean it before going any further. This will prevent that stray plaster dust from nestling into the carpet or getting mixed up with your paint.
Smooth any repairs, bumps, and nibs with a drywall pole sander. For smoother walls and better adhesion, some of our pros sand all previously painted walls regardless of the shape they're in.
Let the primer dry completely, then sand it down before painting.
Cleaning walls and trim will remove grime, cobwebs, dust and stains that can prevent your paint from adhering. Use a mixture of lukewarm water and mild soap, gently rubbing in a circular motion. Rinse your walls using a slightly damp cellulose sponge.
You need to fill holes, spackle and sand*, maybe even cut a new piece of drywall in to the existing wall. Your best bet is to use a good layer of primer to ensure a smooth, consistent base layer for the colored paint. In this case, your primer will mask many of the imperfections you're trying to fix.
The Golden Rule of Sanding
The golden rule for choosing your sequence is to never skip more than 1 grit. For example, if you start with P80, and need to finish at P240, rather than using every grit from P80 – P220, you can do P80 – P120 – P180 – P240.
After sanding a piece of wood, you'll need to clean it before adding a stain or paint. You can use a variety of tools and techniques to remove sanding dust from your wooden surface. Just make sure you get the surface of your project as clean as possible before adding any paint or stains to finish the piece.
You can use a plain board with paper attached and sand by hand. Or you can use electric sanders, which reduce the work. Round orbital sanders are very good on plaster walls, but on woodwork you have to be careful because they can leave marks on your wood.
Fine-grit sandpaper (120 and above) – The finer the grit, the smoother the finish. Flashlight or work light – Most automatic pole sanders come with a light built in, but if you're wet sanding or dry sanding, having a handheld light or a headlamp that you can shine on the walls really helps show any imperfections.