How To Prepare a Wall for the Primer Paint

Painting a wall is not as simple as taking a paintbrush, dipping it into paint, and applying paint to the surface. When you are painting a wall or any surface, it is essential to prepare the surface first. It should be clean and dry as well as sealed. The surface to be painted should be even and smooth. This basic preparation is crucial to have the wall ready for the primer paint, the initial coating that you apply to the surface to be painted, which forms the base for better adherence of the top coats. There are three types of primer paints – alkyd, which is compatible with oil-based paints and suitable for almost all kinds of surfaces; latex and acrylic, which is economical and versatile; and tinted shellac, which works great with slick and difficult surfaces. Here are some of the things that you should do to prepare a wall for the primer paint.  

1. Make sure that the wall to be primed is very clean and dry. If it is bare wood, use fine sandpaper to smooth and even out the surface. Sand the wood following its grain. Brush cracks with an old toothbrush and add wood filler. Sand the wood only when it is completely dry. If the wall has wood knots, fill them with wood filler and paint them with shellac first to prevent the resin from seeping through the primer and staining the top coat later. Wipe with a slightly damp cloth afterwards to remove dust. If your wall is made from resinous wood or have been previously stained, use aluminum primer to seal in the resin.
2. Check for molds if the wall is quite old. Wash moldy spots with water and bleach solution and rinse with clean water. Allow the wall to dry completely before applying fungicide to prevent future mold growth. Heavier primer will be needed for walls that have been treated in this way.
3. Strip wallpaper and remove the stubborn parts with warm soapy water. You can also rent a steamer to make the removal easier and faster. Make sure that the remaining glue will be completely removed. Rinse the wall and allow it to completely dry. Sand the wall to make it even and smooth and remove bumps and indentations. Deeper indentations, cracks, gaps and holes should be filled with wood filler, which should be allowed to dry before sanding. If the wall had been painted before wallpaper had been applied, sand the whole wall with a sander to remove the gloss from the previous paint job.
4. Clean and seal drywalls before you apply primer paint. Use a sander to make it easier to even out the surface of the drywall and go over other parts by hand. Check for signs of staining as you will have to use a different primer if there are stains on the drywall. Repair any abnormalities you find on the surface of the drywall. New drywalls should be coated with primer as soon as possible to prevent them from turning yellow. 
5. Washed and rinse previously painted walls with warm soapy water. Scrape and remove peeling paint and repair cracks and gaps before sanding the entire wall to remove the gloss from the old paint. If you do not want to apply primer over the old paintwork, you have to use paint stripper to remove the old paint, before preparing the wall for the application of new primer paint.

Remember that there are different primers for different types of wall surfaces. Use the right one that will be suitable for the top coats of paint. You should also consider the location of the wall when applying primers and top coats, as exterior and exterior primers and paints are made differently.
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