No diy advice is ignored as often as the recommendation to thoroughly wash the walls before priming and painting.
Sand bathroom walls before painting.
If your bathroom has a window open it.
Sand the walls lightly with medium grit sandpaper brush them off with a dry cloth and vacuum up all residue.
Wear rubber gloves when using tsp or a bleach solution.
For other small imperfections on the wall such as plaster bumps smooth them away with sandpaper.
Smoothing walls before painting is necessary for surfaces previously painted with a gloss or high gloss paint.
When painting a bathroom or kitchen wash the walls with a solution of approximately three teaspoons of laundry detergent to one gallon of water.
Dust and sanding debris will mar your wet paint.
You can always tell when an uneven surface was painted because you will see darker and lighter patches on the wall.
Tsp is a stronger cleaner.
Using a pole sander fitted with 120 grit paper sand the walls make sure to wear a dust mask.
Again wipe away any debris and allow to dry completely.
Alternatively dilute concentrated tsp trisodium phosphate cleaner with water as directed.
For oil based paint a medium grit sandpaper 100 to 150 grit should be used.
Sweep the sander side to side as you work your way from the top down.
Scrape any cracked or flaking paint with a paint scraper.
Don t sand so hard that you cut into.
Wall dirt makes it difficult for paint to stick to the surface so make sure your wall is spotless before you start painting.
Always sand and paint the ceiling completely following these same steps before addressing the walls.
For previously painted water based paint sand with a fine grit sandpaper.
It takes away any bumps and impurities which would otherwise cause an uneven painted surface even if you are using the best paint sprayer for walls or a basic roller.
For stubborn stains try baking soda a substance that s used to clean everything from sinks to toilets.