If you want to get a perfectly painted wall, it is important not to neglect the preparation work which is vital. Here’s how to do everything, from cleaning to filling holes and cracks.
Prep the room
Before anything else, take care of the floor and furniture. It is important to empty the room out completely.
Remove any furniture, or group them in the center, covering them with a tarp. Also add some protection to your floor (plastic, newspaper, cardboard, etc.). Cover with plastic bags and adhesive anything that cannot be removed.
Then check there isn’t anything on the walls. Remove paintings, pictures, frames, or other decorative object. Don’t forget curtains and rods.
Protect with some tape baseboards, corners of the ceiling, windows and door jambs.
Next, turn off the electricity to avoid any short-circuits.
Remove the various outlets in your room, and protect any cables.
Don’t forget your own security. Avoid dust and wear gloves and eyewear when handling anything dangerous.
Clean the wall
Clean your wall thoroughly with a sponge and detergent. Start from the ceiling and go down to the baseboards. Rinse with clear water and let it dry.
If your wall has some mold: clean them out with bleach or fungicide.
Then wash and rinse the wall again.
If you have removed wallpaper from the wall, but there are a few pieces, or glue remaining: moisten them, then remove with a scraper. Allow the wall to dry off before cleaning it.
Repair the wall
Removing nails and screws
Once your wall is perfectly clean, remove the screws.
Use a pair of pliers to remove nails.
Filling holes and cracks
Start by widening the holes and cracks (reasonably) with a triangular scraper. Scrape off the bits and pieces not fitting properly.
To make coating stick properly, moisten with a sponge the areas to reseal.
Apply, with a putty knife, a spackle over the cracks or holes.
Smooth coating to prevent thickening and let it dry.
Once it is dry, sand the area with a medium grit sandpaper (80).
When the major asperities and defects eliminated, you must reseal the pinholes.
Coat the wall
Once the wall is prepped, it is time for the under-layer. Apply a primer first. This will allow better adhesion of paint to the surface and increased durability.
Start by painting angles and borders of the room (ceiling, baseboards, windows, doors) with a simple paint brush. Spread it well across the surface to make it as thin as possible.
To ensure that the paint adheres well to the substrate, dilute the first coat with 10% of the recommended solvent (water or mineral spirits).
Then attack the large areas of the wall with a roller. This will allow you to spread the undercoat faster.
Work in areas of about ten square feet, using two directions.
For example, you can do a first run vertically, and a second one horizontally. Both ways will be perpendicular to each other.
Always start at the top of the wall, gradually going to the floor.
Once you have covered several areas, smooth it together with large movements. Don’t add any more primer. The goal is to blur out any traces of your movements.
It is sometimes necessary to repeat a second coat of primer, using the same application technique as for the first layer.
Let the wall dry for a few hours between coats, and about 24 hours after laying the last one.
Clean all your tools using the solvent recommended by the manufacturer.
Once all is done, you only need to apply the finishing paint.