Interior painting is a job that most people can and will complete themselves. However, as an amateur, you may make some painting mistakes as you work. Most mistakes can be fixed fairly easily, and this is true of a stain that has not been treated properly and leaches through the new paint. Keep reading to learn about this painting issue and how it can be fixed.
Stains can appear and make your newly painted wall look discolored or dark in spots. Stains are common if grease, mildew, or fire-damaged areas are not properly cleaned before you start painting. Fire-damaged areas are particularly difficult to paint over, because smoke leaves organic matter behind and this material is often gritty and greasy in nature.
If a stain has leached through your paint, you can remove the stain and add a topcoat of paint over the stain. You will need some trisodium phosphate (TSP) to remove the stain. Trisodium phosphate is a white powder that is mixed with water to create a basic or alkaline cleaning material. Mix the powder by placing two tablespoons in a bowl and adding one teaspoon of water. Mix the cleaner and add water as needed to create a thick paste. Place gloves on your hands, because the strong basic material can burn the skin, and use a cloth to spread the mixture on the stain.
Allow the TSP to sit for 15 minutes and then use warm water and a cloth to remove the cleaner. Clean the area gently with a soapy sponge. The stain should appear lighter in color after the cleaning is completed. If it is not, then you will need to remove the paint from the area and treat the stained wall underneath. Use a piece of sandpaper to remove the paint. You can place the TSP cleaner directly on the wall or you can purchase a dry cleaning or chemical sponge to treat the area.
Dry cleaning sponges are made from rubber and the material absorbs debris, like soot, as it is moved across the stain. Gently rub at the stain with the sponge until the area lightens.
Painting The Stain
Once the stain has been treated, you should cover the spot with a stain blocking primer paint. These primers are typically oil-based products that create a solid barrier over the stain to keep it from seeping through the paint. Add a thick coat of the primer to the stained area and allow it to dry. Make sure the primer is white or the undercoat may change or darken the coat of paint placed over the top of it. The area will appear darker, much like the stain, if you use a gray, brown, or black primer.
You can add the paint over the top of the primer afterwards with either a paintbrush or a roller. Cover the main part of the stain first and then use a small paintbrush around the edges to feather them out. Use very gentle pressure when doing this and move the paintbrush up, down, and side to side. This will help to blend the edges of the newly painted area with the dry paint around it.
If you do see overlapping paint that is obvious around the stain area, then place about one cup of your paint in a paint tray and mix in about one-eighth of a cup of water. Use a roller to apply the paint over the stained area and about six inches on all sides of the paint. The watered down paint will blend much more seamlessly with the dried paint and help to obscure lap marks and overlapping paint edges.
For professional help with a project like this, contact a company like Above Average Painting & Drywall.