Things You'll Need
Liquid dish soap
Mild paint stripper
Plastic paint tray
Painting a room can drastically change its appearance without breaking your budget. However, some paints cannot be applied over other types of paint successfully. Using latex paint over oil-based paint without first applying a primer will create nothing but a mess. Latex paint generally cannot adhere to oil-based paint and--after a short time--will begin to peel away from the wall, leaving an unsightly eyesore. Fortunately, you can correct the problem by removing the latex paint without harming the underlying oil-based paint.
Mix 1 gallon of warm water and 1 tbsp. of liquid dish-washing soap. Mix with a wooden spoon. Saturate a sponge in the mixture and wring out the excess liquid so the sponge is damp, not soggy.
Scrub the walls with the sponge to remove the latex paint. Keep scrubbing the walls and peeling away any loose latex paint from the walls until all latex paint is removed. Continue to Step 3 if latex paint is still present.
Pour a mild paint stripper into a plastic paint tray. Dip a paintbrush into the mild paint stripper and apply it to the latex paint.
Allow the paint stripper to sit on the wall for the predetermined time. Each brand of paint stripper has its own specific time frame. However, paint strippers typically need 20 to 30 minutes to soften the latex paint. Refer to the instructions on your brand's label.
Remove the paint stripper and softened latex paint from the walls using a plastic paint scraper. Wipe the chemical and paint off the scraper with paper towels after each pass. Continue in this manner until you have removed all latex paint from the oil-based paint.
Wash the walls clean to remove any paint stripper residue with a solution of 1 gallon of water and 1 tbsp. of liquid dish soap. Use a lint-free cloth saturated in the mixture to thoroughly clean the walls. Allow the walls to dry completely.
Wear rubber gloves when working with paint strippers.
Provide proper air ventilation during the paint removal process.