Yes, you can absolutely put primer on top of existing paint. This is a common and recommended step when repainting walls or other surfaces.
Why Use Primer Over Existing Paint?
Applying primer over existing paint serves several important purposes, making the new paint application more successful and durable.
Key Benefits of Priming Over Paint:
- Improved Adhesion: Primer creates a bonding layer that helps the new paint stick better to the existing surface, preventing peeling or bubbling.
- Color Blocking: As highlighted in the reference, "You can use a primer to thoroughly cover the old color, then apply 1 or 2 coats of the new paint." This is especially crucial when changing from a dark color to a light one, or vice versa.
- Uniform Finish: Primer helps create a smooth, consistent surface for the new paint, minimizing imperfections.
- Enhanced Durability: A primed surface often results in a more durable and longer-lasting paint finish.
When Should You Apply Primer Over Existing Paint?
Priming is beneficial in many repainting scenarios:
- Changing Colors: When the new paint color is significantly different from the old one (e.g., light over dark or dark over light). The primer helps achieve true color with fewer coats of the new paint.
- Surface Preparation: If the existing paint is glossy, stained, or slightly damaged, primer can help seal it, block stains, and provide a better base for the new coat.
- Switching Paint Types: While the reference mentions staying with similar types (like both latex), using a primer is often recommended when switching between oil-based and latex paints to ensure compatibility.
- Painting Over Repairs: If you've patched holes or cracks, primer is essential over the patched areas to prevent the new paint from looking dull or absorbing differently.
How to Apply Primer Over Existing Paint
Before applying primer, proper preparation is key.
Simple Steps:
- Clean the Surface: Wash the walls to remove dirt, grease, and grime.
- Repair Imperfections: Fill any holes or cracks and sand them smooth.
- Sand (If Needed): Lightly sand glossy surfaces to dull them, helping the primer adhere.
- Apply Primer: Use a brush, roller, or sprayer to apply an even coat of the appropriate primer for your project.
- Let it Dry: Allow the primer to dry completely according to the manufacturer's instructions.
- Inspect: Check for any areas that need touch-ups or a second coat of primer, especially if the old color is still showing through.
Once the primer is dry and provides good coverage, you are ready to apply your new paint color, typically one or two coats as mentioned in the reference.
Example Scenario:
Imagine you have a wall painted a vibrant red and want to paint it a soft beige. Trying to cover the red directly with beige paint would likely require many coats and might still appear slightly pinkish. By applying a quality primer first, you effectively create a neutral base, allowing the beige paint to achieve its true color and coverage in fewer coats.
