How to Paint Interior Doors for a Factory-Smooth Finish

D**oors** are the most abused surfaces in your home. They take constant contact from hands, pets, and vacuum cleaners, which is why a slap-dash coat of wall paint will peel, chip, and scuff within months. To make a paint job last, you have to treat the door like a piece of furniture rather than a wall. Professional results rely entirely on prep work. If you skip the scuff-sanding or fail to remove the door from its hinges, you are setting yourself up for runs, drips, and a surface that collects dust like a magnet. Follow these steps to ensure your finish is rock-hard, smooth to the touch, and resistant to the daily grind.

1. Lay the Door Flat First. Take the door off its hinges and lay it flat on a pair of sawhorses. Remove all handles, latches, and plates to prevent hardware clumping and ensure even paint coverage.
2. Degloss Every Surface. Use a 150-grit sanding sponge to degloss the entire door, including the edges and profiles. Wipe away all sanding dust with a microfiber cloth and a final pass of a tack cloth.
3. Prime for Perfect Adhesion. Apply a coat of high-adhesion bonding primer using a synthetic brush for the panels and a 4-inch foam roller for the flat surfaces. Ensure full, even coverage without leaving puddles in the corners.
4. Feel for Hidden Bumps. Once the primer is dry, perform a very light sanding with a 220-grit sponge to knock down any raised wood grain or primer nibs. Wipe clean once more before moving to the topcoat.
5. Keep a Wet Edge Always. Using a high-quality waterborne alkyd paint, roll the flat sections first, then brush the profiles. Work quickly to maintain a wet edge to avoid visible lap marks.
6. Wait the Full 24 Hours. Allow the first coat to cure for the recommended time on the can, then apply a second thin coat. Let the door sit flat for at least 24 hours before rehanging it to prevent the paint from sticking to the door frame.