There are several reasons as to why paint lifts from an interior door. Here, there were successive layers of oil and acrylic paint over an original base coat of varnish, going back about 80 years. The preparation between coats appears minimal, the paint isn’t always compatible, plus it’s always difficult for paint to stick to old varnish. Repainting properly means removing the multiple layers and preparing what’s left for a modern paint job.
Gather your supplies
primer, sealer, undercoat
oil-based gloss enamel (we used Dulux Super Enamel in Cherry Race)
Lead alert: When repainting, remember old paint may contain lead. If in doubt, check with a testing kit or just assume it’s present and take the necessary precautions such as wearing your safety gear. Also, wash thoroughly after working on it, especially if you stop to eat while you’re on the job.
- Step 1: Remove door from frame. To do this, support door on a wedge, then undo all screws, leaving 1 in top hinge until last. This way, door remains supported and you can remove it in a controlled manner. If screws, usually slotted screws, are stuck, loosen them by putting a screwdriver in slot and tapping with a hammer. If door is old and has been painted many times, prevent potential damage to the frame by cutting around hinges with a utility knife. This enables you to break through bond the paint forms with frame.
- Step 2: Lay door on a work surface, preferably outside. Using a heat gun, gently warm paint, then scrape off with a 50mm scraper. Remember, the idea is to soften the paint, not burn it. Once most of the paint is removed, go over surface thoroughly with a sander using 120-grit paper, until it’s smooth and last traces of paint are gone. Finish off sanding by hand, using 180-grit paper, especially around panels where a machine can’t reach. All old varnish must be dull to look at so it gives paint a surface to adhere to. Repeat this step to prepare other side of door.
- Step 3: Remove dust on door with a damp rag. It’s easiest to paint both sides of door while on its hinges, but first paint top and bottom edges so door is fully sealed. This helps prevent door from swelling and sticking in humid weather conditions.
- Step 4: Hanging the door is a reverse of taking it down, so support it on a wedge and put in top screw. Align, then put in remaining screws.
- Step 5: Apply primer, sealer, undercoat to both sides of door. If painting in a strong colour, have a grey tint added to primer (this enhances colour). Apply with as few brushstrokes as possible. Let dry. Sand lightly with fine paper.
- Step 6: Paint both sides of door with oil-based gloss enamel. This type of paint is great for hiding brushstrokes. Be careful not to apply it too thickly as it may sag and run. Work fairly quickly, painting 1 panel at a time, starting with internal panels. Give it a good cover, then brush out evenly in direction of panel. This is known as laying off. When dry, sand with fine paper and apply a second coat. Let dry.