Yes, factory-finished doors and molding can cause a dusty, rough, or textured finish when painted with new paint if they are not properly prepared. This issue is common when applying new paint over factory-primed or factory-finished surfaces, which are often designed only for industrial spraying, not top-coating with household paint.
Why Factory-Finished Doors Cause Dusty Finishes
Factory Primers are Absorbent: Many factory-primed doors and molding are "hungry," meaning they are highly absorbent. When you apply new, water-based paint, the door or molding pulls the water out of the paint too fast, causing it to look dull, dry, and textured (like dust) rather than smooth.
"Orange Peel" Texture: Factory-sprayed doors and molding often have a slight, high-speed commercial texture known as "orange peel." If you paint directly over this without sanding it flat first, the new paint will just be a glossier version of that rough surface, making it look dusty.
Contamination/Dust Residue: Factory-primed doors and molding often have a layer of light, powdery dust from the production process. If this is not completely removed before painting, it will mix with your new paint, causing a gritty, dusty finish.
Low-Density Fiberboard (LDF/MDF) Issues: If the door or molding is cheap LDF, the water in your paint can lift the wood fibers, creating a rough, fuzzy texture that feels like dust.
How to Fix or Prevent a Dusty Finish
Lightly Sand the Surface: Use 220-grit sandpaper to scuff sand the factory finish, removing the grainy texture and improving adhesion.
Remove All Dust (Tack Cloth): After sanding, use a vacuum and then a tack cloth to remove every speck of dust. If you leave sanding dust behind, it will ruin the finish.
Apply a Primer: Use a high-quality primer to seal the "hungry" factory primer. This stops the new paint from being absorbed too fast.
Avoid Dry Rolling/Spraying: Ensure you are applying a "wet" coat of paint rather than a thin, dry layer.