This story shows how to prepare trim for painting.
Door and window trim, as well as baseboards, cornices, moldings, and chair rails, make a major design contribution to the style of a room. Whether finished with paint or stain, trim must be properly prepared. This normally means setting nailheads below the surface of the wood, filling and sanding holes, cleaning, and repairing or replacing damaged wood. It can also require the removal of old paint or varnish to provide a fresh surface for the finish.
Whether you finish your trim before or after painting the walls, it's best to have all the preparation work completed on both the trim and the walls before finishing either surface.
Be sure to wear protective glasses when stripping and a dust mask when sanding. Chemical strippers can contain toxic fumes, so ventilate the room adequately before applying the stripping solution. Rubber gloves are also a must to keep the chemicals from burning your hands.
After scuff sanding, the surface will contain microscopic dust particles left in the grooves by the sandpaper. Pull these particles off the surface with a soft cloth dampened in mineral spirits or water. Don't use a tack cloth; it can leave a residue that will interfere with the paint bond.
Apply a thick coat of stripper to the surface with an old natural-bristle paintbrush (many strippers will melt nylon bristles). Brush in only one direction to avoid lifting the stripper off the surface. Let the stripper work for about 20 minutes, then remove it and the paint with a scraper.
Reapply stripper where paint is still adhered and repeat the process. Remove small flecks of paint with a coarse abrasive pad, cleaning it with water or mineral spirits, depending on the stripper you've used. Finally, clean the surface with a fine abrasive pad dipped in denatured alcohol.