Johannes Boonstra, a technical advisor for Akzo Coatings, Inc., in Troy, Michigan, replies: Most door manufacturers suggest you apply stain directly over their gray or white primer to get a woodgrain effect, but you’ll get nicer results by first applying a coat of tinted primer resembling the fond (base) color of a particular wood. You can have primer tinted at a paint store. Experiment with different samples to get a color you like.
To avoid runs, work with the doors laid flat on sawhorses. Once the primer has dried, clean the surface with denatured alcohol and clean rags, lightly sand the surface using 220-grit sandpaper or Scotch-Brite pads, then vacuum the door and follow with a water-dampened cloth to remove fine dust particles.
You create the wood-grain effect by applying a solvent-based wiping stain over the primer, then wiping the stain down with a lint-free cloth after the stain sets up—usually within 10 to 15 minutes. You might consider practicing on the inside of a closet door to get some application experience. If you don’t like what you see, the stain can be wiped off with mineral spirits.
Let the wiped-down stain dry, which may take 24 hours or longer, then either brush or spray on two coats of a high-quality clear top coat (gloss, satin or matte) to finish the project. This top coat protects the stain and assures easy cleaning. Allow the stain to dry completely before you apply the top coat; otherwise, it will dissolve the stain and ruin the wood-grain effect. Oil or waterborne top coats may be used, though some oil products, polyurethanes especially, tend to yellow. If you choose a waterborne top coat, contact the manufacturer to make sure it’s compatible with the wiping stain.
Take your time and work in a dust-free environment. The application sequence to the panel door may work best in the following order: First wipe down the panels, let them dry and apply the top coat; then finish the inner stiles, followed by the rails and finally the outer stiles. Always follow recommended drying times and contact the manufacturers to assure the compatibility of all the finish products.
By the way, most hardboard-door manufacturers have finishing manuals available; some even provide videotapes. When purchasing these doors, always request a finishing manual and read it carefully before you start painting.