It's easy to give your plain steel doors the look of rich wood. An inexpensive wood-graining tool and a heavy-bodied wood stain are the keys to this decorative-finish technique. You can apply the finish while the door is on its hinges, but it's easier if you remove the door and lay it on padded sawhorses.
Steel doors usually come primed white, gray, or tan. If your door is colored, apply a neutral base coat and let dry. Mask off glass and remove all hardware. Wipe the door with a cloth dampened with mineral spirits.
1. Use a lint-free cloth to wipe a thin, uniform coat of wood stain on a small section of the door. Complete one section of the door at a time, beginning with the interior panels and working out. Create a horizontal grain on crosswise sections and a vertical grain on lengthwise sections.
2. Draw the graining tool down the stained section while exerting pressure with your index finger. Move at a constant speed. While pulling the tool toward you, slowly rock it up and down to create a varied pattern. If you make a mistake, just wipe on more stain and try again. Occasionally, clean the graining tool so it doesn't clog. Use a dry brush or cloth in tight corners.
3. When you have grained all sections, allow the door to dry for 24 to 48 hours.
4. Brush on a coat of polyurethane. Use exterior polyurethane on doors exposed to direct sunlight for extended periods.