Things You'll Need
Soap and water
Oil-based painting primer
If your home has a steel door, you may think that you cannot change the look of the door because it is not made of wood. This is incorrect. You can make your steel door nearly any color that you want just by using a few simple steps to alter the staining process to suit the metal. Although you will need a little bit of patience to insure that the process works out correctly, you will be surprised at how simple this decorating task can be.
Wash your door with soap and water. Even automobile detergent will work. Let the door dry completely. If you like, you can hasten the process by wiping the door down with a clean rag, but you still need to let it air-dry for a good 20 minutes. Generally, you can leave the door in place while you clean and then stain it, but if the door is extremely weathered and will take more than a day's worth of work to clean, then you may wish to remove it from its hinges and place it on sawhorses. Of course, if you do this then you will need to have made arrangements for a stand-in door while you are working on your steel one.
Scuff up your steel door with sandpaper. You are not looking for beauty here, just a lot of little scratches so the primer will have edges to adhere to. Hold the sandpaper in one hand and "buff" the door with it so that you can see scratches in the surface of the door.
Prime the door. Fill your paint tray up with an oil-based primer, and carefully roll it on. All that scuffing will let the primer stick to the steel door and will make a good undercoat for the finish stain to come. Be liberal with the primer, because it is the primer that allows your stain to work. Allow the primer to dry overnight.
Stain the door. Pour the latex into your paint tray, and carefully roll on the top coat. If you like the way it looks, stop there and allow the stain to dry for about 24 hours. After the stain dries completely you may notice blotches or unevenness in the stain. If this is the case, put on a second coat.
The important step is the primer coat. Stain will easily stick to a primer, but because stains are made to soak into and penetrate a top coating, the finish on a regular steel door without primer will be disastrous. For this application, always use a primer first.