Step 1
Sweep the stairs to remove all dust and debris before beginning your work. If needed, go over the stairs with a clean damp rag for further dust and debris removal. Allow the steps to dry fully.
Step 2
Sand the stairs using a 220-grit sandpaper or sand sponge to remove any old paint, if applicable, and to create a smooth surface for staining the wood. Use even strokes; if any knots are present in the wood, go over them with the sandpaper until they are even with the rest of the stair surface.
Step 3
Vacuum each stair to remove any residue left over from the sanding. Apply mineral spirits to the stairs with a rag for further cleaning action, and allow to dry fully for about 10 minutes.
Step 4
Apply one coat of your chosen stain to the stairs using a paintbrush. Unless you are painting the stairs, primer is not required, as most stains contain linseed oil, which helps the stain adhere to the stairs without the use of a primer. Apply the stain to a few stairs at a time and allow them to dry fully before going further up or down the stairs. Allow the first coat on each stair to dry completely for at least two hours.
Step 5
Apply a second coat of primer to each stair and allow to dry for at least two hours before use.