Unlike some wood stain finishes on hardwood floors that have a reflective or shiny finish, most exterior deck stains are not meant to be shiny. A deck stain works best when it is applied to a clean wood surface. This allows the deck stain to penetrate deep into the wood pores to ensure a solid wall of protection against sun and water damage. The amount of deck stain that is applied depends on different factors like wood age, condition, and porosity. Not all wood surfaces will absorb the same amount of deck stain when they are being refinished.