National Stucco Filler is recommended as an interior body filling or surface leveling putty for concrete, plaster, gypsum, masonry works etc. This can be used for filling up open grains of hard wood, MDF and other wooden surfaces, to obtain a smooth even surface. Mostly used in the carpentry work as repair and dent filler. It is highly recommended as a surface leveling putty for concrete surfaces. It is always to be used as an undercoat only.