DAP Plastic Wood Hardener is a high quality, latex-based wood hardener formulated to seal and restore soft wood fibers to create a surface that can be repaired with either a wood filler or wood putty. It can be used in repairs such as windows, trim, frames, and doors. This easy-to-use hardener is brush applied, can be applied on damp wood, and is tack free in 30 minutes. When dry, DAP Plastic Wood Hardener can be sanded and painted. Interior/exterior use.