TW Deck Bright - 100% Pure Oxalic Acid Crystals is meant for neutralizing and brightening wood surfaces after cleaning or stripping. Oxalic acid is great to use on soft or hardwood decks, fences, patios, siding or any other wood installation. TW Deck Bright can act as a cleaner on its own and even remove iron staining from wood surfaces. We highly recommend using oxalic acid after cleaning or stripping a deck. Oxalic acid also balances the pH in the wood and lifts the tannins of the wood in preparation for staining. If you want to take your wood restoration to the next level, be sure to add TW Deck Bright into your wood cleaning and restoration process!