What Does a Wood Deck Brightener Actually Do?

Wood Brightener Basics

• Deck wood brighteners are products designed to brighten and restore wood. Many brighteners contain oxalic acid, sodium hydroxide or are phosphoric-based. These active ingredients allow the wood brighteners to remove discoloration caused by tannin bleeds and rust stains caused by nails and other metal objects. Woods naturally turn gray as they age and become weathered. Brighteners remove this gray to restore a color to the wood that resembles its original hue.

Applying Brightener

• Follow the manufacturer's instructions to prepare and use wooden deck brightener. Liquid brighteners may require dilution, and powdered brighteners require mixing into water before they can be applied. Typically, the brightener is applied following cleaning before the deck dries, and is either sprayed or rolled onto the deck. The brightener is then left on the wood for five to 15 minutes, depending on the degree of lightening desired. Following this period of time, rinse the deck thoroughly and let it dry for at least two days before applying finish.

Other Deck Restoration Steps

• Brighteners are meant to be applied as a part of a broader cleaning and restoration regimen. If the deck has been finished previously, any remaining finish will have to be removed. A scraper or sander is generally utilized to remove the finish. Any remaining dirt and grime can be removed using a combination of scrubbing with a plastic bristle brush, power washing and deck cleaner. This is followed by brightener application. After the brightener has been applied, left on for a suitable amount of time and then rinsed off thoroughly, the deck should dry completely before any finish is applied. There are multiple finishing or sealing options, including clear sealers, oils, exterior polyurethane and semitransparent stains. Certain woods, such as cedar, are commonly left unfinished because they weather attractively.

Possible Negative Impact

• As with many other cleaners or chemicals, wood brighteners can potentially be damaging to vegetation, animals and surfaces if used improperly or spilled. The University of California also reports that deck washes that contain brighteners can dislodge some amount of arsenic, chromium and copper from CCA-treated wood.