During and after construction, logs can become stained from rain hitting the logs and leaving water stains, as well as black spots from water hitting nails, spikes, or lag screws used in construction and they leave unsightly black stains on logs and other wood. This can be easily removed using several methods:
- Oxalic acid For black nail stains you can use oxalic acid and water. A cup of oxalic acid in a gallon of warm water is the best mix for normal stains. If you have any stains, simply rub the solution off with a soft cloth and you’re good to go…they’re gone. If you have a lot of stains or want to brighten the logs before you stain the house, you can use a hand pump sprayer for the job. This solution is poison, so stay away from any living things. Also wear eye protection and a face mask to filter out any of the chemicals. This chemical is available at most home centers and is known as “wood bleach.”
- bleach and water Another way to shine and clean your logs or deck before finishing is to use a mixture of half household bleach and half water. This can be sprayed with a hand-pump sprayer and worked into difficult spots with a brush. Never try to make your own super stain remover and mix oxalic acid (wood bleach) and household bleach. This will give off a tremendous volume of noxious vapors that can damage your lungs.
- Sodium Percarbonate (CPR) CPR is used to clean and shine bare wood that is dirty, discolored, or gray from UV exposure. Mix CPR with the concentration of polish solution for use on new construction just prior to staining to remove dirt and grime from logs during the construction process and to break down mill glaze. Mixed with Log Cleaning Solution Concentration – Use for periodic cleaning of stained logs to extend the life of the stain. It can be easily applied using a garden sprayer.
- phosphoric acid Phosphoric acid is a liquid concentrate for cleaning logs and wooden surfaces. It is commonly known by the name of Log Wash. It can be used as a maintenance cleaner or to prepare the wood surface for a new coat of stain or finish. The exterior surfaces of a log home are a settling ground for dust, pollen, and other airborne contaminants that tarnish the surface and encourage mold growth. A light cleaning once or twice a year will keep the house looking beautiful and help extend the life of the exterior wood finish. To prepare the bare or finished wood surface or for a new coat of stain or finish, Log Wash removes surface dirt, grime, pollen and mold and mildew without damaging the wood or finish. Unlike bleach solutions, Log Wash does not alter the natural pH balance of wood, thus preventing wood fiber damage and iron tannate staining. It can be easily applied using a garden sprayer.