Barn wood can add character to your home and can be used in many different projects. Barn wood is popular for its rustic look and people often appreciate that the wood is generally old and may come from interesting places, therefore bringing a sense of history to a project. Unlike some types of wood, extra care should be taken when refinishing barn wood and only certain types of tools and products should be used, in order to preserve the character and look of the wood.
Clean the wood thoroughly by using an environmentally sensitive and somewhat mild-strength borate cleaner mixed with water. Use a stronger cleaner such as trisodium phosphate (TSP) dissolved in warm water if you would like the barn wood to have a newer, cleaner look. However, this approach may take away from the essential "barn look" of the wood that makes it so appealing in the first place.
Use plastic bristle brushes in conjunction with the previously-listed cleaners when cleaning the wood. Plastic bristles are much softer and are less likely to destroy the character of the wood than wire brushes. Refrain from sandblasting the wood as this may also take away from the wood's natural appeal.
Rinse out the cleaning solution with water and let the wood dry completely before moving on.
Apply a sealer to all four sides of the wood as sealant can protect it from future water damage, rot, day to day abuse and wood fungus.
Some people prefer a cleaner look both in appearance and fit of their barn wood. In this case, it is possible to re-mill barn wood for the specific shape desired. You can also sand down the wood, initially beginning with a rough grade sandpaper and working your way up to finer and finer sandpaper. This can bring out the grain of the wood. If you prefer a painted look as opposed to natural, be sure to use an oil-based primer on the wood before painting it.
The cleaning solvents are quite volatile and protective gloves should be used when working with them.