Wood Finishes

Wood finishes are clear, protective coatings applied on the surface of wood. Bare wood is highly susceptible to moisture changes, resulting in constant expansion and contraction. Wooden handicrafts coated with finishes are less susceptible to the variations in humidity. Wood finishes keep them durable as well as beautiful. They make the wood shine and also give it smooth surface with color. Clear wood finishes protect them from outer elements such as chemicals used for cleaning the wood furniture, extreme weather conditions that are tolerated by wooden garden furniture and also from abrasion like which occurs when something is dragged on to a wood table. Wood finishing actually protects wood from water, dirt and grime apart from the wear and tear of everyday life

Types of Wood Finishes

Wood finishes are identified on the basis of two criteria- how the finish is applied and what is left behind on the wood surface? The first category includes the wipe-on, brush-on and spray-only wood finishes. The second category includes film forming finishes and penetrating or absorbing wood finishes.

Penetrating wood finishes are those that are absorbed by the wood whereas the other type of finish forms a protective film above the wood. Almost all the penetrating finishes are of wipe-on types. Even if they are initially applied with the help of a brush, the excess is removed after some time, generally after about 8-10 minutes.

Wood finishes can also be classified as water based wood finishes and oil finishes. Water-based finish are simple latex paint without any pigment. They are non-flammable, easy to use, fade-resistant and eco friendly wood finishes. Non toxic wood finishes are used for certain wood crafts that come in contact with human mouth such as wooden toys. Oil finishes are natural wood finishes derived from plants. Various types of oil finishes are used to treat and preserve wood products.

Penetrating Oil Finishes

Penetrating wood finishes are absorbent in nature and get soaked into the wood. They act as a wood sealant and protect the wood. Usually the following three types of oil is used for such finishing.

• » Linseed Oil Finishes: They are generally used on exterior wood siding and log homes.
• » Tung Oil Finishes: are commonly used in the home interiors. They are safe wood finishes and can be used on food contact surfaces like in wood kitchen accessories.
  
• » Danish Oil Finishes: are mostly used on interior doors and trim like for wood shutters.
  

Tung Oil and Linseed Oil take a long time to dry. Particularly, linseed oil can take days to get dry and remain rather soft for a very long time. However, application of linseed Oil is easy though somewhat messy. Maintenance of wood surfaces finished with tung Oil is very simple and it is also very easy to apply another coat on such surfaces. Danish Oil is a mixture of tung oil and varnish with pigments added to give color. Danish Oil is applied on wood surfaces in similar ways as the other penetrating oil finishes.

Protective Film Wood Finishes

Those wood finishes that form a film on the exterior of wood surfaces, cannot penetrate into the wood nor do they let any outer element penetrate the wooden surface. As such, they prove to be the toughest clear wood finishes.

• Wood Varnish: Varnish is one of the most durable finishes. The level of protection increases with each additional coat of wood finishes varnish. It can be brush-on as well as spray finish. It acts as a smooth, glossy finish. They are available in a wide variety of sheens and degrees of hardness. Varnish is usually combined with polyurethane for extended durability and protection of the finish.
  
• Polyurethane: Polyurethane too can be brush-on as well as spray finish. It is very popular now days due to the clear look and abrasion-resistance it provides to the wooden crafts. It is basically a plastic coating and can be used for interiors and exteriors. Though a single coat of polyurethane may be better than a few coats of water-based finish, it is prone to cracking after four to five coats.
  
• Lacquer finishes: Lacquer is one of the darker finishes. It is flexible, durable, and easy to maintain. Regular lacquer dries very quickly, and spray guns can be used to finish with lacquer. However, the fumes are hazardous to health. It is more common as interior wood finish. Though brush on lacquers are available, they are rarely used these days.
  
• Shellac Finishes: Wood shellac is a natural resin. It has an alcohol base, and gives a dark finish. Shellac dries very fast and is less likely to collect dust. It is available in two forms - flaked and liquid. Both are mixed with alcohol to acquire a thin consistency. It is fairly durable finish, but not as durable as lacquer or varnish. Although, it is a natural resin it is not recommended for food contact surfaces.