Common Types of Wood Finishes

Wood finishes are designed to protect the wood and to enhance the grain of the wood so as to bring out it’s natural beauty. There are many wood finishes. Wood polish and finish shield wooden surfaces from humidity, moisture, ultraviolet rays of the sun and general wear and tear. Moreover, they enhance the aesthetics of the wood surface by adding a rich, luxurious, and glossy sheen to it. Applying polish and finish can close the pores of the wood to prevent bacteria from harboring and sanitize the surface as well. Since wood polish finishes can affect the property of the wood, they may be used to enhance its functionality and strength.

Different finishes provide different measures of durability, protection, ease of application and looks, it is important to know and understand the difference between each wood polish and finish available so that you can use them in most appropriate way for different purposes and applications.

Wood finishes are divided in two basic types. Surface finishes and penetrating finishes. Woodworkers may decide to apply Single or multiple coats of paint on furniture depending upon how often particular surface will be touched or used. Let's take a look on some of the most popular wood finishes that are used today. Knowing what they are made of, their characteristics, pros and cons will definitely help you choose the best finish for your valuable wooden pieces and furniture.

Common Types of Wood Finishes

1. Varnish

Available in high-gloss, satin, or matte forms, water-based or solvent-based, varnishes are the most durable finish compared to other finishes in their resistance to water, heat, solvents and other chemicals. Made of tough and durable synthetic resins that have been modified with drying oils, varnishes provide excellent protection against many substances.

They are usually clear and transparent. They give better UV protection. Varnishes dry slowly. Application of the varnish on the top of dyes also gives better protection.

Varnish polish is durable and can be applied to both stained and bare wood. It comes in different varieties of sheen as well. Before applying any varnish wood polish, the surface needs to be cleaned and dried properly to obtain the best results.

2. Wax

Available in both water-based and oil-based types, waxes look really good with more of a sheen than a gloss and are easy to use and apply. However, they are not very durable and therefore require regular maintenance. Available in paste and liquid forms, they can protect the wood from moisture and improve its life. They are obtained from plants, minerals and animal sources.

At first glance, when you start to apply a coat, wax can darken the surface of the wood.

But once the wax dries, the surface will return somewhat to its original shade (although it will be a shade or two darker). Adding more and more coats, over time, will darken the color of the wood too. However, if keeping the natural original color of the timber is important, then you could decide to go for a more translucent substitute; such as Hard Wax Oil. Wax, due to its ability to seep right through wood layers, is one of the best-protecting finishes you can opt for. But it is not the best sealant option against heavy water drenching (in other words, you wouldn’t make it your first choice for outdoor furniture). It can be wiped off the surface with a rag and a simple white vinegar solution. You can wax over varnished wood – in fact, you can wax over almost any type of coat, whether it be varnish, paint, lacquer, etc. So, if you want to have a finish with great preservative qualities and retain the natural character of wood, wax is a great option for indoor furniture.

3. Oil

Similar to waxes, oils are easy to work with and easily repairable. The only difference as compared to waxes is that oils offer more durability. Despite their slow drying times, oils nourish and protect the wood. They are designed for both interior and exterior use.

Oil wood finishes improve the appearance of unfurnished wood. Natural oils that are present in the wood dries out over time. Oils finishes replace the natural oils and nourish the wood grain. Oil-based wood polish easily covers up the nicks and scratches on the wood surface. Be cautious to protect the eyes while applying the polish.

4. Shellacs

Shellac is a natural wax finish that is secreted from a bug that thrives on a tree. A mixture of the collected wax from the tree and an Alcohol solvent gives better consistency. Shellac is available in a variety of colors. It’s easy to apply and dries quickly. It gives a glossy finish to the wood. Shellacs, available in a variety of colors that are non-toxic, are the easiest to apply. Shellacs are easy to repair and can also be used as a sealer before applying a stain. The shellac polish is quick to dry and is a hard finish.

Nevertheless, shellacs are not very durable and can be easily damaged as they are dissolvable in both water and alcohol and therefore are not suitable for outdoor use.

5. Lacquer

Lacquers are thin solvent-based finishes as compared to the other finishes. They are usually applied by spraying. Available in matte, high-gloss and satin finishes, in clear form and in clear stain colors, lacquers are considered the best all-around finish for wood. This is due to the fact that they are the fastest-drying finish and they are more durable than shellacs. Lacquers add an amazing depth and richness to the wood. It is quite easy to remove, you can apply a new polish and finish to the wood whenever needed. The finish is sensitive to heat, and some may emit fumes so appropriate safety measures are necessary while application. You might also need a skilled person to do this job effectively.

6. Wood Dye

Wood dyes may match the existing color of the wood or change the color of the surface. Dyes are colorants that are dissolved in solvents like mineral spirit, alcohol or water. Wood dye works in a similar manner that cloth dyes do. When mixed with the proper solvent, dye crystals dissociate into individual molecules. That makes them tiny enough to penetrate deep into the wood. The most common wood dyes are powders that are mixed with water or alcohol. Because they’re so small, dye molecules go deep into wood and bond directly to it, so it is not necessary to have a separate binder included. That’s an advantage since there is no film left on the wood surface that could cause problems when the finish is applied. They allow the addition of deep, vibrant colors without obscuring the grain and therefore are better suited to dense or figured woods. However, dyes can be more prone to fading in sunlight. It can be applied with a brush, sponge or spray gun. Wood dyes are finishes that are both water-based and oil-based.

7. Stain Wood Finish

A stain is a colorant applied to wood to change its color. Unlike paint, stains are designed to soak pigment into wood fibers with a solvent and then as it sets or cures, the color binds to the wood. They can be oil, water, varnish or gel-based. Wood stain finish changes or rather improves the wood color and the visibility of the grains. It is used to enhance the color of the woodwork and to achieve uniformity when there is inconsistency in the appearance of the wood. Wood stain finish is best suited where the stain is darker than the color of the wood. Wood stains are available in a variety of colors. The final outcome will depend on the number of coats applied on the wooden surface. This finish does not protect the wood. Once the wood stain is applied, a final coat of wood protective finish is required to protect the wood.

8. Water-based Finish

They contain acrylic resin along with urethane and alkyd. They are thin in consistency and dry easily. After application, the liquid adheres to the surface as the water begins to evaporate. Water-based finishes give a natural appearance to the surface and are easy to maintain. They give a very clean and clear finish. Water-based finishes have fewer odors than oil-based finishes. The flexibility of the water-based wood finish allows it to adhere to any surface quickly. The water-based wood polish can be applied on painted, bare, and stained wood surfaces. Unlike oil-based polishes that turn light amber with age, the water-based polish puts on a coat that stays clear over time. So, it can be safely used on light-colored floors without darkening them with age. Many decorative wood items, handicrafts, and articles are coated with this finish for an elegant look that doesn’t go away over a period of time. You might need to employ skilled applicator water-based wood finishes.

9. French Polish

French polish is not a product. Rather, French polishing is a method of applying shellac to wood furniture, musical instruments, or decorative accents in many thin layers—typically well over 100—that results in a highly glossy, glass-smooth surface with a rich depth that beautifully highlights the grain of the wood. A mixture of shellac and alcohol is used for this purpose. While it’s been around since the 1600s, French polish today has somewhat fallen out of favor, due to its labor-intensive process. A cloth dabber is used to apply the shellac, along with a few other basic supplies. It is suitable for any type of wood, but you’ll find it far easier to achieve the glossy, perfect French polish finish on hardwoods with closed grains, such as maple, spruce, and cedar. If used on an open-grain wood, such as walnut, mahogany, and rosewood, you’ll need to fill the grain with pumice powder, adding an extra step to the (already lengthy) process.

While there are certainly other methods of finishing wood that produce a glossy finish—including varnish, polyurethane, and high-gloss stains and paints—none of those produce the depth and richness of French polish.

French-polished shellac is durable and doesn’t require much in the way of polishing once dry. It’s flexible, so resists cracking, scratches, and wear—a definite advantage if you drop your keys onto a shellacked table, for example. Shellac also dries quickly and is nontoxic. It won’t yellow over time, as varnish will, and it’s fairly easy to patch up your French-polished piece without leaving obvious signs of repair. While shellac is naturally amber to orange, you’ll also find bleached shellac that’s useful over light-colored wood like maple. On the downside, however, shellac burns if exposed to high heat.

10. Polyurethane Finish or PU polish

Polyurethane is a water- or oil-based plastic resin used for coating wood or as a wood finish. They are essentially liquid plastic coatings that harden. Polyurethane itself is a type of polymer that is connected to a chemical compound group known as carbamates. These coatings can be formulated to be glossy, muted, opaque or transparent. Due to its water-resistant properties, the polyurethane wood finish can be ideally used for kitchen cabinets, doors, windows, cupboards and almost all kinds of furniture and flooring. It is a durable finish and enhances the longevity of your wooden items. However, polyurethane once it dries into a hard plastic film, is more susceptible to splitting, cracking, delamination if subjected to heat or sudden shocks, making it a sub-optimal choice for intricately curving furniture or flexing deck boards for example. Polyurethanes can be applied in a variety of ways to suit the purpose, from brushing and spraying to being applied by hand-rubbing, which is a popular method on furniture.

Ultraviolet rays from the sun can cause the polyurethane wood polish to turn yellow, so it is not recommended to use them for outdoor furniture. However, UV light absorbers can be added to it to avoid the adverse effects of the sun. Once applied, it is very difficult to repair the polyurethane finishing.