Wood finishes come in various types, and if you want to raise the quality of your woodworking projects a notch, it will help to know these different types of wood finish. These different types of wood finishes include stain, wood dye, rub-in oils, polyurethane, paint, and varnish. Among these different types of wood finishes, the varnish is one of the favorites and most popular among woodworkers.
Varnish provides a hard and transparent protective coat or film for the wood, and you can also buy a pigmented version of varnish with various shades to choose from. The use of varnish is perfect for wood projects wherein you want the wood’s distinctive grains and tones to come out.
Varnish provides a glossy finish to wood, although you can buy varnishes that offer semi-gloss and satin sheens. Moreover, the film-like coat provided by varnish repels moisture and dust, giving the wood protection against damage caused by moisture and water. Besides, varnish protects the wood from abrasion, impact, UV rays, and food stains.
List of 13 Types of Wood Varnish
As mentioned above, varnish comes in different varieties, and if it is your first time using it, you might get confused upon learning that you need to choose from myriads of varnish options at hand. However, if you know the following different types of varnish, you can wisely choose the most suitable varnish type for your woodworking project:
1) Acid-based Wood Varnish
One of the primary types of wood varnish is acid-based wood varnish. This varnish type is pigmented but can also be transparent and clear. It can provide your wood project with a protective coat to make the wood surface not vulnerable to scratches, impact, abrasion, and UV rays.
This varnish type, however, offers low viscosity. However, it dries fast, and thus, it is easy to use and apply. Moreover, its clear coat penetrates the fibers of the wood, protecting against moisture and UV rays.
You can use this varnish type if you want to change the floor’s color or only want to leave any wood with less treatment.
2) Oil-based Varnish
The oil-based varnish might not be genuine varnish, but it contains the oil ingredients of the varnish sans the solvent and resin of the varnish. Since it has only the oily ingredients, it dries slowly compared to the acid-based varnish. Nevertheless, it offers a clear finish characterized by high quality. You can use this varnish for finishing wood surfaces, masonry, and metal.
The oil-based varnish offers a clear appearance on the wood surface. It differs from a water-based finish because it dries slowly but offers better protection against abrasion and moisture than water-based varnish.
Its clear coat does not penetrate the wood as it dries into a hard film. However, this hard film is durable and offers high resistance to scratches.
Oil-based finishes are suitable for wood furniture, flooring, fences, and exterior decks. They also offer a variety of glossiness, depending on how you apply the finishing.
This varnish type is referred to as “drying oils” because when you apply this varnish to wood, the solvent dissolves or evaporates, leaving the oil behind. The oil then penetrates the wood’s pores and combines with the wood fibers. Linseed oil and tung oil are good examples of this varnish type.
3) Water-based Clear Varnish
Another type of varnish is water-based clear varnish. This varnish type dries fast and offers low viscosity. Moreover, it offers a nice clear coat over the wood surface. Besides, this clear coat bonds well with the wood substrates and is durable. Thus, it is a perfect complement to water-based stains. You can also utilize this varnish type over oil-based stains.
The water-based clear finish is perfect for finishing doors, wood floors, and window sashes. You can also use it over acid-based finishes if you want to avoid the yellowing of the acid-based clear finishes.
4) Acrylic Varnish
The acrylic varnish is a quick-drying varnish that is non-toxic. It is water-based and is perfect for protecting wood against UV rays. For this reason, you can use it for outdoor wood and other materials. Moreover, it is a versatile option, for you can use it on different materials.
The acrylic varnish offers a clear and highly transparent finish that doesn’t turn yellowish over time. Nevertheless, this varnish doesn’t penetrate deep into the wood compared to oil-based varnishes.
Since it is water-based, it is easy to clean using water. Thus, it is user-friendly. Nevertheless, there will be instances when it doesn’t spread uniformly, so you need to make an extra effort to spread I uniformly. You can buy this varnish type in matte, satin, and gloss finishes.
5) Spirit Varnish
The spirit-based varnish is a practical finish for protecting and enhancing the beauty of wood furniture. It has long been used by woodworkers and is referred to as “French polish.” This finish, however, despite being popular, is not often referred to as “varnish.”
The spirit varnish consists of natural ingredients derived from the beetles’ secretions. These beetle species are commonly found in The Eastern part of Asia. Thus, it is different from other varnish types because it doesn’t contain synthetic materials.
The secretions of beetles are usually in the form of flakes. These flakes are then collected and dissolved in alcohol to improve their consistency.
This varnish type is also known as “shellac,” though there is a shade of difference between the shellac and spirit varnish. The main difference lies in the waxy consistency of shellac, while spirit varnish has a thinner consistency, causing it to flow or run if you overapply it.
You can use the spirit varnish as a primer for other varnish types and paint. Lastly, this varnish type gets usually preferred by manufacturers of musical instruments.
6) Lacquer Varnish
Lacquer varnish is not a genuine varnish in the strictest sense of the word. This term usually refers to the application process of spraying the finish. Lacquer finish, however, is quick-drying and solvent-based instead of alcohol-based.
You can apply this varnish by spraying it on the wood surface. Besides, the solvent used for this varnish is acetone. After applying this varnish, you can remove the lacquer utilizing lacquer thinner. Furthermore, this varnish doesn’t undergo polymerization.
You can apply this varnish to enhance the appearance of the wood surface. It provides a hard outer layer that is slick. You can also apply this varnish using a brush or roller. Besides, you can buy lacquer varnish in an aerosolized version.
Lacquer is not expensive. It is also easy to apply, and thus, it is user-friendly. Moreover, you can remove it with ease using lacquer thinner or acetone and a clean cloth. Plus, it does contain VOCs; therefore, you should only apply it outdoors.
7) Exterior Varnish
This varnish type is formulated for use outdoors. It comes with UV-protection properties to provide wood with extra protection against damage due to UV rays. This varnish type provides a multi-porous film that lets the wood breathe.
Besides, it comes with fungicide content to stave off mold growth. It is flexible and somewhat similar to the yacht varnish. Nevertheless, it exhibits slow curing.
8) Polyurethane Varnish
The polyurethane varnish provides hard surface protection for the wood. Thus, it is often used in areas with heavy traffic and wear and tear. You can use it for flooring and heavily used areas. Moreover, it is heat resistant and offers a hard but clear finish for the wood. You can buy this varnish in matte, satin, and glossy sheens.
Polyurethane varnish does not penetrate the wood’s pores; thus, it often gets primed using oil-based varnish. You can also use a thin shellac solution to prime it. Please refrain from using an oil-based varnish type on polyurethane varnish because it will fail to bond together.
Additionally, polyurethane exhibits high durability and hardness. It is also resistant to spills of solvents, mild acids, and chemicals. However, it is not designed to withstand UV rays, and thus, it is not recommended for use outdoors.
9) Yacht Varnish
This varnish type is also referred to as marine or spar varnish. It got formulated initially for finishing boats to ensure seawater doesn’t penetrate the wood surface. This formulation is achieved by making it highly flexible because an inflexible varnish will tend to crack when the wood flexes as waves buffet it. Once the wood cracks, it will be susceptible to penetration by seawater.
Yacht varnish initially didn’t exhibit glossiness because it was unnecessary to make it glossy. However, contemporary yacht varnishes come with high glossiness with the addition of phenolic resins and tung oil. Thus, they become perfect for use on outdoor timber that are not walked upon.
In the olden days, yacht varnishes were called “spar varnishes,” for they got used to ensuring that the sailboat’s spars weren’t affected by seawater. The spars are the long and thick poles where you set or hoist the sails. Thus, spar varnishes got designed to make the spars more durable.
Initially, yacht varnishes were also designed for their functionality. Previous manufacturers didn’t care whether yacht varnish’s colors and textures were not pleasing to the sight. Yet, yachts have become more luxuriously looking nowadays. So, it has become imperative for manufacturers to produce yacht varnishes that offer excellently looking finishes.
10) Alkyd Varnish
The alkyd varnish comes with alkyd contents—modified or enhanced vegetable or natural oils. Alkyd-based varnishes are not easy to define because manufacturers can add alkyd to enhance their varnish products’ drying time, durability, and beauty.
Alkyd-based varnishes, however, provide an excellent clear finish to wood pieces without hiding the natural grains and textures of wood.
Alkyd has excellent resistance against UV light and the vicissitudes of weather. As such, it is added to varnish formulations to enhance the properties of varnishes. Alkyd also provides varnishes with high resistance to condensation and water, making them perfect for use in decks and other outdoor wood furniture.
Alkyd varnishes can enhance the wood’s color, thanks to the vegetable oil content of these varnishes. Thus, the alkyd varnish can intensify, lighten, or darken the tone of the wood after application.
Shellac is, strictly speaking, not a genuine varnish. It consists of a natural ingredient derived from an East Asian beetle secretion. Moreover, this secretion comes in flake forms and is collected and dissolved in alcohol.
Shellac has a dewaxed version which you can use as a primer for other types of varnishes like acrylic and polyurethane. You can buy shellac in different shades.
12) Floor Varnish
If you want a clear coat that is abrasion-resistant at the same time, you should go for floor varnish. This varnish can enhance and protect floors well. Besides, it can safeguard floorings from the insidious effects of moisture. You can apply this clear coat onto wood floors and expect the finish to be durable and beautiful.
Floor varnish comes in oil-based and water-based clear finishes. It also comes in a single-component or two-component coating. It can also be pigmented with other colors using dyes, and you can use it over stained wood.
13) Resin or Gum Varnish
Resin or gum varnish gets mostly made of natural ingredients derived from plants or insect secretions. These ingredients get dissolved in a solvent solution, referred to as “solvent varnish” or “spirit varnish.” This solvent can be turpentine, alcohol, or even petroleum-based solvents.
The resins come with dammar, amber, copal, sandarac, rosin, benzoin, elemi, mastic, shellac, balsam, or many lacquers. Manufacturers can also use phenolic resin as an extra component in their resin products.
Throughout the centuries, many resin producers have been able to combine various ingredients like oils, resins, wax, and other components. These ingredients were often made secret. Such components, likewise, were believed to provide excellent tonal qualities. Thus, they were used for finishing musical instruments.
How Do You Select the Ideal Varnish for Wood?
Varnish products have already gone a long way in their evolution. Nowadays, most commercially available varnish products have excellent properties and qualities. Most of them also perform well. However, when applying varnish to wood, you must follow the manufacturer’s instructions on how to use it.
You should not use it for outdoor furniture if it is an interior varnish. Besides, if it is designed for finishing floors, you should not use it for exterior wood because it might be susceptible to cracking, for it lacks flexibility. You should also not use a yacht varnish for heavy traffic areas.
So, always follow what the manufacturer’s instructions tell you and choose varnish that are specifically formulated for the application you intend for it.
If you’re unsatisfied with the varnish products you find in the market or online, you can concoct your varnish formulation. The good thing is that you will find recipes for making varnish online. Thus, you will always be able to make your varnish as long as you have the right ingredients. Making your varnish will enable you to formulate a varnish that best suits your woodworking needs.
The best way to select the best varnish for your wood project is to test several types of varnishes on a test wood piece or scrap. Try to apply the different varnishes until you find the most suitable varnish for your needs. You can buy several types of varnishes, and as an aspiring woodworker, investing in various types of varnishes and finishes is a worthwhile investment.
The varnish is an excellent finish that you can use for many of your woodworking projects. Besides, a well-selected varnish type and color would significantly enhance the appearance and looks of your wood projects. Thus, it will be best to know the abovementioned types of varnishes to enable you to select the ideal varnish for your needs.
The use of varnish, however, is not without danger. Since it is flammable, you should use it with care and follow the safety precautions when using and storing it. Besides, it will be best to dispose of the materials you use to apply the varnish with care. This way, you will always be on the safe side and will not endanger the safety of other people likewise.
Liam is a 37-year-old woodworker and interior designer who loves to make every furniture project an art piece. He is very experienced in furniture design and woodworking project planning.