Whether you are building a new fence, installing a wooden railing, or working with fine wooden furniture, wood should be treated with a protective wood finish to prevent damage from UV radiation, rain, or even high humidity. If left unprotected, these environmental factors can result in the wood drying out, cracking, swelling, or rotting.
Wood furniture that has dried out or rotted will have a reduced ability to support weight, so it's best to select a wood finish to protect your next woodworking project. However, it's important to learn more about the various types of wood finishes and keep in mind several key buying considerations to select the right wood finish for the job.
Before Buying a New Wood Finish
It can be tempting to grab the first wood finish you see in the local home improvement store. However, wood finishes come in a variety of types.
Take the time to properly research the different wood finishes to find the right option for your project. It's also recommended to look into the potential risks of using the product, such as flammability, toxic fumes, and lasting environmental damage. If you need to use a dangerous wood finish, make sure to have the appropriate personal protective equipment (PPE) before you begin and dispose of unused wood finish at a local recycling center.
Buying Considerations for Wood Finish
Durability and Resistances
One of the primary reasons for applying a wood finish to a woodworking project is to help protect the wood from damage. Wood finishes provide a physical layer of protection that can prevent damage from scratches, chemical abrasions, and solvents.
Not every wood finish has the same resistance to UV radiation or moisture, so if you are working on a project outdoors it's necessary to find a wood finish that can help prevent cracking, drying, swelling, and rot.
Ease of Use
Another factor to consider when you are looking for a wood finish is ease of use. This relates to the specific product, but it should also include an honest assessment of your own skills. For example, you can apply a wood finish with a brush, a cloth, or a sprayer. If you don't have any experience using a sprayer, it's probably not the best option if you are working on fine furniture or any other high-quality woodworking project.
If you want to try your hand at using a sprayer or attempting a complicated process, like French polishing, consider using a test piece of wood or even a test project. This will allow you to figure out whether your skills and this application method are suitable for the task. Keep in mind that not every wood finish can be applied in the same way. Some wood finishes are made for use with a fabric dabber, while others can be applied with a paint roller. Always check the manufacturer's directions for application before using a product.
Protection from environmental and physical damage is the primary purpose of using a wood finish, but the appearance of the project can also be drastically changed depending on the type of wood finish. Varnishes and oils, like tung oil, linseed oil, and danish oil, give the wood a natural appearance and may have a slight yellow or golden tinge. Shellac and lacquers are not as easy to apply as many other wood finishes, but they do give the wood a deep, rich appearance.
Water-based finishes are a good option if you want to keep the current look of the wood, while paint or stain can completely cover the wood grain for a more uniform finish. To get the desired result, make sure the wood finish has enough time to properly dry and to fully cure. This timeline can differ depending on the wood finish, so check the manufacturer's information for the suggested drying time.
Types of Wood Finishes
Wood finishes can be split into two primary types based on how the finish interacts with the wood, the appearance of the wood, and the level of protection afforded to the project. These two types include penetrating wood finishes, like tung oil, linseed oil, or cedar oil, and surface wood finishes, like varnish, polyurethane, or paint.
Penetrating Wood Finishes
Penetrating wood finishes tend to give wood projects a more natural appearance. As the name suggests, these wood finishes penetrate deep into the wood, providing protection against drying, cracking, swelling, and rotting.
- Tung oil is an environmentally friendly wood finish that accentuates the natural appearance of the wood while adding a warm, golden glow. It has a high level of durability and resistance, making it suitable for boat decks and floors. Apply tung oil with a cloth or brush for best results.
- Linseed oil is easy to apply using a brush or cloth, though this product tends to take a long time to fully cure. Use this wood finish for a natural look with a warm, yellow matte tone that darkens with age.
- Danish oil is a highly durable wood finish that is made by mixing boiled linseed or tung oil, varnish, and paint thinner. It is regularly applied with a cloth or brush to coat wooden utensils and handles for a natural matte or gloss finish.
- Cedar oil is a popular option that has a woody odor and it's known to help protect woodworking projects from insects, swelling, and rot. This wood finish has a warm, silvery-grey appearance that is great for floors and furniture.
Surface Wood Finishes
While penetrating wood finishes are known for seeping deep into the wood, surface wood finishes are applied to the surface of the wood to create a durable protective layer. Surface finishes are considered a better option for furniture or objects that are exposed to a high level of wear and tear due to the superior physical durability.
- Shellac has an attractive mellow finish that is intended to accentuate the natural grain of the wood. It is especially attractive on walnut and mahogany. Use a sprayer or a badger hair brush to apply shellac and choose from a range of color tones, like blonde or rich orange.
- Lacquer is another wood finish that is made by combining several other finishes, such as shellac, urushiol, or nitrocellulose. It's great for protecting wooden furniture, cabinets, doors, or shelving, and it can be applied with a sprayer or a natural bristle brush.
- Varnish is made for outdoor application due to its high resistance to UV radiation and moisture. This wood finish is typically transparent, though some products can have a yellow or orange tint. Apply varnish with a sprayer or a paint roller for the best results.
- Wax is an easy to apply wood finish that is ideal for hardwood floor and fine wooden furniture. Use a cloth, brush, or sprayer to apply the wax to the wood for increased physical and environmental protection.
- Polyurethane is the most durable option for indoor woodworking projects. It's highly effective at protecting cabinets, doors, furniture, and floors from scratches and abrasive damage. Polyurethane is also water-resistance and is intended to enhance the natural appearance of the wood with a statin or mid-gloss finish.
- Stain is commonly used to protect decks and fences from water and UV radiation in order to prevent cracking, drying, or rotting. This type of wood finish enhances the grain pattern of the wood and it is available in a wide variety of colors.
- Paint, like stain, comes in a wide range of colors. However, paint is intended to fully cover the target surface, instead of allowing the natural appearance of the wood to show through. It can be used for both indoor and outdoor projects, including wood paneling, walls, doors, fences, decks, and furniture.
Paint, stain, and varnish are all well-known wood finishes that are commonly used by homeowners and DIYers, so the price for these products shouldn't come as a surprise. On average, it costs about $25 to $50 for a container of wood finish if you need the product to complete a DIY woodworking project or to finish renovations around the home. If you high a professional painter to finish the project or renovations, the average cost falls between $3.50 to $7.50 per linear foot. This includes the price for materials, delivery, worksite preparation, and labor.
How to Choose a Wood Finish
Given the wide range of wood finishes available, it can be confusing to try to select the right type for your project. Before grabbing the first wood finish on the shelf, take some time to consider these important questions that can help you narrow down the product selection.
What Does the Project Need to be Protected From?
The wood finish will provide an additional layer of protection, but the level of environmental resistance and physical durability depends on the type of wood finish. Varnishes are great for everyday wear-and-tear, as well as being a good choice for resistance against both UV radiation and water. Marine-grade finish is another good option for wood that might be exposed to the elements. However, if the project will primarily be indoors, it may be better to go with a polyurethane wood finish that offers superior physical resistance, despite being less effective against UV radiation. Research the various wood finishes before deciding which option is best for your project.
What Look Do You Want?
Protection shouldn't be the only concern. The final appearance of the woodworking project is an important factor to keep in mind when you are looking for a wood finish product. Paint and stain are common options for indoor and outdoor projects because they come in a variety of colors and tones. Oils, like tung oil, linseed oil, and danish oil, offer a more natural finish that greatly enhances the existing grain pattern of the wood. If you want the protection of a wood finish, but like the current appearance of the wood, try using a transparent polyurethane finish or a clear stain.
What Tools and PPE Do You Need?
Paint, stain, and wood finishing projects typically require gloves, long pants, closed-toe shoes, a long sleeve shirt, safety glasses, a mask, and appropriate ventilation in the workspace. Ventilation can be created by opening doors, opening windows, and setting up fans to filter the air out of the area. When you are selecting a wood finish, it's recommended to check the manufacturer's directions for use in order to better understand the potential risks involved with using the product.
Not every wood finish carries the same risks to the user. For instance, cedar oil is known to have a woody odor instead of the powerful chemical smell produced by polyurethane or varnish. Similarly, some wood finishes, like lacquer, can be incredibly toxic, while others, like polyurethane, are highly flammable. Always take the time to understand how to use a product properly and learn the necessary precautions before use.
Is varnish or polyurethane better for outdoor surfaces?
Polyurethane is a commonly used wood finish that is known for high durability and water-resistance. It also offers modest UV resistance, but varnish is actually a better option for protecting woodworking projects from harmful UV rays, high humidity, and precipitation.
Should you apply polyurethane over stain?
It's generally considered acceptable to apply a layer of polyurethane over stain to increase the durability of your woodworking project. However, it's important to wait at least 24 to 48 hours for the stain to fully cure before applying the polyurethane.
What is the most durable finish for wood?
If you want to prevent damage to fine furniture, cabinets, or hardwood floors, oil-based polyurethane is the most durable wood finish available. This product is also water-resistant and UV-resistant.