Building a woodworking piece takes a special kind of talent. But in woodworking, we all know that the project doesn’t end with the assembly of your piece. Finishing is the next step, and can often intimidate even the most skillful of artisans. The good news: With a little knowledge and some practice, you can find your sweet spot when it comes to finishing. To help, we have identified a few important finishing guidelines you’ll want to follow, as well as seven potential wood finish options to make your woodworking piece a masterpiece.
Before we jump into the finishes themselves, let’s briefly talk about a few finishing guidelines. Although wood finishes vary greatly across the board, there are a few wood finishing steps that are true about every finish. The first: have your project sanded to the desired grit, and make sure it’s sanded well. Finish pulls out the beauty of wood, but it also pulls out any imperfections that were missed. That’s why sanding is important. It’s worth noting: oil finishes absorb into the wood, so there is no limitation to how high of grit the project can be sanded. But for finishes that just stick to the surface of the project (polyurethane, lacquer, or varnish for example), never sand above 250 grit. Sanding above this makes the surface too smooth/polished and doesn’t allow the finish to stick to the project.
Another area where confusion sometimes creeps in is with raising the grain. Raising the grain is when you ever so slightly spray or wipe the surface of the lumber with water or a damp rag. The concept behind this is the water gets absorbed into the tiniest fibers of the wood, causing those fibers to swell. These swollen fibers are then resanded smooth before the finish is applied. Raising the grain can be quite the process. And you’ll find some woodworkers that always raise the grain, but understand this isn’t entirely necessary. Typically, the grain only has to be raised when using a water-based finish. If you aren’t sure if the grain needs to be raised for a particular finish, just contact the company and ask.
After you have completed all of your finish sanding, make sure to thoroughly clean all of the dust off your project. Dust causes imperfections in the finish, oftentimes making it rough. Do yourself a huge favor and take the time to clean your project of all dust and also allow all of the dust in your shop to settle before applying the finish. The dust should also be cleaned if scuffing between coats of finish is required.
Dust can be cleaned with a simple rag, tack cloth, or even with a little bit of mineral spirits. Mineral spirits shouldn’t raise the grain at all and does a great job of removing dust from the hardest places. But make sure to let the mineral spirits evaporate off the surface before applying the finish. Also, do not use mineral spirits if you are using a water-based finish. The mineral spirits can react with the finish and cause imperfections.
Another thing to understand before starting your finishing is exactly how to mix a finish. Most finishes, at a minimum, require a good stir before application. Others can be a two part finish. Either way, if a finish says stir before applying, make sure to stir, don’t shake. If the mixing instructions say thoroughly mix the two parts with a drill mixer or something equivalent, follow the instructions very carefully. Finishes are chemically designed to work when these instructions are followed. If you don’t follow the exact instructions, you run the risk of the finish not working the way it was designed.
Some finishes can be very picky about the temperature. If it’s too cold, it can take an excessive amount of time for the finish to cure. The desired room temperature should be indicated on the finish’s label.
The last finishing guideline we want to share is that not all finishes are extremely durable. Some provide very minimal durability, while others can take quite the abuse. This means some finishes might scratch, dent, or chip easier than others. Another thing to keep in mind is white water rings can appear if a hot pan or condensation from a glass comes in direct contact with the wood and finish. This is more of a concern in finishes that are absorbed into the wood. When these finishes are used, make sure to use hot pads and coasters to prevent condensation from getting trapped underneath pans and glasses.
Basic Wood Finishing Materials
No matter what kind of finish you use, there are always a few finishing supplies to have on hand. Tack cloths are great for thoroughly removing any dust from projects, and as we mentioned before, mineral spirits can be used for this too. But mineral spirits is also very useful if a wood finish needs to get thinned. Quality brushes, whether that’s foam or bristle brushes, are essential as well. Don’t forget the proper PPE (personal protective equipment) like safety glasses, rubber gloves, and good air circulation or respirator. Depending on the finish, a sprayer may also be necessary.
Finish Option 1: Polyurethane
Like many finishes, polyurethane can be purchased as an oil-base or a water-base product. An oil-based poly leaves a yellow tint on the wood. Water-based poly will leave the natural color of the wood intact, making it one of the natural ways to finish wood. Polyurethane is known for its durability, availability, and relatively simple application process. Because of this, polyurethane is often one of the first finishes a woodworker chooses to use.
When using polyurethane, you want to keep your applicator (we recommend bristles or foam brushes) wet. Make sure to apply it evenly across the surface, in the direction of the grain and use thin coats with each application. Too thick of a coat can result in runs, meaning the finish runs down the sides of your project. The key for a smooth finish is to use thin coats and avoid bubbles.
Wipe-on polyurethane is also an option. This type of product is simply oil-based poly mixed with mineral spirits. This thins the finish, reducing the amount of bubbles and allows each coat to dry more quickly. Wipe-on poly can be applied with a clean rag, but can also be applied the same way as regular poly. This can be brought pre-mixed or can be mixed later. A benefit to mixing your own is you can control how thick or thin you want the finish to be.
All types of poly generally use multiple coats in order to provide the most protection. We suggest doing 2-3 coats for regular poly and at least 3-5 coats for wipe-on poly. Where you fall in this range will depend on how thick your finish is. With each application, the finish should be fully cured, scuffed with sandpaper, and dust cleaned before the next coat is applied. Remember: multiple thin coats are more easily controlled than one thick coat.
Finish Option 2: Lacquer
A clear lacquer is a good finish option, particularly if you are in a rush. Lacquers dry quickly and another coat can be applied within an hour of the previous application. They are fairly durable and affordable.
Lacquer can be applied with a brush, but it is typically sprayed. Scuff the finish between each coat and remove any dust before applying the next coat. Once again, multiple thin coats are better than one thick coat. The thin coats reduce bubbles and runs. 2-3 coats is usually sufficient. Beware of using proper respiration equipment if you use the spray.
Finish Option 3: Varnish
Varnish is another great finish for woodworking projects. Varnish is easy to apply with a brush, but is most often sprayed. Catalysts are often added to varnishes to allow for the finish to cure more quickly. One downside to using varnish on white woods is that it will eventually yellow. This is not desirable if you want to keep the natural white appearance of your project. On the plus side, varnish is known for its durability.
Just like the previous finishes, make sure to thoroughly scuff between each coat and remove any dust before applying the next coat of finish. Typically 2-3 coats are applied.
Finish Option 4: Tung Oil
A softer finish option is tung oil. Even though it is an oil, tung oil is clear and will not yellow the piece. The downside of tung oil is, being a soft finish, it requires many coats to be as durable as polyurethane or lacquer. But beware of water spots.
Most tung oil bought off the shelf at a big box store has some hardening agents added to it to help with its durability. But raw tung oil can be purchased and used as well. If raw tung oil is used, there is very little durability in the finish and white water spots and rings are a major concern.
Tung oil can be applied with a rag or brush. Apply a generous coat and let the oil absorb into the lumber. After 15-20 minutes, wipe off the excess oil. Repeat for additional coats. The finish will take approximately 1 month to fully cure after application. Continue to wipe off any excess oil until cured. Tung oil is EXTREMELY flammable, so try to keep the project out of direct sunlight until it’s cured. Also, make sure to soak the applicator in a bucket of water to avoid combustion.
Finish Option 5: Mineral Oil
If you plan to make a cutting board, mineral oil is one of your only options. It’s food safe, very affordable, and extremely easy to apply. This finish will be absorbed by the wood and will need to be reapplied often. The natural luster of the wood will pop when the mineral oil is applied, but know that it will yellow slightly. Mineral oil doesn’t really provide any resistance to wear and tear. It’s primary role is to make the wood pop and be food safe. This makes a great finish for butcher blocks and cutting boards, but don’t count it out for other projects as well. Check out our ultimate cutting board guide on strategies you can use to keep your cutting board looking fresh for months and years to come.
Mineral oil is a simple wipe on wipe off finish. Apply a generous amount of oil, let sit for 10-15 minutes, and wipe off the excess. Repeat for additional coats. Let the project sit for a few days to let the finish fully absorb into the wood.
Finish Option 6: Waxes
Waxes can be another viable option for certain projects. Some are food safe and others are far from it. Depending on the type of wax, durability varies greatly, but waxes typically aren’t known for being the most durable finish. Wax is often used for small projects that don’t see a lot of daily use, like art pieces. Some waxes are designed to be the wood’s only protection, while other waxes are made to wax and polish an already finished piece. Make sure you’re using the right wax for the job. Waxes are typically applied and buffed to a sheen.
Finish Option 7: Shellac
Shellac is another common wood finish. Shellac is a natural finish, but over the years, it has been modified to fit the modern way of woodworking. Shellac comes in two forms, waxed and dewaxed. Dewaxed shellac removes any of the natural wax from the finish. It’s important to use dewaxed shellac when it will be used in conjunction with other finishes. Shellac may also come tinted and can act as a stain for a project. Shellac is reasonably durable and affordable, but water rings can be problematic. Shellac is typically brushed on with thin coats, with scuffing between each coat. Shellac is a great finish for beginning woodworkers given its affordability and ease of application.
Of course, other finishes exist out there; danish oil and linseed oil come to mind. Finishes like these are similar to finishes we’ve already discussed. A quick Google search will help you determine the application process, pros and cons, and the durability of the finish.
Brand Name Finishes
There are a number of brand name finishes that are available. Finishes like Rubio Monocoat, Odie’s Oil, OSMO, Simple Finish, Walrus Oil, etc. have their unique blend of chemical recipes to give your projects a personal touch. All of these finishes are different, which means each have a different application process. Some finishes focus on being easy and simple to use, while others set their eye on being the most durable finish for any project. Depending on the retail store, their availability may be limited, so these products are typically ordered online. If you have any questions on a specific brand name finish, it’s best to directly ask the representatives of that brand.
A Note on Homemade Finishes
Most woodworkers don’t venture into mixing their own finishes, but that’s not to say it doesn’t happen. For those woodworkers that mix their own, sometimes they will share their finish recipe with others, but usually they want to keep it top secret. And even the recipes that have been shared aren’t typically sold as a premix finish. Other times, woodworkers break down what’s exactly in a finish and mix the ratios themselves. This gives the woodworker full control over what’s exactly in the finish.
What’s the Best Finish for Your Projects?
The finish you decide to use should be based on your own personal preferences. You might be looking for the easiest way to finish wood, the most durable wood finish, or the best natural wood finish. The best way to determine what wood finish to use is to experiment with a few different options. Take a day, do some research, find which options would be the best wood finish for you, order them, and go for it. You can make swatches out of scrap wood comparing polyurane to tung oil or shellac and so forth. This will allow you to really get a feel for each finish you are considering and decide whether you would like to use it in the future. Finishing wood furniture takes time and practice to reach the desired outcome, but it’s totally worth it in the end!