5 Key Considerations for Choosing the Perfect Wood Finish
Trying to decide what finish to use for your woodworking project? The number of choices can make your head spin. A lot of woodworkers will sometimes default to a single finish for every project just to keep things "nice and simple".
The reality is that the best finish for a project is one that gives you the look and performance that you want for that project. If you're installing a bar top at a college dive, you might want something that stands up to spilled beer for 3-4 days straight. Finishing a statement piece coffee table for your living room? You will probably care most about aesthetics and how the finish feels to the touch.
Three of the most readily available types of finishes on the market are oils/wax oils, polyurethanes, and epoxy. The comparison below will lead you through five factors to consider, and how each of these chemistries compares, to help you make your choice.
1. Durability
Start by considering the level and type of wear you expect to see when your project is in use. Will water or other liquids be spilled on it? Will things be dragged across its surface? Will it need to stand up to foot traffic?
No product is perfect in addressing all these wear and tear issues, but there are some important things to know.
Film-forming finishes such as epoxy or polyurethane will stand up better to liquid spills that are not cleaned up right away, and they may even be scratch resistant. That said, any scratches will be highly visible.
Oil and wax-oil finishes will not stand up to spills in the same way, and may be more easily scratched, but when they are scratches it is much harder to see. Oil and wax-oil finishes penetrates below the surface, making scratches the same color as the surrounding area.
2. Aesthetics
We all want our projects to look good, but beauty is in the eye of the beholder. Consider what you would like from a color, texture, and physical touch perspective.
Epoxy can provide a glass-like surface; however, it does feel like plastic, and if not applied properly it can look like it too.
Polyurethanes come in various forms; some of them will amber (yellow) the surface of the wood, while others could be virtually invisible. Some are glossy and some are matter. One product can't do everything, but across all the varieties of polyurethane you can probably find one that meets your aesthetic requirement.
Oils bring out the warmth in wood, and, when applied properly, can create a butter-smooth surface that feels like...wood. Because they're not forming a perceptible film over the wood, what you feel is the texture of the wood itself. Oils and wax oils can create anything from rustic to a "contemporary" finish based on the surface preparation used and what additives might be in the product.
3. Maintenance and Repair
When it comes to maintenance and repair, these products are all worlds apart. You need to determine whether you would like a surface that is harder to damage in the first place, or one that is easy to repair when needed.
It can take a lot of effort to scratch an epoxy coating; however, once it has been damaged, your eye may be drawn directly to it as scratches stand out in stark contrast to the glass-like surface.
Repairs themselves are not guaranteed to fully hide the damage, and even a poorly repaired epoxy surface is a lot of work between surface prep and application.
Polyurethanes are a middle of the road solution: Easier to damage than epoxies, but relatively scratch and moisture resistant. Scratches and damage can be highly visible, especially if a gloss finish is used, but are easier to repair with less surface preparation and less temperamental application.
Wax oils are more easily damaged than the other solutions listed here; however, they do not show damage as readily due to there being next to no contrasting color.
Unlike the other technologies, wax oils are also extremely easy to repair. You simply need to clean the area and then wipe on a small amount of fresh product. The repaired area will be generally indistinguishable from its surroundings.
4. Environmental Considerations
A growing number of people are also looking for finishes that reduce their environmental impact or generally have a smaller environmental footprint.
Epoxies fall on the less sustainable side of things. They are typically petroleum-derived plastic products with a high footprint from both an ingredient and processing perspective. Typically, epoxies are not biodegradable, so even after they have served their useful life, they add plastic pollution to the environment.
Better than epoxies, polyurethanes can be manufactured at least partially with renewable ingredients. Historically, oil-based polyurethane products had high volatile organic compounds (VOCs) from solvents and can be quite toxic to human health and the environment. Newer water-borne technologies have improved on both these fronts but are still not perfect.
Wax oils are your most eco-friendly choice. They are typically made from plant-derived ingredients and lead the pack regarding environmental impact. Note that some brands do add synthetic ingredients that increase the impact these products could have.
In this case, the more natural a product is, the more likely it is truly a greener, more sustainable product. All Grand Finishing oil finishes are safe and sustainable, using 100% natural renewable resources, without any petroleum-based ingredients.
5. Ease of Application
Some finishes are more difficult to apply than others. The harder a product is to apply, the more experience needed to achieve a quality result.
Epoxies are the hardest of these wood finish products to apply. Epoxy is supplied as two components; these must be mixed thoroughly and in a specific ratio so that the product will cure properly.
Whether being poured, brushed, or troweled on, care must be taken or the surface can end up with unintended ripples or other imperfections. Trapped air can form bubbles and moisture exposure during curing (including humidity) can sometimes cause hazy effects.
Polyurethanes are easier to apply than epoxies. They don't have the same adhesive properties as epoxy and require a slight surface texture for maximum adhesion. This means surfaces shouldn't be sanded too high, or they will be too smooth for the finish to adhere.
Polyurethanes also need slight sanding between each coat to ensure inter-coat adhesion, as they have trouble bonding to themselves once the first coat is fully cured.
Oils and wax oils are the easiest to apply. They simply need to be wiped on, allowed to soak in and set up, and then have any excess oil wiped off. Oils and wax oils can be buffed up to a soft sheen, and if the surface has not been polished shut, they are tolerant of higher sanding levels that lead to a smoother finish.
Oils make it easy for beginners to get good results, and with more practice you'll be rewarded with jaw-dropping beauty out of the wood grain.
Whatever finish you settle on, it's well worth your time to consider all your project requirements and preferences in advance for a project that gives you years of service and enjoyment.
To help you through this process we have also made the handy chart below to compare wood finishes by key features and benefits:
