Wood finishes are trending back to penetrating oils: Wood Cuts

By Brett Miller

Many would argue that the wood flooring industry is slow to change. While I would agree that it might not change as quickly or as dramatically as other industries, like technology or fashion or even housing, I would counter that our industry has experienced a good deal of change in the last few decades, especially when it comes to finishes and finish technology.

When wood first came into use as a flooring material, it often was installed raw, meaning that no finish was applied to the floor at all. Over time, in an effort to protect the wood a little better, wax finishes were developed. These products penetrated into the wood and enhanced its appearance considerably. Waxed floors are beautiful, and many wax finishes are still in use today. However, due to the tedious maintenance process required with wax floors, which includes applying additional thin coats of wax to maintain luster, many consumers today steer clear of wax finishes. They simply are looking for something easier to maintain.

As technology advanced, polyurethane finishes were developed to meet this consumer demand. Polyurethanes are blends of synthetic resins that form a protective coating on the surface of the floor. These finishes are available in several types, including water-based, oil-based, acid-cured and moisture-cured.

No matter which type is used, all polyurethane finishes are very easy to maintain. In most cases, routine maintenance includes using a microfiber mop to remove surface dust and dirt. If it's prefinished hardwood flooring manufacturing facility, it may contain micro bevels between the floorboards. If this is the case, regular maintenance also should include using a vacuum with the beater bar turned off to remove dust, dirt and grit from between the floorboards. Then, when the floor needs a little more than just dust mopping or vacuuming, a wood flooring cleaner recommended by the manufacturer is all that is needed. It takes just a few minutes with the correct cleaner and a microfiber mop to clean the floor and maintain the shine. This is one of the reasons that these finishes have become so popular with busy consumers.

Today, however, another trend is emerging with finishes. Within the past few years, there has been a subtle shift away from traditional polyurethane finishes and toward oiled finishes. Opinions about the reasons for this movement vary, but many agree that the shift has taken place in part due to the continuing consumer demand for green products and processes.

Alfred Melka, managing director at Loba-Wakol in Pineville, North Carolina, agrees, saying that along with this green movement, there also is a general desire to “do it the way the old timers have done it.” He believes that there is a general shift toward products that look more natural, and that oil finishes help achieve this effect. “The sheen is generally much lower with oil finishes,” he says, “and therefore the final product looks more natural.”

That movement toward the natural look is confirmed by Kellie Hawkins, vice president of Cleveland, Ohio-based Waterlox Coatings Corporation. She agrees that lower sheens are increasing in popularity and points out that polyurethane finishes “form a plastic looking film on top of the wood surface,” which can sometimes detract from the natural look. “We’ve been seeing more and more of the move toward oil finishes every year,” she states, “since our first NWFA show in 1988.”

Ethan Erickson, Arboritec USA’s chemist and operations manager, also confirms that “the impact of penetrating oils is growing.” He believes that their influence on the appearance of the final product is driving the trend. “Penetrating oil finishes tend to appear a lot flatter, or more matte, than traditional oil-modified urethanes,” he says. “Some of this low sheen may be attributed to the profile of the oils on the floor, sitting at or just above grain level. Penetrating oil finishes are designed to penetrate the wood, not necessarily to sit on top of the floor in a thick wearlayer like a traditional oil-modified or waterborne polyurethane finish. Because of this, the grain can really help scatter light, lowering the perceived sheen and enhancing the natural characteristics of the hardwood species. It’s as close as one can get to the look and feel of natural wood, while offering good wear and spill resistance.”

While Erickson believes that contractors and consumers are primarily driving the trend toward oil finishes, Duluth, Georgia-based WoodCare USA sales manager, John Armfield, adds that “the architect and design community has embraced the beauty that you get from an oiled floor” as well. This trend is particularly prevalent with wider width flooring, he says, while adding that “with some of the different textures, including wirebrushing and handscraping, the penetrating oil products are very popular.” Again, this is because the oil finishes enhance the natural characteristics of the wood, which are showcased with these texturing techniques.

Armfield adds that one of the big advantages of oil finishes is that they can be spot repaired. “Since they do not have a film on top,” he says, “you can easily repair scratches by applying additional oil.” This is a unique advantage of penetrating oils, making them particularly suited for some distressed or otherwise character-enhanced flooring. Traditional sanding methods required for simple repairs like minor scratches could remove or alter the flooring texture, but since minor scratches can be repaired with additional oil, sanding is not required and will not alter any textured features of the floor or add to the cost to refinish hardwood flooring. Armfield recognizes that all types of wood flooring will get scratched at some point during its service life, but points out that “the uniqueness of the oil finish is that scratches can be repaired instead of having to leave the scratch in the floor until it gets sanded and refinished.”

Penetrating oils also work to strengthen the wood. These finishes penetrate the wood, oxidize and harden from within, which protects the flooring on the inside. This also works to strengthen the top layer of the surface. Erickson explains that “penetrating oils with hardeners are probably the toughest option, since they bind the oil to the wood grain for a tougher wood/oil layer.” He also points out that because the sheen of a natural oiled floor is usually low, “scratches are typically less glaring than with a waterborne or oil-modified urethane.”

Hawkins reinforces that penetrating oils help protect the wood fibers below the surface. “If a film is breached,” she explains, “there is still some oil below the surface to protect the floor. The elasticity of the oil keeps the film from peeling, especially when worn thin or where substrate movement is high.”

All agree that, over time, oil finishes will amber due to the nature of the product. Penetrating oils are derived from natural oils like linseed, soy or other vegetable oils. In linseed oil, for example, linoleic and linolenic acids are present, which will amber over time. Erickson points out, however, that the ambering effect with penetrating oils usually will not be as noticeable as it might be with polyurethane finishes. He explains that “the ‘window’ you’re looking through is a lot thinner. In other words, the same chemical extent of ambering will appear far more amber in a thick film, like with a polyurethane finish, than with a thin film, like with a penetrating oil.” It is important to note, however, that no matter which type of finish is used, all wood will experience natural changes in color over time due to its organic nature. No finish can alleviate this process.

Routine maintenance for penetrating oil finishes varies from manufacturer to manufacturer, and from product to product. Melka reports that some products require re-oiling the floor every week, but all agree that most penetrating oil products require very little maintenance at all other than routine mopping with a microfiber cloth and a recommended cleaning product, which is much the same process and ease of cleaning required for polyurethane finishes. Erickson does caution, however, that many of the penetrating oils will need to be refreshed every six months or as needed. He recommends that consumers check with the manufacturer of the finish to understand which products to use, and all suggest purchasing cleaning products from reputable flooring specialty stores to get the best results.

These industry experts are also quick to caution both contractors and consumers about using penetrating oil finishes or cleaning products on floors that have existing polyurethane finishes on them. Armfield notes that a polyurethane floor would need to be sanded down to the bare wood before an oil finish could be applied. The reason for this is simple, he explains. “Penetrating oils are designed to penetrate into the wood. The oil needs to be able to penetrate the wood to be effective, and the existing urethane, which would be sitting on the top of the wood, would prevent this from occurring.”

Conversely, using a polyurethane finish or cleaning product on a floor with an existing penetrating oil finish can cause problems as well, so Hawkins recommends conducting a test sample and a cross-hatch test before comingling products. In addition, regular wood floor cleaners can damage a penetrating oil finish. NWFA’s technical hotline receives numerous calls each month from consumers who are using the wrong products on their oiled floors, and the result is that the finish is turning cloudy or losing its color. This can be avoided entirely by simply using the proper cleaner.

Erickson points out that most of the issues regarding penetrating oils, and any other finish for that matter, can be avoided with consumer education. Something as simple as telling the customer which type of finish is on his or her floor, and then providing information about the specific maintenance routine that should be followed, should suffice. It makes sense to also provide a recommendation for a specific cleaning product or two that would work well on the floor, and to let the customer know exactly where it can be purchased. The NWFA also would recommend that as a value-added service, contractors and retailers include a bottle of an appropriate cleaner when the floor is completed, as well as an appropriate microfiber mop, so that the customer will have all the tools needed to keep the floor looking great for many years to come. It also makes sense to discuss maintenance programs that can be performed on the customer’s behalf when necessary, which is yet another value-added service that can be provided. This will ensure steady repeat business, and could lead to potential new work down the road.

There is no doubt that wood flooring finishes have changed quite a bit during the past few years, and there is little doubt that they will continue to evolve in response to advances in technology, as well as consumer demand. As a retailer selling these products to the public, a distributor selling these products to the contractor, or a contractor using these products on the jobsite, it is important to have all the information to make sure customers understand how their floors will perform long-term, and how they should take care of them long-term to protect their investment. This knowledge will help educate customers so that their floors will continue to meet their expectations for many decades to come.