I have a neighbor who I refer to as the Lord of the Rings; this has nothing to do with Tolkien’s trilogy; it’s more that he’s constantly leaving beverage glasses on his antiques, resulting in countless white circles that embellish every horizontal surface in his home. He’s been given many a coaster set to no avail; he stores them in his bar, waiting for that special occasion. And I won’t even begin to tell you what damage he’s wreaked with his potted plants…
Almost every house’s decorative interior contains some finished wood; floors, woodwork, ceiling beams, and of course, furniture are all examples. And just about all wood, with the exception of aromatic cedar or teak, must be sealed with some sort of finish to protect it from the ravages of moisture and humidity as well as ground-in dirt and oil that will discolor it.
We should separate wood finishes into two basic functions: woodwork/furniture and wooden floors. For the most part, the former two applications are fairly similar, while flooring must contend with several additional factors such as much greater wear and exposure to moisture.
Natural or clear-finished woodwork became popular during the second half of the 19th century, and the traditional materials to coat and protect it were orange (aka amber) shellac or a natural, oil-based varnish (as the synthetic resins of plastics/polyurethanes had yet to be invented). A note on authenticity: Satin finishes are a modern invention, and woodwork and floors were referred to as “polished”, meaning they were supposed to be glossy!
Orange shellac’s rich and lustrous glow is the preferred finish of many a restorer, despite its lack of resistance to water or alcohol. Properly applied, and protected with a coat of paste wax, its beauty is unrivaled, although it will not survive abuse on such surfaces as dining table, bar and vanity tops. Natural oil-based varnishes such as Valspar are also authentic with the additional benefit of being water and alcohol proof, but have slower drying times and may look too “thick” on fine antiques. Polyurethanes, or synthetic varnishes, are the most durable, but impart an even thicker “wet” look and should be reserved for floors and high-wear areas.
One trick that antique restorers use for extra-durable dining table and bar tops is to apply a shellac finish and then coat the top with a layer or two of natural varnish.
Note: you shouldn’t use polyurethane over shellac; it may “lift” the shellac finish: instead, choose a natural oil varnish such as Valspar.
Clear lacquer finishes made their debut on furniture in the early 20th century; lacquer, while quick-drying and water and alcohol-resistant is usually applied by spray, a messy and potentially 
hazardous scenario. Homeowners wishing for a lacquer finish often use one with an additive that slows the drying process slightly; this is known as Brushing Lacquer, and Deft is the most commonly known brand of this product.
Penetrating oil finishes such as tung or boiled linseed oils have remained favorites of those seeking a low-luster finish; their advantage is ease of application (wiped on with a rag) and repair (just add some more!) but they must be maintained rather frequently and are not as durable.
Currently, the most popular finishes for wood floors are oil or water-based polyurethanes. These became ubiquitous in the 1970s and 80s; they are synthetic, plastic varnishes that are highly resistant to water and most solvents, but are difficult to patch if damaged through wear or scratching. Polyurethanes are similar in appearance to the traditional varnished floor, and their greater durability has far surpassed natural varnish as the finish of choice.
In the past few years, much attention and regulation has been focused on VOC’s, an acronym that stands for Volatile Organic Compounds. These are chemicals released in the fumes of products that can cause health problems ranging from respiratory irritation to prolonged, agonizing death. Many petroleum-based household products contain these, and a concerted effort has been made to reduce them in everyday use; in the case of wood finishes and paints, acrylic and water-based paints and varnishes are becoming the predominant product. While these are safer, they are not always as durable or authentic in appearance, although they have improved greatly over the past few years. Because the square footage of a floor is so much greater than a piece of furniture or the woodwork in a room, more focus has been turned to low VOC floor finishes, although the low-VOC finishes are available for woodwork.
The aforementioned penetrating oils are also becoming more frequently employed due to the low-VOC fervor. These usually have polymers added to them that harden and are create a reasonably tough finish. They won’t yield the thick glossy “bowling alley” finish that many traditionalists favor, but they do retain a certain luster. While the oil has to be reapplied now and then depending on wear, they are much more easily renewable with another application, and require no additional sanding.
Lacquer is to be avoided for floors, as its application produces a great amount of highly volatile fumes that can ignite from a simple light-switch spark or an un-extinguished pilot light in a major appliance.
Incidentally, when using a varnish in an exterior application, make sure that the varnish or polyurethane has “Spar” in the title; this indicates a modification to the formula that allows it to remain somewhat flexible under the extremes of temperature and moisture. Ordinary polyurethane will yellow and crack very quickly when used on a front door.
Dan Cooper is a well-known author, and has published over a thousand articles on the subjects of antiques, architecture, preservation and historic interior design. His first book, New Classic American Houses, was published by The Vendome Press. Dan is also President and CEO of Cooper Lace, has designed and sold historic lace curtains for twenty four years, providing them to private homes, museums and film sets. Dan is recognized as a leading authority on the subject of historic carpeting.