You could fill a library with the different ways of finishing wood. There are oils and lacquers, urethanes and stains, sealers and varnishes. Some are wiped on, some are sprayed, while still others are brushed on. I could fill a book on just this subject alone so this post will be more of a primer to get you pointed in the right direction.
Finishing wood is as much of an art as it is a science. Each finish can come out completely different depending on a multitude of factors like the type of wood it is applied to, the ambient temperature and humidity, air flow or lack thereof, thickness of application, age of the finish.
Polyurethane (a type of varnish) is one of the most commonly used wood finishes today. It excels in high traffic areas like floors where it forms an incredibly hard and resilient coating that can handle just about anything. There are exterior versions of polyurethane call “spar varnish” which are a bit softer than their interior cousins. This softness allows them to remain flexible in the large temperature swings that occur outdoors. A regular polyurethane will crack and fail after a couple short years in brutal exterior settings, whereas a spar urethane can last a decade or so with care. Polyurethane works best for floors though it also excels on doors and woodwork. The downside of this finish is that it leaves the wood feeling like it has a thick plastic coating on it. Good for hardwood flooring Utah that need the protection, but maybe not for furniture that you want to feel silky smooth. You can read more in my post All About Polyurethane.
Laquer is a quick drying finish that is most typical on commercial furniture and cabinets today. Lacquer paints (essentially a tinted, opaque lacquer) are a typical finish for most cabinetry. Lacquer goes on in very thin coats and is almost exclusively sprayed on with HVLP (High Volume Low Pressure) sprayers since it dries so quickly. Without spraying, you’d be stuck with brush marks everywhere. While it is hard for the amateur to work with lacquers, they do provide an incredibly beautiful and rich finish that is worth the extra work, especially if you are looking to put the finishing touches on a furniture project. Lacquers do have a tendency to yellow over the years, which makes them a bit less desirable for light colored woods.
Shellac is an old school finish common on woodwork in old houses. It is a relatively similar product in application to polyurethane, but instead of being made of petrochemicals, it is made from a naturally found resin from the lac bug. Flakes of this resin are dissolved in denatured alcohol and poof you have Shellac. This one of the oldest wood finishes whose history stretches into antiquity.
It is not quite as hard of a finish as oil based finishes like polyurethane and lacquer, but it is resilient enough for woodwork and trim. Floors are not a great place for this finish. One of the great things about Shellac is that is can be easily touched up without looking like it has been repaired. Applying new Shellac to a damaged area causes the old cured Shellac to re-emulsify (turn back into a liquid state). This great feature (along with the fact that Shellac doesn’t yellow over the years) allows Shellac touch ups to seamless blend in with the original finish.
Popular around the same time as oil finishes, wax is best used as an addition to oil finishes. It provides minimal protection and should be reapplied occasionally to maintain its effectiveness. It’s fine when used in this way, but not recommended as a finish in and of itself.
You can read my earlier post on how to make this simple but effective finish at home. This finish really combines the best of both worlds. It gives you the deep penetrating protection of an oil finish with the protective coating of a varnish. Anything that is remarkably easy to use and effective will always keep a prominent place in my shop and this one is my go to finish for woodwork and antique furniture.
