What Are Penetrating Oil Finishes?

Penetrating oil finishes are a liquid fluid, often made from a clear petroleum-based product, that is rubbed into a wood surface to enhance the grain and natural beauty of the wood. They do not produce a solid or hard built-up finish on the surface like many other types of finishing products, but instead they penetrate the grain of the wood. Their presence is detected by a slight darkening of the color of the wood, and until the oil finish dries, the wood feels a little bit slimy. A penetrating oil finish is recognized by many woodworkers to be a relatively easy way to obtain a professional-looking result on a piece of furniture or around the house.

Considerations

Tight-grained woods such as maple, cherry and birch take extremely well to the application of a penetrating oil finish. As the oil penetrates the wood, the natural color of the wood really resonates under the presence of the fluid oil. Applied after a thorough sanding with very fine sandpaper (320 grit works well), the oil finish needs to be applied to the wood with a clean cloth and allowed to sit for half an hour, at which time excess oil can be removed from the surface with another clean cloth. One treatment like this produces a very nice result, but doing this every day (including sanding ) for a few days in a row really produces an extra-fine finish.

History

Modern-day penetrating oil finishes reproduce the effects of the old rubbing finishes that were so common in centuries past. The new oil does this without the necessary constant rubbing that had to be administered many times to produce a lustrous shine. The advent of new petroleum-based clear oils has given the modern-day product a greater penetrating power and thus eliminated much of the need for rubbing..

Expert Insight

All wood finishing needs a near dust-free environment to produce a good result, and oil finishes are no exception. So make sure the place where you apply the finish is clean and as close to dust-free as possible. This means that you may not want to do the finish work in the same workshop where you do your woodcutting. In fact, laying out some newspaper in the main part of the house and applying the oil finish to the piece of furniture while it is sitting on the newspaper is a good idea. The odor from the oil should disperse in a few hours.

Types

Many types of penetrating oil finish are available on the market. Exotic woods such as mahogany, teak and rosewood also take very well to a penetrating oil, and in fact several brands of oil are made especially for these woods. Prepare the wood in the same way as you did for the American hardwoods in Section 1. Also remember that the use of a penetrating oil finish is not limited to hardwood furniture; the oil can be applied to woodwork, trim, paneling, cabinets and baseboards. Just make sure the piece of wood is taken down to its bare surface and sanded extremely well.

Effects

The oil not only penetrates the wood to enhance the appearance of the wood, but it also hardens the surface of the wood from the inside. As a result, wood that has been treated with an oil finish is hard at the surface and thus resistant to water and spills. For this reason an oil finish can be used on outdoor furniture and other woodworking projects.