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In this article, we’ll define and describe Danish oil. After telling you about it’s qualities and uses, we’ll reveal how many coats of Danish oil you should apply to your next project. The article also covers how long to wait between coats of Danish oil, how to burnish wood finished with Danish oil, and how to make Danish oil in your home or workshop.
What Is Danish Oil?
Danish oil is the name given to a liquid wood finish containing a variety of ingredients. The usual ingredients in Danish oil are varnish, a drying oil, and one or more solvents. Mineral spirits are the most common solvent used to formulate Danish oil.
It is highly customizable, and you can even make your own Danish oil at home. The ratio of varnish to oil is about one part varnish to two parts oil. This is called a ‘long oil’ formulation, because it has more oil than varnish.
The oil used is always a drying oil. Boiled linseed oil is a common choice. Tung oil can also be used. Drying oils penetrate into the surface of the wood, where they adhere to the pores to form a barrier. The barrier provides some protection from moisture, mold, and mildew, but has poor resistance when in direct contact with water.
Danish Oil Qualities
Danish oil has additional protective qualities over boiled linseed oil or tung oil, as it contains varnish.
The oils are considered a ‘penetrating’ finish, while varnish is a ‘film-forming’ finish made from resin dissolved in oil. This gives wood finished with Danish oil two layers of protection — one below the surface of the wood and one that sits on top of the wood’s exterior.
Danish oil hardens in two distinct phases:
- The first is drying, where the solvents evaporate, leaving the surface of the wood dry to the touch.
- The second phase of the process is called curing.
- Curing happens over about 30 days, as molecules from the oxygen in the air are integrated into the molecular structure of the finish. This binds them more tightly together, creating a harder and more durable finish.
While Danish oil protects wood from minor impact damage, it is not a robust or highly durable finish. In fact, it is known for its tendency to scuff. For this reason, it is not recommended to use Danish oil to treat high-traffic surfaces such as countertops or wooden floors.
How Many Coats of Danish Oil Do I Need?
Danish oil typically requires at least three coats, as it goes on thin in comparison to other finishes like straight varnish. Four to five coats will provide a rich and robust finish, especially if you sand lightly in between.
Danish oil is not a highly protective finish, though it does provide some protection from impact and moisture. It is nowhere near as robust as polyurethane. The main reason to apply Danish oil is to protect lightly used wood while also enriching its color and appearance.
- Two coats is usually sufficient to provide adequate coverage and protection, while giving you the aesthetic benefits of Danish oil.
- You may prefer the look of three coats, and it’s reasonable to apply up to four coats to build the finish you desire.
- Four to five coats provides the ultimate finish, but might end up being overkill for what you’re trying to achieve. After more than three coats, though, you’re not going to see much of a difference.
For best results, allow each coat to dry for four to eight hours and lightly sand the surface between each coat to promote adhesion.
A dense grained wood will absorb less oil than an open-grained wood. You may choose to apply a drying oil such as boiled linseed oil or tung oil on it’s own before finishing with Danish oil.
If your purpose in applying Danish oil is to refresh the finish, only one coat is necessary.
See our article on Danish oil vs stain for more differences.
Danish Oil Uses
One of the most popular uses of Danish oil is coating wood-handled kitchen utensils. It is also frequently used to finish spindles on staircases or balusters on exterior decking, balconies, and porches.
Danish oil is usually worked into wood with a clean and dry lint-free rag, although it is possible to apply it with a brush. The finish is allowed to penetrate the oil for a period of five to 30 minutes, depending on the manufacturer’s instructions (or your own experience, if you are using self-made Danish oil.)
Any excess oil is then wiped off with clean cloths until the surface is dry. Multiple coats can be added for improved coverage.
Danish oil is untinted, but enhances and darkens the natural tone of the wood. It is applied to clean, dry wood. Danish oil lends a slightly shiny satin finish to wood. A Danish oil finish repels water and provides minor impact damage protections.
To get a shinier finish, consider burnishing the wood.
How to Burnish Wood Finished With Danish Oil
Danish oil should be applied to very smooth, clean and dry wood. After sanding, vacuum the surface or use a tack cloth to remove any debris on the surface. Then, apply the oil and allow it to soak in, removing any excess with a clean rag.
When the finish is dry, sand it again. If the sanding paper gets gummy, stop and allow more drying time. Then, add a second coat, wipe off the excess, and allow it to dry. Lightly scuff the surface with 0000 steel wool before applying a third coat, if desired.
When the last coat is dry, take a square of linen or a linen buffing pad and rub the finished surface vigorously, moving in the direction of the grain. Next, use a square or buffing pad made from a linen/cotton blend. For the final round of buffing, cotton flannel works very well.
The result is a super smooth and shiny glow.
This method is appropriate for use on furniture finished with Danish oil, wood-handled kitchen implements, and hand-crafted pens.
When to Use Danish Oil
Choose Danish oil when the dual protection of a penetrating finish and film finish is desirable. Interior applications include balusters and spindles on staircases, where rag-based application goes more quickly and easily than brush-on application.
The film formed by varnish reduces the flexibility of wood and its ability to expand and contract with changes in moisture and temperature. Thus, it is more suitable for interior furniture and trim than exterior applications.
How to Make Your Own Danish Oil
Making Danish oil at home is easy.
A good starting place is two parts oil, one part varnish, and one part thinner.
For thinner, mineral spirits is the usual choice, although paint thinner will also work.
Use any drying oil that does not go rancid. Walnut oil, linseed oil, and tung oil are likely candidates.
When it comes to the varnish, polyurethane is a popular choice.
Simply mix the ingredients together, stirring well before application. The mixture should be thin enough to apply with a rag. Brushing or spraying Danish oil is also an option.
How Long to Wait Between Coats of Danish Oil?
Danish oil will be dry to the touch in about four to eight hours. At this point, it is safe to lightly sand the surface and apply another coat, although waiting 24 hours may give you better results. The varnish in Danish oil takes about 30 days to cure, or achieve full hardness, but you can apply a second and third coat before the curing process is complete.
Danish oil is a combination of drying oil, varnish, and solvent. Two to three coats are sufficient to achieve maximum aesthetic and protective results. Wait four to eight hours between each coat of Danish oil for best results. Hand-burnishing wood treated with Danish oil produces a gorgeous shiny finish.