Every woodworking project needs a great finish. You can put hours into carving, sanding and turning, but if you don’t finish it well, it isn’t going to stand the test of time.
Whatever your project, whether an antique restore, a new table or refinished wood floors, you are going to want to enhance its beauty and make it durable. There are many finish products out there (falling under two basic categories), and it isn’t always easy to know what will best suit your needs. Finishes vary in their ability to protect and endure. Let’s do a simple primer to get you started.
Finishes that Leave a Protective Layer
Acrylic lacquer is more durable and better for floors, while nitrocellulose lacquer is often used on furniture. Nitrocellulose can be touched up easily because it does not set in the same way as acrylic lacquer. However, neither forms as hard of a coating as varnish or water-based sealers, so lacquer is more susceptible to water and damage. Make sure you look for low volatile organic compounds (VOCs) to reduce the amount of fumes left behind.
Shellac isn’t incredibly durable, so if your project will get lots of wear this may not be your finish. If you are set on shellac, coat it with a water-based sealer to enhance the resistance to scuffs and such. Be aware shellac has a shelf-life of only about six months. The vapors are rough, but dissipate quickly.
Varnish is tough. It will resist most of what you throw at it making it a good choice for things like floors. Varnish will take a longer application time, as it requires a good three coats with lots of drying time and sanding in-between coats. Varnish does emit high levels of VOCs, but since it is so durable you won’t have to refinish nearly as often.
These are pretty environmentally friendly and have a quick dry time along with easy clean up. Water-based sealers offer moderate water, heat, and solvent protection. Even though they are less durable than varnishes, they are more durable than lacquer or shellac.
Finishes that Penetrate
Linseed oil is a natural choice made from flax. It is moderately durable, and offers some water protection. Since this oil absorbs into the wood instead of leaving a protective coating, it does leave the wood open to scuffs and dirt. A yearly application will suffice with no sanding needed.
Tung oil is another natural product made from tung tree nuts. This is often used on things such as cutting boards, but it is a thicker oil than linseed and will most likely need to be thinned with a solvent (there are natural ones like citrus out there). It has a high drying power.