As you undoubtedly know, the steps to refinishing wood are fairly well established. In order to properly refinish wood you have to remove the old finish, and in order to do that it is absolutely essential to know what type of finish is currently on the wood. How to identify wood finish is that single problem which can simply cause many people to throw up their hands in despair and give up. You undoubtedly already know this but wood finish comes in different types, and there are some rather simple tests for each of the more common types of finish.
- Varnish/Shellac. These are the most common types of furniture finishes, flooring that was laid prior to the mid 1960's as well as to some cabinets. To identify this type of finish do a simple scratch test. In a small, or easily hidden area of the wood and attempt to scratch off a small portion of the finish. If you notice that the finish comes up in small flake like patches then you know you have a varnish or shellac type of finish.
- Wax. Next to the urethane/polyurethane forms of finish, wax is the most common that is used today. In order to determine if something has a wax finish, all that you need to do is apply a small drop of mineral oil to the finish, and wait about three minutes. Use a clean white cloth or rag to wipe it up. If the cloth has a yellowish brown stain that feels waxy, well that is because it is a wax finish.
- Urethane/Polyurethane. Urethane and polyurethane are some of the most common flooring finishes that are used today. As such, there is a really simple test you can use to determine if this is the type of finish on your wood. Go to a small corner of the wood, and take a small knife or coin and try to scrape up a little bit. If it crumbles as you scrape it up then you can easily tell that you have a urethane/polyurethane finish.
- Lacquer. To know if you have a lacquer finish, just simply rub a little bit of denatured alcohol onto the wood. If it causes to partially dissolve it is more than likely a combination of shellac and lacquer.
- Penetrating sealers. Penetrating sealers are more easily identified by what there isn't rather than what there is. If there is not a high gloss, or if it just simply feels like wood to the touch then you can tell rather simply that you are dealing with a penetrating sealer.