No matter what type of woodworking project you're working on whether it is a antique four poster bed or a simple wall mounted coat rack there are only two basic finishes that can be applied. The first type of finish is called an evaporated finish as the name implies this wood finish cures hard by evaporation of the solvents in the finish. Some examples of an evaporated finish our lacquers and water-based finishes; these finishes can also be softened by heat and are called thermoplastic.
Another type of wood finish is called a reactive finish it is cures by reacting with another component either an outside component like air or another chemical that is added just prior to application. Some examples of these are oils in oil based varnishes and catalyzed lacquers. These finishes in turn are called thermosetting so on like the thermoplastic finishes the thermosetting finish will not be softened with heat or with the original solvent.
So what about an oil finish? Well there are two types of will finishes oils that dry and oils that do not dry when spread out in the open and are exposed to the oxygen and air. An example of a non drying oil would be mineral oil or baby oil use will not dry when spread out. Drying oils will protect better than the non-drying while and they are the ones that should be used to finish wood.
The two standards in drying oils most commonly used are linseed oil or tung oil. What distinguishes these two oils from all the other products on the shelf calling themselves oil finishes well first of all linseed oil and tung oil are true oils. Both of these oils are a penetrating finish which means that they will enter the wood fibers and Harden with an a wood, this makes these the easiest finish to apply their simply wipe down allow to penetrates the wood for a few minutes and then the excesses can be wiped off with a clean rag, by applying several coats will not build up a hard film like a varnish or lacquer because the film dries very soft.
Linseed oil is made from the flax plant the oil is pressed from the plant it is available in several different forms in unrefined condition it is called raw linseed oil and, usually used on wood because it dries quite slow, boiled linseed oil on the other hand is a thicker substance and dries more quickly chemicals are also added in today's boiled linseed oil to speed up trying time, for wood finishing you should always use boiled linseed oil.